Overt and covert competition in a promiscuous mammal: the importance of weaponry and testes size to male reproductive success.

PubMed

Preston, B T; Stevenson, I R; Pemberton, J M; Coltman, D W; Wilson, K

2003-03-22

Male contests for access to receptive females are thought to have selected for the larger male body size and conspicuous weaponry frequently observed in mammalian species. However, when females copulate with multiple males within an oestrus, male reproductive success is a function of both pre- and postcopulatory strategies. The relative importance of these overt and covert forms of sexual competition has rarely been assessed in wild populations. The Soay sheep mating system is characterized by male contests for mating opportunities and high female promiscuity. We find that greater horn length, body size and good condition each independently influence a male's ability to monopolize receptive females. For males with large horns at least, this behavioural success translates into greater siring success. Consistent with sperm-competition theory, we also find that larger testes are independently associated with both higher copulation rates and increased siring success. This advantage of larger testes emerges, and strengthens, as the number of oestrous females increases, as dominant males can no longer control access to them all. Our results thus provide direct quantitative evidence that male reproductive success in wild populations of mammals is dependent upon the relative magnitude of both overt contest competition and covert sperm competition.

Building integral projection models: a user's guide.

PubMed

Rees, Mark; Childs, Dylan Z; Ellner, Stephen P

2014-05-01

In order to understand how changes in individual performance (growth, survival or reproduction) influence population dynamics and evolution, ecologists are increasingly using parameterized mathematical models. For continuously structured populations, where some continuous measure of individual state influences growth, survival or reproduction, integral projection models (IPMs) are commonly used. We provide a detailed description of the steps involved in constructing an IPM, explaining how to: (i) translate your study system into an IPM; (ii) implement your IPM; and (iii) diagnose potential problems with your IPM. We emphasize how the study organism's life cycle, and the timing of censuses, together determine the structure of the IPM kernel and important aspects of the statistical analysis used to parameterize an IPM using data on marked individuals. An IPM based on population studies of Soay sheep is used to illustrate the complete process of constructing, implementing and evaluating an IPM fitted to sample data. We then look at very general approaches to parameterizing an IPM, using a wide range of statistical techniques (e.g. maximum likelihood methods, generalized additive models, nonparametric kernel density estimators). Methods for selecting models for parameterizing IPMs are briefly discussed. We conclude with key recommendations and a brief overview of applications that extend the basic model. The online Supporting Information provides commented R code for all our analyses. © 2014 The Authors. Journal of Animal Ecology published by John Wiley & Sons Ltd on behalf of British Ecological Society.

Gastrointestinal nematode species diversity in Soay sheep kept in a natural environment without active parasite control.

PubMed

Sinclair, Rona; Melville, Lynsey; Sargison, Fiona; Kenyon, Fiona; Nussey, Dan; Watt, Kathryn; Sargison, Neil

2016-08-30

Molecular methods based on ITS2 sequence analysis were used to identify strongylid parasites and describe their diversity in a management intervention and anthelmintic drug treatment-free sheep flock. Fourteen different nematode parasite species were identified in the flock and the results showed a greater level of nematode species diversity than is normally reported in managed farmed flocks, with the presence of parasites such as Bunostomum trigonocephalum, Ostertagia leptospicularis, Spiculopteragia houdemeri and Trichostrongylus retortaeformis that are considered to be absent or rare in sheep kept in comparable localities. The implied prevalences of Haemonchus contortus in lambs, and of Trichostrongylus axei in lambs, ewes and rams, were higher than those in farmed sheep kept in similar regions, while those of Teladorsagia circumcincta and Trichostrongylus vitrinus were lower. Comparison of the patterns of nematode parasite infection between the summer and autumn sampling periods showed differences from the scenarios that are commonplace in comparable managed flocks; with T. vitrinus burdens of the lambs being higher in the summer than in the winter, and Oesophagostomum venulosum being the predominant nematode species in the adult sheep during the summer, while more-or-less absent from these groups during the winter. Rams played an important role in the epidemiology of certain parasitic nematode species. The relatively non-pathogenic O. venulosum was the only parasitic nematode species to predominate in any group during the study. This preliminary characterisation of the nematode parasite burdens of sheep extensively grazed on diverse unimproved pastures will aid in the understanding of the parasitological consequences of intensive grazing management and of the manner in which modern agriculture upsets the equilibrium between parasites and their hosts. These factors must be accounted for when defining the concept of sustainable parasite control and informing sustainability with reference to commercially efficient sheep farming. Crown Copyright © 2016. Published by Elsevier B.V. All rights reserved.

Multivariate immune defences and fitness in the wild: complex but ecologically important associations among plasma antibodies, health and survival

PubMed Central

Nussey, Daniel H.; Watt, Kathryn A.; Clark, Abigail; Pilkington, Jill G.; Pemberton, Josephine M.; Graham, Andrea L.; McNeilly, Tom N.

2014-01-01

Despite our rapidly advancing mechanistic understanding of vertebrate immunity under controlled laboratory conditions, the links between immunity, infection and fitness under natural conditions remain poorly understood. Antibodies are central to acquired immune responses, and antibody levels circulating in vivo reflect a composite of constitutive and induced functional variants of diverse specificities (e.g. binding antigens from prevalent parasites, self tissues or novel non-self sources). Here, we measured plasma concentrations of 11 different antibody types in adult females from an unmanaged population of Soay sheep on St Kilda. Correlations among antibody measures were generally positive but weak, and eight of the measures independently predicted body mass, strongyle parasite egg count or survival over the subsequent winter. These independent and, in some cases, antagonistic relationships point to important multivariate immunological heterogeneities affecting organismal health and fitness in natural systems. Notably, we identified a strong positive association between anti-nematode immunoglobulin (Ig) G antibodies in summer and subsequent over-winter survival, providing rare evidence for a fitness benefit of helminth-specific immunity under natural conditions. Our results highlight both the evolutionary and ecological importance and the complex nature of the immune phenotype in the wild. PMID:24500168

Marker-dependent associations among oxidative stress, growth and survival during early life in a wild mammal

PubMed Central

Selman, Colin; Blount, Jonathan D.; Pilkington, Jill G.; Watt, Kathryn A.; Pemberton, Josephine M.; Reid, Jane M.

2016-01-01

Oxidative stress (OS) is hypothesized to be a key physiological mechanism mediating life-history trade-offs, but evidence from wild populations experiencing natural environmental variation is limited. We tested the hypotheses that increased early life growth rate increases OS, and that increased OS reduces first-winter survival, in wild Soay sheep (Ovis aries) lambs. We measured growth rate and first-winter survival for four consecutive cohorts, and measured two markers of oxidative damage (malondialdehyde (MDA), protein carbonyls (PC)) and two markers of antioxidant (AOX) protection (total AOX capacity (TAC), superoxide dismutase (SOD)) from blood samples. Faster lamb growth was weakly associated with increased MDA, but not associated with variation in the other three markers. Lambs with higher SOD activity were more likely to survive their first winter, as were male but not female lambs with lower PC concentrations. Survival did not vary with MDA or total TAC. Key predictions relating OS to growth and survival were therefore supported in some OS markers, but not others. This suggests that different markers capture different aspects of the complex relationships between individual oxidative state, physiology and fitness, and that overarching hypotheses relating OS to life-history variation cannot be supported or refuted by studying individual markers. PMID:27733545

Sex differences in telomeres and lifespan in Soay sheep: From the beginning to the end.

PubMed

Dantzer, Ben; Garratt, Michael

2017-06-01

There is tremendous diversity in ageing rates and lifespan not only among taxa but within species, and particularly between the sexes. Women often live longer than men, and considerable research on this topic has revealed some of the potential biological, psychological and cultural causes of sex differences in human ageing and lifespan. However, sex differences in lifespan are widespread in nonhuman animals suggesting biology plays a prominent role in variation in ageing and lifespan. Recently, evolutionary biologists have borrowed techniques from biomedicine to identify whether similar mechanisms causing or contributing to variation in ageing and lifespan in humans and laboratory animals also operate in wild animals. Telomeres are repetitive noncoding DNA sequences capping the ends of chromosomes that are important for chromosomal stability but that can shorten during normal cell division and exposure to stress. Telomere shortening is hypothesized to directly contribute to the ageing process as once telomeres shorten to some length, the cells stop dividing and die. Men tend to have shorter telomeres and faster rates of telomere attrition with age than women, suggesting one possible biological cause of sex differences in lifespan. In this issue of Molecular Ecology, Watson et al. () show that telomere lengths in wild Soay sheep are similar between females and males near the beginning of life but quickly diverge with age because males but not females showed reduced telomere lengths at older ages. The authors further show that some of the observed sex difference in telomere lengths in old age may be due to male investment in horn growth earlier in life, suggesting that sexually dimorphic allocation to traits involved in sexual selection might underlie sex differences in telomere attrition. This study provides a rare example of how biological mechanisms potentially contributing to sex differences in lifespan in humans may also operate in free-living animals. However, future studies using a longitudinal approach are necessary to confirm these observations and identify the ultimate and proximate causes of any sex differences in telomere lengths. Collaborations between evolutionary biologists and gerontologists are especially needed to identify whether telomere lengths have a causal role in ageing, particularly in natural conditions, and whether this directly contributes to sex differences in lifespan. © 2017 John Wiley & Sons Ltd.

Lines of Evidence–Incremental Markings in Molar Enamel of Soay Sheep as Revealed by a Fluorochrome Labeling and Backscattered Electron Imaging Study

PubMed Central

Kierdorf, Horst; Kierdorf, Uwe; Frölich, Kai; Witzel, Carsten

2013-01-01

We studied the structural characteristics and periodicities of regular incremental markings in sheep enamel using fluorochrome injections for vital labeling of forming enamel and backscattered electron imaging in the scanning electron microscope. Microscopic analysis of mandibular first molars revealed the presence of incremental markings with a daily periodicity (laminations) that indicated successive positions of the forming front of interprismatic enamel. In addition to the laminations, incremental markings with a sub-daily periodicity were discernible both in interprismatic enamel and in enamel prisms. Five sub-daily increments were present between two consecutive laminations. Backscattered electron imaging revealed that each sub-daily growth increment consisted of a broader and more highly mineralized band and a narrower and less mineralized band (line). The sub-daily markings in the prisms of sheep enamel morphologically resembled the (daily) prisms cross striations seen in primate enamel. Incremental markings with a supra-daily periodicity were not observed in sheep enamel. Based on the periodicity of the incremental markings, maximum mean daily apposition rates of 17.0 µm in buccal enamel and of 13.4 µm in lingual enamel were recorded. Enamel extension rates were also high, with maximum means of 180 µm/day and 217 µm/day in upper crown areas of buccal and lingual enamel, respectively. Values in more cervical crown portions were markedly lower. Our results are in accordance with previous findings in other ungulate species. Using the incremental markings present in primate enamel as a reference could result in a misinterpretation of the incremental markings in ungulate enamel. Thus, the sub-daily growth increments in the prisms of ungulate enamel might be mistaken as prism cross striations with a daily periodicity, and the laminations misidentified as striae of Retzius with a supra-daily periodicity. This would lead to a considerable overestimation of crown formation times in ungulate teeth. PMID:24040293

Asynchrony of senescence among phenotypic traits in a wild mammal population

PubMed Central

Hayward, Adam D.; Moorad, Jacob; Regan, Charlotte E.; Berenos, Camillo; Pilkington, Jill G.; Pemberton, Josephine M.; Nussey, Daniel H.

2015-01-01

The degree to which changes in lifespan are coupled to changes in senescence in different physiological systems and phenotypic traits is a central question in biogerontology. It is underpinned by deeper biological questions about whether or not senescence is a synchronised process, or whether levels of synchrony depend on species or environmental context. Understanding how natural selection shapes patterns of synchrony in senescence across physiological systems and phenotypic traits demands the longitudinal study of many phenotypes under natural conditions. Here, we examine the patterns of age-related variation in late adulthood in a wild population of Soay sheep (Ovis aries) that have been the subject of individual-based monitoring for thirty years. We examined twenty different phenotypic traits in both males and females, encompassing vital rates (survival and fecundity), maternal reproductive performance (offspring birth weight, birth date and survival), male rutting behaviour, home range measures, parasite burdens, and body mass. We initially quantified age-related variation in each trait having controlled for annual variation in the environment, among-individual variation and selective disappearance effects. We then standardised our age-specific trait means and tested whether age trajectories could be meaningfully grouped according to sex or the type of trait. Whilst most traits showed age-related declines in later life, we found striking levels of asynchrony both within and between the sexes. Of particular note, female fecundity and reproductive performance declined with age, but male annual reproductive success did not. We also discovered that whilst home range size and quality decline with age in females, home range size increases with age in males. Our findings highlight the complexity of phenotypic ageing under natural conditions and, along with emerging data from other wild populations and laboratory models, suggest that the long-standing hypothesis within evolutionary biology that fitness-related traits should senesce in a synchronous manner is seriously flawed. PMID:26277618

Natural Selection on Individual Variation in Tolerance of Gastrointestinal Nematode Infection

PubMed Central

Hayward, Adam D.; Nussey, Daniel H.; Wilson, Alastair J.; Berenos, Camillo; Pilkington, Jill G.; Watt, Kathryn A.; Pemberton, Josephine M.; Graham, Andrea L.

2014-01-01

Hosts may mitigate the impact of parasites by two broad strategies: resistance, which limits parasite burden, and tolerance, which limits the fitness or health cost of increasing parasite burden. The degree and causes of variation in both resistance and tolerance are expected to influence host–parasite evolutionary and epidemiological dynamics and inform disease management, yet very little empirical work has addressed tolerance in wild vertebrates. Here, we applied random regression models to longitudinal data from an unmanaged population of Soay sheep to estimate individual tolerance, defined as the rate of decline in body weight with increasing burden of highly prevalent gastrointestinal nematode parasites. On average, individuals lost weight as parasite burden increased, but whereas some lost weight slowly as burden increased (exhibiting high tolerance), other individuals lost weight significantly more rapidly (exhibiting low tolerance). We then investigated associations between tolerance and fitness using selection gradients that accounted for selection on correlated traits, including body weight. We found evidence for positive phenotypic selection on tolerance: on average, individuals who lost weight more slowly with increasing parasite burden had higher lifetime breeding success. This variation did not have an additive genetic basis. These results reveal that selection on tolerance operates under natural conditions. They also support theoretical predictions for the erosion of additive genetic variance of traits under strong directional selection and fixation of genes conferring tolerance. Our findings provide the first evidence of selection on individual tolerance of infection in animals and suggest practical applications in animal and human disease management in the face of highly prevalent parasites. PMID:25072883

An ecologic study comparing distribution of Pasteurella trehalosi and Mannheimia haemolytica between Sierra Nevada bighorn sheep, White Mountain bighorn sheep, and domestic sheep.

PubMed

Tomassini, Letizia; Gonzales, Ben; Weiser, Glen C; Sischo, William

2009-10-01

The prevalence and phenotypic variability of Pasteurella and Mannheimia isolates from Sierra Nevada bighorn sheep (Ovis canadensis sierrae), White Mountain bighorn sheep (Ovis canadensis nelsoni), and domestic sheep (Ovis aries) from California, USA, were compared. The White Mountain bighorn sheep population had a recent history of pneumonia-associated mortality, whereas the Sierra Nevada bighorn sheep population had no recent history of pneumonia-associated mortality. The domestic sheep flocks were pastured in areas geographically near both populations but were not known to have direct contact with either bighorn sheep population. Oropharyngeal swab samples were collected from healthy domestic and bighorn sheep and cultured to characterize bacterial species, hemolysis, biogroups, and biovariants. Pasteurella trehalosi and Mannheimia haemolytica were detected in all of the study populations, but the relative proportion of each bacterial species differed among sheep populations. Pasteurella trehalosi was more common than M. haemolytica in the bighorn sheep populations, whereas the opposite was true in domestic sheep. Mannheimia haemolytica was separated into 11 biogroups, and P. trehalosi was characterized into two biogroups. Biogroup distributions for M. haemolytica and P. trehalosi differed among the three populations; however, no difference was detected for the distribution of P. trehalosi biogroups between the Sierra Nevada bighorn sheep and domestic sheep. The prevalence odds ratios (pOR) for the distribution of M. haemolytica biogroups suggested little difference between White Mountain bighorn sheep and domestic sheep compared with Sierra Nevada bighorn sheep and domestic sheep, although these comparisons had relatively large confidence intervals for the point estimates. Hemolytic activity of the isolates was not different among the sheep populations for M. haemolytica but was different for P. trehalosi. No clear evidence of association was found in the Pasteurellaceae distribution between the White Mountains bighorn sheep and domestic sheep.

A spatial risk assessment of bighorn sheep extirpation by grazing domestic sheep on public lands.

PubMed

Carpenter, Tim E; Coggins, Victor L; McCarthy, Clinton; O'Brien, Chans S; O'Brien, Joshua M; Schommer, Timothy J

2014-04-01

Bighorn sheep currently occupy just 30% of their historic distribution, and persist in populations less than 5% as abundant overall as their early 19th century counterparts. Present-day recovery of bighorn sheep populations is in large part limited by periodic outbreaks of respiratory disease, which can be transmitted to bighorn sheep via contact with domestic sheep grazing in their vicinity. In order to assess the viability of bighorn sheep populations on the Payette National Forest (PNF) under several alternative proposals for domestic sheep grazing, we developed a series of interlinked models. Using telemetry and habitat data, we characterized herd home ranges and foray movements of bighorn sheep from their home ranges. Combining foray model movement estimates with known domestic sheep grazing areas (allotments), a Risk of Contact Model estimated bighorn sheep contact rates with domestic sheep allotments. Finally, we used demographic and epidemiologic data to construct population and disease transmission models (Disease Model), which we used to estimate bighorn sheep persistence under each alternative grazing scenario. Depending on the probability of disease transmission following interspecies contact, extirpation probabilities for the seven bighorn sheep herds examined here ranged from 20% to 100%. The Disease Model allowed us to assess the probabilities that varied domestic sheep management scenarios would support persistent populations of free-ranging bighorn sheep. Copyright © 2014 Elsevier B.V. All rights reserved.

Demography of Dall's sheep in northwestern Alaska

USGS Publications Warehouse

Kleckner, Christopher; Udevitz, Mark S.; Adams, Layne G.; Shults, Brad S.

2003-01-01

Dall’s sheep in northwestern Alaska declined in the early 1990s following the severe 1989-90 and 1990-91 winters. In the Baird Mountains of Noatak National Preserve, estimates of adult sheep declined by 50% from 800 in 1989 to under 400 in 1991. Population counts remained low throughout 1991 to 1996, reaching a minimum of 244 adult sheep in 1996. Few lambs were observed during annual midsummer aerial surveys in 1991 to 1994. We suspect that these declines resulted from a combination of poorer nutritional condition and increased vulnerability of sheep to predation resulting from severe winter conditions.As a result of these declines, both subsistence and sport hunting seasons were closed by emergency order in 1991, resulting in substantial management controversy. The affected publics, although willing to accept the closures, questioned the validity of the sheep survey data and strongly emphasized their interest in restoring harvests as soon as populations increased sufficiently. In 1995 the Northwest Arctic Regional Advisory Council, the local advisory committee for the Federal Subsistence Board, passed a motion supporting efforts to initiate research on sheep populations in the region to better understand the factors limiting sheep populations and to evaluate sheep survey methodologies.Currently estimates of Dall’s sheep population size and composition in the western Brooks Range are based on intensive fixed-wing aerial surveys conducted annually since 1986 in areas including the Baird Mountains. The annual variation in recent Baird Mountains aerial counts cannot be explained with reasonable assumptions about reproduction and survival, suggesting that there is some variability in the proportion of the population observed each year or that a substantial number of sheep move during the survey. Prior to our research, no attempt had been made to estimate visibility bias or precision for these surveys.Our understanding of Dall’s sheep population biology comes largely from studies in central or southern Alaska and the southern Yukon. However, sheep in northwestern Alaska are at the northwestern extreme of their range and live in a less hospitable environment characterized by short growing seasons and long, severe winters. We expect patterns of productivity and survival for sheep in Noatak National Preserve to differ from the more southerly populations. To adequately manage sheep harvests in northwestern Alaska, we need a better understanding of sheep demography. Along with unbiased population estimates, understanding the dynamics of sheep populations in the region will allow population models to be developed that can provide focus for a useful dialog on management goals and strategies and facilitate a cooperative strategy for managing sheep harvests in northwestern Alaska.

Role of patch size, disease, and movement in rapid extinction of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Zeigenfuss, L.C.; Spicer, L.

2001-01-01

The controversy (Berger 1990, 1999; Wehausen 1999) over rapid extinction in bighorn sheep (Ovis canadensis) has focused on population size alone as a correlate to persistence time. We report on the persistence and population performance of 24 translocated populations of bighorn sheep. Persistence in these sheep was strongly correlated with larger patch sizes, greater distance to domestic sheep, higher population growth rates, and migratory movements, as well as to larger population sizes. Persistence was also positively correlated with larger average home-range size (p = 0.058, n = 10 translocated populations) and home-range size of rams (p = 0.087, n = 8 translocated populations). Greater home-range size and dispersal rates of bighorn sheep were positively correlated to larger patches. We conclude that patch size and thus habitat carrying capacity, not population size per se, is the primary correlate to both population performance and persistence. Because habitat carrying capacity defines the upper limit to population size, clearly the amount of suitable habitat in a patch is ultimately linked to population size. Larger populations (250+ animals) were more likely to recover rapidly to their pre-epizootic survey number following an epizootic (p = 0.019), although the proportion of the population dying in the epizootic also influenced the probability of recovery (p = 0.001). Expensive management efforts to restore or increase bighorn sheep populations should focus on large habitat patches located ≥23 km from domestic sheep, and less effort should be expended on populations in isolated, small patches of habitat.

Genetic distances and phylogenetic trees of different Awassi sheep populations based on DNA sequencing.

PubMed

Al-Atiyat, R M; Aljumaah, R S

2014-08-27

This study aimed to estimate evolutionary distances and to reconstruct phylogeny trees between different Awassi sheep populations. Thirty-two sheep individuals from three different geographical areas of Jordan and the Kingdom of Saudi Arabia (KSA) were randomly sampled. DNA was extracted from the tissue samples and sequenced using the T7 promoter universal primer. Different phylogenetic trees were reconstructed from 0.64-kb DNA sequences using the MEGA software with the best general time reverse distance model. Three methods of distance estimation were then used. The maximum composite likelihood test was considered for reconstructing maximum likelihood, neighbor-joining and UPGMA trees. The maximum likelihood tree indicated three major clusters separated by cytosine (C) and thymine (T). The greatest distance was shown between the South sheep and North sheep. On the other hand, the KSA sheep as an outgroup showed shorter evolutionary distance to the North sheep population than to the others. The neighbor-joining and UPGMA trees showed quite reliable clusters of evolutionary differentiation of Jordan sheep populations from the Saudi population. The overall results support geographical information and ecological types of the sheep populations studied. Summing up, the resulting phylogeny trees may contribute to the limited information about the genetic relatedness and phylogeny of Awassi sheep in nearby Arab countries.

Pneumonia in bighorn sheep: Risk and resilience

USGS Publications Warehouse

Cassirer, E. Frances; Manlove, Kezia R.; Almberg, Emily S.; Kamath, Pauline; Cox, Mike; Wolff, Peregrine L.; Roug, Annette; Shannon, Justin M.; Robinson, Rusty; Harris, Richard B.; Gonzales, Ben J.; Plowright, Raina K.; Hudson, Peter J.; Cross, Paul C.; Dobson, Andrew; Besser, Thomas E.

2018-01-01

Infectious disease was an important driver of historic declines and extirpations of bighorn sheep (Ovis canadensis) in North America and continues to impede population restoration and management. Domestic sheep have long been linked to pneumonia outbreaks in bighorn sheep and this association has now been confirmed in 13 captive commingling experiments. However, ecological and etiological complexities still hinder our understanding and control of the disease. We provide an overview of the current state of knowledge about the biology and management of respiratory disease in bighorn sheep and propose strategies for moving forward. Epizootic pneumonia in bighorn sheep is polymicrobial. Mycoplasma ovipneumoniae, a bacterium host-specific to Caprinae and commonly carried by healthy domestic sheep and goats appears to be a necessary primary agent. All-age epizootics following introduction of M. ovipneumoniae along with other pathogens into bighorn sheep populations are usually severe (median mortality 47%) but fatality rates vary widely, from 15 – 100%. Disease severity may be influenced by the strain of M. ovipneumoniae, by secondary bacterial and viral pathogens, and by factors affecting transmission and host immunity. Once introduced, M. ovipneumoniae can persist in bighorn sheep populations for decades. Carrier dams transmit the pathogen to their susceptible lambs, triggering fatal pneumonia outbreaks in nursery groups, which limits recruitment and slows or prevents population recovery. The result is that demographic costs of pathogen persistence often outweigh the impacts of the initial invasion and die-off. There is currently no effective vaccine or antibiotic for domestic or wild sheep and to date, no management actions have been successful in reducing morbidity, mortality, or disease spread once pathogen invasion has occurred. Molecular-based strain typing suggests that spillover of M. ovipneumoniae into bighorn sheep populations from domestic small ruminants is ongoing, and that consequences of pathogen invasion are amplified by movements of infected bighorn sheep. Therefore, current disease management strategies focus on reducing risk of spillover from reservoir populations of domestic small ruminants and on limiting transmission among bighorn sheep. A broad array of approaches has been tried and more are needed to prevent pathogen introduction, induce disease fadeout in persistently infected populations, and promote population resilience across the diverse landscapes bighorn sheep inhabit. A comprehensive examination of disease dynamics across populations could help elucidate how disease fades out naturally and if population resilience can be increased in the face of infection. Cross-jurisdictional adaptive management experiments and transdisciplinary collaboration, including partnerships with members of the domestic sheep and goat community, are needed to facilitate innovation and speed progress towards sustainable solutions for managing pneumonia to protect and restore bighorn sheep populations.

Origin, genetic diversity, and population structure of Chinese domestic sheep.

PubMed

Chen, Shan-Yuan; Duan, Zi-Yuan; Sha, Tao; Xiangyu, Jinggong; Wu, Shi-Fang; Zhang, Ya-Ping

2006-07-19

To characterize the origin, genetic diversity, and phylogeographic structure of Chinese domestic sheep, we here analyzed a 531-bp fragment of mtDNA control region of 449 Chinese autochthonous sheep from 19 breeds/populations from 13 geographic regions, together with previously reported 44 sequences from Chinese indigenous sheep. Phylogenetic analysis showed that all three previously defined lineages A, B, and C were found in all sampled Chinese sheep populations, except for the absence of lineage C in four populations. Network profiles revealed that the lineages B and C displayed a star-like phylogeny with the founder haplotype in the centre, and that two star-like subclades with two founder haplotypes were identified in lineage A. The pattern of genetic variation in lineage A, together with the divergence time between the two central founder haplotypes suggested that two independent domestication events have occurred in sheep lineage A. Considerable mitochondrial diversity was observed in Chinese sheep. Weak structuring was observed either among Chinese indigenous sheep populations or between Asian and European sheep and this can be attributable to long-term strong gene flow induced by historical human movements. The high levels of intra-population diversity in Chinese sheep and the weak phylogeographic structuring indicated three geographically independent domestication events have occurred and the domestication place was not only confined to the Near East, but also occurred in other regions.

Influence of trophy hunting and horn size on mating behavior and survivorship of mountain sheep

USGS Publications Warehouse

Singer, F.J.; Zeigenfuss, L.C.

2002-01-01

We conducted a study of the effects of horn sizes and trophy hunting on mating behavior and survival of rams in hunted and unhunted populations of Dall sheep (Ovis dalli), Rocky Mountain bighorn (O. canadensis canadensis), and desert bighorn (O. c. nelsoni) sheep. Mating success was positively correlated with horn size in Dall sheep (P = 0.03) and Rocky Mountain bighorns (P = 0.05), but not in the desert bighorn (P > 0.05) taxa. Group sizes, rams per rut group, and competition between rams were lowest in desert bighorn sheep. There were indications of greater harassment of ewes by young rams in trophy-hunted populations. In hunted populations, compared with unhunted, ewes ran away more often from approaching rams, ewes moved farther away from courting young rams (P = 0.003), younger rams performed fewer courtship displays (P = 0.042) and more aggressive displays to ewes, and sheep interacted 27% more of the time. Ram-to-ewe interaction times per individual ewe did not differ for any of the taxa (P > 0.05), and, apparently as a consequence of this, we found no discernable effects of trophy hunting on survivorship of ewes, ewe fecundity, or recruitment of young (P > 0.05). There were greater energy expenditures by young rams in the heavily hunted Dall sheep population versus the paired Dall sheep unhunted population, but not in the lightly hunted Rocky Mountain and desert bighorn populations when compared with unhunted populations. This was consistent with evidence for depressed survivorship of rams too young or too small to be hunted (approximately ages 4–6) in the heavily hunted Dall sheep population (P = 0.0001), but not in the bighorn sheep populations (P > 0.05).

Dynamics and life histories of northern ungulates in changing environments

NASA Astrophysics Data System (ADS)

Hendrichsen, D. K.

2011-12-01

Regional climate and local weather conditions can profoundly influence life history parameters (growth, survival, fecundity) and population dynamics in northern ungulates (Post and Stenseth 1999, Coulson et al. 2001). The influence is both direct, for example through reduced growth or survival (Aanes et al. 2000, Tyler et al. 2008), and indirect, for example through changes in resource distribution, phenology and quality, changes which subsequently influence consumer dynamics (Post et al. 2008). By comparing and contrasting data from three spatially independent populations of ungulates, I discuss how variation in local weather parameters and vegetation growth influence spatial and temporal dynamics through changes in life history parameters and/or behavioural dynamics. The data originate from long term (11-15 years) monitoring data from three populations of ungulates in one subarctic and two high Arctic sites; semi-domesticated reindeer (Rangifer tarandus tarandus) in northern Norway, Svalbard reindeer (R. t. platyrhynchus) on Spitsbergen and muskoxen (Ovibos moschatus) in Northeast Greenland. The results show that juvenile animals can be particularly vulnerable to changes in their environment, and that this is mirrored to different degrees in the spatio-temporal dynamics of the three populations. Adverse weather conditions, acting either directly or mediated through access to and quality of vegetation, experienced by young early in life, or even by their dams during pregnancy, can lead to reduced growth, lower survival and reduced reproductive performance later in life. The influence of current climatic variation, and the predictions of how local weather conditions may change over time, differs between the three sites, resulting in potentially different responses in the three populations. Aanes R, Saether BE and Øritsland NA. 2000. Fluctuations of an introduced population of Svalbard reindeer: the effects of density dependence and climatic variation. Ecography, 23: 437-443 Coulson T, Catchpole EA, Albon SD, Morgan BJT, Pemberton JM, Clutton-Brock TH, Crawley MJ and Grenfell BT. 2001. Age, sex, density, winter weather, and population crashes in Soay sheep. Science, 292: 1528-1531 Post, E and Stenseth NC. 1999. Climatic variability, plant phenology, and northern ungulates. Ecology, 80: 1322-1339 Post E, Pedersen C, Wilmers CC and Forchhammer MC. 2008. Warming, plant phenology and the spatial dimension of trophic mismatch for large herbivores. Proc. Roy Soc. B., 275: 2005-2013 Tyler NJC, Forchhammer MC and Øritsland NA. 2008. Nonlinear effects of climate and density in the dynamics of a fluctuating population of reindeer. Ecology, 89: 1675-1686

Three Thousand Years of Continuity in the Maternal Lineages of Ancient Sheep (Ovis aries) in Estonia

PubMed Central

Rannamäe, Eve; Lõugas, Lembi; Speller, Camilla F.; Valk, Heiki; Maldre, Liina; Wilczyński, Jarosław; Mikhailov, Aleksandr; Saarma, Urmas

2016-01-01

Although sheep (Ovis aries) have been one of the most exploited domestic animals in Estonia since the Late Bronze Age, relatively little is known about their genetic history. Here, we explore temporal changes in Estonian sheep populations and their mitochondrial genetic diversity over the last 3000 years. We target a 558 base pair fragment of the mitochondrial hypervariable region in 115 ancient sheep from 71 sites in Estonia (c. 1200 BC–AD 1900s), 19 ancient samples from Latvia, Russia, Poland and Greece (6800 BC–AD 1700), as well as 44 samples of modern Kihnu native sheep breed. Our analyses revealed: (1) 49 mitochondrial haplotypes, associated with sheep haplogroups A and B; (2) high haplotype diversity in Estonian ancient sheep; (3) continuity in mtDNA haplotypes through time; (4) possible population expansion during the first centuries of the Middle Ages (associated with the establishment of the new power regime related to 13th century crusades); (5) significant difference in genetic diversity between ancient populations and modern native sheep, in agreement with the beginning of large-scale breeding in the 19th century and population decline in local sheep. Overall, our results suggest that in spite of the observed fluctuations in ancient sheep populations, and changes in the natural and historical conditions, the utilisation of local sheep has been constant in the territory of Estonia, displaying matrilineal continuity from the Middle Bronze Age through the Modern Period, and into modern native sheep. PMID:27732668

Genetic Diversity and Population Structure of Ethiopian Sheep Populations Revealed by High-Density SNP Markers

PubMed Central

Edea, Zewdu; Dessie, Tadelle; Dadi, Hailu; Do, Kyoung-Tag; Kim, Kwan-Suk

2017-01-01

Sheep in Ethiopia are adapted to a wide range of environments, including extreme habitats. Elucidating their genetic diversity is critical for improving breeding strategies and mapping quantitative trait loci associated with productivity. To this end, the present study investigated the genetic diversity and population structure of five Ethiopian sheep populations exhibiting distinct phenotypes and sampled from distinct production environments, including arid lowlands and highlands. To investigate the genetic relationships in greater detail and infer population structure of Ethiopian sheep breeds at the continental and global levels, we analyzed genotypic data of selected sheep breeds from the Ovine SNP50K HapMap dataset. All Ethiopian sheep samples were genotyped with Ovine Infinium HD SNP BeadChip (600K). Mean genetic diversity ranged from 0.29 in Arsi-Bale to 0.32 in Menz sheep, while estimates of genetic differentiation among populations ranged from 0.02 to 0.07, indicating low to moderate differentiation. An analysis of molecular variance revealed that 94.62 and 5.38% of the genetic variation was attributable to differences within and among populations, respectively. Our population structure analysis revealed clustering of five Ethiopian sheep populations according to tail phenotype and geographic origin—i.e., short fat-tailed (very cool high-altitude), long fat-tailed (mid to high-altitude), and fat-rumped (arid low-altitude), with clear evidence of admixture between long fat-tailed populations. North African sheep breeds showed higher levels of within-breed diversity, but were less differentiated than breeds from Eastern and Southern Africa. When African breeds were grouped according to geographic origin (North, South, and East), statistically significant differences were detected among groups (regions). A comparison of population structure between Ethiopian and global sheep breeds showed that fat-tailed breeds from Eastern and Southern Africa clustered together, suggesting that these breeds were introduced to the African continent via the Horn and migrated further south. PMID:29312441

Genetic structure of South African Nguni (Zulu) sheep populations reveals admixture with exotic breeds.

PubMed

Selepe, Mokhethi Matthews; Ceccobelli, Simone; Lasagna, Emiliano; Kunene, Nokuthula Winfred

2018-01-01

The population of Zulu sheep is reported to have declined by 7.4% between 2007 and 2011 due to crossbreeding. There is insufficient information on the genetic diversity of the Zulu sheep populations in the different area of KwaZulu Natal where they are reared. The study investigated genetic variation and genetic structure within and among eight Zulu sheep populations using 26 microsatellite markers. In addition, Damara, Dorper and South African Merino breeds were included to assess the genetic relationship between these breeds and the Zulu sheep. The results showed that there is considerable genetic diversity among the Zulu sheep populations (expected heterozygosity ranging from 0.57 to 0.69) and the level of inbreeding was not remarkable. The structure analysis results revealed that Makhathini Research Station and UNIZULU research station share common genetic structure, while three populations (Nongoma, Ulundi and Nquthu) had some admixture with the exotic Dorper breed. Thus, there is a need for sustainable breeding and conservation programmes to control the gene flow, in order to stop possible genetic dilution of the Zulu sheep.

Genetic structure of South African Nguni (Zulu) sheep populations reveals admixture with exotic breeds

PubMed Central

Kunene, Nokuthula Winfred

2018-01-01

The population of Zulu sheep is reported to have declined by 7.4% between 2007 and 2011 due to crossbreeding. There is insufficient information on the genetic diversity of the Zulu sheep populations in the different area of KwaZulu Natal where they are reared. The study investigated genetic variation and genetic structure within and among eight Zulu sheep populations using 26 microsatellite markers. In addition, Damara, Dorper and South African Merino breeds were included to assess the genetic relationship between these breeds and the Zulu sheep. The results showed that there is considerable genetic diversity among the Zulu sheep populations (expected heterozygosity ranging from 0.57 to 0.69) and the level of inbreeding was not remarkable. The structure analysis results revealed that Makhathini Research Station and UNIZULU research station share common genetic structure, while three populations (Nongoma, Ulundi and Nquthu) had some admixture with the exotic Dorper breed. Thus, there is a need for sustainable breeding and conservation programmes to control the gene flow, in order to stop possible genetic dilution of the Zulu sheep. PMID:29698497

Conservation genetics in Chinese sheep: diversity of fourteen indigenous sheep (Ovis aries) using microsatellite markers.

PubMed

E, Guang-Xin; Zhong, Tao; Ma, Yue-Hui; Gao, Hui-Jiang; He, Jian-Ning; Liu, Nan; Zhao, Yong-Ju; Zhang, Jia-Hua; Huang, Yong-Fu

2016-02-01

The domestic sheep (Ovis aries) has been an economically and culturally important farm animal species since its domestication around the world. A wide array of sheep breeds with abundant phenotypic diversity exists including domestication and selection as well as the indigenous breeds may harbor specific features as a result of adaptation to their environment. The objective of this study was to investigate the population structure of indigenous sheep in a large geographic location of the Chinese mainland. Six microsatellites were genotyped for 611 individuals from 14 populations. The mean number of alleles (±SD) ranged from 7.00 ± 3.69 in Gangba sheep to 10.50 ± 4.23 in Tibetan sheep. The observed heterozygote frequency (±SD) within a population ranged from 0.58 ± 0.03 in Gangba sheep to 0.71 ± 0.03 in Zazakh sheep and Minxian black fur sheep. In addition, there was a low pairwise difference among the Minxian black fur sheep, Mongolian sheep, Gansu alpine merino, and Lanzhou fat-tailed sheep. Bayesian analysis with the program STRUCTURE showed support for 3 clusters, revealing a vague genetic clustering pattern with geographic location. The results of the current study inferred high genetic diversity within these native sheep in the Chinese mainland.

Bighorn sheep (Ovis canadensis) survivorship and habitat studies in Bighorn Canyon National Recreation Area and surrounding lands, Wyoming and Montana, 2000–2003

USGS Publications Warehouse

Schoenecker, Kathryn A.; Singer, Francis J.; Grams, Kayla A.; Roelle, James E.

2004-01-01

In the 1850s, bighorn sheep (Ovis canadensis) were numerous and distributed throughout the Bighorn and Pryor Mountains of Montana and Wyoming. After European settlement, bighorn sheep populations declined, and local extinctions occurred in much of their historic range in the western United States. The current bighorn sheep population of Bighorn Canyon National Recreation Area (BICA) is the product of several reintroductions into BICA and surrounding lands. Following a release in 1973 and growth rates near maximum potential of 19.8% per year, the population grew to an estimated peak population of about 211 animals in 1993 and 1994 (Kissell and others, 1996). Recent counts indicate the bighorn sheep population has declined. Kissell and others (1996) reported that the population began to decline rapidly in 1995 and 1996. He noted low ewe:lamb ratios during the decline phase. Bighorn sheep numbers declined to the lowest minimum viable population size of 100 animals recommended by several bighorn sheep experts (Bailey, 1990; Berger, 1990; Smith and others, 1991). National Park Service (NPS) and Bureau of Land Management (BLM) managers were concerned about the decline and requested a study of its causes. In 2000, the U.S. Geological Survey- Biological Resources Division (USGS-BRD) received funding to start a 3-year study of survivorship, condition, and population growth rate of the BICA bighorn sheep population.Several possibilities exist for the bighorn sheep decline. The herd may have experienced a rapid population expansion, followed by a decline to stability at a lower long-term carrying capacity. This pattern of apparently overshooting carrying capacity following an initial release has been reported for a number of ungulates (Caughley, 1976). Disease may have caused the decline; predation and/or competition with wild horses (Equus caballus) may also have been factors. A spatial model of wild horse carrying capacity (Coughenour, 1999) was developed to assist managers in evaluating wild horse population numbers. Studies of summer consumption rates by wild horses and other ungulates were conducted by James Detling and students from Colorado State University (Peterson and others, 1997; Gerhardt and Detling, 1998; Fahnestock, 1998). Diets and habitat use of wild horses, bighorn sheep and mule deer were studied by Coates and Schemnitz (1989) and Kissell and others (1996). Both Coates and Schemnitz (1989) and Kissell and others (1996) reported a high degree of dietary overlap between wild horses and bighorn sheep. However, Kissell and others (1996) concluded that a high degree of spatial separation between wild horses and bighorn sheep, at least under the study conditions, precluded any significant negative competitive influences. The most important overlap of bighorn sheep and wild horses seems to be on winter range. Competition can be difficult to determine, since current conditions may not reveal competition that has already occurred. Managers remained concerned about the declining bighorn population for the following reasons: Our objectives for the study were to: Evaluate current disease problems and mortality rates, including predation rates, in bighorn sheep through captures and monitoring of bighorn sheep.Determine winter spatial relations of wild horses and bighorn sheep through aerial surveys of winter range.Conduct habitat measurements to determine why bighorn sheep were not using what had been mapped with a GIS-based habitat model as suitable bighorn sheep habitat, and sample winter and summer consumption rates of key forage species to see if there were other factors precluding use of these areas by bighorn sheep.Compare winter lamb recruitment rates and total vegetation consumption rates on bighorn sheep winter use areas, with and without wild horses present.Complete year-round GIS-based distribution maps for wild horses and bighorn sheep in order to identify key areas of species overlap and key areas of species separation for potential habitat improvements.NPS park staff asked USGS to answer the following questions: (a) how large is the population?; (b) how many rams are in the population?; (c) in addition to low lamb recruitment, is mortality or dispersal of adults likely contributing to the decline?; and (d) is trophy hunting of rams contributing to the decline?

Prevalence of Mycoplasma ovipneumoniae in desert bighorn sheep in Arizona

USGS Publications Warehouse

Justice-Allen, Anne E.; Luedtke, Clint J.; Overstreet, Matthew; Cain, James W.; Stephenson, Thomas R.

2011-01-01

To assess the potential for an epizootic of pneumonia to result from either natural immigration or translocation, we compared the seroprevalence to Mycoplasma ovipneumoniae in several populations of desert bighorn sheep in Arizona. We collected blood samples and nasal or oropharyngeal swabs from 124 desert bighorn sheep (Ovis canadensis nelsoni) from 6 populations in Arizona in 2009 and 2010. M. ovipneumoniae organisms were detected by PCR in 22%, whereas antibodies to M. ovipneumoniae were detected in 47% of tested bighorn sheep. Mycoplasma antibodies were not found in 2 of 6 populations, indicating some bighorn sheep populations in Arizona are naïve to this bacterium. In contrast, others had seroprevalence rates up to 80%. We were able to compare seroprevalence rates and titers over time in 9 individuals (7 individuals included in the 124 bighorn sheep sampled in 2009 and 2010, and 2 individuals originally captured in 2006). Antibody titers persisted for 12 months in individuals from the Kofa National Wildlife Refuge (n = 7) while antibody titers appeared to decline in the Kanab Creek population (n = 2). M. ovipneumoniae is present or has been present in several, but not all, populations of bighorn sheep in Arizona. The results demonstrate the importance of routine health testing for future translocation efforts to reduce disease risk for naive populations.

Translating effects of inbreeding depression on component vital rates to overall population growth in endangered bighorn sheep.

PubMed

Johnson, Heather E; Mills, L Scott; Wehausen, John D; Stephenson, Thomas R; Luikart, Gordon

2011-12-01

Evidence of inbreeding depression is commonly detected from the fitness traits of animals, yet its effects on population growth rates of endangered species are rarely assessed. We examined whether inbreeding depression was affecting Sierra Nevada bighorn sheep (Ovis canadensis sierrae), a subspecies listed as endangered under the U.S. Endangered Species Act. Our objectives were to characterize genetic variation in this subspecies; test whether inbreeding depression affects bighorn sheep vital rates (adult survival and female fecundity); evaluate whether inbreeding depression may limit subspecies recovery; and examine the potential for genetic management to increase population growth rates. Genetic variation in 4 populations of Sierra Nevada bighorn sheep was among the lowest reported for any wild bighorn sheep population, and our results suggest that inbreeding depression has reduced adult female fecundity. Despite this population sizes and growth rates predicted from matrix-based projection models demonstrated that inbreeding depression would not substantially inhibit the recovery of Sierra Nevada bighorn sheep populations in the next approximately 8 bighorn sheep generations (48 years). Furthermore, simulations of genetic rescue within the subspecies did not suggest that such activities would appreciably increase population sizes or growth rates during the period we modeled (10 bighorn sheep generations, 60 years). Only simulations that augmented the Mono Basin population with genetic variation from other subspecies, which is not currently a management option, predicted significant increases in population size. Although we recommend that recovery activities should minimize future losses of genetic variation, genetic effects within these endangered populations-either negative (inbreeding depression) or positive (within subspecies genetic rescue)-appear unlikely to dramatically compromise or stimulate short-term conservation efforts. The distinction between detecting the effects of inbreeding depression on a component vital rate (e.g., fecundity) and the effects of inbreeding depression on population growth underscores the importance of quantifying inbreeding costs relative to population dynamics to effectively manage endangered populations. ©2011 Society for Conservation Biology.

Molecular evidence for the subspecific differentiation of blue sheep (Pseudois nayaur) and polyphyletic origin of dwarf blue sheep (Pseudois schaeferi).

PubMed

Tan, Shuai; Zou, Dandan; Tang, Lei; Wang, Gaochao; Peng, Quekun; Zeng, Bo; Zhang, Chen; Zou, Fangdong

2012-06-01

Blue sheep (Pseudois nayaur), a Central Asian ungulate with restricted geographic distribution, exhibits unclear variation in morphology and phylogeographic structure. The composition of species and subspecies in the genus Pseudois is controversial, particularly with respect to the taxonomic designation of geographically restricted populations. Here, 26 specimens including 5 dwarf blue sheep (Pseudois schaeferi), which were collected from a broad geographic region in China, were analyzed for 2 mitochondrial DNA fragments (cytochrome b and control region sequences). In a pattern consistent with geographically defined subspecies, we found three deeply divergent mitochondrial lineages restricted to different geographic regions. The currently designated two subspecies of blue sheep, Pseudois nayaur nayaur and Pseudois nayaur szechuanensis, were recognized in the phylogenetic trees. In addition, the Helan Mountain population showed distinct genetic characteristics from other geographic populations, and thus should be classified as a new subspecies. In contrast, dwarf blue sheep clustered closely with some blue sheep from Sichuan Province in the phylogenetic trees. Therefore, dwarf blue sheep appear to be a subset of Pseudois nayaur szechuanensis. After considering both population genetic information and molecular clock analysis, we obtained some relevant molecular phylogeographic information concerning the historical biogeography of blue sheep. These results also indicate that western Sichuan was a potential refugium for blue sheep during the Quaternary period.

Genome-wide set of SNPs reveals evidence for two glacial refugia and admixture from postglacial recolonization in an alpine ungulate.

PubMed

Sim, Zijian; Hall, Jocelyn C; Jex, Bill; Hegel, Troy M; Coltman, David W

2016-08-01

Past glaciation events have played a major role in shaping the genetic diversity and distribution of wild sheep in North America. The advancement of glaciers can isolate populations in ice-free refugia, where they can survive until the recession of ice sheets. The major Beringian refugium is thought to have held thinhorn sheep (Ovis dalli) populations during times of glacial advance. While isolation in the major refugium can account for much of the genetic and morphological diversity seen in extant thinhorn sheep populations, mounting evidence suggests the persistence of populations in smaller minor refugia. We investigated the refugial origins of thinhorn sheep using ~10 000 SNPs obtained via a cross-species application of the domestic sheep ovine HD BeadChip to genotype 52 thinhorn sheep and five bighorn sheep (O. canadensis) samples. Phylogenetic inference revealed a distinct lineage of thinhorn sheep inhabiting British Columbia, which is consistent with the survival of a group of thinhorn sheep in a minor refugium separate from the Beringian refugium. Isolation in separate glacial refugia probably mediated the evolution of the two thinhorn sheep subspecies, the white Dall's sheep (O. d. dalli), which persisted in Beringia, and the dark Stone's sheep (O. d. stonei), which utilized the minor refugium. We also found the first genetic evidence for admixture between sheep from different glacial refugia in south-central Yukon as a consequence of post glacial expansion and recolonization. These results show that glaciation events can have a major role in the evolution of species inhabiting previously glaciated habitats and the need to look beyond established refugia when examining the evolutionary history of such species. © 2016 John Wiley & Sons Ltd.

Evaluating apparent competition in limiting the recovery of an endangered ungulate.

PubMed

Johnson, Heather E; Hebblewhite, Mark; Stephenson, Thomas R; German, David W; Pierce, Becky M; Bleich, Vernon C

2013-01-01

Predation can disproportionately affect endangered prey populations when generalist predators are numerically linked to more abundant primary prey. Apparent competition, the term for this phenomenon, has been increasingly implicated in the declines of endangered prey populations. We examined the potential for apparent competition to limit the recovery of Sierra Nevada bighorn sheep (Ovis canadensis sierrae), an endangered subspecies under the US Endangered Species Act. Using a combination of location, demographic, and habitat data, we assessed whether cougar (Puma concolor) predation on endangered bighorn sheep was a consequence of their winter range overlap with abundant mule deer (Odocoileus hemionus). Consistent with the apparent competition hypothesis, bighorn sheep populations with higher spatial overlap with deer exhibited higher rates of cougar predation which had additive effects on adult survival. Bighorn sheep killed by cougars were primarily located within deer winter ranges, even though those areas constituted only a portion of the bighorn sheep winter ranges. We suspect that variation in sympatry between bighorn sheep and deer populations was largely driven by differences in habitat selection among bighorn sheep herds. Indeed, bighorn sheep herds that experienced the highest rates of predation and the greatest spatial overlap with deer also exhibited the strongest selection for low elevation habitat. Although predator-mediated apparent competition may limit some populations of bighorn sheep, it is not the primary factor limiting all populations, suggesting that the dynamics of different herds are highly idiosyncratic. Management plans for endangered species should consider the spatial distributions of key competitors and predators to reduce the potential for apparent competition to hijack conservation success.

Precipitation, density, and population dynamics of desert bighorn sheep on San Andres National Wildlife Refuge, New Mexico

USGS Publications Warehouse

Bender, L.C.; Weisenberger, M.E.

2005-01-01

Understanding the determinants of population size and performance for desert bighorn sheep (Ovis canadensis mexicana) is critical to develop effective recovery and management strategies. In arid environments, plant communities and consequently herbivore populations are strongly dependent upon precipitation, which is highly variable seasonally and annually. We conducted a retrospective exploratory analysis of desert bighorn sheep population dynamics on San Andres National Wildlife Refuge (SANWR), New Mexico, 1941-1976, by modeling sheep population size as a function of previous population sizes and precipitation. Population size and trend of desert bighorn were best and well described (R 2=0.89) by a model that included only total annual precipitation as a covariate. Models incorporating density-dependence, delayed density-dependence, and combinations of density and precipitation were less informative than the model containing precipitation alone (??AlCc=8.5-22.5). Lamb:female ratios were positively related to precipitation (current year: F1,34=7.09, P=0.012; previous year: F1,33=3.37, P=0.075) but were unrelated to population size (current year. F1,34=0.04, P=0.843; previous year: F1,33 =0.14, P=0.715). Instantaneous population rate of increase (r) was related to population size (F1,33=5.55; P=0.025). Precipitation limited populations of desert bighorn sheep on SANWR primarily in a density-independent manner by affecting production or survival of lambs, likely through influences on forage quantity and quality. Habitat evaluations and recovery plans for desert bighorn sheep need to consider fundamental influences on desert bighorn populations such as precipitation and food, rather than focus solely on proximate issues such as security cover, predation, and disease. Moreover, the concept of carrying capacity for desert bighorn sheep may need re-evaluation in respect to highly variable (CV =35.6%) localized precipitation patterns. On SANWR carrying capacity for desert bighorn sheep was zero when total annual precipitation was <28.2 cm.

Correlates to colonizations of new patches by translocated populations of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Moses, M.E.; Bellew, S.; Sloan, W.

2000-01-01

By 1950, bighorn sheep were extirpated from large areas of their range. Most extant populations of bighorn sheep (Ovis canadensis) in the Intermountain West consist of <100 individuals occurring in a fragmented distribution across the landscape. Dispersal and successful colonizations of unoccupied habitat patches has been rarely reported, and, in particular, translocated populations have been characterized by limited population growth and limited dispersal rates. Restoration of the species is greatly assisted by dispersal and successful colonization of new patches within a metapopulation structure versus the existing scenario of negligible dispersal and fragmented, small populations. We investigated the correlates for the rate of colonizations of 79 suitable, but unoccupied, patches by 31 translocated populations of bighorn sheep released into nearby patches of habitat. Population growth rates of bighorn sheep in the release patches were correlated to Ne of the founder group, and early contact with a second released population in a nearby release patch (logistic regression, p = 0.08). Largest population size of all extant released populations in 1994 was correlated to potential Ne of the founder group, the number of different source populations represented in the founder, and early contact with a second released population (p = 0.016). Dispersal rates were 100% higher in rams than ewes (p = 0.001). Successful colonizations of unoccupied patches (n = 24 of 79 were colonized) were associated with rapid growth rates in the released population, years since release, larger area of suitable habitat in the release patch, larger population sizes, and a seasonal migratory tendency in the released population (p = 0.05). Fewer water barriers, more open vegetation and more rugged, broken terrain in the intervening habitat were also associated with colonizations (p = <0.05). We concluded that high dispersal rates and rapid reoccupation of large areas could occur if bighorn sheep are placed in large patches of habitat with few barriers to movements to other patches and with no domestic sheep present. Many restorations in the past that did not meet these criteria may have contributed to an insular population structure of bighorn sheep with limited observations of dispersal.

Correlates to colonizations of new patches by translocated populations of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Moses, M.E.; Bellew, S.; Sloan, W.

2000-01-01

By 1950, bighorn sheep were extirpated from large areas of their range. Most extant populations of bighorn sheep (Ovis canadensis) in the Intermountain West consist of <100 individuals occurring in a fragmented distribution across the landscape. Dispersal and successful colonizations of unoccupied habitat patches has been rarely reported, and, in particular, translocated populations have been characterized by limited population growth and limited dispersal rates. Restoration of the species is greatly assisted by dispersal and successful colonization of new patches within a metapopulation structure versus the existing scenario of negligible dispersal and fragmented, small populations. We investigated the correlates for the rate of colonizations of 79 suitable, but unoccupied, patches by 31 translocated populations of bighorn sheep released into nearby patches of habitat. Population growth rates of bighorn sheep in the release patches were correlated to Ne of the founder group, and early contact with a second released population in a nearby release patch (logistic regression, p = 0.08). Largest population size of all extant released populations in 1994 was correlated to potential Ne of the founder group, the number of different source populations represented in the founder, and early contact with a second released population (p = 0.016). Dispersal rates were 100% higher in rams than ewes (p = 0.001). Successful colonizations of unoccupied patches (n = 24 of 79 were colonized) were associated with rapid growth rates in the released population, years since release, larger area of suitable habitat in the release patch, larger population sizes, and a seasonal migratory tendency in the released population (p = 0.05). Fewer water barriers, more open vegetation and more rugged, broken terrain in the intervening habitat were also associated with colonizations (p = <0.05). We concluded that high dispersal rates and rapid reoccupation of large areas could occur if bighorn sheep are placed in large patches of habitat with few barriers to movements to other patches and with no domestic sheep present. Many restorations in the past that did not meet these criteria may have contributed to an insular population structure of bighorn sheep with limited observations of dispersal.

Behavioral connectivity among bighorn sheep suggests potential for disease spread

USGS Publications Warehouse

Borg, Nathan J.; Mitchell, Michael S.; Lukacs, Paul M.; Mack, Curt M.; Waits, Lisette P.; Krausman, Paul R.

2017-01-01

Connectivity is important for population persistence and can reduce the potential for inbreeding depression. Connectivity between populations can also facilitate disease transmission; respiratory diseases are one of the most important factors affecting populations of bighorn sheep (Ovis canadensis). The mechanisms of connectivity in populations of bighorn sheep likely have implications for spread of disease, but the behaviors leading to connectivity between bighorn sheep groups are not well understood. From 2007–2012, we radio-collared and monitored 56 bighorn sheep in the Salmon River canyon in central Idaho. We used cluster analysis to define social groups of bighorn sheep and then estimated connectivity between these groups using a multi-state mark-recapture model. Social groups of bighorn sheep were spatially segregated and linearly distributed along the Salmon River canyon. Monthly probabilities of movement between adjacent male and female groups ranged from 0.08 (±0.004 SE) to 0.76 (±0.068) for males and 0.05 (±0.132) to 0.24 (±0.034) for females. Movements of males were extensive and probabilities of movement were considerably higher during the rut. Probabilities of movement for females were typically smaller than those of males and did not change seasonally. Whereas adjacent groups of bighorn sheep along the Salmon River canyon were well connected, connectivity between groups north and south of the Salmon River was limited. The novel application of a multi-state model to a population of bighorn sheep allowed us to estimate the probability of movement between adjacent social groups and approximate the level of connectivity across the population. Our results suggest high movement rates of males during the rut are the most likely to result in transmission of pathogens among both male and female groups. Potential for disease spread among female groups was smaller but non-trivial. Land managers can plan grazing of domestic sheep for spring and summer months when males are relatively inactive. Removal or quarantine of social groups may reduce probability of disease transmission in populations of bighorn sheep consisting of linearly distributed social groups.

Bighorn sheep habitat studies, population dynamics, and population modeling in Bighorn Canyon National Recreation Area, Wyoming and Montana, 2000-2003

USGS Publications Warehouse

Singer, Francis J.; Schoenecker, Kathryn A.

2004-01-01

The bighorn sheep population of the greater Bighorn Canyon National Recreation Area (BICA) was extirpated in the 1800s, and then reintroduced in 1973. The herd increased to a peak population of about 211 animals (Kissell and others, 1996), but then declined sharply in 1995 and 1996. Causes for the decline were unknown. Numbers have remained around 100 ± 20 animals since 1998. Previous modeling efforts determined what areas were suitable bighorn sheep habitat (Gudorf and others, 1996). We tried to determine why sheep were not using areas that were modeled as suitable or acceptable habitat, and to evaluate population dynamics of the herd.

Mitochondrial DNA and Y-chromosomal diversity in ancient populations of domestic sheep (Ovis aries) in Finland: comparison with contemporary sheep breeds.

PubMed

Niemi, Marianna; Bläuer, Auli; Iso-Touru, Terhi; Nyström, Veronica; Harjula, Janne; Taavitsainen, Jussi-Pekka; Storå, Jan; Lidén, Kerstin; Kantanen, Juha

2013-01-22

Several molecular and population genetic studies have focused on the native sheep breeds of Finland. In this work, we investigated their ancestral sheep populations from Iron Age, Medieval and Post-Medieval periods by sequencing a partial mitochondrial DNA D-loop and the 5'-promoter region of the SRY gene. We compared the maternal (mitochondrial DNA haplotypes) and paternal (SNP oY1) genetic diversity of ancient sheep in Finland with modern domestic sheep populations in Europe and Asia to study temporal changes in genetic variation and affinities between ancient and modern populations. A 523-bp mitochondrial DNA sequence was successfully amplified for 26 of 36 sheep ancient samples i.e. five, seven and 14 samples representative of Iron Age, Medieval and Post-Medieval sheep, respectively. Genetic diversity was analyzed within the cohorts. This ancient dataset was compared with present-day data consisting of 94 animals from 10 contemporary European breeds and with GenBank DNA sequence data to carry out a haplotype sharing analysis. Among the 18 ancient mitochondrial DNA haplotypes identified, 14 were present in the modern breeds. Ancient haplotypes were assigned to the highly divergent ovine haplogroups A and B, haplogroup B being the major lineage within the cohorts. Only two haplotypes were detected in the Iron Age samples, while the genetic diversity of the Medieval and Post-Medieval cohorts was higher. For three of the ancient DNA samples, Y-chromosome SRY gene sequences were amplified indicating that they originated from rams. The SRY gene of these three ancient ram samples contained SNP G-oY1, which is frequent in modern north-European sheep breeds. Our study did not reveal any sign of major population replacement of native sheep in Finland since the Iron Age. Variations in the availability of archaeological remains may explain differences in genetic diversity estimates and patterns within the cohorts rather than demographic events that occurred in the past. Our ancient DNA results fit well with the genetic context of domestic sheep as determined by analyses of modern north-European sheep breeds.

Mitochondrial DNA and Y-chromosomal diversity in ancient populations of domestic sheep (Ovis aries) in Finland: comparison with contemporary sheep breeds

PubMed Central

2013-01-01

Background Several molecular and population genetic studies have focused on the native sheep breeds of Finland. In this work, we investigated their ancestral sheep populations from Iron Age, Medieval and Post-Medieval periods by sequencing a partial mitochondrial DNA D-loop and the 5’-promoter region of the SRY gene. We compared the maternal (mitochondrial DNA haplotypes) and paternal (SNP oY1) genetic diversity of ancient sheep in Finland with modern domestic sheep populations in Europe and Asia to study temporal changes in genetic variation and affinities between ancient and modern populations. Results A 523-bp mitochondrial DNA sequence was successfully amplified for 26 of 36 sheep ancient samples i.e. five, seven and 14 samples representative of Iron Age, Medieval and Post-Medieval sheep, respectively. Genetic diversity was analyzed within the cohorts. This ancient dataset was compared with present-day data consisting of 94 animals from 10 contemporary European breeds and with GenBank DNA sequence data to carry out a haplotype sharing analysis. Among the 18 ancient mitochondrial DNA haplotypes identified, 14 were present in the modern breeds. Ancient haplotypes were assigned to the highly divergent ovine haplogroups A and B, haplogroup B being the major lineage within the cohorts. Only two haplotypes were detected in the Iron Age samples, while the genetic diversity of the Medieval and Post-Medieval cohorts was higher. For three of the ancient DNA samples, Y-chromosome SRY gene sequences were amplified indicating that they originated from rams. The SRY gene of these three ancient ram samples contained SNP G-oY1, which is frequent in modern north-European sheep breeds. Conclusions Our study did not reveal any sign of major population replacement of native sheep in Finland since the Iron Age. Variations in the availability of archaeological remains may explain differences in genetic diversity estimates and patterns within the cohorts rather than demographic events that occurred in the past. Our ancient DNA results fit well with the genetic context of domestic sheep as determined by analyses of modern north-European sheep breeds. PMID:23339395

Blue sheep in the Annapurna Conservation Area, Nepal: habitat use, population biomass and their contribution to the carrying capacity of snow leopards.

PubMed

Aryal, Achyut; Brunton, Dianne; Ji, Weihong; Raubenheimer, David

2014-01-01

The Himalaya region of Nepal provides a habitat for the endangered snow leopard (Panthera uncia) and its principal prey species, the blue sheep (Pseudois nayaur). The aim of this study was to describe the habitat, the distribution and the population structure of blue sheep, and to estimate their contribution to the carrying capacity of snow leopard in the upper Mustang region of Nepal. Blue sheep were recorded at altitudes from 3209-5498 m on slopes with gradients of 16-60° and aspects of 40°NE to 140°SE. A total of 939 blue sheep were counted in the upper Mustang region, and 98 were counted in the Yak Kharka region of Manang district; however, upper Mustang had the lowest population density of blue sheep recorded within their distribution range in Nepal (0.86 blue sheep/km(2)). The results of the study show that a higher density of blue sheep is associated with greater plant species diversity. The most important species present in the blue sheep habitat were Kobresia pygmaea, Artemesia spp., Lonicera spp., Lancea tibetica, Poa spp., Astragalus spp. and Ephedra gerardiana. It is estimated that the existing blue sheep population biomass of approximately 38 925 kg in the upper Mustang region could support approximately 19 snow leopards (1.6 snow leopards/100 km(2)). © 2012 Wiley Publishing Asia Pty Ltd, ISZS and IOZ/CAS.

Effect of rumen protozoa on Escherichia coli O157:H7 in the rumen and feces of specifically faunated sheep.

PubMed

Stanford, K; Bach, S J; Stephens, T P; McAllister, T A

2010-12-01

The effects of rumen protozoal populations on ruminal populations and fecal shedding of Escherichia coli O157:H7 were evaluated by using specifically faunated sheep. Nine fauna-free sheep (three animals per treatment) were inoculated with Dasytricha spp. (DAS sheep); with mixed population A (PopA) comprising Entodinium spp., Isotricha spp., Diplodinium spp., and Polyplastron spp.; or with mixed population B (PopB) comprising Entodinium spp., Isotricha spp., Dasytricha spp., and Epidinium spp.; six sheep were maintained fauna-free (FF sheep) to serve as controls. Sheep were fed barley silage-based diets, and treatment groups were housed in isolated rooms. Sheep were inoculated orally with 10(10) CFU of a four-strain mixture of nalidixic acid-resistant E. coli O157:H7. Samples of ruminal fluid and feces were collected over 77 days. Polyplastron spp. were detected in only one sheep in PopA, and Dasytricha spp. were detected only once within the PopB cohort. Sheep in the DAS group were 2.03 times more likely (P < 0.001) to shed E. coli O157:H7 than were those in the other three treatments, whereas the PopB sheep were less likely (0.65; P < 0.05) to shed this bacterium. The likelihood of harboring ruminal E. coli O157:H7 also tended (P = 0.06) to be higher in DAS and was lower (P < 0.01) in FF than in other cohorts. Possibly, Dasytricha spp. had a hosting effect, and Epidinium spp. had a predatory relationship, with E. coli O157:H7. Additional study into predator-prey and hosting relationships among rumen protozoa and E. coli O157:H7 is warranted.

Genetic diversity and population structure of the endangered Namaqua Afrikaner sheep.

PubMed

Qwabe, Sithembele O; van Marle-Köster, Este; Visser, Carina

2013-02-01

The Namaqua Afrikaner is an endangered sheep breed indigenous to South Africa, primarily used in smallholder farming systems. Genetic characterization is essential for the breed's conservation and utilization. In this study, a genetic characterization was performed on 144 Namaqua Afrikaner sheep kept at the Karakul Experimental Station (KES), Carnarvon Experimental Station (CES), and a private farm Welgeluk (WGK) using 22 microsatellite markers. The mean number of alleles observed was low (3.7 for KES, 3.9 for CES, and 4.2 for WGK). Expected heterozygosity values across loci ranged between 46 % for WGK, 48 % for KES, and 55 % for CES, indicating low to moderate genetic variation. The analysis of molecular variance revealed that 89.5 % of the genetic variation was due to differences within populations. The population structure confirmed the differentiation of three clusters with high relationships between the CES and WGK populations. In the population structure comparison with Pedi and South African Mutton Merino sheep, limited hybridization between the Namaqua Afrikaner sheep and both of these breeds was observed. The results of this study will serve as a reference for genetic management and conservation of Namaqua Afrikaner sheep.

Genetic Diversity and Phylogenetic Evolution of Tibetan Sheep Based on mtDNA D-Loop Sequences

PubMed Central

Yue, Yaojing; Guo, Xian; Guo, Tingting; Chu, Min; Wang, Fan; Han, Jilong; Feng, Ruilin; Sun, Xiaoping; Niu, Chune; Yang, Bohui; Guo, Jian; Yuan, Chao

2016-01-01

The molecular and population genetic evidence of the phylogenetic status of the Tibetan sheep (Ovis aries) is not well understood, and little is known about this species’ genetic diversity. This knowledge gap is partly due to the difficulty of sample collection. This is the first work to address this question. Here, the genetic diversity and phylogenetic relationship of 636 individual Tibetan sheep from fifteen populations were assessed using 642 complete sequences of the mitochondrial DNA D-loop. Samples were collected from the Qinghai-Tibetan Plateau area in China, and reference data were obtained from the six reference breed sequences available in GenBank. The length of the sequences varied considerably, between 1031 and 1259 bp. The haplotype diversity and nucleotide diversity were 0.992±0.010 and 0.019±0.001, respectively. The average number of nucleotide differences was 19.635. The mean nucleotide composition of the 350 haplotypes was 32.961% A, 29.708% T, 22.892% C, 14.439% G, 62.669% A+T, and 37.331% G+C. Phylogenetic analysis showed that all four previously defined haplogroups (A, B, C, and D) were found in the 636 individuals of the fifteen Tibetan sheep populations but that only the D haplogroup was found in Linzhou sheep. Further, the clustering analysis divided the fifteen Tibetan sheep populations into at least two clusters. The estimation of the demographic parameters from the mismatch analyses showed that haplogroups A, B, and C had at least one demographic expansion in Tibetan sheep. These results contribute to the knowledge of Tibetan sheep populations and will help inform future conservation programs about the Tibetan sheep native to the Qinghai-Tibetan Plateau. PMID:27463976

Association of Mycoplasma ovipneumoniae Infection with Population-Limiting Respiratory Disease in Free-Ranging Rocky Mountain Bighorn Sheep (Ovis canadensis canadensis)▿

PubMed Central

Besser, Thomas E.; Cassirer, E. Frances; Potter, Kathleen A.; VanderSchalie, John; Fischer, Allison; Knowles, Donald P.; Herndon, David R.; Rurangirwa, Fred R.; Weiser, Glen C.; Srikumaran, Subramaniam

2008-01-01

Bronchopneumonia is a population-limiting disease in bighorn sheep in much of western North America. Previous investigators have isolated diverse bacteria from the lungs of affected sheep, but no single bacterial species is consistently present, even within single epizootics. We obtained high-quality diagnostic specimens from nine pneumonic bighorn sheep in three populations and analyzed the bacterial populations present in bronchoalveolar lavage specimens of seven by using a culture-independent method (16S rRNA gene amplification and clone library analyses). Mycoplasma ovipneumoniae was detected as a predominant member of the pneumonic lung flora in lambs with early lesions of bronchopneumonia. Specific PCR tests then revealed the consistent presence of M. ovipneumoniae in the lungs of pneumonic bighorn sheep in this study, and M. ovipneumoniae was isolated from lung specimens of five of the animals. Retrospective application of M. ovipneumoniae PCR to DNA extracted from archived formalin-fixed, paraffin-embedded lung tissues of historical adult bighorn sheep necropsy specimens supported the association of this agent with bronchopneumonia (16/34 pneumonic versus 0/17 nonpneumonic sheep were PCR positive [P < 0.001]). Similarly, a very strong association was observed between the presence of one or more M. ovipneumoniae antibody-positive animals and the occurrence of current or recent historical bronchopneumonia problems (seropositive animals detected in 9/9 versus 0/9 pneumonic and nonpneumonic populations, respectively [P < 0.001]). M. ovipneumoniae is strongly associated with bronchopneumonia in free-ranging bighorn sheep and is a candidate primary etiologic agent for this disease. PMID:18057131

Phylogenetic diversity of Pasteurellaceae and horizontal gene transfer of leukotoxin in wild and domestic sheep.

PubMed

Kelley, Scott T; Cassirer, E Frances; Weiser, Glen C; Safaee, Shirin

2007-01-01

Wild and domestic animal populations are known to be sources and reservoirs of emerging diseases. There is also a growing recognition that horizontal genetic transfer (HGT) plays an important role in bacterial pathogenesis. We used molecular phylogenetic methods to assess diversity and cross-transmission rates of Pasteurellaceae bacteria in populations of bighorn sheep, Dall's sheep, domestic sheep and domestic goats. Members of the Pasteurellaceae cause an array of deadly illnesses including bacterial pneumonia known as "pasteurellosis", a particularly devastating disease for bighorn sheep. A phylogenetic analysis of a combined dataset of two RNA genes (16S ribosomal RNA and RNAse P RNA) revealed remarkable evolutionary diversity among Pasteurella trehalosi and Mannheimia (Pasteurella) haemolytica bacteria isolated from sheep and goats. Several phylotypes appeared to associate with particular host species, though we found numerous instances of apparent cross-transmission among species and populations. Statistical analyses revealed that host species, geographic locale and biovariant classification, but not virulence, correlated strongly with Pasteurellaceae phylogeny. Sheep host species correlated with P. trehalosi isolates phylogeny (PTP test; P=0.002), but not with the phylogeny of M. haemolytica isolates, suggesting that P. trehalosi bacteria may be more host specific. With regards to populations within species, we also discovered a strong correlation between geographic locale and isolate phylogeny in the Rocky Mountain bighorn sheep (PTP test; P=0.001). We also investigated the potential for HGT of the leukotoxin A (lktA) gene, which produces a toxin that plays an integral role in causing disease. Comparative analysis of the combined RNA gene phylogeny and the lktA phylogenies revealed considerable incongruence between the phylogenies, suggestive of HGT. Furthermore, we found identical lktA alleles in unrelated bacterial species, some of which had been isolated from sheep in distantly removed populations. For example, lktA sequences from P. trehalosi isolated from remote Alaskan Dall's sheep were 100% identical over a 900-nucleotide stretch to sequences determined from M. haemolytica isolated from domestic sheep in the UK. This extremely high degree of sequence similarity of lktA sequences among distinct bacterial species suggests that HGT has played a role in the evolution of lktA in wild hosts.

Genome-wide cross-amplification of domestic sheep microsatellites in bighorn sheep and mountain goats.

PubMed

Poissant, J; Shafer, A B A; Davis, C S; Mainguy, J; Hogg, J T; Côté, S D; Coltman, D W

2009-07-01

We tested for cross-species amplification of microsatellite loci located throughout the domestic sheep (Ovis aries) genome in two north American mountain ungulates (bighorn sheep, Ovis canadensis, and mountain goats, Oreamnos americanus). We identified 247 new polymorphic markers in bighorn sheep (≥ 3 alleles in one of two study populations) and 149 in mountain goats (≥ 2 alleles in a single study population) using 648 and 576 primer pairs, respectively. Our efforts increased the number of available polymorphic microsatellite markers to 327 for bighorn sheep and 180 for mountain goats. The average distance between successive polymorphic bighorn sheep and mountain goat markers inferred from the Australian domestic sheep genome linkage map (mean ± 1 SD) was 11.9 ± 9.2 and 15.8 ± 13.8 centimorgans, respectively. The development of genomic resources in these wildlife species enables future studies of the genetic architecture of trait variation. © 2009 Blackwell Publishing Ltd.

Identification of quantitative trait loci affecting resistance to gastro-intestinal parasites in a double backcross population of Red Maasai and Dorper sheep

USDA-ARS?s Scientific Manuscript database

A genome-wide scan for quantitative trait loci (QTL) affecting gastrointestinal (GI) nematode resistance was completed using a double backcross sheep population derived from Red Maasai and Dorper ewes bred to F1 rams. These breeds were chosen, because Red Maasai sheep are known to be more tolerant ...

Genetic diversity of Haemonchus contortus isolated from sympatric wild blue sheep (Pseudois nayaur) and sheep in Helan Mountains, China.

PubMed

Shen, Dong-Dong; Wang, Ji-Fei; Zhang, Dan-Yu; Peng, Zhi-Wei; Yang, Tian-Yun; Wang, Zhao-Ding; Bowman, Dwight D; Hou, Zhi-Jun; Liu, Zhen-Sheng

2017-09-19

Haemonchus contortus is known among parasitic nematodes as one of the major veterinary pathogens of small ruminants and results in great economic losses worldwide. Human activities, such as the sympatric grazing of wild with domestic animals, may place susceptible wildlife hosts at risk of increased prevalence and infection intensity with this common small ruminant parasite. Studies on phylogenetic factors of H. contortus should assist in defining the amount of the impact of anthropogenic factors on the extent of sharing of agents such as this nematode between domestic animals and wildlife. H. contortus specimens (n = 57) were isolated from wild blue sheep (Pseudois nayaur) inhabiting Helan Mountains (HM), China and additional H. contortus specimens (n = 20) were isolated from domestic sheep that were grazed near the natural habitat of the blue sheep. Complete ITS2 (second internal transcribed spacer) sequences and partial sequences of the nad4 (nicotinamide dehydrogenase subunit 4 gene) gene were amplified to determine the sequence variations and population genetic diversities between these two populations. Also, 142 nad4 haplotype sequences of H. contortus from seven other geographical regions of China were retrieved from database to further examine the H. contortus population structure. Sequence analysis revealed 10 genotypes (ITS2) and 73 haplotypes (nad4) among the 77 specimens, with nucleotide diversities of 0.007 and 0.021, respectively, similar to previous studies in other countries, such as Pakistan, Malaysia and Yemen. Phylogenetic analyses (BI, MP, NJ) of nad4 sequences showed that there were no noticeable boundaries among H. contortus populations from different geographical origin and population genetic analyses revealed that most of the variation (94.21%) occurred within H. contortus populations. All phylogenetic analyses indicated that there was little genetic differentiation but a high degree of gene flow among the H. contortus populations among wild blue sheep and domestic ruminants in China. The current work is the first genetic characterization of H. contortus isolated from wild blue sheep in the Helan Mountains region. The results revealed a low genetic differentiation and high degree of gene flow between the H. contortus populations from sympatric wild blue sheep and domestic sheep, indicating regular cross-infection between the sympatrically reared ruminants.

Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island

USGS Publications Warehouse

Wilder, Benjamin T.; Betancourt, Julio L.; Epps, Clinton W.; Crowhurst, Rachel S.; Mead, Jim I.; Ezcurra, Exequiel

2014-01-01

Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ~500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476–1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ~1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct.

Local extinction and unintentional rewilding of bighorn sheep (Ovis canadensis) on a desert island.

PubMed

Wilder, Benjamin T; Betancourt, Julio L; Epps, Clinton W; Crowhurst, Rachel S; Mead, Jim I; Ezcurra, Exequiel

2014-01-01

Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476-1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct.

Local Extinction and Unintentional Rewilding of Bighorn Sheep (Ovis canadensis) on a Desert Island

PubMed Central

Wilder, Benjamin T.; Betancourt, Julio L.; Epps, Clinton W.; Crowhurst, Rachel S.; Mead, Jim I.; Ezcurra, Exequiel

2014-01-01

Bighorn sheep (Ovis canadensis) were not known to live on Tiburón Island, the largest island in the Gulf of California and Mexico, prior to the surprisingly successful introduction of 20 individuals as a conservation measure in 1975. Today, a stable island population of ∼500 sheep supports limited big game hunting and restocking of depleted areas on the Mexican mainland. We discovered fossil dung morphologically similar to that of bighorn sheep in a dung mat deposit from Mojet Cave, in the mountains of Tiburón Island. To determine the origin of this cave deposit we compared pellet shape to fecal pellets of other large mammals, and extracted DNA to sequence mitochondrial DNA fragments at the 12S ribosomal RNA and control regions. The fossil dung was 14C-dated to 1476–1632 calendar years before present and was confirmed as bighorn sheep by morphological and ancient DNA (aDNA) analysis. 12S sequences closely or exactly matched known bighorn sheep sequences; control region sequences exactly matched a haplotype described in desert bighorn sheep populations in southwest Arizona and southern California and showed subtle differentiation from the extant Tiburón population. Native desert bighorn sheep previously colonized this land-bridge island, most likely during the Pleistocene, when lower sea levels connected Tiburón to the mainland. They were extirpated sometime in the last ∼1500 years, probably due to inherent dynamics of isolated populations, prolonged drought, and (or) human overkill. The reintroduced population is vulnerable to similar extinction risks. The discovery presented here refutes conventional wisdom that bighorn sheep are not native to Tiburón Island, and establishes its recent introduction as an example of unintentional rewilding, defined here as the introduction of a species without knowledge that it was once native and has since gone locally extinct. PMID:24646515

Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum

PubMed Central

Rico, Y; Wagner, H H

2016-01-01

Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations. PMID:27381322

Reduced fine-scale spatial genetic structure in grazed populations of Dianthus carthusianorum.

PubMed

Rico, Y; Wagner, H H

2016-11-01

Strong spatial genetic structure in plant populations can increase homozygosity, reducing genetic diversity and adaptive potential. The strength of spatial genetic structure largely depends on rates of seed dispersal and pollen flow. Seeds without dispersal adaptations are likely to be dispersed over short distances within the vicinity of the mother plant, resulting in spatial clustering of related genotypes (fine-scale spatial genetic structure, hereafter spatial genetic structure (SGS)). However, primary seed dispersal by zoochory can promote effective dispersal, increasing the mixing of seeds and influencing SGS within plant populations. In this study, we investigated the effects of seed dispersal by rotational sheep grazing on the strength of SGS and genetic diversity using 11 nuclear microsatellites for 49 populations of the calcareous grassland forb Dianthus carthusianorum. Populations connected by rotational sheep grazing showed significantly weaker SGS and higher genetic diversity than populations in ungrazed grasslands. Independent of grazing treatment, small populations showed significantly stronger SGS and lower genetic diversity than larger populations, likely due to genetic drift. A lack of significant differences in the strength of SGS and genetic diversity between populations that were recently colonized and pre-existing populations suggested that populations colonized after the reintroduction of rotational sheep grazing were likely founded by colonists from diverse source populations. We conclude that dispersal by rotational sheep grazing has the potential to considerably reduce SGS within D. carthusianorum populations. Our study highlights the effectiveness of landscape management by rotational sheep grazing to importantly reduce genetic structure at local scales within restored plant populations.

The effects of diet and breed on the volatile compounds of cooked lamb.

PubMed

Elmore, J S; Mottram, D S; Enser, M; Wood, J D

2000-06-01

The effect of varying the n-3 polyunsaturated fatty acid (PUFA) composition of lamb muscle on the formation of aroma volatiles during cooking has been examined. The meat was obtained from four groups of Suffolk and Soay lambs fed different supplementary fats: a palm-oil based control; bruised whole linseed, which increased muscle levels of α-linolenic acid (C18:3 n-3); fish oil, which increased eicosapentaenoic acid (EPA, C20:5 n-3) and docosahexaenoic acid (DHA, C22:6 n-3); and equal quantities of linseed and fish oil (fat basis). Higher quantities of lipid oxidation products were found in the aroma volatiles of lamb muscle from animals fed fish oil, compared to the control. In particular, unsaturated aldehydes, unsaturated hydrocarbons and alkylfurans increased up to fourfold. These compounds derived from the autoxidation of PUFAs during cooking. Although some of these volatiles were increased in meat from animals fed the linseed supplement, the effect was not as great as with the fish oil fed lambs. Levels of volatiles derived from the Maillard reaction, such as pyrazines and sulfur compounds, were up to four times higher in Soays than Suffolks.

Genetic signatures of a Mediterranean influence in Iberian Peninsula sheep husbandry.

PubMed

Pereira, Filipe; Davis, Simon J M; Pereira, Luísa; McEvoy, Brian; Bradley, Daniel G; Amorim, António

2006-07-01

Highly adaptable and versatile populations of domestic sheep, the result of millennia of intense husbandry, are found in almost every corner of the world. Here we describe a genetic survey of sheep from the western fringe of its European distribution. We studied the mitochondrial DNA control region sequences from 161 individuals belonging to 7 Portuguese sheep breeds. Our study revealed a high level of genetic diversity, with an average breed haplotype diversity of 0.983, substantially above that observed in central European breeds, as well as the presence of maternal lineages until now only found in the Middle East and Asia. A broad north-south pattern describes the most important trend in the Portuguese sheep population with a southern population clearly distinct from most other breeds. A recurrent influx of new genetic diversity, probably via the Mediterranean Sea, may explain these patterns and appears to corroborate the importance of this maritime route in the history of both mankind and livestock. Zooarchaeological studies of sheep bones from southern Portugal indicate a marked size increase during the Moslem period that may reflect an improvement of this animal--perhaps part of the well known "Arab agricultural revolution" in Andalusia. This could have been a time when the gene pool of Iberian sheep was substantially enriched and may help to explain the history of modern sheep breeds in this peninsula.

Genetic diversity of selected genes that are potentially economically important in feral sheep of New Zealand

PubMed Central

2010-01-01

Background Feral sheep are considered to be a source of genetic variation that has been lost from their domestic counterparts through selection. Methods This study investigates variation in the genes KRTAP1-1, KRT33, ADRB3 and DQA2 in Merino-like feral sheep populations from New Zealand and its offshore islands. These genes have previously been shown to influence wool, lamb survival and animal health. Results All the genes were polymorphic, but no new allele was identified in the feral populations. In some of these populations, allele frequencies differed from those observed in commercial Merino sheep and other breeds found in New Zealand. Heterozygosity levels were comparable to those observed in other studies on feral sheep. Our results suggest that some of the feral populations may have been either inbred or outbred over the duration of their apparent isolation. Conclusion The variation described here allows us to draw some conclusions about the likely genetic origin of the populations and selective pressures that may have acted upon them, but they do not appear to be a source of new genetic material, at least for these four genes. PMID:21176141

Shared Bacterial and Viral Respiratory Agents in Bighorn Sheep (Ovis canadensis), Domestic Sheep (Ovis aries), and Goats (Capra hircus) in Montana

PubMed Central

Miller, David S.; Weiser, Glen C.; Aune, Keith; Roeder, Brent; Atkinson, Mark; Anderson, Neil; Roffe, Thomas J.; Keating, Kim A.; Chapman, Phillip L.; Kimberling, Cleon; Rhyan, Jack; Clarke, P. Ryan

2011-01-01

Transmission of infectious agents from livestock reservoirs has been hypothesized to cause respiratory disease outbreaks in bighorn sheep (Ovis canadensis), and land management policies intended to limit this transmission have proven controversial. This cross-sectional study compares the infectious agents present in multiple populations of bighorn sheep near to and distant from their interface with domestic sheep (O. aries) and domestic goat (Capra hircus) and provides critical baseline information needed for interpretations of cross-species transmission risks. Bighorn sheep and livestock shared exposure to Pasteurellaceae, viral, and endoparasite agents. In contrast, although the impact is uncertain, Mycoplasma sp. was isolated from livestock but not bighorn sheep. These results may be the result of historic cross-species transmission of agents that has resulted in a mosaic of endemic and exotic agents. Future work using longitudinal and multiple population comparisons is needed to rigorously establish the risk of outbreaks from cross-species transmission of infectious agents. PMID:22195293

Shared Bacterial and Viral Respiratory Agents in Bighorn Sheep (Ovis canadensis), Domestic Sheep (Ovis aries), and Goats (Capra hircus) in Montana.

PubMed

Miller, David S; Weiser, Glen C; Aune, Keith; Roeder, Brent; Atkinson, Mark; Anderson, Neil; Roffe, Thomas J; Keating, Kim A; Chapman, Phillip L; Kimberling, Cleon; Rhyan, Jack; Clarke, P Ryan

2011-01-01

Transmission of infectious agents from livestock reservoirs has been hypothesized to cause respiratory disease outbreaks in bighorn sheep (Ovis canadensis), and land management policies intended to limit this transmission have proven controversial. This cross-sectional study compares the infectious agents present in multiple populations of bighorn sheep near to and distant from their interface with domestic sheep (O. aries) and domestic goat (Capra hircus) and provides critical baseline information needed for interpretations of cross-species transmission risks. Bighorn sheep and livestock shared exposure to Pasteurellaceae, viral, and endoparasite agents. In contrast, although the impact is uncertain, Mycoplasma sp. was isolated from livestock but not bighorn sheep. These results may be the result of historic cross-species transmission of agents that has resulted in a mosaic of endemic and exotic agents. Future work using longitudinal and multiple population comparisons is needed to rigorously establish the risk of outbreaks from cross-species transmission of infectious agents.

Shared bacterial and viral respiratory agents in bighorn sheep (Ovis canadensis), domestic sheep (Ovis aries), and goats (Capra hircus) in Montana

USGS Publications Warehouse

Miller, David S.; Weiser, Glen C.; Aune, Keith; Roeder, Brent; Atkinson, Mark; Anderson, Neil; Roffe, Thomas J.; Keating, Kim A.; Chapman, Phillip L.; Kimberling, Cleon; Rhyan, Jack C.; Clarke, P. Ryan

2011-01-01

Transmission of infectious agents from livestock reservoirs has been hypothesized to cause respiratory disease outbreaks in bighorn sheep (Ovis canadensis), and land management policies intended to limit this transmission have proven controversial. This cross-sectional study compares the infectious agents present in multiple populations of bighorn sheep near to and distant from their interface with domestic sheep (O. aries) and domestic goat (Capra hircus) and provides critical baseline information needed for interpretations of cross-species transmission risks. Bighorn sheep and livestock shared exposure to Pasteurellaceae, viral, and endoparasite agents. In contrast, although the impact is uncertain, Mycoplasma sp. was isolated from livestock but not bighorn sheep. These results may be the result of historic cross-species transmission of agents that has resulted in a mosaic of endemic and exotic agents. Future work using longitudinal and multiple population comparisons is needed to rigorously establish the risk of outbreaks from cross-species transmission of infectious agents.

Potential foraging decisions by a desert ungulate to balance water and nutrient intake in a water-stressed environment

USGS Publications Warehouse

Gedir, Jay V.; Cain, James W.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.; Morgart, John R.

2016-01-01

Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8–55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during water-stressed periods may not be necessary for desert bighorn sheep.

Potential Foraging Decisions by a Desert Ungulate to Balance Water and Nutrient Intake in a Water-Stressed Environment.

PubMed

Gedir, Jay V; Cain, James W; Krausman, Paul R; Allen, Jamison D; Duff, Glenn C; Morgart, John R

2016-01-01

Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8-55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during water-stressed periods may not be necessary for desert bighorn sheep.

Potential Foraging Decisions by a Desert Ungulate to Balance Water and Nutrient Intake in a Water-Stressed Environment

PubMed Central

Gedir, Jay V.; Cain, James W.; Krausman, Paul R.; Allen, Jamison D.; Duff, Glenn C.

2016-01-01

Arid climates have unpredictable precipitation patterns, and wildlife managers often provide supplemental water to help desert ungulates endure the hottest, driest periods. When surface water is unavailable, the only source of water for ungulates comes from the forage they consume, and they must make resourceful foraging decisions to meet their requirements. We compared two desert bighorn sheep (Ovis canadensis nelsoni) populations in Arizona, USA: a treatment population with supplemental water removed during treatment, and a control population. We examined whether sheep altered their seasonal diets without supplemental water. We calculated water and nutrient intake and metabolic water production from dry matter intake and forage moisture and nitrogen content, to determine whether sheep could meet their seasonal daily water and nutrient requirements solely from forage. Diets of sheep were higher in protein (all seasons) and moisture (autumn and winter) during treatment compared to pretreatment. During treatment, sheep diet composition was similar between the treatment and control populations, which suggests, under the climatic conditions of this study, water removal did not influence sheep diets. We estimated that under drought conditions, without any surface water available (although small ephemeral potholes would contain water after rains), female and male sheep would be unable to meet their daily water requirements in all seasons, except winter, when reproductive females had a nitrogen deficit. We determined that sheep could achieve water and nutrient balances in all seasons by shifting their total diet proportions by 8–55% from lower to higher moisture and nitrogen forage species. We elucidate how seasonal forage quality and foraging decisions by desert ungulates allow them to cope with their xeric and uncertain environment, and suggest that, with the forage conditions observed in our study area during this study period, providing supplemental water during water-stressed periods may not be necessary for desert bighorn sheep. PMID:26894504

Alternative foraging strategies enable a mountain ungulate to persist after migration loss

USGS Publications Warehouse

Courtemanch, Alyson B.; Kauffman, Matthew J.; Kilpatrick, Steve; Dewey, Sarah R.

2017-01-01

The persistence of many migratory ungulate populations worldwide is threatened due to anthropogenic impacts to seasonal ranges and migration routes. While many studies have linked migratory ungulate declines to migration disruption or loss, very few have explored the underlying factors that determine whether a population perishes or persists. In some cases, populations undergo severe declines and extirpation after migration loss; however, others appear able to persist as residents. We predict that to persist, populations must replace the traditional benefits of migration by altering the foraging strategies they employ as residents within one seasonal range. We propose the alternative foraging strategies (AFS) hypothesis as a framework for identifying various behavioral strategies that populations may use to cope with migration loss. We tested the hypothesis using the formerly migratory Teton bighorn sheep population in northwest Wyoming, which ceased migrating over 60 yr ago, but has persisted as a resident population. We used global positioning system data to evaluate winter and summer habitat selection and seasonal elevational movements for 28 adult female bighorn sheep (Ovis canadensis) from 2008 to 2010. Resource selection functions revealed that bighorn sheep employ winter foraging strategies to survive as residents by seeking out rugged, high-elevation, windswept ridgelines. Seasonal movement analyses indicated that bighorn sheep undergo a newly documented “abbreviated migration” strategy that is closely synchronized with vegetation green-up patterns within their one range. Bighorn sheep descend 500 m in elevation and travel up to 10 km in spring, gaining access to newly emergent forage approximately 30 d before it appears on their high-elevation winter and summer ranges. Our findings indicate that the Teton bighorn sheep population has persisted due to its habitat selection, AFS, and unique movement patterns, which allow migration loss to be mediated to some extent. The identification of AFS and the habitats that support them can help reveal the underlying benefits of migration and conserve populations in the face of future migration loss.

Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. II. Protozoa population and diversity of bacterial communities.

PubMed

Martínez, M E; Ranilla, M J; Tejido, M L; Saro, C; Carro, M D

2010-08-01

Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of dietary characteristics on microbial populations and bacterial diversity. The purpose of the study was to assess how closely fermenters can mimic the differences between diets found in vivo. The 4 experimental diets contained forage to concentrate (F:C) ratios of 70:30 (high forage; HF) or 30:70 (high concentrate; HC) with either alfalfa hay (A) or grass hay (G) as the forage. Total bacterial numbers were greater in the rumen of sheep fed HF diets compared with those fed HC diets, whereas the opposite was found in fermenters. The numbers of cellulolytic bacteria were not affected by F:C ratio in any fermentation system, but cellulolytic numbers were 2.7 and 1.8 times greater in sheep than in fermenters for HF and HC diets, respectively. Neither total bacterial nor cellulolytic numbers were affected by the type of forage in sheep or fermenters. Decreasing F:C ratio increased total protozoa and Entodiniae numbers in sheep by about 29 and 25%, respectively, but it had no effect in fermenters. Isotrichidae and Ophryoscolecinae numbers in sheep were not affected by changing F:C ratio, but both disappeared completely from fermenters fed HC diets. Total protozoa and Entodiniae numbers were greater in sheep fed A diets than in those fed G diets, whereas the opposite was found in fermenters. Results indicate that under the conditions of the present study, protozoa population in Rusitec fermenters was not representative of that in the rumen of sheep fed the same diets. In addition, protozoa numbers in fermenters were 121 and 226 times lower than those in the sheep rumen for HF and HC diets, respectively. The automated ribosomal intergenic spacer analysis of the 16S ribosomal DNA was used to analyze the diversity of liquid- and solid-associated bacteria in both systems. A total of 170 peaks were detected in the automated ribosomal intergenic spacer analysis electropherograms of bacterial pellets across the full set of 64 samples, from which 160 were detected in at least 1 individual from each system (sheep or fermenter). Diversity of liquid-associated bacterial pellets was greater with G diets in fermenters but seemed to be unaffected by diet in sheep. Bacterial diversity in solid-associated bacteria pellets was greater for G diets compared with A diets in sheep and fermenters. Different conditions in the fermenters compared with sheep rumen might have caused a selection of some bacterial strains. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Restoring critical habitat for Hawaii's endangered pall la by reducing ungulate populations

Treesearch

Paul G. Scowcroft; C. Eugene. Conrad

1988-01-01

Drastically reducing populations of feral sheep (Ovis aries), mouflon sheep (Ovis musimon), feral-mouflon hybrids, and feral goats (Capra hircus) on Mauna Kea were key management actions done to promote recovery of critical habitat for palila Loxioides bailleui), an endangered Hawaiian...

Ecotypic variation in population dynamics of reintroduced bighorn sheep

USGS Publications Warehouse

Bleich, Vernon C.; Sargeant, Glen A.; Wiedmann, Brett P.

2018-01-01

Selection of bighorn sheep (Ovis canadensis) for translocation historically has been motivated by preservation of subspecific purity rather than by adaptation of source stocks to similar environments. Our objective was to estimate cause‐specific, annual, and age‐specific mortality of introduced bighorn sheep that originated at low elevations in southern British Columbia, Canada (BC ecotype), or in the Missouri River Breaks region of central Montana, USA (MT ecotype). In North Dakota, USA, mortality was similar and typically low for adult female bighorn sheep from Montana (0.09 ± 0.029 [SE]) and British Columbia (0.08 ± 0.017) during 2000–2016. Median life expectancy was 11 years for females that reached adulthood (2 yrs old); however, mortality accelerated with age and reached 86% by age 16. Mortalities resulted primarily from low rates of predation, disease, accidents, and unknown natural causes (<0.04 [upper 90% CI]). Similar survival rates of female bighorn sheep from female bighorn sheep from British Columbia and Montana, coupled with greater recruitment of bighorn sheep from Montana, resulted in a greater projected rate of increase for the MT ecotype (λ = 1.21) than for the BC ecotype (1.02), and a more youthful age structure. These results support translocation of bighorn sheep from areas that are environmentally similar to areas that will be stocked. Potential benefits include more rapid population growth, greater resilience to and more rapid recovery from density‐independent losses, an increased possibility that rapidly growing populations will expand into adjacent habitat, increased hunter opportunity, increased connectivity among herds, and a more complete restoration of ecosystem processes.

Influence of several feeds on bacteria in sheep and goat rumen liquor in vitro.

PubMed

Gonzalez-Lopez, J; Salmeron, V; Ramos-Cormenzana, A; Silva-Colomer, J; Boza, J

1990-01-01

Bacteriological studies were made with in vitro sheep and goat ruminal fluids supplemented with several feeds (alfalfa hay, wheat straw, Agave americana, Opuntia ficus indica and Atriplex nummularia) during anaerobic incubation at 38-39 degrees C. Drastic changes in the bacterial population of sheep ruminal fluids occurred in the presence of different feeds, particularly with addition of feeds of low nutritional quality (wheat straw, A. americana and O. ficus indica). However, the bacterial population in goat rumen liquor was little affected by the addition of the same feeds. These results, which suggest that the rumen bacteria in goats are less affected by different nutritional conditions than the rumen bacteria in sheep, are discussed.

Ecotypic variation in recruitment of reintroduced bighorn sheep: implications for translocation

USGS Publications Warehouse

Wiedmann, Brett P.; Sargeant, Glen A.

2014-01-01

European settlement led to extirpation of native Audubon's bighorn sheep (formerly Ovis canadensis auduboni) from North Dakota during the early 20th century. The North Dakota Game and Fish Department subsequently introduced California bighorn sheep (formerly O. c. californiana) that were indigenous to the Williams Lake region of British Columbia, Canada, and Rocky Mountain bighorn sheep (O. c. canadensis) that were indigenous to the Sun River region of Montana. Although California bighorn sheep are no longer recognized as a distinct subspecies, they are smaller and adapted to a milder climate than either the native bighorn sheep of North Dakota or introduced bighorn sheep from Montana. Because reintroductions still play a key role in the management of bighorn sheep and because local adaptation may have substantial demographic consequences, we evaluated causes of variation in recruitment of bighorn sheep reintroduced in North Dakota. During 2006–2011, Montana stock recruited 0.54 juveniles/adult female (n = 113), whereas British Columbia stock recruited 0.24 juveniles/adult female (n = 562). Our most plausible mixed-effects logistic regression model (53% of model weight) attributed variation in recruitment to differences between source populations (odds ratio = 4.5; 90% CI = 1.5, 15.3). Greater recruitment of Montana stock (fitted mean = 0.56 juveniles/adult female; 90% CI = 0.41, 0.70) contributed to a net gain in abundance (r = 0.15), whereas abundance of British Columbia stock declined (fitted mean = 0.24 juveniles/adult female; 90% CI = 0.09, 0.41; r = − 0.04). Translocations have been the primary tool used to augment and restore populations of wild sheep but often have failed to achieve objectives. Our results show that ecotypic differences among source stocks may have long-term implications for recruitment and demographic performance of reintroduced populations.

Restoration of bighorn sheep metapopulations in and near 15 national parks: Conservation of a severely fragmented species; Volume I, Planning, problem definition, findings, and restoration

USGS Publications Warehouse

Singer, Francis J.; Gudorf, Michelle A.

1999-01-01

Bighorn sheep (Ovis canadensis) were historically a ubiquitous species. Prior to the arrival of Europeans, they were seemingly widespread in nearly all steep habitats in the mountains, foothills, river breaks, and prairie badlands of the western United States. However, since catastrophic declines in the late 1800s and early 1900s, most extant populations have existed as small, isolated groups in a highly fragmented distribution. Stochastic events such as seasonal weather change or population fluctuations render these small populations more prone to extirpation than larger populations. Three different subspecies of bighorn sheep were eliminated from 14 of 18 National Park System (NPS) units in the 6-state Intermountain Region of the western United States (Singer 1994). In 1990, when this restoration was initiated, only 4 (18%) of 22 discrete park populations or metapopulations were considered large enough (300-500 animals) to be secure for long-term management. Five (23%) other populations numbered 100-299 animals and 3 (14%) populations numbered 75-99 animals. But, the remaining 10 populations (45%) were either extirpated (n = 2), remnant populations (n = 5, populations of 7-10 animals), or vulnerable to extirpation (n = 3, populations of less than 50 animals). Restoration prior to 1991-96 was largely completed in one NPS unit, but was incomplete in the remaining units. Most bighorn sheep are not federally listed as endangered or threatened species, although the California peninsular population of desert bighorn sheep was recently listed as endangered. The bighorn sheep is a rare or uncommon species that is declining in many parts of its range but is abundant in other areas and still relatively easy to study and manage. The Secretary of the Department of the Interior, Bruce Babbitt, directed the Biological Resources Division of the U.S. Geological Survey in 1993 (when this agency was still the National Biological Service) to research and recover species that were declining to avoid expensive and controversial federal listing. Because the capture and moving of the species are still relatively uncomplicated and because some source stocks are available, aggressive restoration in 15 National Park System units in the former Rocky Mountain Region was recommended in 1990. This report details the 7-year restoration of bighorn sheep to all currently suitable historic habitats in the national parks of the former Rocky Mountain Region (now the Intermountain and Midwest regions of the National Park Service). The purpose of the first phase of the restoration during 1991-93 was to conduct research and population surveys and to formulate the restoration plans. The purpose of the second phase of the initiative during 1994-97 was to conduct GIS-based habitat and biological assessments of prospective restoration sites, write restoration plans, and restore and monitor the released bighorn sheep.

Serological survey for antibodies against pestiviruses in Wyoming domestic sheep.

PubMed

Silveira, S; Falkenberg, S M; Elderbrook, M J; Sondgeroth, K S; Dassanayake, R P; Neill, J D; Ridpath, J F; Canal, C W

2018-06-01

Pestiviruses including Bovine viral diarrhea virus type 1 (BVDV-1), BVDV-2 and Border disease virus (BDV) have been reported in both sheep and cattle populations, together with the HoBi-like, an emerging group of pestiviruses. Pestivirus control programs in the United States have focused on the control of BVDV-1 and 2. The incidence of pestivirus infection in sheep in the United States and the risk of transmission between cattle and sheep populations are unknown. The aim of this study was to perform serological surveillance for pestivirus exposure in sheep from an important sheep producing state in the Unites States, Wyoming. For this, sera from 500 sheep, collected across the state of Wyoming (US) in 2015-2016, were examined by comparative virus neutralization assay against four species/proposed species of pestiviruses: BVDV-1, BVDV-2, BDV and HoBi-like virus. Rates of exposure varied between geographic regions within the state. The overall pestivirus prevalence of antibodies was 5.6%. Antibodies were most frequently detected against BVDV-1 (4%), and the highest antibody titers were also against BVDV-1. Data from this study highlights understanding of the dynamics of sheep pestivirus exposure, consideration of reference strains used for VN assays, transmission patterns, and potential vaccination history should be taken into account in implementation of control measures against pestiviruses in sheep and for successful BVDV control programs in cattle. Published by Elsevier B.V.

A multi-species model to assess the effect of refugia on worm control and anthelmintic resistance in sheep grazing systems.

PubMed

Dobson, R J; Barnes, E H; Tyrrell, K L; Hosking, B C; Larsen, J W A; Besier, R B; Love, S; Rolfe, P F; Bailey, J N

2011-06-01

Develop a computer simulation model that uses daily meteorological data and farm management practices to predict populations of Trichostrongylus colubriformis, Haemonchus contortus and Teladorsagia (Ostertagia) circumcincta and the evolution of anthelmintic resistance within a sheep flock. Use the model to explore if increased refugia, provided by leaving some adult sheep untreated, would delay development of anthelmintic resistance without compromising nematode control. Compare model predictions with field observations from a breeding flock in Armidale, NSW. Simulate the impact of leaving 1-10% of adult sheep untreated in diverse sheep-grazing systems. Predicted populations of Tr. colubriformis and T. circumcincta were less than those observed in the field, attributed to nutritional stress experienced by the sheep during drought and not accounted for by the model. Observed variation in faecal egg counts explained by the model (R(2) ) for these species was 40-50%. The H. contortus populations and R(2) were both low. Leaving some sheep untreated worked best in situations where animals were already grazing or were moved onto pastures with low populations of infective larvae. In those cases, anthelmintic resistance was delayed and nematode control was maintained when 1-4% of adult stock remained untreated. In general, the model predicted that leaving more than 4% of adults untreated did not sufficiently delay the development of anthelmintic resistance to justify the increased production risk from such a strategy. The choice of a drug rotation strategy had an equal or larger effect on nematode control, and selection for resistance, than leaving 1-10% of adults untreated. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Seasonal dynamics and variation among sheep in densities of the sheep biting louse, Bovicola ovis.

PubMed

James, P J; Moon, R D; Brown, D R

1998-02-01

Cyclic patterns and variations among sheep in numbers of Bovicola ovis are described in Polypay and Columbia ewes that were initially infested with equal numbers of lice and penned indoors continuously for 2 years. Bovicola ovis populations were censused at 3-4-week intervals at 69 body sites on each animal. In the second year of the study, the ewes were reinfested and half were mated. Louse populations were monitored on the resulting lambs from birth until 25 weeks of age. Strong seasonal cycles in louse numbers were observed on the ewes, with peaks in spring and troughs in summer. These cycles occurred in the absence of shearing, direct solar radiation or rainfall. Populations began to decline when daily mean and maximum temperatures were 11.5 degrees C and 15 degrees C, respectively, well below temperatures thought to cause warm season decline. Louse densities on Polypay ewes were approximately 10 times higher than on Columbias at most inspections. There were also large differences among sheep within breeds and sheep counts were highly correlated among dates, both within and between years. One third of the ewes failed to become infested despite having lice applied on five separate occasions and being penned together with other infested sheep. Pregnancy and lactation did not significantly affect louse numbers on the ewes. There was a significant negative correlation between louse counts and weight gains in the lambs, and lamb counts were significantly correlated with those of their dams up until, but not after, weaning. It is suggested that sheep may exert regulatory influences on lice which contribute to cycles in B. ovis populations.

Serological survey for antibodies against pestiviruses in sheep in Wyoming

USDA-ARS?s Scientific Manuscript database

Pestiviruses including Bovine Viral Diarrhea Virus type 1 (BVDV1), BVDV-2 and Border Disease Virus (BDV) have been reported in sheep populations worldwide. These viruses are not strictly host specific and can also infect cattle, goats, swine and wild ruminants. In sheep, clinical signs are related t...

Environmental conditions associated with lesions in introduced free-ranging sheep in Hawai‘i

USGS Publications Warehouse

Powers, Jenny G.; Duncan, Colleen G.; Spraker, Terry R.; Schuler, Bridget A.; Hess, Steven C.; Faford, Jonathan K.J.; Sin, Hans

2014-01-01

Wildlife species which have been translocated between temperate and tropical regions of the world provide unique opportunities to understand how disease processes may be affected by environmental conditions. European mouflon sheep (Ovis gmelini musimon) from the Mediterranean Islands were introduced to the Hawaiian Islands for sport hunting beginning in 1954 and were subsequently hybridized with feral domestic sheep (O. aries), which had been introduced in 1793. Three isolated mouflon populations have become established in the Hawaiian Islands but diseases in these populations have been little studied. The objective of this study was to evaluate and compare gross and histologic lesions in respiratory, renal, and hepatic systems of free-ranging sheep in two isolated volcanic environments on Hawai‘i Island. Tissue and fecal samples were collected in conjunction with population reductions during February 2011. We found gross or histologic evidence of lungworm infection in 44/49 sheep from Mauna Loa which were exposed to gaseous emissions from Kīlauea Volcano. In contrast, only 7/50 sheep from Mauna Kea had lesions consistent with lungworm, but Mauna Kea sheep had significantly more upper respiratory tract inflammation and hyperplasia consistent with chronic antigenic stimulation, possibly associated with exposure to fine airborne particulates during extended drought conditions. We hypothesize that gasses from Kīlauea Volcano contributed to severity of respiratory disease principally associated with chronic lungworm infections at Mauna Loa; however, there were numerous other potentially confounding environmental factors and interactions that merit further investigation.

Genetic diversity of Ovis aries populations near domestication centers and in the new world

USDA-ARS?s Scientific Manuscript database

Domestic sheep in Kazakhstan may provide an interesting source of genetic variability due to their proximately to the center of domestication and the Silk Route. Additionally, those breeds have never been compared to new world sheep populations. This report compares genetic diversity among five Kaza...

Helminths community of veterinary importance of livestock in relation to some ecological and biological factors.

PubMed

Ibrahim, Mohamed M; Ghamdi, Manea; Gahmdi, Mesfer

2008-01-01

The goals of this study were: (I) to report the helminth population in cattle, sheep and goats; (II) to determine the concentration and diversity of the population; and (III) to study the role of host age, host sex, diet and season in structuring the population. A total of 485 cattle, 1144 sheep and 989 goats were examined for helminth population for four seasons. The helminth population consisted of nine species, four trematodes, four cestodes and one nematode. The overall infection prevalence in cattle, sheep and goats was 12.92%, 18.63% and 13.45%, respectively. Echinococcus granulosus was the most prevalent parasite. The overall mean species concentration per host was 1.23, 0.95 and 0.53 in cattle, sheep and goats, respectively. Species concentration, prevalence and mean abundance varied significantly in relation to host age, sex, diet and season. In conclusion, the influence of the factors investigated on structuring the helminth population of livestock, varied from species to another. We cannot say if the low species concentration and the recorded infection rates observed in the present study are typical of the host species or if they are due to characteristics of the study area, since there is no data available for other host populations.

Chlamydial-caused infectious keratoconjunctivitis in bighorn sheep of Yellowstone National Park

USGS Publications Warehouse

Meagher, Mary; Quinn, William J.; Stackhouse, Larry

1992-01-01

An epizootic of infectious keratoconjuctivitis occurred in bighorn sheep (Ovis canadensis) in Yellowstone National Park during the winter of 1981-82. The causative organism was identified as Chlamydia sp. Mortality related to the epizootic was approximately 60% of an estimated 500 bighorn sheep in the northern range population. The infection probably affected all sex and age classes, but field surveys of live animals and mortality suggested that mature rams died disproportionately. Limited field observations the following winter on individuals having both normal and cloudy-appearing eyes suggested that half of the bighorns then present on the core units of winter range had contracted the disease and survived. By 1988, there were about 300 bighorn sheep in the population.

Evaluation of aerial survey methods for Dall's sheep

USGS Publications Warehouse

Udevitz, Mark S.; Shults, Brad S.; Adams, Layne G.; Kleckner, Christopher

2006-01-01

Most Dall's sheep (Ovis dalli dalli) population-monitoring efforts use intensive aerial surveys with no attempt to estimate variance or adjust for potential sightability bias. We used radiocollared sheep to assess factors that could affect sightability of Dall's sheep in standard fixed-wing and helicopter surveys and to evaluate feasibility of methods that might account for sightability bias. Work was conducted in conjunction with annual aerial surveys of Dall's sheep in the western Baird Mountains, Alaska, USA, in 2000–2003. Overall sightability was relatively high compared with other aerial wildlife surveys, with 88% of the available, marked sheep detected in our fixed-wing surveys. Total counts from helicopter surveys were not consistently larger than counts from fixed-wing surveys of the same units, and detection probabilities did not differ for the 2 aircraft types. Our results suggest that total counts from helicopter surveys cannot be used to obtain reliable estimates of detection probabilities for fixed-wing surveys. Groups containing radiocollared sheep often changed in size and composition before they could be observed by a second crew in units that were double-surveyed. Double-observer methods that require determination of which groups were detected by each observer will be infeasible unless survey procedures can be modified so that groups remain more stable between observations. Mean group sizes increased during our study period, and our logistic regression sightability model indicated that detection probabilities increased with group size. Mark–resight estimates of annual population sizes were similar to sightability-model estimates, and confidence intervals overlapped broadly. We recommend the sightability-model approach as the most effective and feasible of the alternatives we considered for monitoring Dall's sheep populations.

Epizootic pneumonia of bighorn sheep following experimental exposure to Mycoplasma ovipneumoniae.

PubMed

Besser, Thomas E; Cassirer, E Frances; Potter, Kathleen A; Lahmers, Kevin; Oaks, J Lindsay; Shanthalingam, Sudarvili; Srikumaran, Subramaniam; Foreyt, William J

2014-01-01

Bronchopneumonia is a population limiting disease of bighorn sheep (Ovis canadensis). The cause of this disease has been a subject of debate. Leukotoxin expressing Mannheimia haemolytica and Bibersteinia trehalosi produce acute pneumonia after experimental challenge but are infrequently isolated from animals in natural outbreaks. Mycoplasma ovipneumoniae, epidemiologically implicated in naturally occurring outbreaks, has received little experimental evaluation as a primary agent of bighorn sheep pneumonia. In two experiments, bighorn sheep housed in multiple pens 7.6 to 12 m apart were exposed to M. ovipneumoniae by introduction of a single infected or challenged animal to a single pen. Respiratory disease was monitored by observation of clinical signs and confirmed by necropsy. Bacterial involvement in the pneumonic lungs was evaluated by conventional aerobic bacteriology and by culture-independent methods. In both experiments the challenge strain of M. ovipneumoniae was transmitted to all animals both within and between pens and all infected bighorn sheep developed bronchopneumonia. In six bighorn sheep in which the disease was allowed to run its course, three died with bronchopneumonia 34, 65, and 109 days after M. ovipneumoniae introduction. Diverse bacterial populations, predominantly including multiple obligate anaerobic species, were present in pneumonic lung tissues at necropsy. Exposure to a single M. ovipneumoniae infected animal resulted in transmission of infection to all bighorn sheep both within the pen and in adjacent pens, and all infected sheep developed bronchopneumonia. The epidemiologic, pathologic and microbiologic findings in these experimental animals resembled those seen in naturally occurring pneumonia outbreaks in free ranging bighorn sheep.

Passive transfer in domestic and bighorn lambs Total IgG in ewe sera and colostrum and serum IgG kinetics in lambs following colostrum ingestion are similar in domestic sheep and bighorn sheep (ovis aries and ovis canadensis)

USDA-ARS?s Scientific Manuscript database

Pneumonia is a population-limiting disease of bighorn sheep (BHS; Ovis canadensis) and a recognized disease entity in domestic sheep (DS; Ovis aries) worldwide. Respiratory disease in BHS lambs can persist for years after all-age outbreaks, resulting in suppressed lamb recruitment. It has been sugge...

Genome-wide linkage disequilibrium and genetic diversity in five populations of Australian domestic sheep.

PubMed

Al-Mamun, Hawlader Abdullah; Clark, Samuel A; Kwan, Paul; Gondro, Cedric

2015-11-24

Knowledge of the genetic structure and overall diversity of livestock species is important to maximise the potential of genome-wide association studies and genomic prediction. Commonly used measures such as linkage disequilibrium (LD), effective population size (N e ), heterozygosity, fixation index (F ST) and runs of homozygosity (ROH) are widely used and help to improve our knowledge about genetic diversity in animal populations. The development of high-density single nucleotide polymorphism (SNP) arrays and the subsequent genotyping of large numbers of animals have greatly increased the accuracy of these population-based estimates. In this study, we used the Illumina OvineSNP50 BeadChip array to estimate and compare LD (measured by r (2) and D'), N e , heterozygosity, F ST and ROH in five Australian sheep populations: three pure breeds, i.e., Merino (MER), Border Leicester (BL), Poll Dorset (PD) and two crossbred populations i.e. F1 crosses of Merino and Border Leicester (MxB) and MxB crossed to Poll Dorset (MxBxP). Compared to other livestock species, the sheep populations that were analysed in this study had low levels of LD and high levels of genetic diversity. The rate of LD decay was greater in Merino than in the other pure breeds. Over short distances (<10 kb), the levels of LD were higher in BL and PD than in MER. Similarly, BL and PD had comparatively smaller N e than MER. Observed heterozygosity in the pure breeds ranged from 0.3 in BL to 0.38 in MER. Genetic distances between breeds were modest compared to other livestock species (highest F ST = 0.063) but the genetic diversity within breeds was high. Based on ROH, two chromosomal regions showed evidence of strong recent selection. This study shows that there is a large range of genome diversity in Australian sheep breeds, especially in Merino sheep. The observed range of diversity will influence the design of genome-wide association studies and the results that can be obtained from them. This knowledge will also be useful to design reference populations for genomic prediction of breeding values in sheep.

Spatio-temporal dynamics of pneumonia in bighorn sheep

USGS Publications Warehouse

Cassirer, E. Frances; Plowright, Raina K.; Manlove, Kezia R.; Cross, Paul C.; Dobson, Andrew P.; Potter, Kathleen A.; Hudson, Peter J.

2013-01-01

Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and adult-only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia-induced mortality occurring simultaneously across age classes (i.e. all-age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all-age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia-induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality. 3. Acute pneumonia-induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups. 4. We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape-scale extrinsic variables as drivers of disease. 5. We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade-out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management.

Genetic linkage map of a wild genome: genomic structure, recombination and sexual dimorphism in bighorn sheep

PubMed Central

2010-01-01

Background The construction of genetic linkage maps in free-living populations is a promising tool for the study of evolution. However, such maps are rare because it is difficult to develop both wild pedigrees and corresponding sets of molecular markers that are sufficiently large. We took advantage of two long-term field studies of pedigreed individuals and genomic resources originally developed for domestic sheep (Ovis aries) to construct a linkage map for bighorn sheep, Ovis canadensis. We then assessed variability in genomic structure and recombination rates between bighorn sheep populations and sheep species. Results Bighorn sheep population-specific maps differed slightly in contiguity but were otherwise very similar in terms of genomic structure and recombination rates. The joint analysis of the two pedigrees resulted in a highly contiguous map composed of 247 microsatellite markers distributed along all 26 autosomes and the X chromosome. The map is estimated to cover about 84% of the bighorn sheep genome and contains 240 unique positions spanning a sex-averaged distance of 3051 cM with an average inter-marker distance of 14.3 cM. Marker synteny, order, sex-averaged interval lengths and sex-averaged total map lengths were all very similar between sheep species. However, in contrast to domestic sheep, but consistent with the usual pattern for a placental mammal, recombination rates in bighorn sheep were significantly greater in females than in males (~12% difference), resulting in an autosomal female map of 3166 cM and an autosomal male map of 2831 cM. Despite differing genome-wide patterns of heterochiasmy between the sheep species, sexual dimorphism in recombination rates was correlated between orthologous intervals. Conclusions We have developed a first-generation bighorn sheep linkage map that will facilitate future studies of the genetic architecture of trait variation in this species. While domestication has been hypothesized to be responsible for the elevated mean recombination rate observed in domestic sheep, our results suggest that it is a characteristic of Ovis species. However, domestication may have played a role in altering patterns of heterochiasmy. Finally, we found that interval-specific patterns of sexual dimorphism were preserved among closely related Ovis species, possibly due to the conserved position of these intervals relative to the centromeres and telomeres. This study exemplifies how transferring genomic resources from domesticated species to close wild relative can benefit evolutionary ecologists while providing insights into the evolution of genomic structure and recombination rates of domesticated species. PMID:20920197

Quantification of historical livestock importation into New Zealand 1860-1979.

PubMed

Binney, B M; Biggs, P J; Carter, P E; Holland, B R; Holland, B M; French, N P

2014-11-01

To quantify the numbers of live cattle, sheep and poultry imported into New Zealand and, where possible, their country of origin from 1860 to 1979. Information on the origin and number of live animal importations into New Zealand was collected for cattle, sheep and poultry for the period 1868-1979 from the annual reports compiled by the New Zealand Registrar General's Office, Government Statistician's Office, Census and Statistics Office, Census and Statistics Department, Customs Department and Department of Statistics. Census data from 1851 to 1871 were also used to estimate the livestock population during this period. The number of animals imported and the mean population for each species in a decade were determined, and the major countries of origin were identified. A large number of cattle (53,384) and sheep (604,525) were imported in the 1860s, and then there was a marked reduction in importations. Live poultry were imported in relatively small numbers (20,701) from 1880 to 1939, then 1,564,330 live poultry were imported between 1960 and 1979. Australia was the predominant country of origin for sheep between 1868 and 1959 (51,347/60,918; 84.3%) and of cattle between 1868 and 1979 (10,080/15,157; 66.5%). Only 6,712 (11.0%) sheep and 3,909 (25.8%) cattle were imported from the United Kingdom over the same periods, and even fewer from other countries. The collated data and historical reports show that from 1860 to 1979 Australia has been the main source of livestock introduced into New Zealand. The pattern of importation showed that large numbers of cattle and sheep were initially imported in the 1860s, probably in response to rapid agricultural expansion. Thereafter importations continued at much reduced numbers. In contrast, relatively small numbers of poultry were introduced until the 1960s when large numbers were imported as part of the development of a modern high-production industry. The overall pattern for both cattle and sheep was of a bottleneck event, as initially a relatively limited number of animals arrived from outside populations, followed by population expansion with ongoing but limited immigration (admixture). Investigation into the genetic population structure of New Zealand's cattle and sheep, as well as their host-associated microorganisms, could reflect the impact of these early historical events.

Linkage disequilibrium compared between five populations of domestic sheep.

PubMed

Meadows, Jennifer R S; Chan, Eva K F; Kijas, James W

2008-09-30

The success of genome-wide scans depends on the strength and magnitude of linkage disequilibrium (LD) present within the populations under investigation. High density SNP arrays are currently in development for the sheep genome, however little is known about the behaviour of LD in this livestock species. This study examined the behaviour of LD within five sheep populations using two LD metrics, D' and x2'. Four economically important Australian sheep flocks, three pure breeds (White Faced Suffolk, Poll Dorset, Merino) and a crossbred population (Merino x Border Leicester), along with an inbred Australian Merino museum flock were analysed. Short range LD (0 - 5 cM) was observed in all five populations, however the persistence with increasing distance and magnitude of LD varied considerably between populations. Average LD (x2') for markers spaced up to 20 cM exceeded the non-syntenic average within the White Faced Suffolk, Poll Dorset and Macarthur Merino. LD decayed faster within the Merino and Merino x Border Leicester, with LD below or consistent with observed background levels. Using marker-marker LD as a guide to the behaviour of marker-QTL LD, estimates of minimum marker spacing were made. For a 95% probability of detecting QTL, a microsatellite marker would be required every 0.1 - 2.5 centimorgans, depending on the population used. Sheep populations were selected which were inbred (Macarthur Merino), highly heterogeneous (Merino) or intermediate between these two extremes. This facilitated analysis and comparison of LD (x2') between populations. The strength and magnitude of LD was found to differ markedly between breeds and aligned closely with both observed levels of genetic diversity and expectations based on breed history. This confirmed that breed specific information is likely to be important for genome wide selection and during the design of successful genome scans where tens of thousands of markers will be required.

Estimating bighorn sheep (Ovis Canadensis) abundance using noninvasive sampling at a mineral lick within a national park wilderness area

Treesearch

Kathryn A. Schoenecker; Mary Kay Watry; Laura E. Ellison; Michael K. Schwartz; Gordon L. Luikart

2015-01-01

Conservation of species requires accurate population estimates. We used genetic markers from feces to determine bighorn sheep abundance for a herd that was hypothesized to be declining and in need of population status monitoring. We sampled from a small but accessible portion of the population’s range where animals naturally congregate at a natural mineral lick to test...

Epizootic Pneumonia of Bighorn Sheep following Experimental Exposure to Mycoplasma ovipneumoniae

PubMed Central

Besser, Thomas E.; Cassirer, E. Frances; Potter, Kathleen A.; Lahmers, Kevin; Oaks, J. Lindsay; Shanthalingam, Sudarvili; Srikumaran, Subramaniam; Foreyt, William J.

2014-01-01

Background Bronchopneumonia is a population limiting disease of bighorn sheep (Ovis canadensis). The cause of this disease has been a subject of debate. Leukotoxin expressing Mannheimia haemolytica and Bibersteinia trehalosi produce acute pneumonia after experimental challenge but are infrequently isolated from animals in natural outbreaks. Mycoplasma ovipneumoniae, epidemiologically implicated in naturally occurring outbreaks, has received little experimental evaluation as a primary agent of bighorn sheep pneumonia. Methodology/Principal Findings In two experiments, bighorn sheep housed in multiple pens 7.6 to 12 m apart were exposed to M. ovipneumoniae by introduction of a single infected or challenged animal to a single pen. Respiratory disease was monitored by observation of clinical signs and confirmed by necropsy. Bacterial involvement in the pneumonic lungs was evaluated by conventional aerobic bacteriology and by culture-independent methods. In both experiments the challenge strain of M. ovipneumoniae was transmitted to all animals both within and between pens and all infected bighorn sheep developed bronchopneumonia. In six bighorn sheep in which the disease was allowed to run its course, three died with bronchopneumonia 34, 65, and 109 days after M. ovipneumoniae introduction. Diverse bacterial populations, predominantly including multiple obligate anaerobic species, were present in pneumonic lung tissues at necropsy. Conclusions/Significance Exposure to a single M. ovipneumoniae infected animal resulted in transmission of infection to all bighorn sheep both within the pen and in adjacent pens, and all infected sheep developed bronchopneumonia. The epidemiologic, pathologic and microbiologic findings in these experimental animals resembled those seen in naturally occurring pneumonia outbreaks in free ranging bighorn sheep. PMID:25302992

Estimation of genetic diversity in Gute sheep: pedigree and microsatellite analyses of an ancient Swedish breed.

PubMed

Rochus, Christina M; Johansson, Anna M

2017-01-01

Breeds with small population size are in danger of an increased inbreeding rate and loss of genetic diversity, which puts them at risk for extinction. In Sweden there are a number of local breeds, native breeds which have adapted to specific areas in Sweden, for which efforts are being made to keep them pure and healthy over time. One example of such a breed is the Swedish Gute sheep. The objective of this study was to estimate inbreeding and genetic diversity of Swedish Gute sheep. Three datasets were analysed: pedigree information of the whole population, pedigree information for 100 animals of the population, and microsatellite genotypes for 94 of the 100 animals. The average inbreeding coefficient for lambs born during a six year time period (2007-2012) did not increase during that time period. The inbreeding calculated from the entire pedigree (0.038) and for a sample of the population (0.018) was very low. Sheep were more heterozygous at the microsatellite markers than expected (average multilocus heterozygosity and Ritland inbreeding estimates 1.01845 and -0.03931) and five of seven microsatellite markers were not in Hardy Weinberg equilibrium due to heterozygosity excess. The total effective population size estimated from the pedigree information was 155.4 and the average harmonic mean effective population size estimated from microsatellites was 88.3. Pedigree and microsatellite genotype estimations of inbreeding were consistent with a breeding program with the purpose of reducing inbreeding. Our results showed that current breeding programs of the Swedish Gute sheep are consistent with efforts of keeping this breed viable and these breeding programs are an example for other small local breeds in conserving breeds for the future.

Orange peel products can reduce Salmonella populations in ruminants.

PubMed

Callaway, Todd R; Carroll, Jeffery A; Arthington, John D; Edrington, Tom S; Anderson, Robin C; Rossman, Michelle L; Carr, Mandy A; Genovese, Ken J; Ricke, Steve C; Crandall, Phil; Nisbet, David J

2011-10-01

Salmonella can live undetected in the gut of food animals and be transmitted to humans. Animal diets can impact intestinal populations of foodborne pathogens, including Salmonella spp. Orange juice production results in a waste product, orange peel and orange pulp, which has a high nutritive value and is often included in cattle diets as a least-cost ration ingredient. Here we show that the inclusion of orange peel products reduced Salmonella Typhimurium populations in the gut of experimentally inoculated sheep. Sheep (n=24) were fed a cracked corn grain-based high grain diet that was supplemented with a 50%/50% (dry matter [DM], w/w) mixture of dried orange pellet and fresh orange peel to achieve a final concentration (DM, basis) of 0%, 10%, or 20% orange product (OP) for 10 days before inoculation with Salmonella Typhimurium. Sheep were experimentally inoculated with 10(10) colony forming units Salmonella Typhimurium, and fecal samples were collected every 24 h after inoculation. Sheep were humanely euthanized at 96 h after oral Salmonella inoculation. Populations of inoculated Salmonella Typhimurium were numerically reduced by OP treatment throughout the gastrointestinal tract, and this reduction only reached significant levels in the cecum (p<0.05) of sheep fed 10% OP diets. Apparent palatability issues decreased the consumption of OP in sheep fed 20% OP to intake levels below that of 10% OP (approximately 7% dry matter intake [DMI]/d feed refusal), thereby reducing the potential effects of OP feeding at this higher level. Our results demonstrate that orange peel and pellets are environmentally friendly and low-cost products that can be used as a pre-harvest intervention as part of an integrated pathogen reduction scheme.

Maternal and paternal genetic diversity of ancient sheep in Estonia from the Late Bronze Age to the post-medieval period and comparison with other regions in Eurasia.

PubMed

Rannamäe, E; Lõugas, L; Niemi, M; Kantanen, J; Maldre, L; Kadõrova, N; Saarma, U

2016-04-01

Sheep were among the first domesticated animals to appear in Estonia in the late Neolithic and became one of the most widespread livestock species in the region from the Late Bronze Age onwards. However, the origin and historical expansion of local sheep populations in Estonia remain poorly understood. Here, we analysed fragments of the hypervariable D-loop of mitochondrial DNA (mtDNA; 213 bp) and the Y-chromosome SRY gene (130 bp) extracted from 31 archaeological sheep bones dated from approximately 800 BC to 1700 AD. The ancient DNA data of sheep from Estonia were compared with ancient sheep from Finland as well as a set of contemporary sheep breeds from across Eurasia in order to place them in a wider phylogeographical context. The analysis shows that: (i) 24 successfully amplified and analysed mtDNA sequences of ancient sheep cluster into two haplogroups, A and B, of which B is predominant; (ii) four of the ancient mtDNA haplotypes are novel; (iii) higher mtDNA haplotype diversity occurred during the Middle Ages as compared to other periods, a fact concordant with the historical context of expanding international trade during the Middle Ages; (iv) the proportion of rarer haplotypes declined during the expansion of sheep from the Near Eastern domestication centre to the northern European region; (v) three male samples showed the presence of the characteristic northern European haplotype, SNP G-oY1 of the Y-chromosome, and represent the earliest occurrence of this haplotype. Our results provide the first insight into the genetic diversity and phylogeographical background of ancient sheep in Estonia and provide basis for further studies on the temporal fluctuations of ancient sheep populations. © 2016 Stichting International Foundation for Animal Genetics.

Seasonal movement and spatial distribution of the sheep ked (Diptera: Hippoboscidae) on Wyoming lambs.

PubMed

Legg, D E; Kumar, R; Watson, D W; Lloyd, J E

1991-10-01

When populations of adult sheep ked, Melophagus ovinus (L.), infesting unshorn lambs were monitored at the University of Wyoming Paradise Farm during 1986, we determined the body regions on which keds would be found at various times of the year and their seasonal population trends for optimal sampling. Results suggested that ked populations were consistently greater on the ribs than on any other area of the lamb. No significant differences were detected for ked populations between sides of a lamb. Distinct and similar ked population trends over time occurred only in the rib, thigh, shoulder, hind leg, belly, and hind flank areas of the lambs, suggesting that a significant seasonal migration did not occur. Analyses for seasonal population fluctuations indicated that ked populations increased in the winter and spring, decreased in summer and then increased again in the fall. Thus, sampling for keds in the rib area at shearing, which begins in March in Wyoming and runs through mid-April, would be an opportune time to detect keds. At other times of the year, the rib area should be inspected for presence of sheep ked.

Seroprevalence of Toxoplasma gondii in domestic sheep in Belgium.

PubMed

Verhelst, D; De Craeye, S; Vanrobaeys, M; Czaplicki, G; Dorny, P; Cox, E

2014-09-15

Even though infected sheep are a potential source of Toxoplasma gondii infection in humans, information is lacking concerning the seroprevalence of T. gondii infection in sheep in Belgium. We examined 3170 serum samples for anti-Toxoplasma IgG in sheep by total lysate antigen (TLA) enzyme-linked immunosorbent assay (ELISA). IgG to T. gondii was demonstrated in 87.4% of the tested sheep and in 96.2% of the 209 tested flocks. The seroprevalences in Antwerp (65.2%) and Wallonia (68.6%) are statistically lower than in the other regions in Belgium (96.7-97.8%) (P<0.05). The present study is the first report that analyzed the prevalence of T. gondii infection in sheep in Belgium and confirms the high prevalence of Toxoplasma-specific IgG antibodies in the sheep population. Copyright © 2014 Elsevier B.V. All rights reserved.

Genomic Reconstruction of the History of Native Sheep Reveals the Peopling Patterns of Nomads and the Expansion of Early Pastoralism in East Asia

PubMed Central

Zhao, Yong-Xin; Yang, Ji; Lv, Feng-Hua; Hu, Xiao-Ju; Xie, Xing-Long; Zhang, Min; Li, Wen-Rong; Liu, Ming-Jun; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Ren, Yan-Ling; Wang, Feng; Hehua, EEr; Kantanen, Juha; Arjen Lenstra, Johannes; Han, Jian-Lin; Li, Meng-Hua

2017-01-01

Abstract China has a rich resource of native sheep (Ovis aries) breeds associated with historical movements of several nomadic societies. However, the history of sheep and the associated nomadic societies in ancient China remains poorly understood. Here, we studied the genomic diversity of Chinese sheep using genome-wide SNPs, mitochondrial and Y-chromosomal variations in > 1,000 modern samples. Population genomic analyses combined with archeological records and historical ethnic demographics data revealed genetic signatures of the origins, secondary expansions and admixtures, of Chinese sheep thereby revealing the peopling patterns of nomads and the expansion of early pastoralism in East Asia. Originating from the Mongolian Plateau ∼5,000‒5,700 years ago, Chinese sheep were inferred to spread in the upper and middle reaches of the Yellow River ∼3,000‒5,000 years ago following the expansions of the Di-Qiang people. Afterwards, sheep were then inferred to reach the Qinghai-Tibetan and Yunnan-Kweichow plateaus ∼2,000‒2,600 years ago by following the north-to-southwest routes of the Di-Qiang migration. We also unveiled two subsequent waves of migrations of fat-tailed sheep into northern China, which were largely commensurate with the migrations of ancestors of Hui Muslims eastward and Mongols southward during the 12th‒13th centuries. Furthermore, we revealed signs of argali introgression into domestic sheep, extensive historical mixtures among domestic populations and strong artificial selection for tail type and other traits, reflecting various breeding strategies by nomadic societies in ancient China. PMID:28645168

Genomic Reconstruction of the History of Native Sheep Reveals the Peopling Patterns of Nomads and the Expansion of Early Pastoralism in East Asia.

PubMed

Zhao, Yong-Xin; Yang, Ji; Lv, Feng-Hua; Hu, Xiao-Ju; Xie, Xing-Long; Zhang, Min; Li, Wen-Rong; Liu, Ming-Jun; Wang, Yu-Tao; Li, Jin-Quan; Liu, Yong-Gang; Ren, Yan-Ling; Wang, Feng; Hehua, EEr; Kantanen, Juha; Arjen Lenstra, Johannes; Han, Jian-Lin; Li, Meng-Hua

2017-09-01

China has a rich resource of native sheep (Ovis aries) breeds associated with historical movements of several nomadic societies. However, the history of sheep and the associated nomadic societies in ancient China remains poorly understood. Here, we studied the genomic diversity of Chinese sheep using genome-wide SNPs, mitochondrial and Y-chromosomal variations in > 1,000 modern samples. Population genomic analyses combined with archeological records and historical ethnic demographics data revealed genetic signatures of the origins, secondary expansions and admixtures, of Chinese sheep thereby revealing the peopling patterns of nomads and the expansion of early pastoralism in East Asia. Originating from the Mongolian Plateau ∼5,000‒5,700 years ago, Chinese sheep were inferred to spread in the upper and middle reaches of the Yellow River ∼3,000‒5,000 years ago following the expansions of the Di-Qiang people. Afterwards, sheep were then inferred to reach the Qinghai-Tibetan and Yunnan-Kweichow plateaus ∼2,000‒2,600 years ago by following the north-to-southwest routes of the Di-Qiang migration. We also unveiled two subsequent waves of migrations of fat-tailed sheep into northern China, which were largely commensurate with the migrations of ancestors of Hui Muslims eastward and Mongols southward during the 12th‒13th centuries. Furthermore, we revealed signs of argali introgression into domestic sheep, extensive historical mixtures among domestic populations and strong artificial selection for tail type and other traits, reflecting various breeding strategies by nomadic societies in ancient China. © The Author 2017. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Spatio-temporal dynamics of pneumonia in bighorn sheep.

PubMed

Cassirer, E Frances; Plowright, Raina K; Manlove, Kezia R; Cross, Paul C; Dobson, Andrew P; Potter, Kathleen A; Hudson, Peter J

2013-05-01

1. Bighorn sheep mortality related to pneumonia is a primary factor limiting population recovery across western North America, but management has been constrained by an incomplete understanding of the disease. We analysed patterns of pneumonia-caused mortality over 14 years in 16 interconnected bighorn sheep populations to gain insights into underlying disease processes. 2. We observed four age-structured classes of annual pneumonia mortality patterns: all-age, lamb-only, secondary all-age and adult-only. Although there was considerable variability within classes, overall they differed in persistence within and impact on populations. Years with pneumonia-induced mortality occurring simultaneously across age classes (i.e. all-age) appeared to be a consequence of pathogen invasion into a naïve population and resulted in immediate population declines. Subsequently, low recruitment due to frequent high mortality outbreaks in lambs, probably due to association with chronically infected ewes, posed a significant obstacle to population recovery. Secondary all-age events occurred in previously exposed populations when outbreaks in lambs were followed by lower rates of pneumonia-induced mortality in adults. Infrequent pneumonia events restricted to adults were usually of short duration with low mortality. 3. Acute pneumonia-induced mortality in adults was concentrated in fall and early winter around the breeding season when rams are more mobile and the sexes commingle. In contrast, mortality restricted to lambs peaked in summer when ewes and lambs were concentrated in nursery groups. 4. We detected weak synchrony in adult pneumonia between adjacent populations, but found no evidence for landscape-scale extrinsic variables as drivers of disease. 5. We demonstrate that there was a >60% probability of a disease event each year following pneumonia invasion into bighorn sheep populations. Healthy years also occurred periodically, and understanding the factors driving these apparent fade-out events may be the key to managing this disease. Our data and modelling indicate that pneumonia can have greater impacts on bighorn sheep populations than previously reported, and we present hypotheses about processes involved for testing in future investigations and management. © 2013 The Authors. Journal of Animal Ecology © 2013 British Ecological Society.

Detection of bacterial-reactive natural IgM antibodies in desert bighorn sheep populations

PubMed Central

Palmer, Amy L.; Zielke, Ryszard A.; Sikora, Aleksandra E.; Beechler, Brianna R.; Jolles, Anna E.; Epps, Clinton W.

2017-01-01

Ecoimmunology is a burgeoning field of ecology which studies immune responses in wildlife by utilizing general immune assays such as the detection of natural antibody. Unlike adaptive antibodies, natural antibodies are important in innate immune responses and often recognized conserved epitopes present in pathogens. Here, we describe a procedure for measuring natural antibodies reactive to bacterial antigens that may be applicable to a variety of organisms. IgM from desert bighorn sheep plasma samples was tested for reactivity to outer membrane proteins from Vibrio coralliilyticus, a marine bacterium to which sheep would have not been exposed. Immunoblotting demonstrated bighorn sheep IgM could bind to a variety of bacterial cell envelope proteins while ELISA analysis allowed for rapid determination of natural antibody levels in hundreds of individual animals. Natural antibody levels were correlated with the ability of plasma to kill laboratory strains of E. coli bacteria. Finally, we demonstrate that natural antibody levels varied in two distinct populations of desert bighorn sheep. These data demonstrate a novel and specific measure of natural antibody function and show that this varies in ecologically relevant ways. PMID:28662203

Fifty years after Welles and Welles: Distribution and genetic structure of Desert Bighorn Sheep in Death Valley National Park

USGS Publications Warehouse

Epps, Clinton W.; Wehausen, John D.; Sloan, William B.; Holt, Stacy; Creech, Tyler G.; Crowhurst, Rachel S.; Jaeger, Jef R.; Longshore, Kathleen M.; Monello, Ryan J.

2013-01-01

Where possible, we revisited many of the water sources and other locations originally investigated by Welles and Welles (1961) and earlier researchers. We extracted DNA from fecal pellets, carcass tissue samples, and blood samples archived from earlier captures and genotyped them using highly variable genetic markers (15 microsatellite loci) with sufficient power to distinguish individuals and characterize gene flow and genetic structure. We also analyzed DNA samples collected from other bighorn sheep populations extending north to the White Mountains, west to the Inyo Mountains, south to the Avawatz Mountains, and southeast to the Clark Mountain Range, Kingston Range, and Spring Mountains of Nevada. We estimated genetic structure and recent gene flow among nearly all known populations of bighorn sheep in and around Death Valley National Park (DEVA), and used assignment tests to evaluate individual and population-level genetic structure to infer connectivity across the region. We found that bighorn sheep are still widely distributed in mountain ranges throughout DEVA, including many of the areas described by Welles and Welles (1961), although some use patterns appear to have changed and other areas still require resurvey. Gene flow was relatively high through some sections of fairly continuous habitat, such as the Grapevine and Funeral Mountains along the eastern side of Death Valley, but other populations were more isolated. Genetic diversity was relatively high throughout the park. Although southern Death Valley populations were genetically distinct from populations to the southeast, population assignment tests and recent gene flow estimates suggested that individuals occasionally migrate between those regions, indicating the potential for the recent outbreak of respiratory disease in the southern Mojave Desert to spread into the Death Valley system. We recommend careful monitoring of bighorn sheep using remote cameras to check for signs of respiratory disease in southeastern DEVA and ground surveys in the still-understudied southwestern part of DEVA.

Long-term dynamics of Mycoplasma conjunctivae at the wildlife-livestock interface in the Pyrenees

PubMed Central

Cabezón, Oscar; Frey, Joachim; Velarde, Roser; Serrano, Emmanuel; Colom-Cadena, Andreu; Gelormini, Giuseppina; Marco, Ignasi; Mentaberre, Gregorio; Lavín, Santiago; López-Olvera, Jorge Ramón

2017-01-01

Functional roles of domestic and wild host populations in infectious keratoconjunctivitis (IKC) epidemiology have been extensively discussed claiming a domestic reservoir for the more susceptible wild hosts, however, based on limited data. With the aim to better assess IKC epidemiology in complex host-pathogen alpine systems, the long-term infectious dynamics and molecular epidemiology of Mycoplasma conjunctivae was investigated in all host populations from six study areas in the Pyrenees and one in the Cantabrian Mountains (Northern Spain). Detection of M. conjunctivae was performed by qPCR on 3600 eye swabs collected during seven years from hunted wild ungulates and sympatric domestic sheep (n = 1800 animals), and cluster analyses of the strains were performed including previous reported local strains. Mycoplasma conjunctivae was consistently detected in three Pyrenean chamois (Rupicapra p. pyrenaica) populations, as well as in sheep flocks (17.0% of sheep) and occasionally in mouflon (Ovis aries musimon) from the Pyrenees (22.2% in one year/area); statistically associated with ocular clinical signs only in chamois. Chamois populations showed different infection dynamics with low but steady prevalence (4.9%) and significant yearly fluctuations (0.0%– 40.0%). Persistence of specific M. conjunctivae strain clusters in wild host populations is demonstrated for six and nine years. Cross-species transmission between chamois and sheep and chamois and mouflon were also sporadically evidenced. Overall, independent M. conjunctivae sylvatic and domestic cycles occurred at the wildlife-livestock interface in the alpine ecosystems from the Pyrenees with sheep and chamois as the key host species for each cycle, and mouflon as a spill-over host. Host population characteristics and M. conjunctivae strains resulted in different epidemiological scenarios in chamois, ranging from the fading out of the mycoplasma to the epidemic and endemic long-term persistence. These findings highlight the capacity of M. conjunctivae to establish diverse interactions and persist in host populations, also with different transmission conditions. PMID:29016676

Investigation of genetic divergence and polymorphism of nuclear DNA in species and populations of domestic and wild sheep

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mel`nikova, M.N.; Grechko, V.V.; Mednikov, B.M.

1995-08-01

Genetic divergence in repetitive sequences of nuclear DNA of wild and domestic sheep was studied by general restriction endonuclease mapping (i.e., the taxonoprint method). The PCR RAPD method with one and two arbitrary primers was also used to analyze the nuclear DNA polymorphism in some other regions. The taxonoprint method, performed using six endonucleases, showed specificity and virtually complete similarity in the patterns of repetitive DNA sequences of two wild forms, argali and moufflon, and five domestic sheep breeds. Central Asian breeds, Kazakh fine-fleeced, karakuk, ghissar, and eadeelbay, and an English breed, Lincoln, were examined. The results confirm the opinionmore » that wild and domestic sheep may be considered one polytypic species. The PCR-RAPD method, both with one and two arbitrary primers, revealed a closer similarity of all the sheep breeds examined when aragali, rather than with moufflon, was used. These results indicate that the domestication area of sheep was much more broader than was earlier presumed. Otherwise, hybridizations of domestic and wild forms could occasionally occur in the area of their coexistence. The amplification patterns of PCR-RAPD products are the most promising population genetic markers. 27 refs., 4 figs., 7 tabs.« less

Prevalence, intensity and population dynamics of hard ticks (Acari: Ixodidae) on sheep in the humid tropics of Mexico.

PubMed

Coronel-Benedett, Karen C; Ojeda-Robertos, Nadia Florencia; González-Garduño, Roberto; Ibañez, Francisco Martínez; Rodríguez-Vivas, Roger Iván

2018-01-01

Hard ticks are a perennial problem in livestock systems throughout Mexico. No data are currently available on tick prevalence, infestation intensity and population dynamics for sheep in the humid tropics of Mexico. Blackbelly sheep (n = 30) in Tabasco state, Mexico, were examined every 3 weeks for 1 year, and all Ixodidae ticks were counted and removed for analysis. Tick species were identified, infestation prevalence and intensity calculated per animal, and infestation per body zone determined. Overall infestation on the studied animals was 51.9%. Four tick species were identified (Amblyomma mixtum, A. imitator, Rhipicephalus microplus and R. annulatus), the most abundant being A. mixtum (94.9%). Prevalence was highest during the northwinds season (61.9%), followed by the dry (48.5%) and rainy (47.3%) seasons; however, the intensity (2.01-2.07 ticks/sheep) did not differ between seasons. Infestation was most frequent in certain zones including the axilla, crotch, udder, abdomen, thorax and rib area. Sheep in the humid tropics of Tabasco, Mexico, are parasitized by four hard tick species and prevalence is highest in the northwinds season. The present data constitute an important baseline for developing sustainable tick control programs for sheep in the humid tropics of Mexico.

A review of some characteristics, socio-economic aspects and utilization of Zulu sheep: implications for conservation.

PubMed

Kunene, Nokuthula Winfred; Bezuidenhout, Carlos C; Nsahlai, Ignatius V; Nesamvuni, Edward A

2011-08-01

Zulu sheep are Nguni sheep of Zululand and are adapted to the harsh conditions of KwaZulu-Natal. They are used by rural farmers for economic purposes. Their numbers are declining, indicating a potential extinction threat. Knowledge of their phenotypic and genotypic characteristics is essential for conservation planning. In this review, there is a focus on the utilization, socio-economic aspects, phenotypic and genotypic characteristics as well as a proposed breeding programme. A survey has shown that rural farmers in the areas of northern KwaZulu-Natal prefer to keep this breed for its adaptability, resistance to diseases and meat quality. Zulu sheep are small-framed multi-coloured animals. Mature males weigh up to 38 kg and females up to 32 kg. Based on four morphological traits and live weight, phenotypic diversity between three populations was estimated at 48%. A genetic diversity between these three populations was estimated at 22%. Live weight of Zulu sheep can be estimated using the heart girth and wither height measurements. Scrotum circumference of young rams (up to 22 months old) is reliable for estimating the live weight. Animals that were characterized in the studies were grazed extensively and no supplements were provided. There is therefore a potential of weight increase if these animals are reared in a semi-extensive environment. An open nucleus breeding scheme is thus recommended for a sustainable use and conservation of this breed. For more conclusive results, larger numbers of phenotypic and genetic characteristics, in larger numbers of Zulu sheep populations, should be investigated.

Detection of anthelmintic resistance in sheep and goat against fenbendazole by faecal egg count reduction test.

PubMed

Singh, Ramandeep; Bal, M S; Singla, L D; Kaur, Paramjit

2017-06-01

Anthelmintic resistance against commonly used anthelmintic fenbendazole was evaluated by employing faecal egg count reduction test (FECRT) in naturally occurring gastrointestinal (GI) nematodes in the semi organized sheep and goat farms of Ludhiana and Amritsar districts. A total of 80 animals (20 each for sheep and goat in both districts) were randomly selected and their faecal samples were examined by qualitative and quantitative parasitological techniques. Results indicate presence of high level of resistance against fenbendazole in both sheep and goat population of Ludhiana and Amritsar districts. More resistance was observed in the GI nematodes from animals reared in Amritsar district as compared to Ludhiana district. The level of anthelmintic resistance observed was apparently more in sheep than goats.

Cystic echinococcosis in the sheep: causes of its persistence in Sardinia.

PubMed

Scala, A; Mazzette, R

2009-09-01

The authors analyse the current epidemiological situation of sheep Cystic Echinococcosis (CE) in Sardinia, where the prevalence of ovine CE is still very high (70%) and this parasitosis is also frequently found in the human population. For this reason Sardinia represents a peculiar model for CE study, because there are particular conditions that allow Echinococcus granulosus to complete its life cycle. Some social and economical factors support the persistence of sheep CE: over 3 million Sarda breed heads are extensively bred; the presence, at farm level, of a strong relationship between dog, sheep and human; the low commercial value of meat coming from adult sheep, which results in a large number of sheep being slaughtered at home or on the farm rather than in authorized slaughterhouses. Moreover Sardinia is the only Italian region where partially successful echinococcosis control plans have been applied. The authors suggest some indirect and direct initiatives, including the use of a new vaccine against the development of this metacestode in sheep, to reduce the prevalence of CE.

Epidemic pasteurellosis in a bighorn sheep population coinciding with the appearance of a domestic sheep.

PubMed

George, Janet L; Martin, Daniel J; Lukacs, Paul M; Miller, Michael W

2008-04-01

A pneumonia epidemic reduced bighorn sheep (Ovis canadensis) survival and recruitment during 1997-2000 in a population comprised of three interconnected wintering herds (Kenosha Mountains, Sugarloaf Mountain, Twin Eagles) that inhabited the Kenosha and Tarryall Mountain ranges in central Colorado, USA. The onset of this epidemic coincided temporally and spatially with the appearance of a single domestic sheep (Ovis aires) on the Sugarloaf Mountain herd's winter range in December 1997. Although only bighorns in the Sugarloaf Mountain herd were affected in 1997-98, cases also occurred during 1998-99 in the other two wintering herds, likely after the epidemic spread via established seasonal movements of male bighorns. In all, we located 86 bighorn carcasses during 1997-2000. Three species of Pasteurella were isolated in various combinations from affected lung tissues from 20 bighorn carcasses where tissues were available and suitable for diagnostic evaluation; with one exception, beta-hemolytic mannheimia (Pasteurella) haemolytica (primarily reported as biogroup 1(G) or 1(alphaG)) was isolated from lung tissues of cases evaluated during winter 1997-98. The epidemic dramatically lowered adult bighorn monthly survival in all three herds; a model that included an acute epidemic effect, differing between sexes and with vaccination status, that diminished linearly over the next 12 mo best represented field data. In addition to the direct mortality associated with epidemics in these three herds, lamb recruitment in years following the pneumonia epidemic also was depressed as compared to years prior to the epidemic. Based on observations presented here, pasteurellosis epidemics in free-ranging bighorn sheep can arise through incursion of domestic sheep onto native ranges, and thus minimizing contact between domestic and bighorn sheep appears to be a logical principle for bighorn sheep conservation.

Whole genome structural analysis of Caribbean hair sheep reveals quantitative link to West African ancestry

PubMed Central

Spangler, Gordon L.; Ilori, Moses Babatunde; Hanotte, Olivier; Kim, Eui-Soo; Sonstegard, Tad S.; Burke, Joan M.; Morgan, James L. M.; Notter, David R.; Van Tassell, Curtis P.

2017-01-01

Hair sheep of Caribbean origin have become an important part of the U.S. sheep industry. Their lack of wool eliminates a number of health concerns and drastically reduces the cost of production. More importantly, Caribbean hair sheep demonstrate robust production performance even in the presence of drug-resistant gastrointestinal nematodes, a rising concern to the industry. Despite the growing importance of hair sheep in the Americas their genetic origins have remained speculative. Prior to this report no genetic studies were able to identify a unique geographical origin of hair sheep in the New World. Our study clarifies the African and European ancestry of Caribbean hair sheep. Whole-genome structural analysis was conducted on four established breeds of hair sheep from the Caribbean region. Using breeds representing Africa and Europe we establish an objective measure indicating Caribbean hair sheep are derived from Iberian and West African origins. Caribbean hair sheep result from West African introgression into established ecotypes of Iberian descent. Genotypes from 47,750 autosomal single nucleotide polymorphism markers scored in 290 animals were used to characterize the population structure of the St. Croix, Barbados Blackbelly, Morada Nova, and Santa Ines. Principal components, admixture, and phylogenetic analyses results correlate with historical patterns of colonization and trade. These patterns support co-migration of these sheep with humans. PMID:28662044

Respiratory disease, behavior, and survival of mountain goat kids

USGS Publications Warehouse

Blanchong, Julie A.; Anderson, Christopher A.; Clark, Nicholas J.; Klaver, Robert W.; Plummer, Paul J.; Cox, Mike; Mcadoo, Caleb; Wolff, Peregrine L.

2018-01-01

Bacterial pneumonia is a threat to bighorn sheep (Ovis canadensis) populations. Bighorn sheep in the East Humboldt Mountain Range (EHR), Nevada, USA, experienced a pneumonia epizootic in 2009–2010. Testing of mountain goats (Oreamnos americanus) that were captured or found dead on this range during and after the epizootic detected bacteria commonly associated with bighorn sheep pneumonia die‐offs. Additionally, in years subsequent to the bighorn sheep epizootic, the mountain goat population had low kid:adult ratios, a common outcome for bighorn sheep populations that have experienced a pneumonia epizootic. We hypothesized that pneumonia was present and negatively affecting mountain goat kids in the EHR. From June–August 2013–2015, we attempted to observe mountain goat kids with marked adult females in the EHR at least once per week to document signs of respiratory disease; identify associations between respiratory disease, activity levels, and subsequent disappearance (i.e., death); and estimate weekly survival. Each time we observed a kid with a marked adult female, we recorded any signs of respiratory disease and collected behavior data that we fit to a 3‐state discrete hidden Markov model (HMM) to predict a kid's state (active vs. sedentary) and its probability of disappearing. We first observed clinical signs of respiratory disease in kids in late July–early August each summer. We observed 8 of 31 kids with marked adult females with signs of respiratory disease on 13 occasions. On 11 of these occasions, the HMM predicted that kids were in the sedentary state, which was associated with increased probability of subsequent death. We estimated overall probability of kid survival from June–August to be 0.19 (95% CI = 0.08–0.38), which was lower than has been reported in other mountain goat populations. We concluded that respiratory disease was present in the mountain goat kids in the EHR and negatively affected their activity levels and survival. Our results raise concerns about potential effects of pneumonia to mountain goat populations and the potential for disease transmission between mountain goats and bighorn sheep where the species are sympatric. 

Numbers of fecal streptococci and Escherichia coli in fresh and dry cattle, horse, and sheep manure.

PubMed

Weaver, R W; Entry, J A; Graves, Alexandria

2005-10-01

Livestock are known contributors to stream pollution. Numbers of fecal streptococci and Escherichia coli in manure naturally deposited by livestock in the field are needed for activities related to bacterial source tracking and determining maximum daily bacterial loading of streams. We measured populations of fecal streptococci and E. coli in fresh and dry manure from cattle (Bos taurus L.), horses (Equus caballus L.), and sheep (Ovis aires L.) on farms in southern Idaho. Populations of indicator bacteria in dry manure were often as high as that in fresh manure from horse and sheep. There was a 2 log10 drop in the population of fecal coliform numbers in dry cattle manure from cattle in pastures but not from cattle in pens. Bacterial isolates used in source tracking should include isolates from both fresh and dry manure to better represent the bacterial source loading of streams.

Genome-Wide Analysis of the World's Sheep Breeds Reveals High Levels of Historic Mixture and Strong Recent Selection

PubMed Central

Kijas, James W.; Lenstra, Johannes A.; Hayes, Ben; Boitard, Simon; Porto Neto, Laercio R.; San Cristobal, Magali; Servin, Bertrand; McCulloch, Russell; Whan, Vicki; Gietzen, Kimberly; Paiva, Samuel; Barendse, William; Ciani, Elena; Raadsma, Herman; McEwan, John; Dalrymple, Brian

2012-01-01

Through their domestication and subsequent selection, sheep have been adapted to thrive in a diverse range of environments. To characterise the genetic consequence of both domestication and selection, we genotyped 49,034 SNP in 2,819 animals from a diverse collection of 74 sheep breeds. We find the majority of sheep populations contain high SNP diversity and have retained an effective population size much higher than most cattle or dog breeds, suggesting domestication occurred from a broad genetic base. Extensive haplotype sharing and generally low divergence time between breeds reveal frequent genetic exchange has occurred during the development of modern breeds. A scan of the genome for selection signals revealed 31 regions containing genes for coat pigmentation, skeletal morphology, body size, growth, and reproduction. We demonstrate the strongest selection signal has occurred in response to breeding for the absence of horns. The high density map of genetic variability provides an in-depth view of the genetic history for this important livestock species. PMID:22346734

Population genetic structure analysis and effect of inbreeding on body weights at different ages in Iranian Mehraban sheep.

PubMed

Yavarifard, Roya; Ghavi Hossein-Zadeh, Navid; Shadparvar, Abdol Ahad

2014-01-01

The objective of this study was to describe the population structure and inbreeding, and to quantify their effects on weights at different ages of Mehraban sheep in Iran. The analysis was based on the pedigree information of 26990 animals and 10278 body weight records from birth to yearling age. Data and pedigree information were collected during 1994 to 2011 by the breeding station of Mehraban sheep. The population structure was analyzed using the CFC program. Inbreeding of all animals was calculated by INBUPGF90 program. All animals were grouped into three classes according to their inbreeding coefficients: the first class included non-inbred animals (F=0); and the second and third classes included inbred animals (0

Phylogenetic Position of a Copper Age Sheep (Ovis aries) Mitochondrial DNA

PubMed Central

Olivieri, Cristina; Ermini, Luca; Rizzi, Ermanno; Corti, Giorgio; Luciani, Stefania; Marota, Isolina; De Bellis, Gianluca; Rollo, Franco

2012-01-01

Background Sheep (Ovis aries) were domesticated in the Fertile Crescent region about 9,000-8,000 years ago. Currently, few mitochondrial (mt) DNA studies are available on archaeological sheep. In particular, no data on archaeological European sheep are available. Methodology/Principal Findings Here we describe the first portion of mtDNA sequence of a Copper Age European sheep. DNA was extracted from hair shafts which were part of the clothes of the so-called Tyrolean Iceman or Ötzi (5,350 - 5,100 years before present). Mitochondrial DNA (a total of 2,429 base pairs, encompassing a portion of the control region, tRNAPhe, a portion of the 12S rRNA gene, and the whole cytochrome B gene) was sequenced using a mixed sequencing procedure based on PCR amplification and 454 sequencing of pooled amplification products. We have compared the sequence with the corresponding sequence of 334 extant lineages. Conclusions/Significance A phylogenetic network based on a new cladistic notation for the mitochondrial diversity of domestic sheep shows that the Ötzi's sheep falls within haplogroup B, thus demonstrating that sheep belonging to this haplogroup were already present in the Alps more than 5,000 years ago. On the other hand, the lineage of the Ötzi's sheep is defined by two transitions (16147, and 16440) which, assembled together, define a motif that has not yet been identified in modern sheep populations. PMID:22457789

Serological survey for antibodies against pestiviruses in Wyoming domestic sheep

USDA-ARS?s Scientific Manuscript database

Pestiviruses including Bovine Viral Diarrhea Virus type 1 (BVDV-1), BVDV-2 and Border Disease Virus (BDV) have been reported in both sheep and cattle populations, together with an emerging pestivirus, HoBi-like virus. Pestivirus control programs in the United States have focused on the control of BV...

Estimating heritability of wool shedding in a cross-bred ewe population

USDA-ARS?s Scientific Manuscript database

Low wool prices and high production costs in sheep systems have resulted in the introduction of hair sheep genetics into flocks to reduce shearing costs. Wool shedding occurs naturally in a few breeds, and can be incorporated by crossbreeding. The opportunity to enhance shedding through selection de...

Use of Genomics in Economically Important Traits in Ovine Populations

USDA-ARS?s Scientific Manuscript database

The objective of this review is to summarize relevant results from the use of genomics in sheep. Genomics has been used to identify genes associated with production, reproduction, carcass traits, and disease-related traits in sheep. A brief discussion on the concept of genomics is included. Genome-w...

Immunization of bighorn sheep against mannheimia haemolytica with a bovine herpesvirus 1-vectored vaccine

USDA-ARS?s Scientific Manuscript database

Pneumonia has significantly contributed to the drastic decline of bighorn sheep (BHS, Ovis canadensis) population in North America. Pneumonia outbreaks in BHS herds can incur mortalities up to 90%. Transplantation of healthy BHS into habitats that suffered pneumonia outbreaks has failed to restore B...

A Genome Wide Survey of SNP Variation Reveals the Genetic Structure of Sheep Breeds

PubMed Central

Kijas, James W.; Townley, David; Dalrymple, Brian P.; Heaton, Michael P.; Maddox, Jillian F.; McGrath, Annette; Wilson, Peter; Ingersoll, Roxann G.; McCulloch, Russell; McWilliam, Sean; Tang, Dave; McEwan, John; Cockett, Noelle; Oddy, V. Hutton; Nicholas, Frank W.; Raadsma, Herman

2009-01-01

The genetic structure of sheep reflects their domestication and subsequent formation into discrete breeds. Understanding genetic structure is essential for achieving genetic improvement through genome-wide association studies, genomic selection and the dissection of quantitative traits. After identifying the first genome-wide set of SNP for sheep, we report on levels of genetic variability both within and between a diverse sample of ovine populations. Then, using cluster analysis and the partitioning of genetic variation, we demonstrate sheep are characterised by weak phylogeographic structure, overlapping genetic similarity and generally low differentiation which is consistent with their short evolutionary history. The degree of population substructure was, however, sufficient to cluster individuals based on geographic origin and known breed history. Specifically, African and Asian populations clustered separately from breeds of European origin sampled from Australia, New Zealand, Europe and North America. Furthermore, we demonstrate the presence of stratification within some, but not all, ovine breeds. The results emphasize that careful documentation of genetic structure will be an essential prerequisite when mapping the genetic basis of complex traits. Furthermore, the identification of a subset of SNP able to assign individuals into broad groupings demonstrates even a small panel of markers may be suitable for applications such as traceability. PMID:19270757

The Bolivian "Altiplano" and "Valle" sheep are two different peripatric breeds.

PubMed

Parés-Casanova, Pere M; Pérezgrovas Garza, Raúl

2014-06-01

Forty-nine sheep belonged to the Andean Altiplano region ("Altiplano") and 30 in the lowland regions of Bolivia ("Valle"), aged 1 to 4 years, were wool sampled to determine the extent of difference between these local breeds. Fibre length and the percentage of each type of fibre (long-thick, short-thin and kemp), yield and fibre diameter were measured. There was a highly significant difference between the two sheep populations that were not clearly separated in the first two principal component of a principal components analysis (PC); the first PC explained 67.1 % and the second PC explained 26.6 % of the total variation. The variables that contributed most to the separation of the sheep populations were the percentage of long-thick and short-thin fibres in the first PC and yield in the second PC. A discriminant analysis, which was used to classify individuals with respect to their breeding, achieved an accurate classification rate of 84.2 %. Thus, the Altiplano and Valle sheep must be viewed as two closely peripatric breeds rather than different "ecotypes", as more than 80 % could be correctly assigned to one of the breeds; however, the differences are based on composition of long-thick and short-thin fibres and yield after alcohol scouring.

Association of methionine synthase gene polymorphisms with wool production and quality traits in Chinese Merino population.

PubMed

Rong, E G; Yang, H; Zhang, Z W; Wang, Z P; Yan, X H; Li, H; Wang, N

2015-10-01

Methionine synthase (MTR) plays a crucial role in maintaining homeostasis of intracellular methionine, folate, and homocysteine, and its activity correlates with DNA methylation in many mammalian tissues. Our previous genomewide association study identified that 1 SNP located in the gene was associated with several wool production and quality traits in Chinese Merino. To confirm the potential involvement of the gene in sheep wool production and quality traits, we performed sheep tissue expression profiling, SNP detection, and association analysis with sheep wool production and quality traits. The semiquantitative reverse transcription PCR analysis showed that the gene was differentially expressed in skin from Merino and Kazak sheep. The sequencing analysis identified a total of 13 SNP in the gene from Chinese Merino sheep. Comparison of the allele frequencies revealed that these 13 identified SNP were significantly different among the 6 tested Chinese Merino strains ( < 0.001). Linkage disequilibrium analysis showed that SNP 3 to 11 were strongly linked in a single haplotype block in the tested population. Association analysis showed that SNP 2 to 11 were significantly associated with the average wool fiber diameter and the fineness SD and that SNP 4 to 11 were significantly associated with the CV of fiber diameter trait ( < 0.05). Single nucleotide polymorphism 2 and SNP 5 to 12 were weakly associated with wool crimp. Similarly, the haplotypes derived from these 13 identified SNP were also significantly associated with the average wool fiber diameter, fineness SD, and the CV of fiber diameter ( < 0.05). Our results suggest that is a candidate gene for sheep wool production and quality traits, and the identified SNP might be used in sheep breeding.

Candidate Gene Approach for Parasite Resistance in Sheep – Variation in Immune Pathway Genes and Association with Fecal Egg Count

PubMed Central

Periasamy, Kathiravan; Pichler, Rudolf; Poli, Mario; Cristel, Silvina; Cetrá, Bibiana; Medus, Daniel; Basar, Muladno; A. K., Thiruvenkadan; Ramasamy, Saravanan; Ellahi, Masroor Babbar; Mohammed, Faruque; Teneva, Atanaska; Shamsuddin, Mohammed; Podesta, Mario Garcia; Diallo, Adama

2014-01-01

Sheep chromosome 3 (Oar3) has the largest number of QTLs reported to be significantly associated with resistance to gastro-intestinal nematodes. This study aimed to identify single nucleotide polymorphisms (SNPs) within candidate genes located in sheep chromosome 3 as well as genes involved in major immune pathways. A total of 41 SNPs were identified across 38 candidate genes in a panel of unrelated sheep and genotyped in 713 animals belonging to 22 breeds across Asia, Europe and South America. The variations and evolution of immune pathway genes were assessed in sheep populations across these macro-environmental regions that significantly differ in the diversity and load of pathogens. The mean minor allele frequency (MAF) did not vary between Asian and European sheep reflecting the absence of ascertainment bias. Phylogenetic analysis revealed two major clusters with most of South Asian, South East Asian and South West Asian breeds clustering together while European and South American sheep breeds clustered together distinctly. Analysis of molecular variance revealed strong phylogeographic structure at loci located in immune pathway genes, unlike microsatellite and genome wide SNP markers. To understand the influence of natural selection processes, SNP loci located in chromosome 3 were utilized to reconstruct haplotypes, the diversity of which showed significant deviations from selective neutrality. Reduced Median network of reconstructed haplotypes showed balancing selection in force at these loci. Preliminary association of SNP genotypes with phenotypes recorded 42 days post challenge revealed significant differences (P<0.05) in fecal egg count, body weight change and packed cell volume at two, four and six SNP loci respectively. In conclusion, the present study reports strong phylogeographic structure and balancing selection operating at SNP loci located within immune pathway genes. Further, SNP loci identified in the study were found to have potential for future large scale association studies in naturally exposed sheep populations. PMID:24533078

Initial Results from a Study of Climatic Changes and the Effect on Wild Sheep Habitat in Selected Study Areas of Alaska

USGS Publications Warehouse

Pfeifer, Edwin; Ruhlman, Jana; Middleton, Barry; Dye, Dennis; Acosta, Alex

2010-01-01

Climate change theorists have projected striking changes in local weather on earth due to increases in temperature. These predicted changes may cause melting glaciers and ice caps, rising sea levels, increasing desertification and other environmental changes which seem likely to affect presumed indicator species as harbingers of more significant changes. Wild sheep, even though they are one of the more successful mammalian taxa since Pleistocene times, exhibit a suite of adaptations to glacier driven environments which may be presumed to render them sensitive to environmental changes. The authors began investigation with these assumptions by comparing changes, as determined by satellite imagery, in glacier extent in our study areas in Denali National Park, Alaska, during the last 30 years. Our findings showed the extent of glacial retreat in Alaska during this time period was approximately 40-50 percent as measured by ablation zone and retreat of terminal moraines. During the first half of this 30-year period, Dall sheep (Ovis dalli dalli) populations were stable at historically recorded highs. In the early to mid-1990s, Dall sheep populations in Alaska declined from an historical estimated high of 75,000 sheep to the presently estimated 40-50,000. The declines seemed to be weather related, on the basis of the presumption that lamb survival rates are primarily weather-mediated in Alaska. Changes in local weather appear, at this point, to be correlated with oscillation in the Pacific Current in the Northern Pacific ocean. Of course, changes in local weather affect forage abundance and quality seasonally. In investigating a possible linkage of weather to seasonal forage abundance and quality, we also investigated changes in snow and ice extent and distribution, as well as increased water runoff associated with permafrost and depleted glaciers. Databases were assembled from a wide variety of remotely sensed satellite data, ground-based observations, and historical data bases relating to Dall sheep habitats in selected study areas. Alaska's sheep habitats are typified by long, narrow bands of mountainous uplifts generally arrayed west-to-east, and perpendicular to prevailing south-to-north weather-front movements. Classic Dall sheep habitat occurs on snow-shadowed slopes within these narrow mountainous habitats. On the basis of these data, we offer an explanatory hypothesis relating Dall sheep welfare to weather and climate-influenced nutrition and a monitoring scheme, which should produce data sufficient to test the robustness of this hypothesis. If correlated with population changes, the methods used in our comparative observations may provide long-term monitoring tools for wildlife managers and be applicable in other widely-dispersed wild sheep habitats. If no significant correlations emerge from our modeling exercises, the notion that wild sheep are a sufficiently sensitive species to be seen as an indicator species will have to be reexamined.

Development and validation of a low-density SNP panel related to prolificacy in sheep

USDA-ARS?s Scientific Manuscript database

High-density SNP panels (e.g., 50,000 and 600,000 markers) have been used in exploratory population genetic studies with commercial and minor breeds of sheep. However, routine genetic diversity evaluations of large numbers of samples with large panels are in general cost-prohibitive for gene banks. ...

Evolutionary dynamics of endogenous Jaagsiekte sheep retroviruses proliferation in the domestic sheep, mouflon and Pyrenean chamois.

PubMed

Sistiaga-Poveda, M; Jugo, B M

2014-06-01

The oncogenic exogenous Jaagsiekte sheep retrovirus (JSRV), responsible for ovine pulmonary adenocarcinoma, has several endogenous counterparts termed enJSRVs. Although many of these elements have been inactivated over time by the accumulation of deleterious mutations or internal recombination leading to solo long terminal repeat (LTR) formation, several members of enJSRVs have been identified as nearly intact and probably represent recent integration events. To determine the level of enJSRV polymorphism in the sheep population and related species, we have undertaken a study by characterizing enJSRVs copies and independent integration sites in six domestic sheep and two wild species of the sheep lineage. enJSRVs copies were detected by amplifying the env-LTR region by PCR, and for the detection of the insertion sites, we used two approaches: (1) an in silico approach based on the recently published Sheep Reference Genome Assembly (OARv3.0) and (2) an experimental approach based on PCR suppression and inverse PCR techniques. In total, 103 enJSRV sequences were generated across 10 individuals and enJSRV integrations were found on 11 of the 28 sheep chromosomes. These findings suggest that there are still uncharacterized enJSRVs, and that some of the integration sites are variable among the different species, breeds of the same species, subspecies and geographic locations.

Exposure of bighorn sheep to domestic goats colonized with Mycoplasma ovipneumoniae induces sub-lethal pneumonia

PubMed Central

Cassirer, E. Frances; Potter, Kathleen A.; Foreyt, William J.

2017-01-01

Background Bronchopneumonia is a population limiting disease of bighorn sheep (Ovis canadensis) that has been associated with contact with domestic Caprinae. The disease is polymicrobial but is initiated by Mycoplasma ovipneumoniae, which is commonly carried by both domestic sheep (O. aries) and goats (Capra aegagrus hircus). However, while previous bighorn sheep comingling studies with domestic sheep have resulted in nearly 100% pneumonia mortality, only sporadic occurrence of fatal pneumonia was reported from previous comingling studies with domestic goats. Here, we evaluated the ability of domestic goats of defined M. ovipneumoniae carriage status to induce pneumonia in comingled bighorn sheep. Methodology/Principal findings In experiment 1, three bighorn sheep naïve to M. ovipneumoniae developed non-fatal respiratory disease (coughing, nasal discharge) following comingling with three naturally M. ovipneumoniae-colonized domestic goats. Gross and histological lesions of pneumonia, limited to small areas on the ventral and lateral edges of the anterior and middle lung lobes, were observed at necropsies conducted at the end of the experiment. A control group of three bighorn sheep from the same source housed in isolation during experiment 1 remained free of observed respiratory disease. In experiment 2, three bighorn sheep remained free of observed respiratory disease while comingled with three M. ovipneumoniae-free domestic goats. In experiment 3, introduction of a domestic goat-origin strain of M. ovipneumoniae to the same comingled goats and bighorn sheep used in experiment 2 resulted in clinical signs of respiratory disease (coughing, nasal discharge) in both host species. At the end of experiment 3, gross and histological evidence of pneumonia similar to that observed in experiment 1 bighorn sheep was observed in both affected bighorn sheep and domestic goats. Conclusions/Significance M. ovipneumoniae strains carried by domestic goats were transmitted to comingled bighorn sheep, triggering development of pneumonia. However, the severity of the disease was markedly milder than that seen in similar experiments with domestic sheep strains of the bacterium. PMID:28591169

Exposure of bighorn sheep to domestic goats colonized with Mycoplasma ovipneumoniae induces sub-lethal pneumonia.

PubMed

Besser, Thomas E; Cassirer, E Frances; Potter, Kathleen A; Foreyt, William J

2017-01-01

Bronchopneumonia is a population limiting disease of bighorn sheep (Ovis canadensis) that has been associated with contact with domestic Caprinae. The disease is polymicrobial but is initiated by Mycoplasma ovipneumoniae, which is commonly carried by both domestic sheep (O. aries) and goats (Capra aegagrus hircus). However, while previous bighorn sheep comingling studies with domestic sheep have resulted in nearly 100% pneumonia mortality, only sporadic occurrence of fatal pneumonia was reported from previous comingling studies with domestic goats. Here, we evaluated the ability of domestic goats of defined M. ovipneumoniae carriage status to induce pneumonia in comingled bighorn sheep. In experiment 1, three bighorn sheep naïve to M. ovipneumoniae developed non-fatal respiratory disease (coughing, nasal discharge) following comingling with three naturally M. ovipneumoniae-colonized domestic goats. Gross and histological lesions of pneumonia, limited to small areas on the ventral and lateral edges of the anterior and middle lung lobes, were observed at necropsies conducted at the end of the experiment. A control group of three bighorn sheep from the same source housed in isolation during experiment 1 remained free of observed respiratory disease. In experiment 2, three bighorn sheep remained free of observed respiratory disease while comingled with three M. ovipneumoniae-free domestic goats. In experiment 3, introduction of a domestic goat-origin strain of M. ovipneumoniae to the same comingled goats and bighorn sheep used in experiment 2 resulted in clinical signs of respiratory disease (coughing, nasal discharge) in both host species. At the end of experiment 3, gross and histological evidence of pneumonia similar to that observed in experiment 1 bighorn sheep was observed in both affected bighorn sheep and domestic goats. M. ovipneumoniae strains carried by domestic goats were transmitted to comingled bighorn sheep, triggering development of pneumonia. However, the severity of the disease was markedly milder than that seen in similar experiments with domestic sheep strains of the bacterium.

Spatial analysis of cattle and shoat population in Ethiopia: growth trend, distribution and market access.

PubMed

Leta, Samson; Mesele, Frehiwot

2014-01-01

The livestock subsector has an enormous contribution to Ethiopia's national economy and livelihoods of many Ethiopians. The subsector contributes about 16.5% of the national Gross Domestic Product (GDP) and 35.6% of the agricultural GDP. It also contributes 15% of export earnings and 30% of agricultural employment. The livestock subsector currently support and sustain livelihoods for 80% of all rural population. The GDP of livestock related activities valued at 59 billion birr. Ethiopian livestock population trends, distribution and marketing vary considerably across space and time due to a variety of reasons. This study was aimed to assess cattle and shoat population growth trend, distribution and their access to market. Regression analysis was used to assess the cattle and shoat population growth trend and Geographic Information Systems (GIS) techniques were used to determine the spatial distribution of cattle and shoats, and their relative access to market. The data sets used are agricultural census (2001/02) and annual CSA agricultural sample survey (1995/96 to 2012/13). In the past eighteen years, the livestock population namely cattle, sheep and goat grew from 54.5 million to over 103.5 million with average annual increment of 3.4 million. The current average national cattle, sheep and goat population per km(2) are estimated to be 71, 33 and 29 respectively (excluding Addis Ababa, Afar and Somali regions). From the total livestock population the country owns about 46% cattle, 43% sheep and 40% goats are reared within 10 km radius from major livestock market centres and all-weather roads. On the other hand, three fourth of the country's land mass which comprises 15% of the cattle, 20% of the sheep and 21% of goat population is not accessible to market (greater than 30 km from major livestock market centres). It is found that the central highland regions account for the largest share of livestock population and also more accessible to market. Defining the spatial and temporal variations of livestock population is crucial in order to develop a sound and geographically targeted livestock development policy.

Ovine leukocyte profiles do not associate with variation in the prion gene, but are breed-dependent

USDA-ARS?s Scientific Manuscript database

Prion genotype in sheep confer resistance to scrapie. In cattle, lymphocyte profile has been found to be associated with prion genotype. Therefore, the aim of this study was to determine if variations in the sheep prion gene were associated with leukocyte populations as measured by complete blood ce...

Haemophilus somnus (Histophilus somni) in bighorn sheep.

PubMed

Ward, Alton C S; Weiser, Glen C; Anderson, Bruce C; Cummings, Patrick J; Arnold, Karen F; Corbeil, Lynette B

2006-01-01

Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host-parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection.

Haemophilus somnus (Histophilus somni) in bighorn sheep

PubMed Central

2006-01-01

Abstract Respiratory disease and poor lamb recruitment have been identified as limiting factors for bighorn-sheep populations. Haemophilus somnus (recently reclassified as Histophilus somni) is associated with respiratory disease in American bison, domestic sheep, and cattle. It is also harbored in their reproductive tracts and has been associated with reproductive failure in domestic sheep and cattle. Therefore, reproductive tract and lung samples from bighorn sheep were evaluated for the presence of this organism. Organisms identified as H. somnus were isolated from 6 of 62 vaginal but none of 12 preputial swab samples. Antigen specific to H. somnus was detected by immunohistochemical study in 4 of 12 formalin-fixed lung tissue samples of bighorn sheep that died with evidence of pneumonia. Notably, H. somnus was found in alveolar debris in areas of inflammation. The 6 vaginal isolates and 2 H. somnus isolates previously cultured from pneumonic lungs of bighorn sheep were compared with 3 representative isolates from domestic sheep and 2 from cattle. The profiles of major outer membrane proteins and antigens for all of the isolates were predominantly similar, although differences that may be associated with the host–parasite relationship and virulence were detected. The DNA restriction fragment length profiles of the bighorn-sheep isolates had similarities not shared with the other isolates, suggesting distinct phylogenetic lines. All of the isolates had similar antimicrobial profiles, but the isolates from the bighorn sheep produced less pigment than those from the domestic livestock, and growth of the former was not enhanced by CO2. Wildlife biologists and diagnosticians should be aware of the potential of these organisms to cause disease in bighorn sheep and of growth characteristics that may hinder laboratory detection. PMID:16548330

Effective Population Size, Genetic Variation, and Their Relevance for Conservation: The Bighorn Sheep in Tiburon Island and Comparisons with Managed Artiodactyls

PubMed Central

Gasca-Pineda, Jaime; Cassaigne, Ivonne; Alonso, Rogelio A.; Eguiarte, Luis E.

2013-01-01

The amount of genetic diversity in a finite biological population mostly depends on the interactions among evolutionary forces and the effective population size (N e) as well as the time since population establishment. Because the N e estimation helps to explore population demographic history, and allows one to predict the behavior of genetic diversity through time, N e is a key parameter for the genetic management of small and isolated populations. Here, we explored an N e-based approach using a bighorn sheep population on Tiburon Island, Mexico (TI) as a model. We estimated the current (N crnt) and ancestral stable (N stbl) inbreeding effective population sizes as well as summary statistics to assess genetic diversity and the demographic scenarios that could explain such diversity. Then, we evaluated the feasibility of using TI as a source population for reintroduction programs. We also included data from other bighorn sheep and artiodactyl populations in the analysis to compare their inbreeding effective size estimates. The TI population showed high levels of genetic diversity with respect to other managed populations. However, our analysis suggested that TI has been under a genetic bottleneck, indicating that using individuals from this population as the only source for reintroduction could lead to a severe genetic diversity reduction. Analyses of the published data did not show a strict correlation between H E and N crnt estimates. Moreover, we detected that ancient anthropogenic and climatic pressures affected all studied populations. We conclude that the estimation of N crnt and N stbl are informative genetic diversity estimators and should be used in addition to summary statistics for conservation and population management planning. PMID:24147115

Variant discovery in the sheepmeat odour and flavour in javanese fat tailed sheep using RNA sequencing

NASA Astrophysics Data System (ADS)

Abuzahra, M. A. M.; Jakaria; Listyarini, K.; Furqon, A.; Sumantri, C.; Uddin, M. J.; Gunawan, A.

2018-05-01

High-throughput RNA sequencing (RNA-Seq) reveals new challenges for the detection of transcriptome variants (SNPs) in different tissues and species. The aims of this study was to characterize a SNP discovery analysis in the sheep meat odour and flavour transcriptome using RNA-Seq. Six liver samples from divergent sheep meat odour and flavour were analyzed using the Illumina Genome Hiseq 2500 Analyzer. The SNP detection analysis revealed 142 SNPs in sheep meat samples, and a large number of those corresponded to differences between high and low sheep meat odour and flavour ovis genome assembly OAR v4.0. Among them, about 90.4% of genes had multiple polymorphisms within 12 genes (JAML, ANGPTL8, LOC101103463, SEPW1, SCN5A, LOC101113036, DOCK6, GTSE1, KIF12, KCTD17, KANK2, CYP2A6). Several of the SNPs (JAML, CYP2A6, SEPW1, and KIF12) found in this study could be included as suitable markers in genotyping platforms to perform association analyses in commercial populations and apply genomic selection protocols in the sheep meat production.

Sex-based differences in the adaptive value of social behavior contrasted against morphology and environment.

PubMed

Vander Wal, E; Festa-Bianchet, M; Réale, D; Coltman, D W; Pelletier, F

2015-03-01

The adaptive nature of sociality has long been a central question in ecology and evolution. However, the relative importance of social behavior for fitness, compared to morphology and environment, remains largely unknown. We assessed the importance of sociality for fitness (lamb production and survival) in a population of mark6d bighorn sheep (Ovis canadensis) over 16 years (n = 1022 sheep-years). We constructed social networks from observations (n = 38,350) of group membership (n = 3150 groups). We then tested whether consistent individual differences in social behavior (centrality) exist and evaluated their relative importance compared to factors known to affect fitness: mass, age, parental effects, and population density. Sheep exhibited consistent individual differences in social centrality. Controlling for maternal carryover effects and age, the positive effect of centrality in a social network on adult female lamb production and survival was equal or greater than the effect of body mass or population density. Social centrality had less effect on male survival and no effect on adult male lamb production or lamb survival. Through its effect on lamb production and survival, sociality in fission-fusion animal societies may ultimately influence population dynamics equally or more than morphological or environmental effects.

Evolutionary dynamics of endogenous Jaagsiekte sheep retroviruses proliferation in the domestic sheep, mouflon and Pyrenean chamois

PubMed Central

Sistiaga-Poveda, M; Jugo, B M

2014-01-01

The oncogenic exogenous Jaagsiekte sheep retrovirus (JSRV), responsible for ovine pulmonary adenocarcinoma, has several endogenous counterparts termed enJSRVs. Although many of these elements have been inactivated over time by the accumulation of deleterious mutations or internal recombination leading to solo long terminal repeat (LTR) formation, several members of enJSRVs have been identified as nearly intact and probably represent recent integration events. To determine the level of enJSRV polymorphism in the sheep population and related species, we have undertaken a study by characterizing enJSRVs copies and independent integration sites in six domestic sheep and two wild species of the sheep lineage. enJSRVs copies were detected by amplifying the env-LTR region by PCR, and for the detection of the insertion sites, we used two approaches: (1) an in silico approach based on the recently published Sheep Reference Genome Assembly (OARv3.0) and (2) an experimental approach based on PCR suppression and inverse PCR techniques. In total, 103 enJSRV sequences were generated across 10 individuals and enJSRV integrations were found on 11 of the 28 sheep chromosomes. These findings suggest that there are still uncharacterized enJSRVs, and that some of the integration sites are variable among the different species, breeds of the same species, subspecies and geographic locations. PMID:24690757

Population growth, fecundity, and survivorship in recovering populations of bighorn sheep

USGS Publications Warehouse

Singer, F.J.; Williams, E.; Miller, M.W.; Zeigenfuss, L.C.

2000-01-01

The single greatest obstacle to the restoration of large, healthy, populations of bighorn sheep (Ovis canadensis) in the western United States is epizootic outbreaks of bronchopneumonia that may kill 20–100% of the animals in populations. Although the species is capable of rapid initial growth rates following restoration into new habitat (λ = 1.23–1.30 have been observed), these rates of increase are typical only a few years following the release of a population, and then most populations either decline to extirpation or remnant status (<30 animals) or remain at <100 individuals. We studied the fecundity and survivorship of three increasing, and three declining and suspected diseased, populations of bighorn sheep (the latter were subjected to outbreaks of bronchopneumonia) located in or near several large national parks in the western United States from 1991 to 1996. Titers verified both population categories were exposed to the bacteria Pasteurella haemolytica serotypes 3; 4; and 3, 4, 10; Moraxella sp., and parainfluenza-3 and bluetongue (BT) viruses. Pregnancy rates of adult ewes were not different in increasing or decreasing populations (pooled rate = 0.93; p = 0.57), but pregnancy rates of yearlings were lower (0.00 for decreasing vs. 0.33 for increasing populations), initial production of lambs and annual recruitment of lambs was lower (0.14, decreasing vs. 0.66, p < 0.05). Adult survival was lower during the first year of an epizootic, 0.62, in one population, but recovered to 0.85 by the second and subsequent years. Survival of adult rams was variable in diseased populations; in two populations rams appeared to be disproportionately impacted, but in a third population rams survived better during the epizootic. In all the increasing park (unhunted) populations, adult ram survival (0.94 ± 0.01) was higher than adult ewe survival (0.89 ± 0.02) (p = 0.10), in contrast to published information from hunted populations where ram survival was lower. Removal of about 20% of one population for restorations severely impacted one declining population. Removals of 12–20% appeared to be excessive and were not readily compensated for in the Canyonlands National Park desert bighorn population. Disease was a significant limiting factor to restoration of bighorn sheep in the study areas; six of 11 total recovering populations we monitored closely were negatively influenced by apparent disease at some time during our observations.

Effects of syndyphalin-33 on feed intake and circulating measures of growth hormone, cortisol, and immune cell populations in the recently-weaned pig

USDA-ARS?s Scientific Manuscript database

The synthetic met-enkephalin syndyphalin-33 (SD-33) increases feed intake in sheep and transiently increases circulating growth hormone (GH) concentrations in sheep, rats, and pigs. Two experiments were performed to evaluate the effects of SD-33 on recently-weaned pigs. In a preliminary experiment, ...

Who's in, Who's out of New Zealand Public Schools? How Decisions Are Shaped

ERIC Educational Resources Information Center

Wills, Rod; McLean, Margaret A.

2008-01-01

Mechanisms of selection and control are utilized in both farming and special education. In a nation where sheep outnumber the population at a ratio of 10 to 1, the processes of drafting and selection have been refined over 150 years of New Zealand focusing on its agricultural primary production. Practices of sheep farming offer an interesting…

Expansion of the known distribution of Asiatic mouflon (Ovis orientalis) in the Late Pleistocene of the Southern Levant

NASA Astrophysics Data System (ADS)

Yeomans, Lisa; Martin, Louise; Richter, Tobias

2017-08-01

Wild sheep (Ovis orientalis) bones recovered from the Natufian site of Shubayqa 1 demonstrate a wider distribution of mouflon in the Late Pleistocene of the Southern Levant than previously known. Early Epipalaeolithic sites are common in the limestone steppe region of eastern Jordan but have yielded only a handful of caprine bones that cannot be identified to species level and few faunal remains from excavated Late Epipalaeolithic sites have been reported. Analysis of animal bone from Shubayqa 1 suggests a significant population of wild sheep could be found concentrated in the basalt desert environment of eastern Jordan during the Late Pleistocene, especially where higher rainfall over the Jebel Druze provided more water. A population of wild sheep was still present in the Pre-Pottery Neolithic A when the nearby site of Shubayqa 6 was occupied. Hunting of diverse, locally available resources including wild sheep at the end of the Pleistocene illustrates the flexible and adaptive exploitation strategies that hunter-forager groups engaged in. This provides further evidence to the increasing body of data showing the creative and opportunistic approach of terminal Pleistocene groups allowing continued occupation even in more marginal environments in a period of environmental change.

An animal location-based habitat suitability model for bighorn sheep and wild horses in Bighorn Canyon National Recreation Area and the Pryor Mountain Wild Horse Range, Montana, and Wyoming

USGS Publications Warehouse

Wockner, Gary; Singer, Francis J.; Schoenecker, Kathryn A.

2004-01-01

The purpose of this habitat suitability model is to provide a tool that will help managers and researchers better manage bighorn sheep and wild horses in the Bighorn Canyon National Recreation Area (BICA) and Pryor Mountain Wild Horse Range (PMWHR). A concern in the management of the Pryor Mountain wild horse population is whether or not the wild horses compete with bighorn sheep for available forage or available space. Two studies have been conducted that have shown no obvious, convincing competition between the two species. A study of diets and habitat-use of both species revealed substantial diet overlap only during some seasons, but there were considerable spatial and habitat separations between wild horses and bighorns during all seasons (Kissell and others, 1996). This empirical data was then used in a modeling exercise that predicted that neither the current (about 160 horses at the time of the analysis) nor larger numbers of wild horses on the area (e.g., about 200 horses) would result in reduced numbers or condition of bighorn sheep (Coughenour 1999). But competition is a very complex biological process to document. Bighorns might have already been spatially avoiding wild horses when these studies were conducted. A second concern for managers is that earlier studies suggest both species are not using many areas of the range that appear to be suitable (Gudorf and others, 1996; Kissell and others, 1996). A primary goal for the management of both species is to increase their numbers for purposes of genetic conservation and viability. The bighorn sheep population declined during the mid-1990’s from a peak of about 211 animals to ~ 100 animals at present. Absolute minimum goals for genetic viability in the bighorn sheep herd (genetic effective population size of N >50) suggest at least 150 animals should be present, while studies of persistence suggest populations of 250+ are e more likely to recover rapidly and persist should the population experience an epizootic die-off (Singer and others, 2001). Since all bighorn sheep populations are potentially vulnerable to disease epizootics, managing for larger populations of 200–300 animals appears to increase the potential for long-term persistence (Berger, 1990; Singer and others, 2001). Wild horses are not prone to rapid disease die-offs. However, minimum goals for genetic viability in the Pryor Mountain wild horses ( Ne > 50) require that at least 160 animals be present on the range (Singer and others, 2000). Since the Ne > 50 goal is set for the breeding of domestic animals, and since the vagaries of drought, severe winters, predation, and other stochastic events cause stress in wild animals, larger goals for Ne (e.g. Ne > 100) for wild horses are even more desirable (USDI, BLM, 1999; Gross, 2000). Expanding the area of the wild horse range is one option, but the prospects for expanding the range do not appear to be great (L. Coates-Markle, BLM, oral comm.). A second option would be to increase the amount of useable habitat for horses on the existing range. One goal of this modeling effort was to use GIS-based habitat analyses to determine the reason wild horses are not using some areas of the range, and to explore the potential for making some of these areas useable. The National Park Service (NPS) has shown considerable interest in management actions within BICA that will increase the range, useable habitat, and population size of bighorn sheep. There has also been interest expressed by the Bureau of Land Management (BLM) and wild horse advocates to improve the useable habitat for wild horses and to possibly increase the size of the horse range.

Seroprevalence of Capripoxvirus infection in sheep and goats among different agro-climatic zones of Odisha, India

PubMed Central

Hota, Abhishek; Biswal, Sangram; Sahoo, Niranjana; Venkatesan, Gnanavel; Arya, Sargam; Kumar, Amit; Ramakrishnan, Muthannan Andavar; Pandey, Awadh Bihari; Rout, Manoranjan

2018-01-01

Aim: The study was undertaken to assess the prevalence of antibodies to Capripoxviruses among small ruminants of Odisha, India. Materials and Methods: A total of 500 random serum samples collected from 214 sheep and 286 goats across 10 agro-climatic zones of Odisha, were screened using whole virus antigen-based indirect ELISA for antibodies against Capripoxviruses. Results were analyzed by suitable statistical methods. Results: Screening of 500 serum samples showed seropositivity of 8.88% and 31.47% in sheep and goats, respectively, for Capripoxviruses. The prevalence rate according to agro-climatic zone ranged from 0% (North Eastern coastal plain zone) to 48.57% (North central plateau zone) for goat pox, and 0% (Western undulating zone and North central plateau) to 22.22% (South Eastern ghat zone) for sheep pox. The difference in prevalence rates among the various agro-climatic zones was statistically significant (p<0.05) for goats, but not for sheep. Antibody prevalence rates among various districts were recorded to be the highest in Jagatsinghpur (30%) for sheep pox and Dhenkanal (80%) for goat pox. Conclusions: The study revealed serological evidence of Capripoxvirus infection in sheep and goat populations in the study area, in the absence of vaccination. Systematic investigation, monitoring, and reporting of outbreaks are necessary to devise control strategies. PMID:29479159

Genomic footprints of dryland stress adaptation in Egyptian fat-tail sheep and their divergence from East African and western Asia cohorts.

PubMed

Mwacharo, Joram M; Kim, Eui-Soo; Elbeltagy, Ahmed R; Aboul-Naga, Adel M; Rischkowsky, Barbara A; Rothschild, Max F

2017-12-15

African indigenous sheep are classified as fat-tail, thin-tail and fat-rump hair sheep. The fat-tail are well adapted to dryland environments, but little is known on their genome profiles. We analyzed patterns of genomic variation by genotyping, with the Ovine SNP50K microarray, 394 individuals from five populations of fat-tail sheep from a desert environment in Egypt. Comparative inferences with other East African and western Asia fat-tail and European sheep, reveal at least two phylogeographically distinct genepools of fat-tail sheep in Africa that differ from the European genepool, suggesting separate evolutionary and breeding history. We identified 24 candidate selection sweep regions, spanning 172 potentially novel and known genes, which are enriched with genes underpinning dryland adaptation physiology. In particular, we found selection sweeps spanning genes and/or pathways associated with metabolism; response to stress, ultraviolet radiation, oxidative stress and DNA damage repair; activation of immune response; regulation of reproduction, organ function and development, body size and morphology, skin and hair pigmentation, and keratinization. Our findings provide insights on the complexity of genome architecture regarding dryland stress adaptation in the fat-tail sheep and showcase the indigenous stocks as appropriate genotypes for adaptation planning to sustain livestock production and human livelihoods, under future climates.

Contrasting Patterns of Genomic Diversity Reveal Accelerated Genetic Drift but Reduced Directional Selection on X-Chromosome in Wild and Domestic Sheep Species.

PubMed

Chen, Ze-Hui; Zhang, Min; Lv, Feng-Hua; Ren, Xue; Li, Wen-Rong; Liu, Ming-Jun; Nam, Kiwoong; Bruford, Michael W; Li, Meng-Hua

2018-04-01

Analyses of genomic diversity along the X chromosome and of its correlation with autosomal diversity can facilitate understanding of evolutionary forces in shaping sex-linked genomic architecture. Strong selective sweeps and accelerated genetic drift on the X-chromosome have been inferred in primates and other model species, but no such insight has yet been gained in domestic animals compared with their wild relatives. Here, we analyzed X-chromosome variability in a large ovine data set, including a BeadChip array for 943 ewes from the world's sheep populations and 110 whole genomes of wild and domestic sheep. Analyzing whole-genome sequences, we observed a substantially reduced X-to-autosome diversity ratio (∼0.6) compared with the value expected under a neutral model (0.75). In particular, one large X-linked segment (43.05-79.25 Mb) was found to show extremely low diversity, most likely due to a high density of coding genes, featuring highly conserved regions. In general, we observed higher nucleotide diversity on the autosomes, but a flat diversity gradient in X-linked segments, as a function of increasing distance from the nearest genes, leading to a decreased X: autosome (X/A) diversity ratio and contrasting to the positive correlation detected in primates and other model animals. Our evidence suggests that accelerated genetic drift but reduced directional selection on X chromosome, as well as sex-biased demographic events, explain low X-chromosome diversity in sheep species. The distinct patterns of X-linked and X/A diversity we observed between Middle Eastern and non-Middle Eastern sheep populations can be explained by multiple migrations, selection, and admixture during the domestic sheep's recent postdomestication demographic expansion, coupled with natural selection for adaptation to new environments. In addition, we identify important novel genes involved in abnormal behavioral phenotypes, metabolism, and immunity, under selection on the sheep X-chromosome.

Mitogenomic Meta-Analysis Identifies Two Phases of Migration in the History of Eastern Eurasian Sheep.

PubMed

Lv, Feng-Hua; Peng, Wei-Feng; Yang, Ji; Zhao, Yong-Xin; Li, Wen-Rong; Liu, Ming-Jun; Ma, Yue-Hui; Zhao, Qian-Jun; Yang, Guang-Li; Wang, Feng; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Zhao, Sheng-Guo; Hehua, Eer; Gorkhali, Neena A; Farhad Vahidi, S M; Muladno, Muhammad; Naqvi, Arifa N; Tabell, Jonna; Iso-Touru, Terhi; Bruford, Michael W; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua

2015-10-01

Despite much attention, history of sheep (Ovis aries) evolution, including its dating, demographic trajectory and geographic spread, remains controversial. To address these questions, we generated 45 complete and 875 partial mitogenomic sequences, and performed a meta-analysis of these and published ovine mitochondrial DNA sequences (n = 3,229) across Eurasia. We inferred that O. orientalis and O. musimon share the most recent female ancestor with O. aries at approximately 0.790 Ma (95% CI: 0.637-0.934 Ma) during the Middle Pleistocene, substantially predating the domestication event (∼8-11 ka). By reconstructing historical variations in effective population size, we found evidence of a rapid population increase approximately 20-60 ka, immediately before the Last Glacial Maximum. Analyses of lineage expansions showed two sheep migratory waves at approximately 4.5-6.8 ka (lineages A and B: ∼6.4-6.8 ka; C: ∼4.5 ka) across eastern Eurasia, which could have been influenced by prehistoric West-East commercial trade and deliberate mating of domestic and wild sheep, respectively. A continent-scale examination of lineage diversity and approximate Bayesian computation analyses indicated that the Mongolian Plateau region was a secondary center of dispersal, acting as a "transportation hub" in eastern Eurasia: Sheep from the Middle Eastern domestication center were inferred to have migrated through the Caucasus and Central Asia, and arrived in North and Southwest China (lineages A, B, and C) and the Indian subcontinent (lineages B and C) through this region. Our results provide new insights into sheep domestication, particularly with respect to origins and migrations to and from eastern Eurasia. © The Author 2015. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Mitogenomic Meta-Analysis Identifies Two Phases of Migration in the History of Eastern Eurasian Sheep

PubMed Central

Lv, Feng-Hua; Peng, Wei-Feng; Yang, Ji; Zhao, Yong-Xin; Li, Wen-Rong; Liu, Ming-Jun; Ma, Yue-Hui; Zhao, Qian-Jun; Yang, Guang-Li; Wang, Feng; Li, Jin-Quan; Liu, Yong-Gang; Shen, Zhi-Qiang; Zhao, Sheng-Guo; Hehua, EEr; Gorkhali, Neena A.; Farhad Vahidi, S. M.; Muladno, Muhammad; Naqvi, Arifa N.; Tabell, Jonna; Iso-Touru, Terhi; Bruford, Michael W.; Kantanen, Juha; Han, Jian-Lin; Li, Meng-Hua

2015-01-01

Despite much attention, history of sheep (Ovis aries) evolution, including its dating, demographic trajectory and geographic spread, remains controversial. To address these questions, we generated 45 complete and 875 partial mitogenomic sequences, and performed a meta-analysis of these and published ovine mitochondrial DNA sequences (n = 3,229) across Eurasia. We inferred that O. orientalis and O. musimon share the most recent female ancestor with O. aries at approximately 0.790 Ma (95% CI: 0.637–0.934 Ma) during the Middle Pleistocene, substantially predating the domestication event (∼8–11 ka). By reconstructing historical variations in effective population size, we found evidence of a rapid population increase approximately 20–60 ka, immediately before the Last Glacial Maximum. Analyses of lineage expansions showed two sheep migratory waves at approximately 4.5–6.8 ka (lineages A and B: ∼6.4–6.8 ka; C: ∼4.5 ka) across eastern Eurasia, which could have been influenced by prehistoric West–East commercial trade and deliberate mating of domestic and wild sheep, respectively. A continent-scale examination of lineage diversity and approximate Bayesian computation analyses indicated that the Mongolian Plateau region was a secondary center of dispersal, acting as a “transportation hub” in eastern Eurasia: Sheep from the Middle Eastern domestication center were inferred to have migrated through the Caucasus and Central Asia, and arrived in North and Southwest China (lineages A, B, and C) and the Indian subcontinent (lineages B and C) through this region. Our results provide new insights into sheep domestication, particularly with respect to origins and migrations to and from eastern Eurasia. PMID:26085518

Computation of a high-resolution MRI 3D stereotaxic atlas of the sheep brain.

PubMed

Ella, Arsène; Delgadillo, José A; Chemineau, Philippe; Keller, Matthieu

2017-02-15

The sheep model was first used in the fields of animal reproduction and veterinary sciences and then was utilized in fundamental and preclinical studies. For more than a decade, magnetic resonance (MR) studies performed on this model have been increasingly reported, especially in the field of neuroscience. To contribute to MR translational neuroscience research, a brain template and an atlas are necessary. We have recently generated the first complete T1-weighted (T1W) and T2W MR population average images (or templates) of in vivo sheep brains. In this study, we 1) defined a 3D stereotaxic coordinate system for previously established in vivo population average templates; 2) used deformation fields obtained during optimized nonlinear registrations to compute nonlinear tissues or prior probability maps (nlTPMs) of cerebrospinal fluid (CSF), gray matter (GM), and white matter (WM) tissues; 3) delineated 25 external and 28 internal sheep brain structures by segmenting both templates and nlTPMs; and 4) annotated and labeled these structures using an existing histological atlas. We built a quality high-resolution 3D atlas of average in vivo sheep brains linked to a reference stereotaxic space. The atlas and nlTPMs, associated with previously computed T1W and T2W in vivo sheep brain templates and nlTPMs, provide a complete set of imaging space that are able to be imported into other imaging software programs and could be used as standardized tools for neuroimaging studies or other neuroscience methods, such as image registration, image segmentation, identification of brain structures, implementation of recording devices, or neuronavigation. J. Comp. Neurol. 525:676-692, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

A study on sheep farming practices in relation to future production strategies in Bensa district of Southern Ethiopia.

PubMed

Kenfo, Hizkel; Mekasha, Yoseph; Tadesse, Yosef

2018-04-01

The study was carried out in Bensa district of Sidama zone, Southern Ethiopia. Agro-ecologically, the study sites were classified into highland and mid-altitude. The objective of the study was to identify sheep farming practices in relation to future production strategies in the study area. A total of 128 households from four kebeles (lower administrative structure) were selected purposively based on sheep population and production potential and accessibility. Data was collected through semi-structured questionnaire, focus group discussions, and key informants. The result showed that most of the household heads were male (92.75%) and mixed crop-livestock system was the dominant production system. Among the livestock species, sheep accounted for the largest proportion across the two agro ecologies and the average sheep flock size/household was 4.6 ± 0.33 and 22 4.3 ± 0.213 in highland and in mid-altitude, respectively. The primary reason of keeping sheep was for cash income and saving across the two agro ecologies. The major feed resources for sheep during the wet and dry seasons were natural pasture and crop residues respectively across the two agro ecologies. Feed shortages, disease, parasite prevalence, and market were the major sheep production constraints in highland while feed shortage, genotype, disease, parasite prevalence, and market in mid-altitude. It can be concluded that for enhancing future production from sheep in the area, emphasis is to be given on feed availability, disease management, breeding policy, and marketing strategies.

Use of exposure history to identify patterns of immunity to pneumonia in bighorn sheep (Ovis canadensis)

USGS Publications Warehouse

Plowright, Raina K.; Manlove, Kezia; Cassirer, E. Frances; Besser, Thomas H.; Hudson, Peter J.

2013-01-01

Individual host immune responses to infectious agents drive epidemic behavior and are therefore central to understanding and controlling infectious diseases. However, important features of individual immune responses, such as the strength and longevity of immunity, can be challenging to characterize, particularly if they cannot be replicated or controlled in captive environments. Our research on bighorn sheep pneumonia elucidates how individual bighorn sheep respond to infection with pneumonia pathogens by examining the relationship between exposure history and survival in situ. Pneumonia is a poorly understood disease that has impeded the recovery of bighorn sheep (Ovis canadensis) following their widespread extirpation in the 1900s. We analyzed the effects of pneumonia-exposure history on survival of 388 radio-collared adults and 753 ewe-lamb pairs. Results from Cox proportional hazards models suggested that surviving ewes develop protective immunity after exposure, but previous exposure in ewes does not protect their lambs during pneumonia outbreaks. Paradoxically, multiple exposures of ewes to pneumonia were associated with diminished survival of their offspring during pneumonia outbreaks. Although there was support for waning and boosting immunity in ewes, models with consistent immunizing exposure were similarly supported. Translocated animals that had not previously been exposed were more likely to die of pneumonia than residents. These results suggest that pneumonia in bighorn sheep can lead to aging populations of immune adults with limited recruitment. Recovery is unlikely to be enhanced by translocating nai¨ve healthy animals into or near populations infected with pneumonia pathogens.

Use of Exposure History to Identify Patterns of Immunity to Pneumonia in Bighorn Sheep (Ovis canadensis)

PubMed Central

Plowright, Raina K.; Manlove, Kezia; Cassirer, E. Frances; Cross, Paul C.; Besser, Thomas E.; Hudson, Peter J.

2013-01-01

Individual host immune responses to infectious agents drive epidemic behavior and are therefore central to understanding and controlling infectious diseases. However, important features of individual immune responses, such as the strength and longevity of immunity, can be challenging to characterize, particularly if they cannot be replicated or controlled in captive environments. Our research on bighorn sheep pneumonia elucidates how individual bighorn sheep respond to infection with pneumonia pathogens by examining the relationship between exposure history and survival in situ. Pneumonia is a poorly understood disease that has impeded the recovery of bighorn sheep (Ovis canadensis) following their widespread extirpation in the 1900s. We analyzed the effects of pneumonia-exposure history on survival of 388 radio-collared adults and 753 ewe-lamb pairs. Results from Cox proportional hazards models suggested that surviving ewes develop protective immunity after exposure, but previous exposure in ewes does not protect their lambs during pneumonia outbreaks. Paradoxically, multiple exposures of ewes to pneumonia were associated with diminished survival of their offspring during pneumonia outbreaks. Although there was support for waning and boosting immunity in ewes, models with consistent immunizing exposure were similarly supported. Translocated animals that had not previously been exposed were more likely to die of pneumonia than residents. These results suggest that pneumonia in bighorn sheep can lead to aging populations of immune adults with limited recruitment. Recovery is unlikely to be enhanced by translocating naïve healthy animals into or near populations infected with pneumonia pathogens. PMID:23637929

Prevalence, distribution, and risk factor for sheep pox and goat pox (SPGP) in Algeria.

PubMed

Kardjadj, Moustafa

2017-03-01

A cross-sectional study using a tested questionnaire was carried out across Algeria between January and June 2014. Our investigation demonstrated that of the 150 flocks visited, 21 were positive for sheep pox and goat pox (SPGP) with an overall flock prevalence of 14% (95% CI 11.08-16.92%) suggesting that SPGP is endemic in Algeria. Our results showed also that the disease appears only in sheep and no case affecting goats has been reported. For the risk factor analysis, univariate analysis of variables followed by a multiple logistic regression identified steppe region (OR = 1.81, 95% CI 0.87-2.57; P = 0.037), large flocks (OR = 2. 19, 95% CI 1.02-3.36; P = 0.027), and transhumance (OR = 3.98, 95% CI 2.59-5.34; P = 0.021) as risk factors in the spread of the disease. Furthermore, our study revealed that the use of vaccination as preventive measures in the selected flocks decreased the odds for SPGP positivity by 5.78 (95% CI 2.22-9.34; P < 0.001) times compared to non vaccinated flocks. In conclusion, our findings documented an evidence of a widespread distribution and endemic establishment of the SPGP in Algerian sheep population despite the annual vaccination program. Consequently, the vaccination must cover all the Algerian sheep population to improve animal welfare and reduce economic losses associated with outbreak episodes.

Molecular phylogeny and phylogeography of genus Pseudois (Bovidae, Cetartiodactyla): New insights into the contrasting phylogeographic structure.

PubMed

Tan, Shuai; Wang, Zhihong; Jiang, Lichun; Peng, Rui; Zhang, Tao; Peng, Quekun; Zou, Fangdong

2017-09-01

Blue sheep, Pseudois nayaur , is endemic to the Tibetan Plateau and the surrounding mountains, which are the highest-elevation areas in the world. Classical morphological taxonomy suggests that there are two subspecies in genus Pseudois (Bovidae, Artiodactyla), namely Pseudois nayaur nayaur and Pseudois nayaur szechuanensis . However, the validity and geographic characteristics of these subspecies have never been carefully discussed and analyzed. This may be partially because previous studies have mainly focused on the vague taxonomic status of Pseudois schaeferi (dwarf blue sheep). Thus, there is an urgent need to investigate the evolutionary relationship and taxonomy system of this genus. This study enriches a previous dataset by providing a large number of new samples, based on a total of 225 samples covering almost the entire distribution of blue sheep. Molecular data from cytochrome b and the mitochondrial control region sequences were used to reconstruct the phylogeny of this species. The phylogenetic inferences show that vicariance plays an important role in diversification within this genus. In terms of molecular dating results and biogeographic analyses, the striking biogeographic pattern coincides significantly with major geophysical events. Although the results raise doubt about the present recognized distribution range of blue sheep, they have corroborated the validity of the identified subspecies in genus Pseudois . Meanwhile, these results demonstrate that the two geographically distinct populations, the Helan Mountains and Pamir Plateau populations, have been significantly differentiated from the identified subspecies, a finding that challenges the conventional taxonomy of blue sheep.

Alternative approaches for the control of gastrointestinal nematodes in sheep farming: a review.

PubMed

Šimpraga, Miljenko; Ljubičić, Iva; Hlede, Jadranka Pejaković; Vugrovečki, Ana Shek; Marinculić, Albert; Tkalčić, Suzana

2015-01-01

Gastrointestinal nematodes (GIN) are a serious health problem and represent the most significant constraint in sheep grazing operations. Problems tend to be worse in organic sheep farming systems, as a consequence of a less restricted access of animals to outdoor environment with a higher exposure to infective larvae. In domestic animals, GIN are effectively controlled by an aggressive prophylactic administration of commercially available anthelmintics. As a consequence to a common overdose and misuse of readily available antiparasitic treatments, there is an inevitable development of populations of GIN resistant to all major classes of anthelmintics. Also, the control of GIN that is based entirely on the anthelmintic use, threatens sustainability of the sheep farming worldwide. The combination of the optimized use of anthelmintic drugs and alternative approaches seem to be a reasonable choice in sustainable parasitic control programs that offer a substantial reduction of anthelmintic treatments and conservation of anthelmintic efficacy. In that aspect, a "targeted selective treatment (TST)" directed towards animals clinically diagnosed with GIN, seems to be an effective approach to leave some parasite populations unexposed to anthelmintics (refugia) and to reduce development of anthelmintic resistance. Also, many current research efforts aim to find and validate sustainable non-chemotherapeutic approaches to GIN control, including changes in grazing management, optimized nutrition, dietary supplementation, consumption of plants with anthelmintic properties, biological control by nematophagous fungi, copper oxide wire particles (COWP), and homeopathic treatments. This manuscript outlines (outlines) and discusses relevant alternative approaches for GIN control in modern sheep farming systems.

Heterotypic antibodies in Liberian sera causing anomalous reactions when using a commercial haemagglutination test for hepatitis-B surface antigen.

PubMed

Willcox, M C

1976-04-01

Agglutinins reacting with normal and tanned sheep erythrocytes were the probable cause of false positive reactions given by 51 of 214 Liberian sera when using a commercial passive-haemagglutination test for hepatitis-B surface antigen. Absorption showed these agglutinins to be identical to those described earlier in Nigerian sera. Rheumatoid factor and anti-sheep-serum antibodies although present in 12 and five per cent respectively of all sera were not responsible for any false positive reactions. The practical conclusion is that such tests, based on sheep erythrocytes are unsuitable for screening this population.

SHEEP: The Search for the High Energy Extragalactic Population

NASA Technical Reports Server (NTRS)

Nandra, K.; Georgantopoulos, I.; Ptak, A.; Turner, T. J.; White, Nicholas E. (Technical Monitor)

2002-01-01

We present the SHEEP survey for serendipitously-detected hard X-ray sources in ASCA GIS images. In a survey area of approx. 40 sq deg, 69 sources were detected in the 5-10 keV band to a limiting flux of approx. 10(exp -13) erg/sq cm/s. The number counts agree with those obtained by the similar BeppoSAX HELLAS survey, and both are in close agreement with ASCA and BeppoSAX 2-10 keV surveys. Spectral analysis of the SHEEP sample reveals that the 2-10 and 5-10 keV surveys do not sample the same populations, however, as we find considerably harder spectra, with an average Gamma approx. 1.0 assuming no absorption. The implication is that the agreement in the number counts is coincidental, with the 5-10 keV surveys gaining approximately as many hard sources as they lose soft ones, when compared to the 2-10 keV surveys. This is hard to reconcile with standard AGN "population synthesis" models for the X-ray background, which posit the existence of a large population of absorbed sources. We find no evidence of the population hardening at faint fluxes, with the exception that the few very brightest objects are anomalously soft. 53 of the SHEEP sources have been covered by ROSAT in the pointed phase. Of these 32 were detected. An additional 3 were detected in the RASS. As expected the sources detected with ROSAT are systematically softer than those detected with ASCA alone, and of the sample as a whole. Although they represent a biased subsample, the ROSAT positions allow relatively secure catalog identifications to be made. We find associations with a wide variety of AGN and a few clusters and groups. At least two X-ray sources identified with high-z QSOs present very hard X-ray spectra indicative of absorption, despite the presence of broad optical lines. A possible explanation for this is that we are seeing relatively dust-free "warm absorbers" in high luminosity/redshift objects. Our analysis defines a new, hard X-ray selected sample of objects - mostly active galactic nuclei - which is less prone to bias due to obscuration than previous optical or soft X-ray samples. They are therefore more representative of the population of AGN in the universe in general, and the SHEEP survey should produce bright examples of the sources that make up the hard X-ray background, the majority of which has recently been resolved by Chandra. This should help elucidate the nature of the new populations.

Stochastic predation events and population persistence in bighorn sheep

PubMed Central

Festa-Bianchet, Marco; Coulson, Tim; Gaillard, Jean-Michel; Hogg, John T; Pelletier, Fanie

2006-01-01

Many studies have reported temporal changes in the relative importance of density-dependence and environmental stochasticity in affecting population growth rates, but they typically assume that the predominant factor limiting growth remains constant over long periods of time. Stochastic switches in limiting factors that persist for multiple time-steps have received little attention, but most wild populations may periodically experience such switches. Here, we consider the dynamics of three populations of individually marked bighorn sheep (Ovis canadensis) monitored for 24–28 years. Each population experienced one or two distinct cougar (Puma concolor) predation events leading to population declines. The onset and duration of predation events were stochastic and consistent with predation by specialist individuals. A realistic Markov chain model confirms that predation by specialist cougars can cause extinction of isolated populations. We suggest that such processes may be common. In such cases, predator–prey equilibria may only occur at large geographical and temporal scales, and are unlikely with increasing habitat fragmentation. PMID:16777749

Responses of desert bighorn sheep to increased human recreation

USGS Publications Warehouse

Papouchis, C.M.; Singer, F.J.; Sloan, W.B.

2001-01-01

Human recreation has been implicated in the decline of several populations of desert bighorn sheep (Ovis canadensis nelsoni). Managers are concerned about the impact of increased recreation on desert bighorn sheep in Canyonlands National Park (NP), Utah, USA, where visitation increased 325% from 1979 to 1994. We compared behavioral responses of sheep to recreational activity between a low visitor use area and a high visitor use area during 1993 and 1994 by observing behavioral responses, distances moved, and duration of responses to vehicles, mountain bikers, and humans on foot. Hikers caused the most severe responses in desert bighorn sheep (animals fled in 61% of encounters), followed by vehicles (17% fled) and mountain bikers (6% fled), apparently because hikers were more likely to be in unpredictable locations and often directly approached sheep. We observed considerable individual heterogeneity in responses of bighorn sheep to the greater human use: some animals lived close to the road corridor and were apparently habituated to the human activities, but other animals avoided the road corridor. In the high-use area, we observed 3 radiocollared sheep that lived closer to the road than expected and found evidence of fewer responses to vehicles by females in spring, less response time of all sheep to vehicles in spring, and fewer responses to mountain bikers compared to the low-use area. Overall, there was an avoidance of the road corridor by most other bighorn sheep in the high-use area where all animals, on average, were found 39% farther from roads (490 ± 19 m vs. 354 ± 36 m) than in the low-use area. This avoidance of the road corridor by some animals represented 15% less use of potential suitable habitat in the high-use area over the low-use area. Increased sensitivity to hikers in the high-use area was suggested by a greater responsiveness by males in autumn and greater distance fled by females in spring. Responses of bighorn sheep were greater when human activity approached at the same elevation, when sheep were moving or standing, when female interactions occurred in spring and summer and male interactions occurred in autumn, and when sheep were farther from escape terrain. We recommend managers confine hikers to designated trails during spring lambing and the autumn rut in desert bighorn sheep habitat.

Microsatellite-based genetic diversity and population structure of domestic sheep in northern Eurasia.

PubMed

Tapio, Miika; Ozerov, Mikhail; Tapio, Ilma; Toro, Miguel A; Marzanov, Nurbiy; Cinkulov, Mirjana; Goncharenko, Galina; Kiselyova, Tatyana; Murawski, Maziek; Kantanen, Juha

2010-08-10

Identification of global livestock diversity hotspots and their importance in diversity maintenance is essential for making global conservation efforts. We screened 52 sheep breeds from the Eurasian subcontinent with 20 microsatellite markers. By estimating and weighting differently within- and between-breed genetic variation our aims were to identify genetic diversity hotspots and prioritize the importance of each breed for conservation, respectively. In addition we estimated how important within-species diversity hotspots are in livestock conservation. Bayesian clustering analysis revealed three genetic clusters, termed Nordic, Composite and Fat-tailed. Southern breeds from close to the region of sheep domestication were more variable, but less genetically differentiated compared with more northern populations. Decreasing weight for within-breed diversity component led to very high representation of genetic clusters or regions containing more diverged breeds, but did not increase phenotypic diversity among the high ranked breeds. Sampling populations throughout 14 regional groups was suggested for maximized total genetic diversity. During initial steps of establishing a livestock conservation program populations from the diversity hot-spot area are the most important ones, but for the full design our results suggested that approximately equal population presentation across environments should be considered. Even in this case, higher per population emphasis in areas of high diversity is appropriate. The analysis was based on neutral data, but we have no reason to think the general trend is limited to this type of data. However, a comprehensive valuation of populations should balance production systems, phenotypic traits and available genetic information, and include consideration of probability of success.

Microsatellite-based genetic diversity and population structure of domestic sheep in northern Eurasia

PubMed Central

2010-01-01

Background Identification of global livestock diversity hotspots and their importance in diversity maintenance is essential for making global conservation efforts. We screened 52 sheep breeds from the Eurasian subcontinent with 20 microsatellite markers. By estimating and weighting differently within- and between-breed genetic variation our aims were to identify genetic diversity hotspots and prioritize the importance of each breed for conservation, respectively. In addition we estimated how important within-species diversity hotspots are in livestock conservation. Results Bayesian clustering analysis revealed three genetic clusters, termed Nordic, Composite and Fat-tailed. Southern breeds from close to the region of sheep domestication were more variable, but less genetically differentiated compared with more northern populations. Decreasing weight for within-breed diversity component led to very high representation of genetic clusters or regions containing more diverged breeds, but did not increase phenotypic diversity among the high ranked breeds. Sampling populations throughout 14 regional groups was suggested for maximized total genetic diversity. Conclusions During initial steps of establishing a livestock conservation program populations from the diversity hot-spot area are the most important ones, but for the full design our results suggested that approximately equal population presentation across environments should be considered. Even in this case, higher per population emphasis in areas of high diversity is appropriate. The analysis was based on neutral data, but we have no reason to think the general trend is limited to this type of data. However, a comprehensive valuation of populations should balance production systems, phenotypic traits and available genetic information, and include consideration of probability of success. PMID:20698974

New insights into mitogenomic phylogeny and copy number in eight indigenous sheep populations based on the ATP synthase and cytochrome c oxidase genes.

PubMed

Xiao, P; Niu, L L; Zhao, Q J; Chen, X Y; Wang, L J; Li, L; Zhang, H P; Guo, J Z; Xu, H Y; Zhong, T

2017-11-16

The origins and phylogeny of different sheep breeds has been widely studied using polymorphisms within the mitochondrial hypervariable region. However, little is known about the mitochondrial DNA (mtDNA) content and phylogeny based on mtDNA protein-coding genes. In this study, we assessed the phylogeny and copy number of the mtDNA in eight indigenous (population size, n=184) and three introduced (n=66) sheep breeds in China based on five mitochondrial coding genes (COX1, COX2, ATP8, ATP6 and COX3). The mean haplotype and nucleotide diversities were 0.944 and 0.00322, respectively. We identified a correlation between the lineages distribution and the genetic distance, whereby Valley-type Tibetan sheep had a closer genetic relationship with introduced breeds (Dorper, Poll Dorset and Suffolk) than with other indigenous breeds. Similarly, the Median-joining profile of haplotypes revealed the distribution of clusters according to genetic differences. Moreover, copy number analysis based on the five mitochondrial coding genes was affected by the genetic distance combining with genetic phylogeny; we also identified obvious non-synonymous mutations in ATP6 between the different levels of copy number expressions. These results imply that differences in mitogenomic compositions resulting from geographical separation lead to differences in mitochondrial function.

Bacterial Population Adherent to the Epithelium on the Roo of the Dorsal Rumen of Sheep †

PubMed Central

Dehority, Burk A.; Grubb, Jean A.

1981-01-01

By anaerobic procedures, the total number of adherent bacteria was determined on tissue samples obtained from the roof of the dorsal rumen of three sheep. After four washings, 1.91 × 107, 0.34 × 107, and 1.23 × 107 bacteria per cm2 were still attached to the rumen epithelium in sheep 1, 2, and 3, respectively. A total of 95 strains of bacteria were isolated from these three samples. Based on morphology, Gram stain, anaerobiosis, motility, and fermentation end products, they were presumptively identified as follows: Butyrivibrio fibrisolvens, 30 strains; atypical Butyrivibrio, 5 strains; Bacteroides ruminicola, 22 strains; Lactobacillus, 1 strain; and unknown Bacteroides species, 37 strains. For sheep 3, washing the rumen epithelium a total of 10 times reduced the adherent bacterial population by 93% (8.4 × 105 bacteria per cm2). Of 30 strains isolated from this sample, 22 were presumptively identified as Butyrivibrio and Bacteroides types. These results suggest that the epithelium on the roof of the dorsal rumen is primarily colonized by two genera of bacteria, Butyrivibrio and Bacteroides. Most Butyrivibrio and Bacteroides ruminicola strains appeared to be similar to previously isolated rumen strains. However, the unknown Bacteroides species differed considerably from the three species of this genus which are commonly isolated from rumen contents. PMID:16345797

Expansion of the known distribution of Asiatic mouflon (Ovis orientalis) in the Late Pleistocene of the Southern Levant

PubMed Central

Martin, Louise; Richter, Tobias

2017-01-01

Wild sheep (Ovis orientalis) bones recovered from the Natufian site of Shubayqa 1 demonstrate a wider distribution of mouflon in the Late Pleistocene of the Southern Levant than previously known. Early Epipalaeolithic sites are common in the limestone steppe region of eastern Jordan but have yielded only a handful of caprine bones that cannot be identified to species level and few faunal remains from excavated Late Epipalaeolithic sites have been reported. Analysis of animal bone from Shubayqa 1 suggests a significant population of wild sheep could be found concentrated in the basalt desert environment of eastern Jordan during the Late Pleistocene, especially where higher rainfall over the Jebel Druze provided more water. A population of wild sheep was still present in the Pre-Pottery Neolithic A when the nearby site of Shubayqa 6 was occupied. Hunting of diverse, locally available resources including wild sheep at the end of the Pleistocene illustrates the flexible and adaptive exploitation strategies that hunter-forager groups engaged in. This provides further evidence to the increasing body of data showing the creative and opportunistic approach of terminal Pleistocene groups allowing continued occupation even in more marginal environments in a period of environmental change. PMID:28878989

Causes of Pneumonia Epizootics among Bighorn Sheep, Western United States, 2008–2010

PubMed Central

Highland, Margaret A.; Baker, Katherine; Cassirer, E. Frances; Anderson, Neil J.; Ramsey, Jennifer M.; Mansfield, Kristin; Bruning, Darren L.; Wolff, Peregrine; Smith, Joshua B.; Jenks, Jonathan A.

2012-01-01

Epizootic pneumonia of bighorn sheep is a devastating disease of uncertain etiology. To help clarify the etiology, we used culture and culture-independent methods to compare the prevalence of the bacterial respiratory pathogens Mannheimia haemolytica, Bibersteinia trehalosi, Pasteurella multocida, and Mycoplasma ovipneumoniae in lung tissue from 44 bighorn sheep from herds affected by 8 outbreaks in the western United States. M. ovipneumoniae, the only agent detected at significantly higher prevalence in animals from outbreaks (95%) than in animals from unaffected healthy populations (0%), was the most consistently detected agent and the only agent that exhibited single strain types within each outbreak. The other respiratory pathogens were frequently but inconsistently detected, as were several obligate anaerobic bacterial species, all of which might represent secondary or opportunistic infections that could contribute to disease severity. These data provide evidence that M. ovipneumoniae plays a primary role in the etiology of epizootic pneumonia of bighorn sheep. PMID:22377321

Can prion diseases be transmitted between individuals via blood transfusion: evidence from sheep experiments.

PubMed

Hunter, N; Houston, F

2002-01-01

We have shown that it is possible to transmit bovine spongiform encephalitis (BSE) to a sheep by transfusion with whole blood taken from another sheep during the pre-clinical phase of an experimental BSE infection when the donor animal appears healthy. BSE and new variant Creutzfeld-Jakob disease (vCJD) in humans are caused by the same infectious agent and the sheep-BSE experimental model has similar pathogenesis, with involvement of the lymphoreticular system, to that of human vCJD. Although we have had only one case of positive transmission of BSE out of a total of 21 transfusions, our studies remain incomplete and further cases could occur. Our studies, however, reinforce the possibility that whole blood donated by pre-clinical vCJD-infected humans may represent a risk of spreading vCJD infection among the human population of the U.K.

Sheep fed with banana leaf hay reduce ruminal protozoa population.

PubMed

Freitas, Cláudio Eduardo Silva; Duarte, Eduardo Robson; Alves, Dorismar David; Martinele, Isabel; D'Agosto, Marta; Cedrola, Franciane; de Moura Freitas, Angélica Alves; Dos Santos Soares, Franklin Delano; Beltran, Makenzi

2017-04-01

A ciliate protozoa suppression can reduce methane production increasing the energy efficiency utilization by ruminants. The physicochemical characteristics of rumen fluid and the profile of the rumen protozoa populations were evaluated for sheep fed banana leaf hay in replacement of the Cynodon dactylon cv. vaqueiro hay. A total of 30 male sheep were raised in intensive system during 15 days of adaptation and 63 days of experimental period. The animals were distributed in a completely randomized design that included six replicates of five treatments with replacement levels (0, 25, 50, 75, and 100%) of the grass vaquero for the banana leaf hay. Samples of fluid were collected directly from the rumen with sterile catheters. Color, odor, viscosity, and the methylene blue reduction potential (MBRP) were evaluated and pH estimated using a digital potentiometer. After decimal dilutions, counts of genus protozoa were performed in Sedgewick Rafter chambers. The averages of pH, MBRP, color, odor, and viscosity were not influenced by the inclusion of the banana leaf hay. However, the total number of protozoa and Entodinium spp. population significantly decreased at 75 and 100% inclusions of banana leaf hay as roughage.

The spread of pathogens through trade in small ruminants and their products.

PubMed

Sherman, D M

2011-04-01

While the international trade in small ruminants and small ruminant products is small relative to the trade in bovine, swine and poultry products, it is still economically important. In addition to wool, it includes some unique products (such as goat and sheep milk cheeses, cashmere fibre and karakul pelts) and the sheep/goat meat trade plays a large part in sustaining livelihoods in several regions of the world. The trade in small ruminants and their products also merits consideration because sheep and goats may transmit zoonotic diseases such as Rift Valley fever, Crimean Congo haemorrhagic fever, brucellosis and listeriosis. They also may transmit highly infectious livestock diseases, such as peste des petits ruminants, to naïve populations of small ruminants in other countries. This can have dramatic consequences, particularly for poor people whose livelihood often depends on small ruminants. In addition, sheep and goats can serve as an important source of foot and mouth disease (FMD) for cattle. This has enormous global trade implications and it is important, therefore, that sheep and goats be considered in FMD control programmes aimed at improving access to trade.

Whole-genome sequences of 89 Chinese sheep suggest role of RXFP2 in the development of unique horn phenotype as response to semi-feralization.

PubMed

Pan, Zhangyuan; Li, Shengdi; Liu, Qiuyue; Wang, Zhen; Zhou, Zhengkui; Di, Ran; Miao, Benpeng; Hu, Wenping; Wang, Xiangyu; Hu, Xiaoxiang; Xu, Ze; Wei, Dongkai; He, Xiaoyun; Yuan, Liyun; Guo, Xiaofei; Liang, Benmeng; Wang, Ruichao; Li, Xiaoyu; Cao, Xiaohan; Dong, Xinlong; Xia, Qing; Shi, Hongcai; Hao, Geng; Yang, Jean; Luosang, Cuicheng; Zhao, Yiqiang; Jin, Mei; Zhang, Yingjie; Lv, Shenjin; Li, Fukuan; Ding, Guohui; Chu, Mingxing; Li, Yixue

2018-04-01

Animal domestication has been extensively studied, but the process of feralization remains poorly understood. Here, we performed whole-genome sequencing of 99 sheep and identified a primary genetic divergence between 2 heterogeneous populations in the Tibetan Plateau, including 1 semi-feral lineage. Selective sweep and candidate gene analysis revealed local adaptations of these sheep associated with sensory perception, muscle strength, eating habit, mating process, and aggressive behavior. In particular, a horn-related gene, RXFP2, showed signs of rapid evolution specifically in the semi-feral breeds. A unique haplotype and repressed horn-related tissue expression of RXFP2 were correlated with higher horn length, as well as spiral and horizontally extended horn shape. Semi-feralization has an extensive impact on diverse phenotypic traits of sheep. By acquiring features like those of their wild ancestors, semi-feral sheep were able to regain fitness while in frequent contact with wild surroundings and rare human interventions. This study provides a new insight into the evolution of domestic animals when human interventions are no longer dominant.

Modulation of Haemonchus contortus infection by depletion of γδ+ T cells in parasite resistant Canaria Hair Breed sheep.

PubMed

Hernández, Julia N; Meeusen, Els; Stear, Michael; Rodríguez, Francisco; Piedrafita, David; González, Jorge F

2017-04-15

Canaria Hair Breed (CHB) sheep display resistance against the adult stage of the nematode, Haemonchus contortus. Previous studies have suggested significant correlations between γδ + T lymphocytes and fecundity of female adult worms, suggesting a novel role in immune modulation by these cells. The largest proportion of γδ + T lymphocytes in sheep are the subpopulation of γδ + /WC1 + T cells. The aim of this study was to evaluate the effect of γδ + ⁄WC1 + T cell depletion via infusion of anti-γδ/WC1 monoclonal antibody (mAb) on the subsequent immune response of CHB sheep infected with H. contortus. Significantly lower γδ + T cell levels in both peripheral blood and in the basal layers of the abomasal tissue resulted following anti-γδ/WC1 mAb infusion of CHB sheep compared to control animals. Worms recovered from the anti-γδ/WC1 mAb treated CHB sheep had significantly longer female worms with correspondingly more eggs in utero than the saline control group. Significant correlations between eosinophils and worm length and fecundity were no longer apparent in the anti-γδ/WC1 mAb treated CHB sheep. These results support the notion that γδ + T cells in CHB sheep play a critical role in fecundity regulation (length and eggs in utero) of H. contortus adult female worms, and highlights a new mechanism of modulation by this lymphocyte population, possibly involving eosinophil activation. Copyright © 2017 Elsevier B.V. All rights reserved.

Isolation of bacterial skin flora of healthy sheep, with comparison between frequent and minimal human handling.

PubMed

Haarstad, Amy C; Eisenschenk, Melissa C; Heinrich, Nicole A; Weese, J Scott; McKeever, Patrick J

2014-06-01

Few data are available regarding skin bacterial flora of healthy sheep and meticillin-resistant Staphylococcus carriage. To compare skin, ear and mucosal bacterial populations between minimally and frequently handled sheep; to determine whether the frequency of meticillin-resistant Staphylococcus aureus varied between groups. One hundred and three healthy feedlot and show sheep from eight farms. Swabs were collected from the dorsum, right ear and right nostril of each sheep. Two groups from each farm were evaluated, except from one farm, which had only one group. Bacterial isolates were identified to the genus or species level using phenotypic analysis or matrix-associated laser desorption/ionization time-of-flight mass spectrometry. Antimicrobial susceptibility testing and spa typing were performed on isolates of S. aureus. Sixteen bacterial genera were identified and 11 staphylococcal species, including S. aureus. The skin and mucosal bacterial flora were compared between the groups. The only statistically significant difference in bacteria was Streptococcus spp. on the dorsum (P = 0.0088), with carriage being more common in frequently handled sheep. Antimicrobial susceptibility testing did not find meticillin-resistant S. aureus. There was no significant difference in S. aureus carriage in the ear (P = 0.33), nostril (P = 0.43) or dorsum (P = 0.053) between frequently and minimally handled sheep. The S. aureus isolates belonged to six different spa types. Three were of the ST398 lineage. Sheep are a potential source of livestock-associated meticillin-sensitive Staphylococcus aureus ST398. © 2014 ESVD and ACVD.

Destructive tension: mathematics versus experience--the progress and control of the 2001 foot and mouth disease epidemic in Great Britain.

PubMed

Mansley, L M; Donaldson, A I; Thrusfield, M V; Honhold, N

2011-08-01

The 2001 foot and mouth disease epidemic in Great Britain was characterised by control using both traditional and novel methods, some resulting from conclusions of mathematical models. Seven days before the implementation of the novel controversial automatic pre-emptive culling of all susceptible livestock on premises adjacent to infected premises (the 'contiguous cull'), the spread of infection had already been controlled by a combination of the traditional stamping out policy with a national movement ban on livestock. A second controversial novel policy requiring the slaughter of sheep within 3 km of premises on which disease had been confirmed (the 3-km cull) also commenced after the peak of infection spread, was untargeted and took several weeks to complete; serosurveillance of culled sheep detected infection in only one flock, suggesting that cryptic infection of sheep was not propagating the epidemic. Extensive post-epidemic serological surveillance of sheep found only a small number of seropositive animals in a very few flocks, suggesting that foot and mouth disease may self-limit in extensive sheep populations. The epidemic was finally brought to an end following the introduction of enhanced agricultural movement restrictions and biosecurity measures. A welfare culling scheme of unaffected animals was required to support the prolonged national livestock movement ban. The models that supported the contiguous culling policy were severely flawed, being based on data from dissimilar epidemics; used inaccurate background population data, and contained highly improbable biological assumptions about the temporal and quantitative parameters of infection and virus emission in infected herds and flocks.

Atypical scrapie in sheep from a UK research flock which is free from classical scrapie

PubMed Central

Simmons, Hugh A; Simmons, Marion M; Spencer, Yvonne I; Chaplin, Melanie J; Povey, Gill; Davis, Andrew; Ortiz-Pelaez, Angel; Hunter, Nora; Matthews, Danny; Wrathall, Anthony E

2009-01-01

Background In the wake of the epidemic of bovine spongiform encephalopathy the British government established a flock of sheep from which scrapie-free animals are supplied to laboratories for research. Three breeds of sheep carrying a variety of different genotypes associated with scrapie susceptibility/resistance were imported in 1998 and 2001 from New Zealand, a country regarded as free from scrapie. They are kept in a purpose-built Sheep Unit under strict disease security and are monitored clinically and post mortem for evidence of scrapie. It is emphasised that atypical scrapie, as distinct from classical scrapie, has been recognised only relatively recently and differs from classical scrapie in its clinical, neuropathological and biochemical features. Most cases are detected in apparently healthy sheep by post mortem examination. Results The occurrence of atypical scrapie in three sheep in (or derived from) the Sheep Unit is reported. Significant features of the affected sheep included their relatively high ages (6 y 1 mo, 7 y 9 mo, 9 y 7 mo respectively), their breed (all Cheviots) and their similar PRNP genotypes (AFRQ/AFRQ, AFRQ/ALRQ, and AFRQ/AFRQ, respectively). Two of the three sheep showed no clinical signs prior to death but all were confirmed as having atypical scrapie by immunohistochemistry and Western immunoblotting. Results of epidemiological investigations are presented and possible aetiologies of the cases are discussed. Conclusion By process of exclusion, a likely explanation for the three cases of atypical scrapie is that they arose spontaneously and were not infected from an exterior source. If correct, this raises challenging issues for countries which are currently regarded as free from scrapie. It would mean that atypical scrapie is liable to occur in flocks worldwide, especially in older sheep of susceptible genotypes. To state confidently that both the classical and atypical forms of scrapie are absent from a population it is necessary for active surveillance to have taken place. PMID:19208228

The effect of rumen ciliates on chitinolytic activity, chitin content and the number of fungal zoospores in the rumen fluid of sheep.

PubMed

Miltko, Renata; Bełżecki, Grzegorz; Herman, Andrzej; Kowalik, Barbara; Skomiał, Jacek

2016-12-01

The objective of this study was to investigate the effect of selected protozoa on the degradation and concentration of chitin and the numbers of fungal zoospores in the rumen fluid of sheep. Three adult ewes were fed a hay-concentrate diet, defaunated, then monofaunated with Entodinium caudatum or Diploplastron affine alone and refaunated with natural rumen fauna. The average density of the protozoa population varied from 6.1 · 10(4) (D. affine) to 42.2 · 10(4) cells/ml rumen fluid (natural rumen fauna). The inoculation of protozoa in the rumen of defaunated sheep increased the total activity of chitinolytic enzymes from 2.9 to 3.6 μmol N-acetylglucosamine/g dry matter (DM) of rumen fluid per min, the chitin concentration from 6.3 to 7.2 mg/g DM of rumen fluid and the number of fungal zoospores from 8.1 to 10.9 · 10(5) cells/ml rumen fluid. All examined indices showed diurnal variations. Ciliate population density was highest immediately prior to feeding and lowest at 4 h thereafter. The opposite effects were observed for the numbers of fungal zoospores, the chitin concentration and chitinolytic activity. Furthermore, it was found that chitin from zoospores may account for up to 95% of total microbial chitin in the rumen fluid of sheep. In summary, the examined ciliate species showed the ability of chitin degradation as well as a positive influence on the development of the ruminal fungal population.

Foraging at the wildland–urban interface decouples weather as a driver of recruitment for desert bighorn sheep

USGS Publications Warehouse

Longshore, Kathleen M.; Lowrey, Chris E.; Cummings, Patrick

2016-01-01

A growing number of ungulate populations are living within or near the wildland–urban interface. When resources at the interface are of greater quality than that of adjacent natural habitat, wildlife can be attracted to these developed areas. Little is known about how use of the wildland–urban interface by wildlife may affect vital rates. Under natural conditions, recruitment by desert bighorn sheep (Ovis canadensis nelsoni) correlates with variation in the timing and amount of rainfall that initiates and enhances growth of annual plant species. However, for populations that forage in developed areas, this relationship may become decoupled. In the River Mountains of Nevada, USA, desert bighorn sheep have been feeding in a municipal park at the wildland–urban interface since its establishment in 1985. Approximately one-third of the population now uses the park during summer months when nutritional content of natural forage is low. We hypothesized that use of this municipal area, with its abundant vegetation and water resources, may have decoupled the previous relationship between precipitation and lamb recruitment. We assessed variables known to affect lamb recruitment before (1971–1986) and after (1987–2006) establishment of the park using linear regression models. Our top candidate model for the pre-park period indicated that total November precipitation was the greatest driver of lamb recruitment in this population. After park establishment, this relationship became decoupled because lamb recruitment was no longer driven by weather variables. These results raise questions about the effects of decoupling drivers of population growth and maintaining natural populations near urban areas.

Genetic diversity and population structure of South African smallholder farmer sheep breeds determined using the OvineSNP50 beadchip.

PubMed

Molotsi, Annelin H; Taylor, Jeremy F; Cloete, Schalk W P; Muchadeyi, Farai; Decker, Jared E; Whitacre, Lynsey K; Sandenbergh, Lise; Dzama, Kennedy

2017-12-01

A population structure study was performed in South African ovine populations using the OvineSNP50 beadchip. Blood samples were obtained from 295 sheep of which 172 had been identified as smallholder Dorpers, 4 smallholder White Dorpers, 46 purebred Dorpers, 26 purebred South African Mutton Merinos and 47 purebred Namaqua Afrikaners. Blood from the latter three breeds were obtained from a resource flock maintained on the Nortier research farm. Genetic diversity was estimated using allelic richness (A r ), observed heterozygosity (H o ), expected heterozygosity (H e ) and inbreeding coefficient (F). Population structure analysis was performed using fastSTRUCTURE to determine the breed composition of each genotyped individual. The Namaqua Afrikaner had the lowest H e of 0.280 ± 0.18 while the H e of smallholder Dorper, Dorper and South African Mutton Merino did not differ and were 0.364 ± 0.13, 0.332 ± 0.16 and 0.329 ± 0.17, respectively. The average inbreeding coefficient was highest for the pure breeds, Namaqua Afrikaner, Dorper and South African Mutton Merino compared to the average inbreeding coefficient for the smallholder Dorper population. The smallholder Dorper were introgressed with Namaqua Afrikaner, South African Mutton Merino and White Dorpers. Similarly, the smallholder Dorper population was more genetically diverse than the purebred Dorper, South African Mutton Merino and Namaqua Afrikaner from the research farm. The higher genetic diversity among the smallholder sheep may be advantageous for their fitness and can be used to facilitate selective breeding.

Nocturnal movements of desert bighorn sheep in the Muddy Mountains, Nevada

USGS Publications Warehouse

Longshore, Kathleen M.; Lowrey, Chris E.; Jeffress, Matthew; Thompson, Daniel B.

2009-01-01

Adequate management of a species requires complete knowledge of its ecology, including both nocturnal and diurnal behavior. Knowledge of the movement behavior of bighorn sheep can provide insight for understanding spatial population processes as the combined result of individual behavior, physiological constraints, and fine-scale environmental influences. However, because of past difficulties in tracking radio-collared animals in the dark, little is known about nocturnal movements of many ungulates, including desert bighorn sheep (Ovis canadensis nelsoni). The use of GPS collars that supply sequential location records over a 24-hour period has provided new opportunities for recording movements of animals. We report findings from a preliminary analysis of data on nocturnal movements of desert bighorn sheep wearing GPS collars in the Muddy Mountains, Nevada. The study is part of a larger research project on movement patterns aimed at assessing the connectivity of bighorn sheep populations that comprise the metapopulation in southern Nevada. We recorded nighttime locations at 2100 and 0400 PST and calculated a total of 8,758 nocturnal movement distances for 12 ewes and 16 rams. Nocturnal movements were characteristic of all individuals. Bighorn sheep varied in the magnitude of movement from night to night and there were significant differences among individuals in the mean distance moved. Females had a greater proportion of short movement distances when compared to males; males had the greatest proportion of long distance movements. Movement distances were affected by sex, season, and percent of the moon’s surface illumination. Mean movement distances of males were greater than those of females. For both males and females, mean movement distances were shortest during the late spring months (April-June) and greatest during summer (July–September). Mean movement distances were greatest when the moon was brightest for all seasons except late spring, when movement distances for both sexes were shortest. We also describe movement distances >1 km (19% ewes, 81% rams) relative to movements within or between 50% core use areas, and nighttime intermountain and intra-mountain travel.

Within- and across-breed genomic predictions and genomic relationships for Western Pyrenees dairy sheep breeds Latxa, Manech, and Basco-Béarnaise.

PubMed

Legarra, A; Baloche, G; Barillet, F; Astruc, J M; Soulas, C; Aguerre, X; Arrese, F; Mintegi, L; Lasarte, M; Maeztu, F; Beltrán de Heredia, I; Ugarte, E

2014-05-01

Genotypes, phenotypes and pedigrees of 6 breeds of dairy sheep (including subdivisions of Latxa, Manech, and Basco-Béarnaise) from the Spain and France Western Pyrenees were used to estimate genetic relationships across breeds (together with genotypes from the Lacaune dairy sheep) and to verify by forward cross-validation single-breed or multiple-breed genetic evaluations. The number of rams genotyped fluctuated between 100 and 1,300 but generally represented the 10 last cohorts of progeny-tested rams within each breed. Genetic relationships were assessed by principal components analysis of the genomic relationship matrices and also by the conservation of linkage disequilibrium patterns at given physical distances in the genome. Genomic and pedigree-based evaluations used daughter yield performances of all rams, although some of them were not genotyped. A pseudo-single step method was used in this case for genomic predictions. Results showed a clear structure in blond and black breeds for Manech and Latxa, reflecting historical exchanges, and isolation of Basco-Béarnaise and Lacaune. Relatedness between any 2 breeds was, however, lower than expected. Single-breed genomic predictions had accuracies comparable with other breeds of dairy sheep or small breeds of dairy cattle. They were more accurate than pedigree predictions for 5 out of 6 breeds, with absolute increases in accuracy ranging from 0.05 to 0.30 points. They were significantly better, as assessed by bootstrapping of candidates, for 2 of the breeds. Predictions using multiple populations only marginally increased the accuracy for a couple of breeds. Pooling populations does not increase the accuracy of genomic evaluations in dairy sheep; however, single-breed genomic predictions are more accurate, even for small breeds, and make the consideration of genomic schemes in dairy sheep interesting. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Contrasting Patterns of Genomic Diversity Reveal Accelerated Genetic Drift but Reduced Directional Selection on X-Chromosome in Wild and Domestic Sheep Species

PubMed Central

Chen, Ze-Hui; Zhang, Min; Lv, Feng-Hua; Ren, Xue; Li, Wen-Rong; Liu, Ming-Jun; Nam, Kiwoong; Bruford, Michael W; Li, Meng-Hua

2018-01-01

Abstract Analyses of genomic diversity along the X chromosome and of its correlation with autosomal diversity can facilitate understanding of evolutionary forces in shaping sex-linked genomic architecture. Strong selective sweeps and accelerated genetic drift on the X-chromosome have been inferred in primates and other model species, but no such insight has yet been gained in domestic animals compared with their wild relatives. Here, we analyzed X-chromosome variability in a large ovine data set, including a BeadChip array for 943 ewes from the world’s sheep populations and 110 whole genomes of wild and domestic sheep. Analyzing whole-genome sequences, we observed a substantially reduced X-to-autosome diversity ratio (∼0.6) compared with the value expected under a neutral model (0.75). In particular, one large X-linked segment (43.05–79.25 Mb) was found to show extremely low diversity, most likely due to a high density of coding genes, featuring highly conserved regions. In general, we observed higher nucleotide diversity on the autosomes, but a flat diversity gradient in X-linked segments, as a function of increasing distance from the nearest genes, leading to a decreased X: autosome (X/A) diversity ratio and contrasting to the positive correlation detected in primates and other model animals. Our evidence suggests that accelerated genetic drift but reduced directional selection on X chromosome, as well as sex-biased demographic events, explain low X-chromosome diversity in sheep species. The distinct patterns of X-linked and X/A diversity we observed between Middle Eastern and non-Middle Eastern sheep populations can be explained by multiple migrations, selection, and admixture during the domestic sheep’s recent postdomestication demographic expansion, coupled with natural selection for adaptation to new environments. In addition, we identify important novel genes involved in abnormal behavioral phenotypes, metabolism, and immunity, under selection on the sheep X-chromosome. PMID:29790980

Genome wide linkage disequilibrium and genetic structure in Sicilian dairy sheep breeds.

PubMed

Mastrangelo, Salvatore; Di Gerlando, Rosalia; Tolone, Marco; Tortorici, Lina; Sardina, Maria Teresa; Portolano, Baldassare

2014-10-10

The recent availability of sheep genome-wide SNP panels allows providing background information concerning genome structure in domestic animals. The aim of this work was to investigate the patterns of linkage disequilibrium (LD), the genetic diversity and population structure in Valle del Belice, Comisana, and Pinzirita dairy sheep breeds using the Illumina Ovine SNP50K Genotyping array. Average r (2) between adjacent SNPs across all chromosomes was 0.155 ± 0.204 for Valle del Belice, 0.156 ± 0.208 for Comisana, and 0.128 ± 0.188 for Pinzirita breeds, and some variations in LD value across chromosomes were observed, in particular for Valle del Belice and Comisana breeds. Average values of r (2) estimated for all pairwise combinations of SNPs pooled over all autosomes were 0.058 ± 0.023 for Valle del Belice, 0.056 ± 0.021 for Comisana, and 0.037 ± 0.017 for Pinzirita breeds. The LD declined as a function of distance and average r (2) was lower than the values observed in other sheep breeds. Consistency of results among the several used approaches (Principal component analysis, Bayesian clustering, F ST, Neighbor networks) showed that while Valle del Belice and Pinzirita breeds formed a unique cluster, Comisana breed showed the presence of substructure. In Valle del Belice breed, the high level of genetic differentiation within breed, the heterogeneous cluster in Admixture analysis, but at the same time the highest inbreeding coefficient, suggested that the breed had a wide genetic base with inbred individuals belonging to the same flock. The Sicilian breeds were characterized by low genetic differentiation and high level of admixture. Pinzirita breed displayed the highest genetic diversity (He, Ne) whereas the lowest value was found in Valle del Belice breed. This study has reported for the first time estimates of LD and genetic diversity from a genome-wide perspective in Sicilian dairy sheep breeds. Our results indicate that breeds formed non-overlapping clusters and are clearly separated populations and that Comisana sheep breed does not constitute a homogenous population. The information generated from this study has important implications for the design and applications of association studies as well as for development of conservation and/or selection breeding programs.

Foods, macronutrients and fibre in the diet of blue sheep (Psuedois nayaur) in the Annapurna Conservation Area of Nepal.

PubMed

Aryal, Achyut; Coogan, Sean C P; Ji, Weihong; Rothman, Jessica M; Raubenheimer, David

2015-09-01

Food resources are often critical regulating factors affecting individual fitness and population densities. In the Himalayan Mountains, Bharal "blue sheep" (Pseudois nayaur) are the main food resource for the endangered snow leopard (Panthera uncia), as well as being preyed upon by other predators. Blue sheep, however, may face a number of challenges including food resource competition with other wild and domestic ungulates, and hunting pressure. Here, we characterized the diet of blue sheep in the Annapurna Conservation Area (ACA) of Nepal and conducted proximate nutritional analysis on a limited number of plants identified as foods. Furthermore, we investigated the macronutrient and fiber balance of these plants using nutritional geometry which is a state-space approach to modeling multidimensional and interactive nutritional aspects of foraging. A total of 19 plant species/genera were identified in blue sheep pellets using microhistological analysis. On average, across seasons and regions of the study area, the two most frequently occurring plants in pellets were graminoids: Kobressia sp. and Carex spp. The macronutrient balance of Kobresia sp. was relatively high in carbohydrate and low in protein, while other plants in the diet were generally higher in protein and lipid content. Analysis of fiber balance showed that the two most consumed plants of blue sheep (i.e., Kobresia spp. and Carex spp.) contained the highest concentration of hemicellulose, which is likely digestible by blue sheep. The hemicellulose and lignin balance of plants ranged relatively widely, yet their cellulose contents showed less variation. Foraging by blue sheep may therefore be a balance between consuming highly digestible high-carbohydrate plants and plants less-digestible but higher in protein and/or lipid.

76 FR 7875 - Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-02-11

..., bighorn sheep, mountain goats, antelope, or bison) as determined by the respective State or Tribe..., will not contribute to reducing the wolf population in the State below 20 breeding pairs and 200 wolves...

76 FR 17439 - Nonessential Experimental Populations of Gray Wolves in the Northern Rocky Mountains; Lethal Take...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-29

... on wild ungulate populations (deer, elk, moose, bighorn sheep, mountain goats, antelope, or bison) as... in the State below 20 breeding pairs and 200 wolves, and will not impede wolf recovery. Draft...

DNA methylation Landscape of body size variation in sheep.

PubMed

Cao, Jiaxue; Wei, Caihong; Liu, Dongming; Wang, Huihua; Wu, Mingming; Xie, Zhiyuan; Capellini, Terence D; Zhang, Li; Zhao, Fuping; Li, Li; Zhong, Tao; Wang, Linjie; Lu, Jian; Liu, Ruizao; Zhang, Shifang; Du, Yongfei; Zhang, Hongping; Du, Lixin

2015-10-16

Sub-populations of Chinese Mongolian sheep exhibit significant variance in body mass. In the present study, we sequenced the whole genome DNA methylation in these breeds to detect whether DNA methylation plays a role in determining the body mass of sheep by Methylated DNA immunoprecipitation - sequencing method. A high quality methylation map of Chinese Mongolian sheep was obtained in this study. We identified 399 different methylated regions located in 93 human orthologs, which were previously reported as body size related genes in human genome-wide association studies. We tested three regions in LTBP1, and DNA methylation of two CpG sites showed significant correlation with its RNA expression. Additionally, a particular set of differentially methylated windows enriched in the "development process" (GO: 0032502) was identified as potential candidates for association with body mass variation. Next, we validated small part of these windows in 5 genes; DNA methylation of SMAD1, TSC1 and AKT1 showed significant difference across breeds, and six CpG were significantly correlated with RNA expression. Interestingly, two CpG sites showed significant correlation with TSC1 protein expression. This study provides a thorough understanding of body size variation in sheep from an epigenetic perspective.

Whole-genome sequences of 89 Chinese sheep suggest role of RXFP2 in the development of unique horn phenotype as response to semi-feralization

PubMed Central

Pan, Zhangyuan; Li, Shengdi; Liu, Qiuyue; Wang, Zhen; Zhou, Zhengkui; Di, Ran; Miao, Benpeng; Hu, Wenping; Wang, Xiangyu; Hu, Xiaoxiang; Xu, Ze; Wei, Dongkai; He, Xiaoyun; Yuan, Liyun; Guo, Xiaofei; Liang, Benmeng; Wang, Ruichao; Li, Xiaoyu; Cao, Xiaohan; Dong, Xinlong; Xia, Qing; Shi, Hongcai; Hao, Geng; Yang, Jean; Luosang, Cuicheng; Zhao, Yiqiang; Jin, Mei; Zhang, Yingjie; Lv, Shenjin; Li, Fukuan; Ding, Guohui; Chu, Mingxing; Li, Yixue

2018-01-01

Abstract Background Animal domestication has been extensively studied, but the process of feralization remains poorly understood. Results Here, we performed whole-genome sequencing of 99 sheep and identified a primary genetic divergence between 2 heterogeneous populations in the Tibetan Plateau, including 1 semi-feral lineage. Selective sweep and candidate gene analysis revealed local adaptations of these sheep associated with sensory perception, muscle strength, eating habit, mating process, and aggressive behavior. In particular, a horn-related gene, RXFP2, showed signs of rapid evolution specifically in the semi-feral breeds. A unique haplotype and repressed horn-related tissue expression of RXFP2 were correlated with higher horn length, as well as spiral and horizontally extended horn shape. Conclusions Semi-feralization has an extensive impact on diverse phenotypic traits of sheep. By acquiring features like those of their wild ancestors, semi-feral sheep were able to regain fitness while in frequent contact with wild surroundings and rare human interventions. This study provides a new insight into the evolution of domestic animals when human interventions are no longer dominant. PMID:29668959

Sequence analysis of the msp4 gene of Anaplasma ovis strains

USGS Publications Warehouse

de la Fuente, J.; Atkinson, M.W.; Naranjo, V.; Fernandez de Mera, I. G.; Mangold, A.J.; Keating, K.A.; Kocan, K.M.

2007-01-01

Anaplasma ovis (Rickettsiales: Anaplasmataceae) is a tick-borne pathogen of sheep, goats and wild ruminants. The genetic diversity of A. ovis strains has not been well characterized due to the lack of sequence information. In this study, we evaluated bighorn sheep (Ovis canadensis) and mule deer (Odocoileus hemionus) from Montana for infection with A. ovis by serology and sequence analysis of the msp4 gene. Antibodies to Anaplasma spp. were detected in 37% and 39% of bighorn sheep and mule deer analyzed, respectively. Four new msp4 genotypes were identified. The A. ovis msp4 sequences identified herein were analyzed together with sequences reported previously for the characterization of the genetic diversity of A. ovis strains in comparison with other Anaplasma spp. The results of these studies demonstrated that although A. ovis msp4 genotypes may vary among geographic regions and between sheep and deer hosts, the variation observed was less than the variation observed between A. marginale and A. phagocytophilum strains. The results reported herein further confirm that A. ovis infection occurs in natural wild ruminant populations in Western United States and that bighorn sheep and mule deer may serve as wildlife reservoirs of A. ovis. ?? 2006.

Chronic arsenic toxicity in sheep of Kurdistan province, western Iran.

PubMed

Keshavarzi, Behnam; Seradj, Afsaneh; Akbari, Zahra; Moore, Farid; Shahraki, Alireza Rahmani; Pourjafar, Mehrdad

2015-07-01

After the detection of arsenic (As) toxicity in sheep from Ebrahim-abad and Babanazar villages in Kurdistan province, the concentration of this element in drinking water, cultivated soil, alfalfa hay, wool, and blood samples was evaluated. Total As concentrations ranged from 119 to 310 μg/L in drinking water, 46.70-819.20 mg/kg in soil 1.90-6.90 mg/kg in vegetation 1.56-10.79 mg/kg in sheep's wool, and 86.30-656 μg/L in blood samples. These very high As contents, in all parts of the biogeochemical cycle, exceed the recommended normal range for this element compared with a control area. Results indicate that As has moved through all compartments of the biogeochemical cycle by way of direct or indirect pathways. The present investigation illustrated decreased packed cell volume and hemoglobin in sheep from the As-contaminated zone. It was concluded that sheep from the contaminated areas suffer from anemia. Chronic As exposure of the liver was determined by liver function tests. For this purpose, blood aspartate transaminase (AST) and alanine transaminase (ALT) were measured. The results show that serum ALT and AST activities are increased significantly (p < 0.01) in the sheep population exposed to As in the contaminated zone. Moreover, chronic As exposure causes injury to hepatocytes and damages the liver.

Ganjam virus.

PubMed

Sudeep, A B; Jadi, R S; Mishra, A C

2009-11-01

Ganjam virus (GANV), a member of genus Nairovirus of family Bunyavirdae is of considerable veterinary importance in India. Though, predominantly tick borne, GANV was also isolated from mosquitoes, man and sheep. Neutralizing and complement fixing antibodies to GANV have been detected in animal and human sera collected from different parts of the country. Thirty three strains of GANV have been isolated from India, mainly from Haemaphysalis ticks. The virus replicated in certain vertebrate and mosquito cell lines and found pathogenic to laboratory animals. One natural infection and five laboratory-acquired infections in men were also reported. GANV is antigenically related to Nairobi sheep disease virus (NSDV) of Africa, which is highly pathogenic for sheep and goats causing 70-90 per cent mortality among the susceptible population. Recent molecular studies have demonstrated that GANV is an Asian variant of NSDV and both these viruses are related to the dreaded Crimean Congo haemorrhagic fever (CCHF) group viruses. The versatility of the virus to replicate in different arthropod species, its ability to infect sheep, goat and man makes it an important zoonotic agent.

A mutation creating a potential illegitimate microRNA target site in the myostatin gene affects muscularity in sheep.

PubMed

Clop, Alex; Marcq, Fabienne; Takeda, Haruko; Pirottin, Dimitri; Tordoir, Xavier; Bibé, Bernard; Bouix, Jacques; Caiment, Florian; Elsen, Jean-Michel; Eychenne, Francis; Larzul, Catherine; Laville, Elisabeth; Meish, Françoise; Milenkovic, Dragan; Tobin, James; Charlier, Carole; Georges, Michel

2006-07-01

Texel sheep are renowned for their exceptional meatiness. To identify the genes underlying this economically important feature, we performed a whole-genome scan in a Romanov x Texel F2 population. We mapped a quantitative trait locus with a major effect on muscle mass to chromosome 2 and subsequently fine-mapped it to a chromosome interval encompassing the myostatin (GDF8) gene. We herein demonstrate that the GDF8 allele of Texel sheep is characterized by a G to A transition in the 3' UTR that creates a target site for mir1 and mir206, microRNAs (miRNAs) that are highly expressed in skeletal muscle. This causes translational inhibition of the myostatin gene and hence contributes to the muscular hypertrophy of Texel sheep. Analysis of SNP databases for humans and mice demonstrates that mutations creating or destroying putative miRNA target sites are abundant and might be important effectors of phenotypic variation.

Lack of sex-biased dispersal promotes fine-scale genetic structure in alpine ungulates

USGS Publications Warehouse

Roffler, Gretchen H.; Talbot, Sandra L.; Luikart, Gordon; Sage, George K.; Pilgrim, Kristy L.; Adams, Layne G.; Schwartz, Michael K.

2014-01-01

Identifying patterns of fine-scale genetic structure in natural populations can advance understanding of critical ecological processes such as dispersal and gene flow across heterogeneous landscapes. Alpine ungulates generally exhibit high levels of genetic structure due to female philopatry and patchy configuration of mountain habitats. We assessed the spatial scale of genetic structure and the amount of gene flow in 301 Dall’s sheep (Ovis dalli dalli) at the landscape level using 15 nuclear microsatellites and 473 base pairs of the mitochondrial (mtDNA) control region. Dall’s sheep exhibited significant genetic structure within contiguous mountain ranges, but mtDNA structure occurred at a broader geographic scale than nuclear DNA within the study area, and mtDNA structure for other North American mountain sheep populations. No evidence of male-mediated gene flow or greater philopatry of females was observed; there was little difference between markers with different modes of inheritance (pairwise nuclear DNA F ST = 0.004–0.325; mtDNA F ST = 0.009–0.544), and males were no more likely than females to be recent immigrants. Historical patterns based on mtDNA indicate separate northern and southern lineages and a pattern of expansion following regional glacial retreat. Boundaries of genetic clusters aligned geographically with prominent mountain ranges, icefields, and major river valleys based on Bayesian and hierarchical modeling of microsatellite and mtDNA data. Our results suggest that fine-scale genetic structure in Dall’s sheep is influenced by limited dispersal, and structure may be weaker in populations occurring near ancestral levels of density and distribution in continuous habitats compared to other alpine ungulates that have experienced declines and marked habitat fragmentation.

Classification and conservation priority of five Deccani sheep ecotypes of Maharashtra, India

PubMed Central

Arora, Reena; Jain, Anand

2017-01-01

Characterization of Indian livestock breeds has mostly been limited to single breed/population focused on either physical description of traditionally recognized breeds/populations or to their genetic description. Usually, morphological and genetic characterization has taken place in isolation. A parallel morphological characterization of genetically identified breeds or genetic characterization of morphologically described breeds is mostly missing, and their conservation priorities have largely been based on solely considering degree of endangerment. This study uses parallel approach based on morphometric and genetic differentiation for classification of five sheep ecotypes of Maharashtra state, and sets their conservation priority using threat parameters, current utilities/merits and contribution to genetic diversity. A total of 1101 animals were described for 7 body measurements for morphometric characterization. From this sample set, 456 animals were genotyped for 25 microsatellite markers for genetic characterization. Conservation priorities were assessed combining genetic and non-genetic factors. All studied traits varied significantly among ecotypes (p<0.05). All morphometric traits exhibited substantial sexual dimorphism except ear length. Males were 42% heavier than females. Madgyal sheep were the largest amongst the five ecotypes. In the stepwise discriminant analysis, all measured traits were significant and were found to have potential discriminatory power. Tail length was the most discriminatory trait. The Mahalanobis distance of the morphological traits between Kolhapuri and Madgyal was maximum (12.07) while the least differentiation was observed between Madgyal and Solapuri (1.50). Discriminant analysis showed that 68.12% sheep were classified into their source population. The Sangamneri sheep showed least assignment error (22%) whilst Solapuri exhibited maximum error level (41%). A total of 407 alleles were observed, with an average of 16.28 alleles per locus. Sufficient levels of genetic diversity were observed in all the ecotypes with observed heterozygosity values exceeding 0.47 and gene diversity values exceeding 0.76. About 6% of the total genetic variation was explained by population differences (FST = 0.059). Pairwise FST values indicated least differentiation between Solapuri and Madgyal (0.025). In terms of genetic distances, Kolhapuri and Lonand were most closely related (Ds = 0.177). The most probable structure clustering of the five studied populations was at K = 5. The study showed a fair congruence between the dendrogram constructed on the basis of Mahalanobis distances and Nei’s as well as Reynolds genetic distances. The findings gave highest conservation priority to Lonand and least to Solapuri ecotype. PMID:28910329

The correlation between ouabain binding and potassium pump inhibition in human and sheep erythrocytes.

PubMed Central

Joiner, C H; Lauf, P K

1978-01-01

1. [3H]Ouabain binding to human and sheep red blood cells was shown to be specific for receptors associated with Na/K transport. Virtually all tritium binding was abolished by dilution with unlabelled drug. Saturation levels of binding were independent of glycoside concentration and were identical to those associated with 100% inhibition of K pumping. 2. [3H]Ouabain binding and 42K influx were measured simultaneously in order to correlate the degree of K pump inhibition with the amount of glycoside bound. Results by this method agreed exactly with those obtained by pre-exposing cells to drug, followed by washing and then measuring K influx. 3. Plots of [3H]oubain binding vs. K pump inhibition were rectilinear for human and low K (LK) sheep red cells, indicating one glycoside receptor per K pump site and functional homogeneity of pump sites. High K (HK) sheep red cells exhibited curved plots of binding versus inhibition, which were best explained in terms of one receptor per pump, but a heterogeneous population of pump sites. 4. External K reduced the rate of glycoside binding, but did not alter the relationship between binding and inhibition. 5. The number of K pump sites was estimated as 450--500 per human cell and 30--50 per LK sheep cell. HK sheep cells had 90--130 sites per cell, of which eighty to ninety were functionally dominant. The number of K pump sites on LK sheep cells was not changed by anti-L, although the maximum velocity of pump turnover was increased. PMID:722573

A high resolution atlas of gene expression in the domestic sheep (Ovis aries)

PubMed Central

Farquhar, Iseabail L.; Young, Rachel; Lefevre, Lucas; Pridans, Clare; Tsang, Hiu G.; Afrasiabi, Cyrus; Watson, Mick; Whitelaw, C. Bruce; Freeman, Tom C.; Archibald, Alan L.; Hume, David A.

2017-01-01

Sheep are a key source of meat, milk and fibre for the global livestock sector, and an important biomedical model. Global analysis of gene expression across multiple tissues has aided genome annotation and supported functional annotation of mammalian genes. We present a large-scale RNA-Seq dataset representing all the major organ systems from adult sheep and from several juvenile, neonatal and prenatal developmental time points. The Ovis aries reference genome (Oar v3.1) includes 27,504 genes (20,921 protein coding), of which 25,350 (19,921 protein coding) had detectable expression in at least one tissue in the sheep gene expression atlas dataset. Network-based cluster analysis of this dataset grouped genes according to their expression pattern. The principle of ‘guilt by association’ was used to infer the function of uncharacterised genes from their co-expression with genes of known function. We describe the overall transcriptional signatures present in the sheep gene expression atlas and assign those signatures, where possible, to specific cell populations or pathways. The findings are related to innate immunity by focusing on clusters with an immune signature, and to the advantages of cross-breeding by examining the patterns of genes exhibiting the greatest expression differences between purebred and crossbred animals. This high-resolution gene expression atlas for sheep is, to our knowledge, the largest transcriptomic dataset from any livestock species to date. It provides a resource to improve the annotation of the current reference genome for sheep, presenting a model transcriptome for ruminants and insight into gene, cell and tissue function at multiple developmental stages. PMID:28915238

A high resolution atlas of gene expression in the domestic sheep (Ovis aries).

PubMed

Clark, Emily L; Bush, Stephen J; McCulloch, Mary E B; Farquhar, Iseabail L; Young, Rachel; Lefevre, Lucas; Pridans, Clare; Tsang, Hiu G; Wu, Chunlei; Afrasiabi, Cyrus; Watson, Mick; Whitelaw, C Bruce; Freeman, Tom C; Summers, Kim M; Archibald, Alan L; Hume, David A

2017-09-01

Sheep are a key source of meat, milk and fibre for the global livestock sector, and an important biomedical model. Global analysis of gene expression across multiple tissues has aided genome annotation and supported functional annotation of mammalian genes. We present a large-scale RNA-Seq dataset representing all the major organ systems from adult sheep and from several juvenile, neonatal and prenatal developmental time points. The Ovis aries reference genome (Oar v3.1) includes 27,504 genes (20,921 protein coding), of which 25,350 (19,921 protein coding) had detectable expression in at least one tissue in the sheep gene expression atlas dataset. Network-based cluster analysis of this dataset grouped genes according to their expression pattern. The principle of 'guilt by association' was used to infer the function of uncharacterised genes from their co-expression with genes of known function. We describe the overall transcriptional signatures present in the sheep gene expression atlas and assign those signatures, where possible, to specific cell populations or pathways. The findings are related to innate immunity by focusing on clusters with an immune signature, and to the advantages of cross-breeding by examining the patterns of genes exhibiting the greatest expression differences between purebred and crossbred animals. This high-resolution gene expression atlas for sheep is, to our knowledge, the largest transcriptomic dataset from any livestock species to date. It provides a resource to improve the annotation of the current reference genome for sheep, presenting a model transcriptome for ruminants and insight into gene, cell and tissue function at multiple developmental stages.

QTL mapping for sexually dimorphic fitness-related traits in wild bighorn sheep

PubMed Central

Poissant, J; Davis, C S; Malenfant, R M; Hogg, J T; Coltman, D W

2012-01-01

Dissecting the genetic architecture of fitness-related traits in wild populations is key to understanding evolution and the mechanisms maintaining adaptive genetic variation. We took advantage of a recently developed genetic linkage map and phenotypic information from wild pedigreed individuals from Ram Mountain, Alberta, Canada, to study the genetic architecture of ecologically important traits (horn volume, length, base circumference and body mass) in bighorn sheep. In addition to estimating sex-specific and cross-sex quantitative genetic parameters, we tested for the presence of quantitative trait loci (QTLs), colocalization of QTLs between bighorn sheep and domestic sheep, and sex × QTL interactions. All traits showed significant additive genetic variance and genetic correlations tended to be positive. Linkage analysis based on 241 microsatellite loci typed in 310 pedigreed animals resulted in no significant and five suggestive QTLs (four for horn dimension on chromosomes 1, 18 and 23, and one for body mass on chromosome 26) using genome-wide significance thresholds (Logarithm of odds (LOD) >3.31 and >1.88, respectively). We also confirmed the presence of a horn dimension QTL in bighorn sheep at the only position known to contain a similar QTL in domestic sheep (on chromosome 10 near the horns locus; nominal P<0.01) and highlighted a number of regions potentially containing weight-related QTLs in both species. As expected for sexually dimorphic traits involved in male–male combat, loci with sex-specific effects were detected. This study lays the foundation for future work on adaptive genetic variation and the evolutionary dynamics of sexually dimorphic traits in bighorn sheep. PMID:21847139

Fasciola hepatica: a comparative survey of adult fluke resistance to triclabendazole, nitroxynil and closantel on selected upland and lowland sheep farms in Northern Ireland using faecal egg counting, coproantigen ELISA testing and fluke histology.

PubMed

Hanna, R E B; McMahon, C; Ellison, S; Edgar, H W; Kajugu, P-E; Gordon, A; Irwin, D; Barley, J P; Malone, F E; Brennan, G P; Fairweather, I

2015-01-15

In order to investigate the incidence and distribution of adult fluke resistance to the fasciolicide tricalbendazole (TCBZ) amongst populations of Fasciola hepatica in sheep flocks in Northern Ireland (NI), individual rectal faeces samples were collected from 3 groups of 20 sheep, before (pre-dose), and 21 days after (post-dose) treatment of the animals with TCBZ, nitroxynil or closantel, on each of 13 well-managed sheep farms distributed across the province. The efficacy of each flukicide was determined for each farm, using faecal egg count reduction (FECRT) and F. hepatica coproantigen ELISA testing. In certain flocks, 2 sheep with high pre-dose faecal egg counts (FEC) were killed 3 days and 21 days respectively after TCBZ treatment, and the histology of the fluke reproductive organs was compared with that of flukes from untreated sheep, and from sheep treated with nitroxynil or closantel 2 days prior to death, using haematoxylin and eosin (H&E) staining and an in situ hybridisation method (TdT-mediated dUDP nick end labelling [TUNEL]) to demonstrate apoptosis. Results from FECRT revealed that in all flocks with a high fluke burden, TCBZ was ineffective in treating chronic fasciolosis, and this finding was generally supported by the results of the coproantigen reduction test (CRT). The histology of reproductive organs of flukes from TCBZ-treated sheep in these flocks was normal, when compared with untreated flukes, and this, together with the FECRT and CRT findings, indicated a likely diagnosis of TCBZ resistance in all the flocks with a high fluke burden. In contrast, nitroxynil and closantel were found to be fully effective against TCBZ-resistant flukes in each of the flocks bearing a high chronic fluke burden. All of the flocks with a high fluke burden and TCBZ resistance were managed on lowland in the South and East of NI. Upland flocks, in the North and West, had low fluke burdens, or were clear of infection; and FECs were too low to allow valid resistance testing. The study highlights the high level of penetration of TCBZ resistance throughout F. hepatica populations in areas of intensively managed sheep production with a high level of fluke challenge. Further, it emphasises the importance of pre-emptive chemotherapeutic action against chronic fasciolosis, using flukicides effective against the egg-producing adult flukes to minimise pasture contamination for the next season's lamb crop. This study also exemplifies the use of several complementary methods (FECRT; CRT; fluke histology; comparative anthelmintic efficacy testing) for confirmation of a diagnosis of fluke drug resistance. Copyright © 2014 Elsevier B.V. All rights reserved.

Serologic survey in animals of 'Q' fever in Nuevo Leon.

PubMed

Salinas-Melédez, J A; Avalos-Ramírez, R; Riojas-Valdez, V; Kawas-Garza, J; Fimbres-Durazo, H; Hernández-Vidal, G

2002-01-01

The serological prevalence of Q fever in Mexico is unknown. A serological survey for Coxiella burnetii was undertaken on a randomly selected population of dairy cattle, beef cattle, goats and sheep flocks. Serological examination of animal sera for antibodies against Coxiella burnetii was carried out by the ELISA technique. The 28% of the dairy cattle and 10% of beef cattle examinated were antibody positive. Sera from goats and sheep also had antibodies against this rickettsia, 35% and 40% respectively.

Revealing the selection history of adaptive loci using genome-wide scans for selection: an example from domestic sheep.

PubMed

Rochus, Christina Marie; Tortereau, Flavie; Plisson-Petit, Florence; Restoux, Gwendal; Moreno-Romieux, Carole; Tosser-Klopp, Gwenola; Servin, Bertrand

2018-01-23

One of the approaches to detect genetics variants affecting fitness traits is to identify their surrounding genomic signatures of past selection. With established methods for detecting selection signatures and the current and future availability of large datasets, such studies should have the power to not only detect these signatures but also to infer their selective histories. Domesticated animals offer a powerful model for these approaches as they adapted rapidly to environmental and human-mediated constraints in a relatively short time. We investigated this question by studying a large dataset of 542 individuals from 27 domestic sheep populations raised in France, genotyped for more than 500,000 SNPs. Population structure analysis revealed that this set of populations harbour a large part of European sheep diversity in a small geographical area, offering a powerful model for the study of adaptation. Identification of extreme SNP and haplotype frequency differences between populations listed 126 genomic regions likely affected by selection. These signatures revealed selection at loci commonly identified as selection targets in many species ("selection hotspots") including ABCG2, LCORL/NCAPG, MSTN, and coat colour genes such as ASIP, MC1R, MITF, and TYRP1. For one of these regions (ABCG2, LCORL/NCAPG), we could propose a historical scenario leading to the introgression of an adaptive allele into a new genetic background. Among selection signatures, we found clear evidence for parallel selection events in different genetic backgrounds, most likely for different mutations. We confirmed this allelic heterogeneity in one case by resequencing the MC1R gene in three black-faced breeds. Our study illustrates how dense genetic data in multiple populations allows the deciphering of evolutionary history of populations and of their adaptive mutations.

Quality and freezing qualities of first and second ejaculates collected from endangered Gulf Coast Native rams.

PubMed

Nel-Themaat, L; Harding, G D; Chandler, J E; Chenevert, J F; Damiani, P; Fernandez, J M; Humes, P E; Pope, C E; Godke, R A

2006-10-01

The Gulf Coast Native sheep, or Louisiana Native sheep, is an endangered previously feral domestic sheep population of European origin that has been under natural selection pressure for reproductive survival in their transplanted range while roaming in the southern Gulf Coast Region of the United States. This sheep population has an increased natural resistance to internal parasites, breeds year-around and has a greater percentage of live lambs as compared with other breeds of sheep raised in similar environments. To preserve the genetic diversity of this important feral sheep population, semen was collected by electro-ejaculation and subjected to cryopreservation for subsequent storage in a genome resource bank. Unrelated rams (n=5) were collected 3 days-a-week, allowing at least 2 days of rest between collections. Two ejaculates were obtained from each ram per collection day, with the second collection conducted 10min after the first ejaculation. Semen was processed using the standard Salamon cryopreservation procedure in a Tris-yolk-glycerol extender, frozen in 0.5ml plastic straws using liquid nitrogen (LN(2)) vapor and stored in LN(2). Each ejaculate was evaluated for volume, sperm concentration/ml (x10(9)/ml), number of spermatozoa/ejaculate (x10(9)), sperm progressive motility (%) for pre-cooled semen, cooled semen and semen after thawing. For the five rams, each semen variable for the first ejaculate was compared with that of the second ejaculate collected 10min later. The mean semen volume, sperm concentration and number of spermatozoa per ejaculate obtained from the first ejaculate were significantly greater (P< or =0.01) than those of the second ejaculate (comparisons being 1.62 and 1.06; 3.2 and 1.5; 5.4 and 1.8, respectively). Overall, the mean motility of pre-cooled (22 degrees Celsius), cooled (5 degrees Celsius) and frozen (-196 degrees Celsius) post-thawed spermatozoa was less (P< or =0.01) in the first ejaculate (71.5, 64.8 and 34.1%, respectively) compared with that of the second ejaculate (75, 72.4 and 44.1%, respectively). Conversely, no differences were detected in loss in the percent progressive motility of sperm from cooled sperm to post-thaw sperm from the first and second ejaculates. In summary, our findings suggest sperm collected during the second ejaculate 10min after the first ejaculate of rams survives thawing with a greater rate of progressive motility than that of the first ejaculate. The ability to collect two consecutive ejaculates in a short period by electro-ejaculation could be valuable for gamete resource banking and preserving genetic diversity of the Gulf Coast Native sheep.

Industry benefits from recent genetic progress in sheep and beef populations.

PubMed

Amer, P R; Nieuwhof, G J; Pollott, G E; Roughsedge, T; Conington, J; Simm, G

2007-11-01

An analytical model that evaluates the benefits from 10 years of genetic improvement over a 20-year time frame was specified. Estimates of recent genetic trends in recorded traits, industry statistics and published estimates of the economic values of trait changes were used to parameterise the model for the UK sheep and beef industries. Despite rates of genetic change in the relevant performance-recorded breeding populations being substantially less than theoretical predictions, the financial benefits of genetic change were substantial. Over 20 years, the benefits from 10 years of genetic progress at recently achieved rates in recorded hill sheep, sheep crossing sire and sheep terminal sire breeding programmes was estimated to be £5.3, £1.0 and £11.5 million, respectively. If dissemination of genetic material is such that these rates of change are also realised across the entire ram breeding industry, the combined benefits would be £110.8 million. For beef cattle, genetic evaluation systems have been operating within all the major breeds for some years with quite widespread use of performance recording, and so genetic trends within the beef breeds were used as predictors of industry genetic change. Benefits from 10 years of genetic progress at recent rates of change, considering a 20-year time frame, in terminal sire beef breeds are expected to be £4.9 million. Benefits from genetic progress for growth and carcass characters in dual-purpose beef breeds were £18.2 million after subtraction of costs associated with a deterioration in calving traits. These benefits may be further offset by unfavourable associated changes in maternal traits. Additional benefits from identification and use of the best animals available from the breeding sector for commercial matings through performance recording and genetic evaluation could not be quantified. When benefits of genetic improvement were expressed on an annual present value basis and compared with lagged annual investment costs to achieve it, the internal rate of return (IRR) on the combined investment in sheep and beef cattle was 32%. Despite a much higher rate of participation in performance recording, the present value of benefits and the IRR were lower for beef cattle than for sheep. The implications of these results for future national and industry investment in genetic improvement infrastructure were discussed.

An ABC estimate of pedigree error rate: application in dog, sheep and cattle breeds.

PubMed

Leroy, G; Danchin-Burge, C; Palhiere, I; Baumung, R; Fritz, S; Mériaux, J C; Gautier, M

2012-06-01

On the basis of correlations between pairwise individual genealogical kinship coefficients and allele sharing distances computed from genotyping data, we propose an approximate Bayesian computation (ABC) approach to assess pedigree file reliability through gene-dropping simulations. We explore the features of the method using simulated data sets and show precision increases with the number of markers. An application is further made with five dog breeds, four sheep breeds and one cattle breed raised in France and displaying various characteristics and population sizes, using microsatellite or SNP markers. Depending on the breeds, pedigree error estimations range between 1% and 9% in dog breeds, 1% and 10% in sheep breeds and 4% in cattle breeds. © 2011 The Authors, Animal Genetics © 2011 Stichting International Foundation for Animal Genetics.

Narcissism and belief in the paranormal.

PubMed

Roe, Chris A; Morgan, Claire L

2002-04-01

The present study was designed to assess whether the relationship between narcissistic personality and paranormal belief identified by Tobacyk and Mitchell earlier could be replicated with a general population and to see whether the effect could be found with a narrower definition of paranormal beliefs that focuses only on belief in psychic phenomena. 75 participants completed the Narcissistic Personality Inventory and two measures of paranormal belief, the Paranormal Belief Scale and the Australian Sheep-Goat Scale. There was no correlation between narcissism and Paranormal Belief Scale scores, but narcissism and Australian Sheep-Goat Scale scores were significantly positively correlated. Of the three subscales to the Australian Sheep-Goat measure, scores for narcissism correlated with belief in ESP and PK but not in Life after death. These relationships were interpreted in terms of need for control.

Disease introduction is associated with a phase transition in bighorn sheep demographics

PubMed Central

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul Chafee; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (lambda =1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (lambda = 0.98) over the next twenty years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. PMID:27859120

Disease introduction is associated with a phase transition in bighorn sheep demographics

USGS Publications Warehouse

Manlove, Kezia; Cassirer, E. Frances; Cross, Paul C.; Plowright, Raina K.; Hudson, Peter J.

2016-01-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles.

Reducing methane emissions and the methanogen population in the rumen of Tibetan sheep by dietary supplementation with coconut oil.

PubMed

Ding, Xuezhi; Long, Ruijun; Zhang, Qian; Huang, Xiaodan; Guo, Xusheng; Mi, Jiandui

2012-10-01

The objective was to evaluate the effect of dietary coconut oil on methane (CH(4)) emissions and the microbial community in Tibetan sheep. Twelve animals were assigned to receive either a control diet (oaten hay) or a mixture diet containing concentrate (maize meal), in which coconut oil was supplemented at 12 g/day or not for a period of 4 weeks. CH(4) emissions were measured by using the 'tunnel' technique, and microbial communities were examined using quantitative real-time PCR. Daily CH(4) production for the control and forage-to-concentrate ratio of 6:4 was 17.8 and 15.3 g, respectively. Coconut oil was particularly effective at reducing CH(4) emissions from Tibetan sheep. The inclusion of coconut oil for the control decreased CH(4) production (in grams per day) by 61.2%. In addition, there was a positive correlation between the number of methanogens and the daily CH(4) production (R = 0.95, P < 0.001). Oaten hay diet containing maize meal (6:4) plus coconut oil supplemented at 12 g/day decreases the number of methanogens by 77% and a decreases in the ruminal fungal population (85-95%) and Fibrobacter succinogenes (50-98%) but an increase in Ruminococcus flavefaciens (25-70%). The results from our experiment suggest that adding coconut oil to the diet can reduce CH(4) emissions in Tibetan sheep and that these reductions persist for at least the 4-week feeding period.

'Bio-load' and bio-type profiles of Mycobacterium avium subspecies paratuberculosis infection in the domestic livestock population endemic for Johne's disease: a survey of 28 years (1985-2013) in India.

PubMed

Singh, S V; Singh, P K; Singh, A V; Sohal, J S; Kumar, N; Chaubey, K K; Gupta, S; Rawat, K D; Kumar, A; Bhatia, A K; Srivastav, A K; Dhama, K

2014-08-01

Bio-load and bio-profile of Mycobacterium avium subspecies paratuberculosis was studied in the domestic livestock population of the country. Of the 23,429 farm and farmer's animals screened, average bio-load was 23.3% (Period of study; 28 years for goats; 13 years for sheep, cattle and buffaloes). Species-wise, bio-load was 20.1, 32.7, 39.3 and 28.3% in goats, sheep, cattle and buffaloes, respectively. Bio-load was significantly lower in time period A (P < 0.001) and B (P < 0.03), compared with period C. Geographical zone-wise, bio-load of MAP was significantly higher (P < 0.05) in Central zone compared with South, West, East and North zones. Bio-load in 11 states ranged from 16.2 to 87.8%. Of 8450, 5643, 8185 and 1151 samples screened by microscopy, culture, indigenous ELISA and IS900 blood PCR, 20.0, 10.6, 35.1 and 26.6% samples were positive, respectively. Bio-load was 32.8 and 31.6% in farm and farmer's goats and sheep, respectively, and 62.1% in farmer's cattle. MAP bio-load was also monitored in four farm units (three goats and one sheep) for breed improvement and three farm goats units for experimental purposes at Central Institute for Research on Goats in Mathura district. Of the 8025 goats and 1525 sheep that died from 1988 to 2013, 10.9 and 3.0% deaths were due to JD, respectively. On the basis of JD and suspected JD, 10.0 and 28.4% goats and 2.2 and 40.9% sheep, respectively were culled from the farm units in 25 years. Microscopic examination of 214 tissues (mesenteric lymph nodes and intestines) of 107 animals, it was observed that bio-load of MAP was high (25.0-60.0%) in farm animals. 'Indian Bison Type' was the dominant biotype, irrespective of domestic livestock species and the geographical zone. © 2014 Blackwell Verlag GmbH.

Microbial protein synthesis, ruminal digestion, microbial populations, and nitrogen balance in sheep fed diets varying in forage-to-concentrate ratio and type of forage.

PubMed

Ramos, S; Tejido, M L; Martínez, M E; Ranilla, M J; Carro, M D

2009-09-01

Six ruminally and duodenally cannulated sheep were used in a partially replicated 4 x 4 Latin square to evaluate the effects of 4 diets on microbial synthesis, microbial populations, and ruminal digestion. The experimental diets had forage to concentrate ratios (F:C; DM basis) of 70:30 (HF) or 30:70 (HC) with alfalfa hay (A) or grass hay (G) as forage and were designated as HFA, HCA, HFG, and HCG. The concentrate was based on barley, gluten feed, wheat middlings, soybean meal, palmkern meal, wheat, corn, and mineral-vitamin premix in the proportions of 22, 20, 20, 13, 12, 5, 5, and 3%, respectively (as-is basis). Sheep were fed the diets at a daily rate of 56 g/kg of BW(0.75) to minimize feed selection. High-concentrate diets resulted in greater (P < 0.001) total tract apparent OM digestibility compared with HF diets, but no differences were detected in NDF digestibility. Ruminal digestibility of OM, NDF, and ADF was decreased by increasing the proportion of concentrate, but no differences between forages were detected. Compared with sheep fed HF diets, sheep receiving HC diets had less ruminal pH values and acetate proportions, but greater butyrate proportions. No differences among diets were detected in numbers of cellulolytic bacteria, but protozoa numbers were less (P = 0.004) and total bacteria numbers tended (P = 0.08) to be less for HC diets. Carboxymethylcellulase, xylanase, and amylase activities were greater for HC compared with HF diets, with A diets showing greater (P = 0.008) carboxymethylcellulase activities than G diets. Retained N ranged from 28.7 to 37.9% of N intake and was not affected by F:C (P = 0.62) or the type of forage (P = 0.31). Microbial N synthesis and its efficiency was greater (P < 0.001) for HC diets compared with HF diets. The results indicate that concentrates with low cereal content can be included in the diet of sheep up to 70% of the diet without detrimental effects on ruminal activity, microbial synthesis efficiency, and N losses.

Study of Helicobacter pylori genotype status in cows, sheep, goats and human beings

PubMed Central

2014-01-01

Background Helicobacter pylori is one of the most controversial bacteria in the world causing diverse gastrointestinal diseases. The transmission way of this bacterium still remains unknown. The possibility of zoonotic transmission of H. pylori has been suggested, but is not proven in nonprimate reservoirs. In the current survey, we investigate the presence of H. pylori in cow, sheep and goat stomach, determine the bacterium virulence factors and finally compare the human H. pylori virulence factors and animals in order to examine whether H. pylori might be transmitted from these animals to human beings. Methods This cross- sectional study was performed on 800 gastric biopsy specimens of cows, sheep, goats and human beings. The PCR assays was performed to detection of H. pylori, vacA and cagA genes. The PCR products of Ruminant’s samples with positive H. pylori were subjected to DNA sequencing analysis. Statistical tests were applied for data analysis. Results Overall 6 (3%) cows, 32 (16%) sheep and 164 (82%) human beings specimens were confirmed to be H. pylori positive; however we were not able to detect this bacterium in all 200 goat samples. The vacA s1a/m1a was the predominant H. pylori genotype in all three kinds of studied population. There was 3.4–8.4% variability and 92.9-98.5% homology between sheep and human samples. Conclusions Considering the high sequence homology among DNA of H. pylori isolated from sheep and human, our data suggest that sheep may act as a reservoir for H. pylori and in the some extent share the ancestral host for the bacteria with human. PMID:24708464

The genomic architecture of mastitis resistance in dairy sheep.

PubMed

Banos, G; Bramis, G; Bush, S J; Clark, E L; McCulloch, M E B; Smith, J; Schulze, G; Arsenos, G; Hume, D A; Psifidi, A

2017-08-16

Mastitis is the most prevalent disease in dairy sheep with major economic, hygienic and welfare implications. The disease persists in all dairy sheep production systems despite the implementation of improved management practises. Selective breeding for enhanced mastitis resistance may provide the means to further control the disease. In the present study, we investigated the genetic architecture of four mastitis traits in dairy sheep. Individual animal records for clinical mastitis occurrence and three mastitis indicator traits (milk somatic cell count, total viable bacterial count in milk and the California mastitis test) were collected monthly throughout lactation for 609 ewes of the Greek Chios breed. All animals were genotyped with a custom-made 960-single nucleotide polymorphism (SNP) DNA array based on markers located in quantitative trait loci (QTL) regions for mastitis resistance previously detected in three other distinct dairy sheep populations. Heritable variation and strong positive genetic correlations were estimated for clinical mastitis occurrence and the three mastitis indicator traits. SNP markers significantly associated with these mastitis traits were confirmed on chromosomes 2, 3, 5, 16 and 19. We identified pathways, molecular interaction networks and functional gene clusters for mastitis resistance. Candidate genes within the detected regions were identified based upon analysis of an ovine transcriptional atlas and transcriptome data derived from milk somatic cells. Relevant candidate genes implicated in innate immunity included SOCS2, CTLA4, C6, C7, C9, PTGER4, DAB2, CARD6, OSMR, PLXNC1, IDH1, ICOS, FYB, and LYFR. The results confirmed the presence of animal genetic variability in mastitis resistance and identified genomic regions associated with specific mastitis traits in the Chios sheep. The conserved genetic architecture of mastitis resistance between distinct dairy sheep breeds suggests that across-breed selection programmes would be feasible.

Outbreaks of abortions by Coxiella burnetii in small ruminant flocks and a longitudinal serological approach on archived bulk tank milk suggest Q fever emergence in Central Portugal.

PubMed

Cruz, Rita; Esteves, Fernando; Vasconcelos-Nóbrega, Carmen; Santos, Carla; Ferreira, Ana S; Mega, Cristina; Coelho, Ana C; Vala, Helena; Mesquita, João R

2018-05-25

Q fever is a worldwide zoonotic infectious disease caused by Coxiella burnetii and sheep and goats are known to be the main reservoir for human infection. This study describes the epidemiological and laboratory findings of C. burnetii outbreaks affecting sheep and goat flocks and also provides the results of a prospective serosurvey in bulk tank milk samples to assess C. burnetii circulation in a population of sheep living in close contact to the human population in Central Portugal. In the epizooties, C. burnetii was identified in tissues of the resulting abortions by qPCR. As for the serological survey, 10.2% (95%CI: 4.5-19.2) of the 78 bulk tank milk samples collected in 2015 presented IgG antibodies against C. burnetii. The same farms were visited and sampled in 2016 and 25.6% (95%CI: 16.4-36.8) were positive. This steep increase in the number of anti-C. burnetii farms between the 2015 and 2016 collections showed to be statistically significant (p = 0.020) and is strongly suggestive of Q fever emergence in Central Portugal. Measures on animal health and on disease spread control to the human population should be considered. © 2018 Blackwell Verlag GmbH.

Food habits of pumas in northwestern Sonora, Mexico

USGS Publications Warehouse

Rosas-Rosas, O. C.; Valdez, R.; Bender, L.C.; Daniel, D.

2003-01-01

It is questionable whether food-habits studies of pumas conducted in the southwestern United States can be extrapolated to northwestern Mexico, because of differences in management, distribution, and abundance of wildlife. We determined food habits of pumas (Puma concolor) in the Sonoran Desert of northwestern Sonora, Mexico. Based on studies in the western United States, we hypothesized that desert mule deer (Odocoileus hemionus) were the major food source of pumas in Sonoran Desert habitats of Mexico. The study area supports populations of desert mule deer, white-tailed deer (Odocoileus virginianus), lagomorphs (Lepus spp. and Sylvilagus audubonii), collared peccary (Pecari tajacu), and the largest population (???300 individuals) of desert bighorn sheep (Ovis canadensis) in Sonora. Based on pugmark characteristics, we recorded 3 different adult resident pumas in approximately 90 km2. We analyzed 60 puma fecal samples collected September 1996-November 1998. Primary prey items based on frequency of occurrence and estimated biomass consumed were desert bighorn sheep (40% and 45%, respectively), lagomorphs (33%, 19%), deer (17%, 17%), and collared peccary (15%, 11%). The high percentage of desert bighorn sheep in puma diets may be due to high abundance relative to mule deer, which declined in number during our study. No differences were found in puma diets between seasons (??22=2.4526, P=0.2934). Fluctuations in mule deer populations in northwestern Sonora may influence prey selection by pumas.

A brucellosis disease control strategy for the Kakheti region of the country of Georgia: an agent-based model.

PubMed

Havas, K A; Boone, R B; Hill, A E; Salman, M D

2014-06-01

Brucellosis has been reported in livestock and humans in the country of Georgia with Brucella melitensis as the most common species causing disease. Georgia lacked sufficient data to assess effectiveness of the various potential control measures utilizing a reliable population-based simulation model of animal-to-human transmission of this infection. Therefore, an agent-based model was built using data from previous studies to evaluate the effect of an animal-level infection control programme on human incidence and sheep flock and cattle herd prevalence of brucellosis in the Kakheti region of Georgia. This model simulated the patterns of interaction of human-animal workers, sheep flocks and cattle herds with various infection control measures and returned population-based data. The model simulates the use of control measures needed for herd and flock prevalence to fall below 2%. As per the model output, shepherds had the greatest disease reduction as a result of the infection control programme. Cattle had the greatest influence on the incidence of human disease. Control strategies should include all susceptible animal species, sheep and cattle, identify the species of brucellosis present in the cattle population and should be conducted at the municipality level. This approach can be considered as a model to other countries and regions when assessment of control strategies is needed but data are scattered. © 2013 Blackwell Verlag GmbH.

Prevalence, pathogenic capability, virulence genes, biofilm formation, and antibiotic resistance of Listeria in goat and sheep milk confirms need of hygienic milking conditions.

PubMed

Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed

2014-01-01

Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow's milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence factors, biofilm formation, and antibiopotential of Listeria isolated from the milk of goat and sheep. Udder milk samples were collected from 107 goats and 102 sheep and screened for mastitis using the California mastitis test (CMT). Samples were then examined for the presence of pathogenic Listeria spp; if detected, the isolation of pathogenic Listeria (L. monocytogenes and Listeria ivanovii) was completed using isolation and identification techniques recommended by the International Organization for Standards (ISO 11290-1, 1996), in addition to serological, in vitro and in vivo pathogenicity tests. The isolates were subjected to PCR assay for virulence associated genes (hlyA, plcA, actA, and iap). Pathogenic Listeria spp. were isolated from 5·6% of goat and 3·9% sheep milk samples, with 33·3 and 25% of these selected samples respectively containing L. monocytogenes. The results of this study provide evidence of the low-likelihood of contamination leading to the presence of L. monocytogenes in raw goat and sheep milk; however, this study also confirmed a strong in vitro ability for biofilm formation and pathogenic capability of L. monocytogenes if discovered in the milk. L. monocytogenes may be present in goat and sheep milk and in order to reduce the exposure, hygienic milking conditions must be employed for the milk to be considered a safe alternative for human consumption.

Prevalence, pathogenic capability, virulence genes, biofilm formation, and antibiotic resistance of Listeria in goat and sheep milk confirms need of hygienic milking conditions

PubMed Central

Osman, Kamelia M; Zolnikov, Tara Rava; Samir, Ahmed; Orabi, Ahmed

2014-01-01

Goat and sheep milk is consumed by human populations throughout the world; as a result, it has been proposed as an alternative, nutrient-rich milk to feed infants allergic to cow’s milk. Unfortunately, potentially harmful bacteria have not been thoroughly tested in goat or sheep milk. Listeria monocytogenes is a harmful bacterium that causes adverse health effects if ingested by humans. The purpose of this study was to estimate the prevalence and characterize the phenotype, genotype, virulence factors, biofilm formation, and antibiopotential of Listeria isolated from the milk of goat and sheep. Udder milk samples were collected from 107 goats and 102 sheep and screened for mastitis using the California mastitis test (CMT). Samples were then examined for the presence of pathogenic Listeria spp; if detected, the isolation of pathogenic Listeria (L. monocytogenes and Listeria ivanovii) was completed using isolation and identification techniques recommended by the International Organization for Standards (ISO 11290-1, 1996), in addition to serological, in vitro and in vivo pathogenicity tests. The isolates were subjected to PCR assay for virulence associated genes (hlyA, plcA, actA, and iap). Pathogenic Listeria spp. were isolated from 5.6% of goat and 3.9% sheep milk samples, with 33.3 and 25% of these selected samples respectively containing L. monocytogenes. The results of this study provide evidence of the low-likelihood of contamination leading to the presence of L. monocytogenes in raw goat and sheep milk; however, this study also confirmed a strong in vitro ability for biofilm formation and pathogenic capability of L. monocytogenes if discovered in the milk. L. monocytogenes may be present in goat and sheep milk and in order to reduce the exposure, hygienic milking conditions must be employed for the milk to be considered a safe alternative for human consumption. PMID:24548157

Mitochondrial DNA Diversity of Modern, Ancient and Wild Sheep (Ovis gmelinii anatolica) from Turkey: New Insights on the Evolutionary History of Sheep

PubMed Central

Pişkin, Evangelia; Engin, Atilla; Özer, Füsun; Yüncü, Eren; Doğan, Şükrü Anıl; Togan, İnci

2013-01-01

In the present study, to contribute to the understanding of the evolutionary history of sheep, the mitochondrial (mt) DNA polymorphisms occurring in modern Turkish native domestic (n = 628), modern wild (Ovis gmelinii anatolica) (n = 30) and ancient domestic sheep from Oylum Höyük in Kilis (n = 33) were examined comparatively with the accumulated data in the literature. The lengths (75 bp/76 bp) of the second and subsequent repeat units of the mtDNA control region (CR) sequences differentiated the five haplogroups (HPGs) observed in the domestic sheep into two genetic clusters as was already implied by other mtDNA markers: the first cluster being composed of HPGs A, B, D and the second cluster harboring HPGs C, E. To manifest genetic relatedness between wild Ovis gmelinii and domestic sheep haplogroups, their partial cytochrome B sequences were examined together on a median-joining network. The two parallel but wider aforementioned clusters were observed also on the network of Ovis gmelenii individuals, within which domestic haplogroups were embedded. The Ovis gmelinii wilds of the present day appeared to be distributed on two partially overlapping geographic areas parallel to the genetic clusters that they belong to (the first cluster being in the western part of the overall distribution). Thus, the analyses suggested that the domestic sheep may be the products of two maternally distinct ancestral Ovis gmelinii populations. Furthermore, Ovis gmelinii anatolica individuals exhibited a haplotype of HPG A (n = 22) and another haplotype (n = 8) from the second cluster which was not observed among the modern domestic sheep. HPG E, with the newly observed members (n = 11), showed signs of expansion. Studies of ancient and modern mtDNA suggest that HPG C frequency increased in the Southeast Anatolia from 6% to 22% some time after the beginning of the Hellenistic period, 500 years Before Common Era (BCE). PMID:24349158

Mitochondrial DNA diversity of modern, ancient and wild sheep(Ovis gmelinii anatolica) from Turkey: new insights on the evolutionary history of sheep.

PubMed

Demirci, Sevgin; Koban Baştanlar, Evren; Dağtaş, Nihan Dilşad; Pişkin, Evangelia; Engin, Atilla; Ozer, Füsun; Yüncü, Eren; Doğan, Sükrü Anıl; Togan, Inci

2013-01-01

In the present study, to contribute to the understanding of the evolutionary history of sheep, the mitochondrial (mt) DNA polymorphisms occurring in modern Turkish native domestic (n = 628), modern wild (Ovis gmelinii anatolica) (n = 30) and ancient domestic sheep from Oylum Höyük in Kilis (n = 33) were examined comparatively with the accumulated data in the literature. The lengths (75 bp/76 bp) of the second and subsequent repeat units of the mtDNA control region (CR) sequences differentiated the five haplogroups (HPGs) observed in the domestic sheep into two genetic clusters as was already implied by other mtDNA markers: the first cluster being composed of HPGs A, B, D and the second cluster harboring HPGs C, E. To manifest genetic relatedness between wild Ovis gmelinii and domestic sheep haplogroups, their partial cytochrome B sequences were examined together on a median-joining network. The two parallel but wider aforementioned clusters were observed also on the network of Ovis gmelenii individuals, within which domestic haplogroups were embedded. The Ovis gmelinii wilds of the present day appeared to be distributed on two partially overlapping geographic areas parallel to the genetic clusters that they belong to (the first cluster being in the western part of the overall distribution). Thus, the analyses suggested that the domestic sheep may be the products of two maternally distinct ancestral Ovis gmelinii populations. Furthermore, Ovis gmelinii anatolica individuals exhibited a haplotype of HPG A (n = 22) and another haplotype (n = 8) from the second cluster which was not observed among the modern domestic sheep. HPG E, with the newly observed members (n = 11), showed signs of expansion. Studies of ancient and modern mtDNA suggest that HPG C frequency increased in the Southeast Anatolia from 6% to 22% some time after the beginning of the Hellenistic period, 500 years Before Common Era (BCE).

Occurrence of Bluetongue in ruminants in Tamil Nadu, South India.

PubMed

Reddy, Y Krishnamohan; Brindha, K; Ganesan, P I; Srinivas, K; Reddy, G S; Minakshi, P

2016-09-30

Tamil Nadu is located in the South-Eastern part of Indian peninsula, between 8.087° and 13.09°N and 76.50° and 80.27°E. Bluetongue (BT) was first reported in this region in sheep during 1982 with regular occurrence thereafter. In 1989-1990, 1997-1998 and 2005-2006, there was wide spread occurrence of BT resulting in huge mortality of sheep. The present study had the goal of isolating the BTV from outbreaks in sheep occurred in Tamil Naadu between 2003-2011 and comparing the VP2 gene sequences of the BTV isolates involved in such outbreaks. Serotypes 1, 2, 16, and 23 of the Bluetongue virus (BTV) have been isolated from sheep during BT outbreaks. BTV-16 has also been isolated in goats and cattle in the region; BTV-2 isolated in Tamil Nadu has homology with BTV-2 isolated in Africa; whereas the BTV-23 isolated in this area has homology with BTV-23 from South East Asia, indicating that both Eastern and Western topotypes of BTV are circulating in ruminant population in Tamil Nadu.

Isolation and biological characteristic evaluation of a novel type of cartilage stem/progenitor cell derived from Small‑tailed Han sheep embryos.

PubMed

Ma, Caiyun; Lu, Tengfei; Wen, Hebao; Zheng, Yanjie; Han, Xiao; Ji, Xongda; Guan, Weijun

2018-07-01

Cartilage stem/progenitor cells (CSPCs) are a novel stem cell population and function as promising therapeutic candidates for cell‑based cartilage repair. Until now, numerous existing research materials have been obtained from humans, horses, cows and other mammals, but rarely from sheep. In the present study, CSPCs with potential applications in repairing tissue damage and cell‑based therapy were isolated from 45‑day‑old Small‑tailed Han Sheep embryos, and examined at the cellular and molecular level. The expression level of characteristic surface markers of the fetal sheep CSPCs were also evaluated by immunofluorescence, reverse transcription‑polymerase chain reaction analysis and flow cytometric assays. Biological growth curves were drawn in accordance with cell numbers. Additionally, karyotype analysis showed no marked differences in the in vitro cultured CSPCs and they were genetically stable among different passages. The CSPCs were also capable of adipogenic, osteogenic and chondrogenic lineage progression under the appropriate induction medium in vitro. Together, these findings provide a theoretical basis and experimental evidence for cellular transplant therapy in tissue engineering.

Occurrence of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats in China.

PubMed

Li, Wen Chao; Wang, Kai; Gu, Youfang

2018-02-17

Global data regarding the molecular epidemiology of Blastocystis sp. and Pentatrichomonas hominis in sheep and goats are sparse. China has one of the largest sheep and goat populations in the world. In this study we investigated the occurrence of Blastocystis sp. and P. hominis in domestic sheep and goats in China, and analyzed the genetic characterization of these two parasite species. In total, we collected fresh fecal samples from 832 sheep and 781 goats located on seven and ten farms, respectively, in the central eastern region of China. The corresponding sequences obtained in this study were subject to molecular analysis for subtype and allele identification of Blastocystis sp., and species and genotype confirmation of P. hominis. The occurrence of Blastocystis sp. was 6.0% (50/832) in sheep and 0.3% (2/781) in goats. The most predominant subtype (ST) of Blastocystis sp. in sheep was ST10 (50.0%), followed by ST14 (20%), ST5 (16%), novel sequence 1 (6%), novel sequence 4 (4%), novel sequence 2 (2%) and novel sequence 3 (2%). However, only ST1 was observed in goats. No mixed infections with different subtypes were found in this study. The 18S alleles showed allele 2 (100%) for ST1; allele 115 (75%) for ST5; and no match allele for ST5 (25%), ST10 (100%), ST14 (100%), novel sequence 1 (100%), novel sequence 2 (100%), novel sequence 3 (100%), and novel sequence 4 (100%) on the Blastocystis subtype (18S) and Sequence Typing (MLST) database. For P. hominis, two goats (0.3%) and zero sheep (0%) were identified as positive in this study. The 18S rRNA gene sequences of two P. hominis isolates from goats displayed 100% identity to type CC1, found previously in dogs, monkeys and humans. These results provide the detailed data on the occurrence and molecular epidemiology of Blastocystis sp. and P. hominis in sheep and goats in China. They also contribute to and expand our knowledge of the Blastocystis sp. and P. hominis epidemiology around the world.

Estimation of flock/herd-level true Mycobacterium avium subspecies paratuberculosis prevalence on sheep, beef cattle and deer farms in New Zealand using a novel Bayesian model.

PubMed

Verdugo, Cristobal; Jones, Geoff; Johnson, Wes; Wilson, Peter; Stringer, Lesley; Heuer, Cord

2014-12-01

The study aimed to estimate the national- and island-level flock/herd true prevalence (HTP) of Mycobacterium avium subsp. paratuberculosis (MAP) infection in pastoral farmed sheep, beef cattle and deer in New Zealand. A random sample of 238 single- or multi-species farms was selected from a postal surveyed population of 1940 farms. The sample included 162 sheep flocks, 116 beef cattle and 99 deer herds from seven of 16 geographical regions. Twenty animals from each species present on farm were randomly selected for blood and faecal sampling. Pooled faecal culture testing was conducted using a single pool (sheep flocks) or two pools (beef cattle/deer herds) of 20 and 10 samples per pool, respectively. To increase flock/herd-level sensitivity, sera from all 20 animals from culture negative flocks/herds were individually tested by Pourquier(®) ELISA (sheep and cattle) or Paralisa™ (deer). Results were adjusted for sensitivity and specificity of diagnostic tests using a novel Bayesian latent class model. Outcomes were adjusted by their sampling fractions to obtain HTP estimates at national level. For each species, the posterior probability (POPR) of HTP differences between New Zealand North (NI) and South (SI) Islands was obtained. Across all species, 69% of farms had at least one species test positive. Sheep flocks had the highest HTP estimate (76%, posterior probability interval (PPI) 70-81%), followed by deer (46%, PPI 38-55%) and beef herds (42%, PPI 35-50%). Differences were observed between the two main islands of New Zealand, with higher HTP in sheep and beef cattle flocks/herds in the NI. Sheep flock HTP was 80% in the NI compared with 70% (POPR=0.96) in the SI, while the HTP for beef cattle was 44% in the NI and 38% in the SI (POPR=0.80). Conversely, deer HTP was higher in the SI (54%) than the NI (33%, POPR=0.99). Infection with MAP is endemic at high prevalence in sheep, beef cattle and deer flocks/herds across New Zealand. Copyright © 2014 Elsevier B.V. All rights reserved.

Pyrethroid resistance in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis.

PubMed

Levot, G W; Johnson, P W; Hughes, P B; Powis, K J; Boray, J C; Dawson, K L

1995-01-01

Synthetic pyrethroid (SP) resistance has developed in Australian field populations of the sheep body louse, Bovicola (Damalinia) ovis. Laboratory bioassays were used to measure the susceptibility of lice to cypermethrin and the other registered SPs. Results of these bioassays indicated resistance to cypermethrin, deltamethrin, cyhalothrin and alphacypermethrin. So far, high-level resistance has been diagnosed in only a few strains. The toxicological responses of these strains were clearly separated from those of the majority of louse strains tested. Furthermore, these strains had survived immersion in commercial SP dips. The level of resistance described in some strains was sufficient to cause pour-on products to fail despite the fact that the LC50s of these strains fell within the normal range of field responses.

[Hepatobiliary fascioliasis and echinococcosis/hydatidosis in domestic animals in Haiti].

PubMed

Blaise, J; Raccurt, C P

2007-12-01

In Haiti, hepatobiliary fascioliasis and hepatic hydatid cysts cause major economic losses among livestock. Surveys show high prevalence rates for bovine distomatosis caused by Fasciola hepatica (10.7% to 22.78%). Among small ruminants, the prevalence of distomatosis is low (sheep: 3.2%, goats: 0.9%) although Dicrocoelium dendriticum is found in 1.1% of sheep. Hepatic hydatidosis is more common among pigs (5.2%) and sheep (2.1%) than among goats (0.9%) and cattle (0.3%). In the case of dogs, 21% excrete egg-bearing segments in their faeces and 25% harbour Echinococcus granulosus in the small intestine. As a result of local dietary habits (consumption of raw cress), environmental pollution by animal faeces, poverty and poor standards of hygiene in Haiti, these flatworms pose serious health risks to the population, even though this is largely unknown at present.

The Role of Individual Traits and Environmental Factors for Diet Composition of Sheep

PubMed Central

Mysterud, Atle; Austrheim, Gunnar

2016-01-01

Large herbivore consumption of forage is known to affect vegetation composition and thereby ecosystem functions. It is thus important to understand how diet composition arises as a mixture of individual variation in preferences and environmental drivers of availability, but few studies have quantified both. Based on 10 years of data on diet composition by aid of microhistological analysis for sheep kept at high and low population density, we analysed how both individual traits (sex, age, body mass, litter size) linked to preference and environmental variation (density, climate proxies) linked to forage availability affected proportional intake of herbs (high quality/low availability) and Avenella flexuosa (lower quality/high availability). Environmental factors affecting current forage availability such as population density and seasonal and annual variation in diet had the most marked impact on diet composition. Previous environment of sheep (switch between high and low population density) had no impact on diet, suggesting a comparably minor role of learning for density dependent diet selection. For individual traits, only the difference between lambs and ewes affected proportion of A. flexuosa, while body mass better predicted proportion of herbs in diet. Neither sex, body mass, litter size, ewe age nor mass of ewe affected diet composition of lambs, and there was no effect of age, body mass or litter size on diet composition of ewes. Our study highlights that diet composition arises from a combination of preferences being predicted by lamb and ewes’ age and/or body mass differences, and the immediate environment in terms of population density and proxies for vegetation development. PMID:26731411

Canine echinococcosis: genetic diversity of Echinococcus granulosus sensu stricto (s.s.) from definitive hosts.

PubMed

Boufana, B; Lett, W; Lahmar, S; Griffiths, A; Jenkins, D J; Buishi, I; Engliez, S A; Alrefadi, M A; Eljaki, A A; Elmestiri, F M; Reyes, M M; Pointing, S; Al-Hindi, A; Torgerson, P R; Okamoto, M; Craig, P S

2015-11-01

Canids, particularly dogs, constitute the major source of cystic echinococcosis (CE) infection to humans, with the majority of cases being caused by Echinococcus granulosus (G1 genotype). Canine echinococcosis is an asymptomatic disease caused by adult tapeworms of E. granulosus sensu lato (s.l.). Information on the population structure and genetic variation of adult E. granulosus is limited. Using sequenced data of the mitochondrial cytochrome c oxidase subunit 1 (cox1) we examined the genetic diversity and population structure of adult tapeworms of E. granulosus (G1 genotype) from canid definitive hosts originating from various geographical regions and compared it to that reported for the larval metacestode stage from sheep and human hosts. Echinococcus granulosus (s.s) was identified from adult tapeworm isolates from Kenya, Libya, Tunisia, Australia, China, Kazakhstan, United Kingdom and Peru, including the first known molecular confirmation from Gaza and the Falkland Islands. Haplotype analysis showed a star-shaped network with a centrally positioned common haplotype previously described for the metacestode stage from sheep and humans, and the neutrality indices indicated population expansion. Low Fst values suggested that populations of adult E. granulosus were not genetically differentiated. Haplotype and nucleotide diversities for E. granulosus isolates from sheep and human origin were twice as high as those reported from canid hosts. This may be related to self-fertilization of E. granulosus and/or to the longevity of the parasite in the respective intermediate and definitive hosts. Improved nuclear single loci are required to investigate the discrepancies in genetic variation seen in this study.

Estimating bighorn sheep (Ovis canadensis) abundance using noninvasive sampling at a mineral lick within a National Park Wilderness Area

USGS Publications Warehouse

Schoenecker, Kathryn A.; Watry, Mary Kay; Ellison, Laura E.; Schwarz, Michael A.; Luikart, Gordon

2015-01-01

Conservation of species requires accurate population estimates. We used genetic markers from feces to determine bighorn sheep abundance for a herd that was hypothesized to be declining and in need of population status monitoring. We sampled from a small but accessible portion of the population's range where animals naturally congregate at a natural mineral lick to test whether we could accurately estimate population size by sampling from an area where animals concentrate. We used mark-recapture analysis to derive population estimates, and compared estimates from this smaller spatial sampling to estimates from sampling of the entire bighorn sheep range. We found that estimates were somewhat comparable; in 2009, the mineral lick sample and entire range sample differed by 20 individuals, and in 2010 they differed by only one individual. However, we captured 13 individuals in the entire range sample that were not captured at the mineral lick, and thus violated a model assumption that all individuals had an equal opportunity of being captured. This eliminated the possibility of inferring a total population estimate from just animals visiting the mineral lick, but because estimates were relatively similar, monitoring at the mineral lick can provide a useful index for management and conservation. We compared our results to a radio-collar study conducted in 2003–2004 and confirmed that the population remained stable since 2004. Our population estimates were 78 (CI 62–114) in 2009 and 95 (CI 77–131) in 2010. Between 7 and 11 sampling dates were needed to achieve a CV of 20% for population estimates, assuming a capture probability between 0.09 and 0.13. We relied on citizen science volunteers to maximize data collection and reduce costs; 71% of all fecal samples were collected by volunteers, compared to 29% collected by paid staff. We conclude that our technique provides a useful monitoring tool for managers. The technique could be tested and applied in similar populations where animals congregate with high fidelity at a mineral lick or other area.

A fuzzy multi-objective linear programming approach for integrated sheep farming and wildlife in land management decisions: a case study in the Patagonian rangelands

NASA Astrophysics Data System (ADS)

Metternicht, Graciela; Blanco, Paula; del Valle, Hector; Laterra, Pedro; Hardtke, Leonardo; Bouza, Pablo

2015-04-01

Wildlife is part of the Patagonian rangelands sheep farming environment, with the potential of providing extra revenue to livestock owners. As sheep farming became less profitable, farmers and ranchers could focus on sustainable wildlife harvesting. It has been argued that sustainable wildlife harvesting is ecologically one of the most rational forms of land use because of its potential to provide multiple products of high value, while reducing pressure on ecosystems. The guanaco (Lama guanicoe) is the most conspicuous wild ungulate of Patagonia. Guanaco ?bre, meat, pelts and hides are economically valuable and have the potential to be used within the present Patagonian context of production systems. Guanaco populations in South America, including Patagonia, have experienced a sustained decline. Causes for this decline are related to habitat alteration, competition for forage with sheep, and lack of reasonable management plans to develop livelihoods for ranchers. In this study we propose an approach to explicitly determinate optimal stocking rates based on trade-offs between guanaco density and livestock grazing intensity on rangelands. The focus of our research is on finding optimal sheep stocking rates at paddock level, to ensure the highest production outputs while: a) meeting requirements of sustainable conservation of guanacos over their minimum viable population; b) maximizing soil carbon sequestration, and c) minimizing soil erosion. In this way, determination of optimal stocking rate in rangelands becomes a multi-objective optimization problem that can be addressed using a Fuzzy Multi-Objective Linear Programming (MOLP) approach. Basically, this approach converts multi-objective problems into single-objective optimizations, by introducing a set of objective weights. Objectives are represented using fuzzy set theory and fuzzy memberships, enabling each objective function to adopt a value between 0 and 1. Each objective function indicates the satisfaction of the decision maker towards the respective objective. Fuzzy logic is closer to intuitive thinking used by decision makers, making it a user-friendly approach for them to select alternatives. The proposed approach was applied in a study area of approximately 40,000 hectares in semiarid Patagonian rangelands where extensive, continuous sheep grazing for wool production is the main land use. Multi- and hyper-spectral data were combined with ancillary data within a GIS environment, and used to derive maps of forage production, guanacos density, soil organic carbon and soil erosion. Different scenarios, with different objectives weights were evaluated. Results showed that under scenario 1, where livestock production is predicted to have the highest values, guanaco numbers decrease substantially as well as soil carbon sequestration, and soil erosion exhibit the highest values. On the other hand, when guanaco population is prioritized, livestock production has the lowest value. A compromise alternative resulted from a scenario where variables are assigned same weight; under this condition, high livestock production is predicted, while conservation of guanaco population is sustainable, carbon sequestration is maximized and soil erosion minimized.

Genetic Distinctiveness of the Herdwick Sheep Breed and Two Other Locally Adapted Hill Breeds of the UK

PubMed Central

Bowles, Dianna; Carson, Amanda; Isaac, Peter

2014-01-01

There is considerable interest in locally adapted breeds of livestock as reservoirs of genetic diversity that may provide important fitness traits for future use in agriculture. In marginal areas, these animals contribute to food security and extract value from land unsuitable for other systems of farming. In England, close to 50% of the national sheep flock is farmed on grassland designated as disadvantaged areas for agricultural production. Many of these areas are in the uplands, where some native breeds of sheep continue to be commercially farmed only in highly localised geographical regions to which they are adapted. This study focuses on three of these breeds, selected for their adaptation to near identical environments and their geographical concentration in regions close to one another. Our objective has been to use retrotyping, microsatellites and single nucleotide polymorphisms to explore the origins of the breeds and whether, despite their similar adaptations and proximity, they are genetically distinctive. We find the three breeds each have a surprisingly different pattern of retrovirus insertions into their genomes compared with one another and with other UK breeds. Uniquely, there is a high incidence of the R0 retrotype in the Herdwick population, characteristic of a primitive genome found previously in very few breeds worldwide and none in the UK mainland. The Herdwick and Rough Fells carry two rare retroviral insertion events, common only in Texels, suggesting sheep populations in the northern uplands have a historical association with the original pin-tail sheep of Texel Island. Microsatellite data and analyses of SNPs associated with RXFP2 (horn traits) and PRLR (reproductive performance traits) also distinguished the three breeds. Significantly, an SNP linked to TMEM154, a locus controlling susceptibility to infection by Maedi-Visna, indicated that all three native hill breeds have a lower than average risk of infection to the lentivirus. PMID:24489968

Identity of Fasciola spp. in sheep in Egypt.

PubMed

Amer, Said; ElKhatam, Ahmed; Zidan, Shereif; Feng, Yaoyu; Xiao, Lihua

2016-12-01

In Egypt, liver flukes, Fasciola spp. (Digenea: Fasciolidae), have a serious impact on the farming industry and public health. Both Fasciola hepatica and Fasciola gigantica are known to occur in cattle, providing the opportunity for genetic recombination. Little is known on the identity and genetic variability of Fasciola populations in sheep. This study was performed to determine the prevalence of liver flukes in sheep in Menofia Province as a representative area of the delta region in Egypt, as measured by postmortem examination of slaughtered animals at three abattoirs. The identity and genetic variability of Fasciola spp. in slaughtered animals were determined by PCR-sequence analysis of the nuclear ribosomal internal transcribed spacer 1 (ITS1) and the mitochondrial NADH dehydrogenase subunit 1 (nad1) genes. Physical inspection of the liver indicated that 302 of 2058 (14.7%) slaughtered sheep were infected with Fasciola spp. Sequence analysis of the ITS1 and nad1 genes of liver flukes from 17 animals revealed that 11 animals were infected with F. hepatica, four with F. gigantica, and two with both species. Seventy eight of 103 flukes genetically characterized from these animals were F. hepatica, 23 were F. gigantica, and two had ITS1 sequences identical to F. hepatica but nad1 sequences identical to F. gigantica. nad1 sequences of Egyptian isolates of F. gigantica showed pronounced differences from those in the GenBank database. Egyptian F. gigantica haplotypes formed haplogroup D, which clustered in a sister clade with haplogroups A, B and C circulating in Asia, indicating the existence of geographic isolation in the species. Both F. hepatica and F. gigantica are prevalent in sheep in Egypt and an introgressed form of the two occurs as the result of genetic recombination. In addition, a geographically isolated F. gigantica population is present in the country. The importance of these observations in epidemiology of fascioliasis needs to be examined in future studies.

Prevalence and seasonal changes in the population of gastrointestinal nematodes of small ruminants in the semi-arid zone of north-eastern Nigeria.

PubMed

Nwosu, C O; Madu, P P; Richards, W S

2007-03-15

A survey was carried out to determine the prevalence and seasonal abundance of the egg and adult stages of nematode parasites of sheep and goats in the semi-arid zone of north-eastern Nigeria between January and December 2002. Faecal samples collected from 102 sheep and 147 goats and examined by the modified McMaster technique using saturated solution of sodium chloride as the floating medium revealed that 44 (43.1%) and 82 (55.8%) of the samples, respectively, contained at least one nematode egg type. Three nematode egg types were recovered with strongyle egg type (22.5% in sheep and 35.4% in goats) being the most prevalent followed, respectively, by Trichuris (5.9% in sheep and 4.1% in goats) and Strongyloides (4.9% in sheep and 4.1% in goats) egg types. Mean faecal egg counts were generally moderate in both sheep (1052+/-922 strongyle, 1000+/-590 Strongyloides and 380+/-110 Trichuris eggs, respectively, per g of faeces) and goats (2092+/-3475 strongyle, 958+/-854 Strongyloides and 683+/-512 Trichuris eggs, respectively, per g of faeces) and showed the same trend irrespective of the age or sex of the animals. The prevalence and counts of strongyle nematode eggs showed a definite seasonal sequence that corresponded with the rainfall pattern in the study area during the period. In both sheep and goats, counts of strongyle egg type increased with the rains and reached peak levels at about the peak of the rainy season in September. The other egg types encountered during the study did not show much variation with the season of the year. Out of the 45 sheep and 75 goats examined at necropsy, 27 (60%) and 39 (52%), respectively, contained adult nematode species. Seven genera of adult nematodes including Strongyloides, Trichostrongylus, Haemonchus, Trichuris, Cooperia, Oesophagostomum and Bunostomum species were encountered during the study. Bunostomum species were recorded only in sheep. Adult worm burdens were generally low and showed seasonal variation that corresponded with the rainfall pattern in the study area during the period. Haemonchus and Trichostrongylus species attained peak counts together in both goats (June) and sheep (August). Strongyloides species were encountered throughout the year in both sheep and goats irrespective of the season. Other genera of nematodes encountered occurred in very low numbers and did not allow any meaningful comparison of seasonal sequence. The results suggest that Haemonchus, Trichostrongylus and Strongyloides species may be the major contributors to small ruminant helminthiasis in the study area.

Disease introduction is associated with a phase transition in bighorn sheep demographics.

PubMed

Manlove, Kezia; Cassirer, E Frances; Cross, Paul C; Plowright, Raina K; Hudson, Peter J

2016-10-01

Ecological theory suggests that pathogens are capable of regulating or limiting host population dynamics, and this relationship has been empirically established in several settings. However, although studies of childhood diseases were integral to the development of disease ecology, few studies show population limitation by a disease affecting juveniles. Here, we present empirical evidence that disease in lambs constrains population growth in bighorn sheep (Ovis canadensis) based on 45 years of population-level and 18 years of individual-level monitoring across 12 populations. While populations generally increased (λ = 1.11) prior to disease introduction, most of these same populations experienced an abrupt change in trajectory at the time of disease invasion, usually followed by stagnant-to-declining growth rates (λ = 0.98) over the next 20 years. Disease-induced juvenile mortality imposed strong constraints on population growth that were not observed prior to disease introduction, even as adult survival returned to pre-invasion levels. Simulations suggested that models including persistent disease-induced mortality in juveniles qualitatively matched observed population trajectories, whereas models that only incorporated all-age disease events did not. We use these results to argue that pathogen persistence may pose a lasting, but under-recognized, threat to host populations, particularly in cases where clinical disease manifests primarily in juveniles. © 2016 by the Ecological Society of America.

New Zealand's 70 million sheep create 350 million methane gallons daily

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

If you could hook up a sheep to the carburetor of a car, you could run it for several kilometers a day. To power the same vehicle by people, you'd need a whole football team and a couple of kegs of beer. That observation is made by David Lowe, a geophysicist with the New Zealand Institute of Nuclear Sciences in Wellington. Scientists are studying the methane output because of its potential serious threat by contributing to global warming via the greenhouse effect. According to a report in the Wall Street Journal, analysis of ancient air bubbles trapped in Antarctic icemore » shows that 30,000 years ago methane concentration in the Earth's atmosphere was only a third as much as it is today. Radioactive dating can distinguish ages of different types of methane in the air, and researchers hope to quantify sources from sheep, swamps, people or industry. Sheep methane is collected at a local agricultural university from sheep with tubes protruding from their intestines. Sample collector Lowe alternates specimens from the university and the digester tank at the sewage treatment plant. The cleanest air samples, by contrast, are collected by Lowe at Baring Head, the first outcrop of land Antarctic winds hit after crossing thousands of miles of open sea. So far, Lowe and his colleagues have found that 75% of methane in the atmosphere is biological and of very recent origin. While the research goes on, New Zealand's sheep population continue to churn out 2.5 billion gallons of methane every week.« less

QTL and association analysis for skin and fibre pigmentation in sheep provides evidence of a major causative mutation and epistatic effects.

PubMed

Raadsma, H W; Jonas, E; Fleet, M R; Fullard, K; Gongora, J; Cavanagh, C R; Tammen, I; Thomson, P C

2013-08-01

The pursuits of white features and white fleeces free of pigmented fibre have been important selection objectives for many sheep breeds. The cause and inheritance of non-white colour patterns in sheep has been studied since the early 19th century. Discovery of genetic causes, especially those which predispose pigmentation in white sheep, may lead to more accurate selection tools for improved apparel wool. This article describes an extended QTL study for 13 skin and fibre pigmentation traits in sheep. A total of 19 highly significant, 10 significant and seven suggestive QTL were identified in a QTL mapping experiment using an Awassi × Merino × Merino backcross sheep population. All QTL on chromosome 2 exceeded a LOD score of greater than 4 (range 4.4-30.1), giving very strong support for a major gene for pigmentation on this chromosome. Evidence of epistatic interactions was found for QTL for four traits on chromosomes 2 and 19. The ovine TYRP1 gene on OAR 2 was sequenced as a strong positional candidate gene. A highly significant association (P < 0.01) of grandparental haplotypes across nine segregating SNP/microsatellite markers including one non-synonymous SNP with pigmentation traits could be shown. Up to 47% of the observed variation in pigmentation was accounted for by models using TYRP1 haplotypes and 83% for models with interactions between two QTL probabilities, offering scope for marker-assisted selection for these traits. © 2013 The Authors, Animal Genetics © 2013 Stichting International Foundation for Animal Genetics.

Geographic distribution of the muscle-dwelling nematode Parelaphostrongylus odocoilei in North America, using molecular identification of first-stage larvae.

PubMed

Jenkins, Emily J; Appleyard, Greg D; Hoberg, Eric P; Rosenthal, Benjamin M; Kutz, Susan J; Veitch, Alasdair M; Schwantje, Helen M; Elkin, Brett T; Polley, Lydden

2005-06-01

Molecular identification of dorsal-spined larvae (DSL) from fecal samples indicates that the protostrongylid parasite Parelaphostrongylus odocoilei occupies a broader geographic range in western North America than has been previously reported. We analyzed 2,124 fecal samples at 29 locations from thinhorn sheep (Ovis dalli dalli and O. d. stonei), bighorn sheep (Ovis canadensis canadensis and O. c. californiana), mountain goats (Oreamnos americanus), woodland caribou (Rangifer tarandus caribou), mule deer (Odocoileus hemionus hemionus), and black-tailed deer (O. h. columbianus). The DSL were recovered from populations of thinhorn sheep south, but not north, of the Arctic Circle, and they were not recovered from any of the bighorn sheep populations that we examined. In total, DSL were recovered from 20 locations in the United States and Canada (Alaska, Yukon Territory, Northwest Territories, British Columbia, Alberta, and California). The DSL were identified as P. odocoilei by comparing sequences of the second internal transcribed spacer (ITS2) region of ribosomal RNA among 9 protostrongylid species validated by adult comparative morphology. The ITS2 sequences were markedly different between Parelaphostrongylus and other protostrongylid genera. Smaller fixed differences served as diagnostic markers for the 3 species of Parelaphostrongylus. The ITS2 sequences (n = 60) of P. odocoilei were strongly conserved across its broad geographic range from California to Alaska. Polymorphism at 5 nucleotide positions was consistent with multiple copies of the ITS2 within individual specimens of P. odocoilei. This work combines extensive fecal surveys, comparative morphology, and molecular diagnostic techniques to describe comprehensively the host associations and geographic distribution of a parasitic helminth.

Adaptations to Climate-Mediated Selective Pressures in Sheep

PubMed Central

Lv, Feng-Hua; Agha, Saif; Kantanen, Juha; Colli, Licia; Stucki, Sylvie; Kijas, James W.; Joost, Stéphane; Li, Meng-Hua; Ajmone Marsan, Paolo

2014-01-01

Following domestication, sheep (Ovis aries) have become essential farmed animals across the world through adaptation to a diverse range of environments and varied production systems. Climate-mediated selective pressure has shaped phenotypic variation and has left genetic “footprints” in the genome of breeds raised in different agroecological zones. Unlike numerous studies that have searched for evidence of selection using only population genetics data, here, we conducted an integrated coanalysis of environmental data with single nucleotide polymorphism (SNP) variation. By examining 49,034 SNPs from 32 old, autochthonous sheep breeds that are adapted to a spectrum of different regional climates, we identified 230 SNPs with evidence for selection that is likely due to climate-mediated pressure. Among them, 189 (82%) showed significant correlation (P ≤ 0.05) between allele frequency and climatic variables in a larger set of native populations from a worldwide range of geographic areas and climates. Gene ontology analysis of genes colocated with significant SNPs identified 17 candidates related to GTPase regulator and peptide receptor activities in the biological processes of energy metabolism and endocrine and autoimmune regulation. We also observed high linkage disequilibrium and significant extended haplotype homozygosity for the core haplotype TBC1D12-CH1 of TBC1D12. The global frequency distribution of the core haplotype and allele OAR22_18929579-A showed an apparent geographic pattern and significant (P ≤ 0.05) correlations with climatic variation. Our results imply that adaptations to local climates have shaped the spatial distribution of some variants that are candidates to underpin adaptive variation in sheep. PMID:25249477

Potential benefits of genomic selection on genetic gain of small ruminant breeding programs.

PubMed

Shumbusho, F; Raoul, J; Astruc, J M; Palhiere, I; Elsen, J M

2013-08-01

In conventional small ruminant breeding programs, only pedigree and phenotype records are used to make selection decisions but prospects of including genomic information are now under consideration. The objective of this study was to assess the potential benefits of genomic selection on the genetic gain in French sheep and goat breeding designs of today. Traditional and genomic scenarios were modeled with deterministic methods for 3 breeding programs. The models included decisional variables related to male selection candidates, progeny testing capacity, and economic weights that were optimized to maximize annual genetic gain (AGG) of i) a meat sheep breeding program that improved a meat trait of heritability (h(2)) = 0.30 and a maternal trait of h(2) = 0.09 and ii) dairy sheep and goat breeding programs that improved a milk trait of h(2) = 0.30. Values of ±0.20 of genetic correlation between meat and maternal traits were considered to study their effects on AGG. The Bulmer effect was accounted for and the results presented here are the averages of AGG after 10 generations of selection. Results showed that current traditional breeding programs provide an AGG of 0.095 genetic standard deviation (σa) for meat and 0.061 σa for maternal trait in meat breed and 0.147 σa and 0.120 σa in sheep and goat dairy breeds, respectively. By optimizing decisional variables, the AGG with traditional selection methods increased to 0.139 σa for meat and 0.096 σa for maternal traits in meat breeding programs and to 0.174 σa and 0.183 σa in dairy sheep and goat breeding programs, respectively. With a medium-sized reference population (nref) of 2,000 individuals, the best genomic scenarios gave an AGG that was 17.9% greater than with traditional selection methods with optimized values of decisional variables for combined meat and maternal traits in meat sheep, 51.7% in dairy sheep, and 26.2% in dairy goats. The superiority of genomic schemes increased with the size of the reference population and genomic selection gave the best results when nref > 1,000 individuals for dairy breeds and nref > 2,000 individuals for meat breed. Genetic correlation between meat and maternal traits had a large impact on the genetic gain of both traits. Changes in AGG due to correlation were greatest for low heritable maternal traits. As a general rule, AGG was increased both by optimizing selection designs and including genomic information.

Genome-Wide Specific Selection in Three Domestic Sheep Breeds.

PubMed

Wang, Huihua; Zhang, Li; Cao, Jiaxve; Wu, Mingming; Ma, Xiaomeng; Liu, Zhen; Liu, Ruizao; Zhao, Fuping; Wei, Caihong; Du, Lixin

2015-01-01

Commercial sheep raised for mutton grow faster than traditional Chinese sheep breeds. Here, we aimed to evaluate genetic selection among three different types of sheep breed: two well-known commercial mutton breeds and one indigenous Chinese breed. We first combined locus-specific branch lengths and di statistical methods to detect candidate regions targeted by selection in the three different populations. The results showed that the genetic distances reached at least medium divergence for each pairwise combination. We found these two methods were highly correlated, and identified many growth-related candidate genes undergoing artificial selection. For production traits, APOBR and FTO are associated with body mass index. For meat traits, ALDOA, STK32B and FAM190A are related to marbling. For reproduction traits, CCNB2 and SLC8A3 affect oocyte development. We also found two well-known genes, GHR (which affects meat production and quality) and EDAR (associated with hair thickness) were associated with German mutton merino sheep. Furthermore, four genes (POL, RPL7, MSL1 and SHISA9) were associated with pre-weaning gain in our previous genome-wide association study. Our results indicated that combine locus-specific branch lengths and di statistical approaches can reduce the searching ranges for specific selection. And we got many credible candidate genes which not only confirm the results of previous reports, but also provide a suite of novel candidate genes in defined breeds to guide hybridization breeding.

Convergent genomic signatures of domestication in sheep and goats.

PubMed

Alberto, Florian J; Boyer, Frédéric; Orozco-terWengel, Pablo; Streeter, Ian; Servin, Bertrand; de Villemereuil, Pierre; Benjelloun, Badr; Librado, Pablo; Biscarini, Filippo; Colli, Licia; Barbato, Mario; Zamani, Wahid; Alberti, Adriana; Engelen, Stefan; Stella, Alessandra; Joost, Stéphane; Ajmone-Marsan, Paolo; Negrini, Riccardo; Orlando, Ludovic; Rezaei, Hamid Reza; Naderi, Saeid; Clarke, Laura; Flicek, Paul; Wincker, Patrick; Coissac, Eric; Kijas, James; Tosser-Klopp, Gwenola; Chikhi, Abdelkader; Bruford, Michael W; Taberlet, Pierre; Pompanon, François

2018-03-06

The evolutionary basis of domestication has been a longstanding question and its genetic architecture is becoming more tractable as more domestic species become genome-enabled. Before becoming established worldwide, sheep and goats were domesticated in the fertile crescent 10,500 years before present (YBP) where their wild relatives remain. Here we sequence the genomes of wild Asiatic mouflon and Bezoar ibex in the sheep and goat domestication center and compare their genomes with that of domestics from local, traditional, and improved breeds. Among the genomic regions carrying selective sweeps differentiating domestic breeds from wild populations, which are associated among others to genes involved in nervous system, immunity and productivity traits, 20 are common to Capra and Ovis. The patterns of selection vary between species, suggesting that while common targets of selection related to domestication and improvement exist, different solutions have arisen to achieve similar phenotypic end-points within these closely related livestock species.

Ural-Tweed Bighorn Sheep Wildlife Mitigation Project, 1986 Annual Report.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yde, Chris A.; Summerfield, Bob; Young, Lewis

This report summarizes the results of the project activities from September 1, 1984 to December 31, 1986. To date, habitat treatments have been initiated on eight areas. The treatments include selective slash and burn, prescribed fire and fertilization. Inclement weather precluded the completion of the prescribed burns scheduled during fall 1985 and fall 1986. The lower Stonehill prescribed fire was rescheduled from fall 1985 to spring 1986 with the burn accomplished, producing varied results. Extensive pretreatment vegetative information has been collected from all units scheduled for habitat manipulations. Additionally, future projects have been delineated for other areas frequented by bighornmore » sheep. Ten adult bighorn sheep (5 ewes and 5 rams) have been fitted with radio transmitters. Systematic aerial and ground surveys were utilized to monitor the movements and seasonal habitat preferences of the instrumented sheep. Age and sex information was gathered whenever possible to aid in the development of a population model, Monthly pallet group collections were initiated in May 1985 to provide samples for 2.6 diaminopimetic acid (DAPA), food habits and lungworm larvae analysis. The majority of the data analysis is ongoing and will be presented in later reports.« less

Genome-Wide Identification of the Mutation Underlying Fleece Variation and Discriminating Ancestral Hairy Species from Modern Woolly Sheep

PubMed Central

Cano, Margarita; Drouilhet, Laurence; Plisson-Petit, Florence; Bardou, Philippe; Fabre, Stéphane; Servin, Bertrand; Sarry, Julien; Woloszyn, Florent; Mulsant, Philippe; Foulquier, Didier; Carrière, Fabien; Aletru, Mathias; Rodde, Nathalie; Cauet, Stéphane; Bouchez, Olivier; Pirson, Maarten; Tosser-Klopp, Gwenola; Allain, Daniel

2017-01-01

Abstract The composition and structure of fleece variation observed in mammals is a consequence of a strong selective pressure for fiber production after domestication. In sheep, fleece variation discriminates ancestral species carrying a long and hairy fleece from modern domestic sheep (Ovis aries) owning a short and woolly fleece. Here, we report that the “woolly” allele results from the insertion of an antisense EIF2S2 retrogene (called asEIF2S2) into the 3′ UTR of the IRF2BP2 gene leading to an abnormal IRF2BP2 transcript. We provide evidence that this chimeric IRF2BP2/asEIF2S2 messenger 1) targets the genuine sense EIF2S2 RNA and 2) creates a long endogenous double-stranded RNA which alters the expression of both EIF2S2 and IRF2BP2 mRNA. This represents a unique example of a phenotype arising via a RNA-RNA hybrid, itself generated through a retroposition mechanism. Our results bring new insights on the sheep population history thanks to the identification of the molecular origin of an evolutionary phenotypic variation. PMID:28379502

Genomic diversity and population structure of three autochthonous Greek sheep breeds assessed with genome-wide DNA arrays.

PubMed

Michailidou, S; Tsangaris, G; Fthenakis, G C; Tzora, A; Skoufos, I; Karkabounas, S C; Banos, G; Argiriou, A; Arsenos, G

2018-06-01

In the present study, genome-wide genotyping was applied to characterize the genetic diversity and population structure of three autochthonous Greek breeds: Boutsko, Karagouniko and Chios. Dairy sheep are among the most significant livestock species in Greece numbering approximately 9 million animals which are characterized by large phenotypic variation and reared under various farming systems. A total of 96 animals were genotyped with the Illumina's OvineSNP50K microarray beadchip, to study the population structure of the breeds and develop a specialized panel of single-nucleotide polymorphisms (SNPs), which could distinguish one breed from the others. Quality control on the dataset resulted in 46,125 SNPs, which were used to evaluate the genetic structure of the breeds. Population structure was assessed through principal component analysis (PCA) and admixture analysis, whereas inbreeding was estimated based on runs of homozygosity (ROHs) coefficients, genomic relationship matrix inbreeding coefficients (F GRM ) and patterns of linkage disequilibrium (LD). Associations between SNPs and breeds were analyzed with different inheritance models, to identify SNPs that distinguish among the breeds. Results showed high levels of genetic heterogeneity in the three breeds. Genetic distances among breeds were modest, despite their different ancestries. Chios and Karagouniko breeds were more genetically related to each other compared to Boutsko. Analysis revealed 3802 candidate SNPs that can be used to identify two-breed crosses and purebred animals. The present study provides, for the first time, data on the genetic background of three Greek indigenous dairy sheep breeds as well as a specialized marker panel that can be applied for traceability purposes as well as targeted genetic improvement schemes and conservation programs.

Real-time PCR assays for monitoring anaerobic fungal biomass and population size in the rumen.

PubMed

Lwin, Khin Ohnmar; Hayakawa, Mika; Ban-Tokuda, Tomomi; Matsui, Hiroki

2011-04-01

The relationship between copy numbers of internal transcribed spacer 1 (ITS1) and biomass or zoospore count of anaerobic fungi was studied to develop a quantitative real-time PCR-based monitoring method for fungal biomass or population in the rumen. Nine fungal strains were used to determine the relationship between ITS1 copy number and fungal biomass. Rumen fluid from three sheep and a cow were used to determine the relationship between ITS1 copy number and fungal population. ITS1 copy number was determined by real-time PCR with a specific primer set for anaerobic fungi. Freeze-dried fungal cells were weighed for fungal biomass. Zoospore counts were determined by the roll-tube method. A positive correlation was observed between both ITS1 copy number and dry weight and ITS1 copy number and zoospore counts, suggesting that the use of ITS1 copy numbers is effective for estimating fungal biomass and population density. On the basis of ITS1 copy numbers, fluctuations in the fungal population in sheep rumen showed that although the values varied among individual animals, the fungal population tended to decrease after feeding. In the present study, a culture-independent method was established that will provide a powerful tool for understanding the ecology of anaerobic fungi in the rumen.

Animal responses to herbage allowance: Forage intake and body weight gain of sheep grazing the Inner Mongolian steppe - Results of a six-year study.

PubMed

Dickhoefer, U; Bösing, B M; Hasler, M; Hao, J; Lin, L; Müller, K; Wang, C; Glindemann, T; Tas, B; Gierus, M; Taube, F; Susenbeth, A

2016-05-01

An increasing human population and the growing demand for food of animal origin are leading to an intensification of sheep production and widespread overgrazing of the grassland steppe in Inner Mongolia. The aim of this study was to analyze the effect of herbage allowance (HA) on OM intake (OMI) and BW gain (BWG) of grazing sheep. In July to September 2005 to 2010, a grazing experiment was conducted in the Xilin River Basin using 15-mo-old female Mongolian fat-tailed sheep (31.5 kg BW [SE 0.2]). Six HA classes were tested on 4 experimental plots per HA class that were alternately used for grazing and haymaking each year (i.e., = 2 grazed plots per HA class and year). Mean HA ranged from 15.4 (SD 4.0) to 1.5 kg (SD 0.8) herbage DM/kg BW in HA class 1 to 6, respectively. In 6 sheep per plot (4 sheep in 2009 and 2010), OMI and BWG were determined. Titanium dioxide was used to determine fecal excretion, and digestibility of ingested OM was estimated from CP concentration in feces. Fecal grab samples were collected during 5 d each in July, August, and September. The animals were weighed monthly. Daily OMI of sheep ranged between 68 and 89 g/kg BW and was not affected by HA class ( = 0.373), so that total OMI per hectare was exponentially decreased with increasing HA (root mean square error [RMSE] ≤ 0.31 g/d; ≤ 0.003 for the slope estimates). The BWG of individual sheep increased with increasing HA in 2 of the 6 yr (RMSE 18.4 g/d; ≤ 0.175 for the positive slope estimates). Nevertheless, BWG per hectare strongly decreased with increasing HA (RMSE 0.25 g/d; ≤ 0.006 for the slope estimates). These data support the common practice of farmers to manage the grassland at low HA to allow for greater animal performance per unit of land area.

Evaluation of the spatial and temporal distribution of and risk factors for Bluetongue serotype 1 epidemics in sheep Extremadura (Spain), 2007-2011.

PubMed

Pascual-Linaza, Ana V; Martínez-López, Beatriz; Pfeiffer, Dirk U; Moreno, José Carlos; Sanz, Cristina; Sánchez-Vizcaíno, José Manuel

2014-10-01

Extremadura has been one of the regions in Spain most severely affected by Bluetongue (BT) epidemics. The first incursion of BTV, which was successfully eradicated one year later, occurred in 2004, involving the BTV-serotype 4. However, a second incursion occurred in September 2007, this time involving serotype 1. Since then, the implementation of intensive vaccination programs have significantly reduced BTV-1 occurrence, but the disease has not been completely eradicated yet. This study aimed to provide, for the first time, a complete description of the spatial and temporal patterns of BTV-1 occurrence in sheep in Extremadura from 2007 to 2011 and to identify the risk factors that contributed to the seasonal occurrence of BTV-1 in this region. The results showed that risk factors contributing to BTV-1 occurrence in sheep changed between 2007 and 2011. Initially, when the population was still immunologically naïve, the main risk factors for BTV-1 occurrence were extensive management practices, large sheep farms and Culicoides abundance on farms. However, after the implementation of vaccination, other factors became more relevant for BTV-1 occurrence, mostly related to BTV reservoirs, such as the proximity of cattle farms or the introduction of cattle into farms. The Talaverana sheep breed also seemed to be associated with a significantly higher risk of BTV-1 occurrence, although it may be due to confounding factors, such as the geographical concentration of where this breed is kept and/or management practises used for this breed. The results of this study suggest that preventive and control strategies, including vaccination and active surveillance strategies, should be primarily focused on cattle farms kept in close vicinity to sheep flocks as well as in high-risk sheep farms (i.e. farms with a large farm size keeping both cattle and sheep and with a high number of animal introductions). Methods and results presented here may be used to guide decisions for the annual update of the control and eradication program in Spain. Crown Copyright © 2014. Published by Elsevier B.V. All rights reserved.

Wildlife habitats in managed rangelands—The Great Basin of southeastern Oregon.

Treesearch

W. Van Dyke; A. Sands; J. Yoakum; A. Polenz; J. Blaisdell

1983-01-01

Bighorn sheep were once abundant throughout Western North America. Since 1900, however, they have declined in most areas and many populations have been eliminated. Population declines have been attributed to hunting, to parasites and disease, and to competition with domestic livestock for forage, and with humans for space. Wildlife agencies in the western regions of...

Fasciola hepatica from naturally infected sheep and cattle in Great Britain are diploid.

PubMed

Beesley, N J; Cwiklinski, K; Williams, D J L; Hodgkinson, J

2015-08-01

Diploid (2n = 2x = 20) and triploid (2n = 3x = 30) Fasciola hepatica have been reported in the UK, and in Asia diploid, triploid and mixoploid (2x/3x) Fasciola spp. exist but there is little information to indicate how common triploidy is, particularly in UK fluke. Here the ploidy of 565 adult F. hepatica from 66 naturally infected British sheep and 150 adult F. hepatica from 35 naturally infected British cattle was determined. All 715 of these parasites were diploid, based on observation of 10 bivalent chromosomes and sperm (n = 335) or, since triploids are aspermic, sperm alone (n = 380). This constitutes the first extensive analysis of the ploidy of F. hepatica field isolates from Great Britain and shows that most F. hepatica isolated from cattle and sheep are diploid and have the capacity to sexually reproduce. These data suggest that triploidy, and by extension parthenogenesis, is rare or non-existent in wild British F. hepatica populations. Given that F. hepatica is the only species of Fasciola present in Britain our results indicate that the parasite is predominantly diploid in areas where F. hepatica exists in isolation and suggests that triploidy may only originate in natural populations where co-infection of F. hepatica and its sister species Fasciola gigantica commonly occurs.

A mixed methods study of ruminant brucellosis in central-eastern Tunisia.

PubMed

Barkallah, Mohamed; Gharbi, Yaakoub; Zormati, Sonia; Karkouch, Nesrine; Mallek, Zouhir; Gautier, Michel; Gdoura, Radhouane; Fendri, Imen

2017-01-01

In this study, we conducted an investigation to determine the true prevalence of bovine and ovine brucellosis in central-eastern Tunisia. A total of 1134 veterinary samples taken from 130 ruminant herds were screened for brucellosis using IS711-based real-time PCR assay. Sera collected from the ruminants were tested using the Rose Bengal test and indirect enzyme-linked immunosorbent assay. Based on serological and molecular results, the true adjusted animal population level prevalence was 23.5 % in cattle, against 13.5 % in sheep. In addition, the true adjusted herd level prevalence of brucellosis was 55.6 % in cattle and 21.8 % in sheep. A statistically significant association was found between vaginal and milk shedding for ruminants. In addition, our results showed that Brucella abortus could be responsible for bovine and ovine brucellosis. Multivariable logistic regression analysis at the animal population level indicated that age and origin variables were important risk factors for cattle. However, age and abortion variables were found to be associated with ovine brucellosis. At the herd level, risk factors for Brucella positivity were as follows: abortion and herd composition for cattle against herd composition, mortality rates, and hygiene for sheep. Animal hygiene, food quality, and sanitary practices on the farm should be applied as strategies to control brucellosis in herds.

Impact of strong selection for the PrP major gene on genetic variability of four French sheep breeds (Open Access publication)

PubMed Central

Palhiere, Isabelle; Brochard, Mickaël; Moazami-Goudarzi, Katayoun; Laloë, Denis; Amigues, Yves; Bed'hom, Bertrand; Neuts, Étienne; Leymarie, Cyril; Pantano, Thais; Cribiu, Edmond Paul; Bibé, Bernard; Verrier, Étienne

2008-01-01

Effective selection on the PrP gene has been implemented since October 2001 in all French sheep breeds. After four years, the ARR "resistant" allele frequency increased by about 35% in young males. The aim of this study was to evaluate the impact of this strong selection on genetic variability. It is focussed on four French sheep breeds and based on the comparison of two groups of 94 animals within each breed: the first group of animals was born before the selection began, and the second, 3–4 years later. Genetic variability was assessed using genealogical and molecular data (29 microsatellite markers). The expected loss of genetic variability on the PrP gene was confirmed. Moreover, among the five markers located in the PrP region, only the three closest ones were affected. The evolution of the number of alleles, heterozygote deficiency within population, expected heterozygosity and the Reynolds distances agreed with the criteria from pedigree and pointed out that neutral genetic variability was not much affected. This trend depended on breed, i.e. on their initial states (population size, PrP frequencies) and on the selection strategies for improving scrapie resistance while carrying out selection for production traits. PMID:18990357

Evaluation of a commercial ELISA kit for detection of antibodies against Toxoplasma gondii in serum, plasma and meat juice from experimentally and naturally infected sheep

PubMed Central

2013-01-01

Background Toxoplasmosis is one of the most common food borne zoonoses worldwide, and can be a serious life-threatening disease in the congenitally infected fetus and in immunosupressed patients. Among food animals, sheep along with goats and pigs possess the highest incidence of T. gondii cysts in meat, and play a major role as a source of human infection. Methods In this study, a new commercial ELISA kit (PrioCHECK® Toxoplasma Ab SR, Prionics Schlieren-Zurich, Switzerland) for the detection of anti-T. gondii antibodies in serum, plasma and meat juice of sheep, was evaluated by comparing it with the indirect fluorescent antibody test (IFAT), indirect haemagglutination test (IHA) and real-time PCR, on samples from experimentally inoculated and naturally exposed sheep. Results The commercial ELISA detected the infection status in 50% and 100% of sheep orally inoculated with 10,000 T. gondii oocysts (n = 6), from two or three weeks post infection (wpi), respectively, both on serum and plasma samples. Meat juice from all experimentally inoculated sheep collected at slaughter (12 wpi) showed positive ELISA values. In naturally exposed sheep (n = 396), the ELISA showed a very good agreement with IFAT (kappa = 0.91-1.0) and IHA (kappa = 0.96-1.0) performed on serum; and a positive correlation was observed between ELISA values and IFAT titers. By a Receiver Operating Characteristics (ROC) curve analysis, the commercial ELISA had relative sensitivities between 93.33% and 100%, and relative specificities between 96.87% and 100% respect to IFAT and IHA, depending on the considered cut-off value and animal groups tested. Furthermore, the ELISA correctly recognized all animals reacting positive in real-time PCR. The ELISA results on meat juice agreed with those on serum samples in all experimentally inoculated animals, and in 94 out of 96 (97.9%) naturally exposed sheep, when meat juice was tested at a 1:10 dilution. Conclusion The commercial ELISA kit evaluated in this study could represent a valuable tool to improve the surveillance and reporting system for T. gondii in sheep populations at the farm level or for diagnosis at the slaughterhouse, contributing to the control of this widespread zoonosis. PMID:23561035

A quantitative analysis of attitudes and behaviours concerning sustainable parasite control practices from Scottish sheep farmers.

PubMed

Jack, Corin; Hotchkiss, Emily; Sargison, Neil D; Toma, Luiza; Milne, Catherine; Bartley, David J

2017-04-01

Nematode control in sheep, by strategic use of anthelmintics, is threatened by the emergence of roundworms populations that are resistant to one or more of the currently available drugs. In response to growing concerns of Anthelmintic Resistance (AR) development in UK sheep flocks, the Sustainable Control of Parasites in Sheep (SCOPS) initiative was set up in 2003 in order to promote practical guidelines for producers and advisors. To facilitate the uptake of 'best practice' approaches to nematode management, a comprehensive understanding of the various factors influencing sheep farmers' adoption of the SCOPS principles is required. A telephone survey of 400 Scottish sheep farmers was conducted to elicit attitudes regarding roundworm control, AR and 'best practice' recommendations. A quantitative statistical analysis approach using structural equation modelling was chosen to test the relationships between both observed and latent variables relating to general roundworm control beliefs. A model framework was developed to test the influence of socio-psychological factors on the uptake of sustainable (SCOPS) and known unsustainable (AR selective) roundworm control practices. The analysis identified eleven factors with significant influences on the adoption of SCOPS recommended practices and AR selective practices. Two models established a good fit with the observed data with each model explaining 54% and 47% of the variance in SCOPS and AR selective behaviours, respectively. The key influences toward the adoption of best practice parasite management, as well as demonstrating negative influences on employing AR selective practices were farmer's base line understanding about roundworm control and confirmation about lack of anthelmintic efficacy in a flock. The findings suggest that improving farmers' acceptance and uptake of diagnostic testing and improving underlying knowledge and awareness about nematode control may influence adoption of best practice behaviour. Copyright © 2017 Elsevier B.V. All rights reserved.

A genome-wide scan study identifies a single nucleotide substitution in ASIP associated with white versus non-white coat-colour variation in sheep (Ovis aries)

PubMed Central

Li, M-H; Tiirikka, T; Kantanen, J

2014-01-01

In sheep, coat colour (and pattern) is one of the important traits of great biological, economic and social importance. However, the genetics of sheep coat colour has not yet been fully clarified. We conducted a genome-wide association study of sheep coat colours by genotyping 47 303 single-nucleotide polymorphisms (SNPs) in the Finnsheep population in Finland. We identified 35 SNPs associated with all the coat colours studied, which cover genomic regions encompassing three known pigmentation genes (TYRP1, ASIP and MITF) in sheep. Eighteen of these associations were confirmed in further tests between white versus non-white individuals, but none of the 35 associations were significant in the analysis of only non-white colours. Across the tests, the s66432.1 in ASIP showed significant association (P=4.2 × 10−11 for all the colours; P=2.3 × 10−11 for white versus non-white colours) with the variation in coat colours and strong linkage disequilibrium with other significant variants surrounding the ASIP gene. The signals detected around the ASIP gene were explained by differences in white versus non-white alleles. Further, a genome scan for selection for white coat pigmentation identified a strong and striking selection signal spanning ASIP. Our study identified the main candidate gene for the coat colour variation between white and non-white as ASIP, an autosomal gene that has been directly implicated in the pathway regulating melanogenesis. Together with ASIP, the two other newly identified genes (TYRP1 and MITF) in the Finnsheep, bordering associated SNPs, represent a new resource for enriching sheep coat-colour genetics and breeding. PMID:24022497

Relationships between in vivo microdamage and the remarkable regional material and strain heterogeneity of cortical bone of adult deer, elk, sheep and horse calcanei

PubMed Central

Skedros, John G; Sybrowsky, Christian L; Anderson, Wm Erick; Chow, Frank

2011-01-01

Natural loading of the calcanei of deer, elk, sheep and horses produces marked regional differences in prevalent/predominant strain modes: compression in the dorsal cortex, shear in medial–lateral cortices, and tension/shear in the plantar cortex. This consistent non-uniform strain distribution is useful for investigating mechanisms that mediate the development of the remarkable regional material variations of these bones (e.g. collagen orientation, mineralization, remodeling rates and secondary osteon morphotypes, size and population density). Regional differences in strain-mode-specific microdamage prevalence and/or morphology might evoke and sustain the remodeling that produces this material heterogeneity in accordance with local strain characteristics. Adult calcanei from 11 animals of each species (deer, elk, sheep and horses) were transversely sectioned and examined using light and confocal microscopy. With light microscopy, 20 linear microcracks were identified (deer: 10; elk: six; horse: four; sheep: none), and with confocal microscopy substantially more microdamage with typically non-linear morphology was identified (deer: 45; elk: 24; horse: 15; sheep: none). No clear regional patterns of strain-mode-specific microdamage were found in the three species with microdamage. In these species, the highest overall concentrations occurred in the plantar cortex. This might reflect increased susceptibility of microdamage in habitual tension/shear. Absence of detectable microdamage in sheep calcanei may represent the (presumably) relatively greater physical activity of deer, elk and horses. Absence of differences in microdamage prevalence/morphology between dorsal, medial and lateral cortices of these bones, and the general absence of spatial patterns of strain-mode-specific microdamage, might reflect the prior emergence of non-uniform osteon-mediated adaptations that reduce deleterious concentrations of microdamage by the adult stage of bone development. PMID:21951210

Safety and Immunogenicity of a Mycoplasma ovipneumoniae bacterin for domestic sheep (Ovis aries).

PubMed

Ziegler, Jessie C; Lahmers, Kevin K; Barrington, George M; Parish, Steven M; Kilzer, Katherine; Baker, Katherine; Besser, Thomas E

2014-01-01

Mortality from epizootic pneumonia is hindering re-establishment of bighorn sheep populations in western North America. Mycoplasma ovipneumoniae, a primary agent of this disease, is frequently carried asymptomatically by the domestic sheep and goats that constitute the reservoir of this agent for transmission to bighorn sheep. Our long-term objective is to reduce the risk of M. ovipneumoniae infection of bighorn sheep; one approach to this objective is to control the pathogen in its reservoir hosts. The safety and immunogenicity of M. ovipneumoniae for domestic sheep was evaluated in three experimental immunization protocols: 1) live M. ovipneumoniae (50 ug protein); 2) killed M. ovipneumoniae (50 ug whole cell protein) in oil adjuvant; and 3) killed M. ovipneumoniae (250 ug whole cell protein) in oil adjuvant. Immunogenicity was assessed by two serum antibody measures: competitive enzyme-linked immunosorbent assay (cELISA) (experiments 1-3) and serum growth inhibition (Experiment 3). Passive immunogenicity was also assessed in the third experiment using the same assays applied to blood samples obtained from the lambs of immunized ewes. Adverse reactions to immunization were generally minor, but local reactions were regularly observed at immunization sites with bacterins in oil adjuvants. No evidence of M. ovipneumoniae specific antibody responses were observed in the first or second experiments and no resistance to colonization was observed in the first experiment. However, the ewes in the third experiment developed strong cELISA serum antibody responses and significant serum M. ovipneumoniae inhibition activity, and these responses were passively transferred to their lambs. The results of these trials indicate that immunization with relatively large antigenic mass combined with an adjuvant is capable of inducing strong active antibody responses in ewes and passively immunizing lambs.

Safety and Immunogenicity of a Mycoplasma ovipneumoniae Bacterin for Domestic Sheep (Ovis aries)

PubMed Central

Ziegler, Jessie C.; Lahmers, Kevin K.; Barrington, George M.; Parish, Steven M.; Kilzer, Katherine; Baker, Katherine; Besser, Thomas E.

2014-01-01

Background Mortality from epizootic pneumonia is hindering re-establishment of bighorn sheep populations in western North America. Mycoplasma ovipneumoniae, a primary agent of this disease, is frequently carried asymptomatically by the domestic sheep and goats that constitute the reservoir of this agent for transmission to bighorn sheep. Our long-term objective is to reduce the risk of M. ovipneumoniae infection of bighorn sheep; one approach to this objective is to control the pathogen in its reservoir hosts. Methods The safety and immunogenicity of M. ovipneumoniae for domestic sheep was evaluated in three experimental immunization protocols: 1) live M. ovipneumoniae (50 ug protein); 2) killed M. ovipneumoniae (50 ug whole cell protein) in oil adjuvant; and 3) killed M. ovipneumoniae (250 ug whole cell protein) in oil adjuvant. Immunogenicity was assessed by two serum antibody measures: competitive enzyme-linked immunosorbent assay (cELISA) (experiments 1–3) and serum growth inhibition (Experiment 3). Passive immunogenicity was also assessed in the third experiment using the same assays applied to blood samples obtained from the lambs of immunized ewes. Results and Conclusions Adverse reactions to immunization were generally minor, but local reactions were regularly observed at immunization sites with bacterins in oil adjuvants. No evidence of M. ovipneumoniae specific antibody responses were observed in the first or second experiments and no resistance to colonization was observed in the first experiment. However, the ewes in the third experiment developed strong cELISA serum antibody responses and significant serum M. ovipneumoniae inhibition activity, and these responses were passively transferred to their lambs. The results of these trials indicate that immunization with relatively large antigenic mass combined with an adjuvant is capable of inducing strong active antibody responses in ewes and passively immunizing lambs. PMID:24752006

Wesselsbron virus antibody in domestic animals in Nigeria: retrospective and prospective studies.

PubMed

Baba, S S; Fagbami, A H; Ojeh, C K; Olaleye, O D; Omilabu, S A

1995-04-01

Retrospective and prospective serological surveys to determine the prevalence of Wesslsbron (WSL) virus infections in animal populations were carried out in different vegetational zones in Nigeria. Sera from 1,492 animals comprising 292 camels, 81 horses, 4 donkeys, 320 cattle, 235 sheep, 260 goats, 114 pigs, 101 dogs and 85 domestic fowls were assayed by haemagglutination-inhibition (HI) test for presence of antibodies to WSL virus and other flavivirus antigens: Yellow Fever (YF), Potiskum (POT), Banzi (BAN), Uganda S (UGS) and West Nile (WN) viruses. Four hundred and eighty one (32%) of the total sera tested were positive for the presence of flavivirus antibodies. The prevalence rates among animals varied with species and vegetational zones of the country. The highest prevalence was noted in animals from a swamp forest zone and was higher among camels, horses, donkeys and sheep when compared with goats, pigs and fowls in different zones. Although monotypic reactions with WSL virus antigen were observed in positive sera, the majority of the WSL virus positive sera cross-reacted with more than two other flavivirus antigens. Serological cross-reactions were most extensive in WSL virus positive horse sera. A ten month sentinel survey among 28 cattle, 68 sheep and 30 goats revealed considerable activity of WSL virus in Nigeria. Of these, 11 cattle and 12 sheep showed antibody conversion to WSL virus antigen. None of the goats seroconverted. Although, there are no records of outbreak of WSL disease in Nigeria, this study revealed that WSL virus is actively circulating among livestock populations in this environment. Flavivirus nucleotide data are needed for final determination of genetic relatedness in this group of viruses.

Impact of "Grain to Green" Programme on echinococcosis infection in Ningxia Hui Autonomous Region of China.

PubMed

Cleary, Eimear; Barnes, Tamsin S; Xu, Yangyang; Zhao, Hengbo; Clements, Archie C A; Gray, Darren J; McManus, Donald P; Atkinson, Jo-An M; Williams, Gail M; Yang, YuRong

2014-10-15

Cystic echinococcosis (CE) is endemic among the human population of Xiji County, Ningxia Hui Autonomous Region, China, where the prevalence is estimated to be between 2.2% and 3.6%. Government-run sheep abattoirs in Xiji County have closed in recent years and, as a consequence, slaughter is carried out mostly at rural market places. The market place in Xinglong Township, Xiji County, is home to an increasing number of stray dogs and the lack of government control over slaughter practices potentially favours Echinococcus granulosus transmission. A survey of sheep, goats and cattle reared in Xiji County was conducted in Xinglong Market and Xinglong Township to determine prevalence and transmission dynamics of E. granulosus infection. The liver and lungs of all livestock aged one year and older were examined macroscopically post mortem; visual examination and palpation of organs determined overall prevalence of E. granulosus. Cysts consistent in appearance with E. granulosus were observed in 2/184 sheep (prevalence 1.0%) and 1/55 of the cattle examined (prevalence 1.8%); 0/13 goats were found to be infected. However, microscopic examination of these suspected cysts failed to confirm these samples as E. granulosus, giving a prevalence of confirmed infection of zero percent in all three species. The prevalence of liver fluke was 61.3% in sheep and 12.7% in cattle with a significant difference between males and females (p ≤ 0.001). Considering the high prevalence of echinococcosis in the local human population, the absence of CE observed among commercially slaughtered livestock was surprising. Several explanations for this discrepancy and their implications are proposed. Copyright © 2014 Elsevier B.V. All rights reserved.

First insights into the genetic diversity of Echinococcus granulosus sensu stricto (s.s.) in Serbia.

PubMed

Debeljak, Zoran; Boufana, Belgees; Interisano, Maria; Vidanovic, Dejan; Kulisic, Zoran; Casulli, Adriano

2016-06-15

Cystic echinococcosis (CE) caused by Echinococcus granulosus sensu stricto (s.s.) is a cosmopolitan zoonotic infection which is endemic in Serbia where it is subject to mandatory reporting. However, information on the incidence of the disease in humans and prevalence of hydatid infection in livestock remains limited. We used sequenced data of the cytochrome c oxidase subunit 1 (cox 1) mitochondrial gene to examine the genetic diversity and population structure of E. granulosus (s.s.) from intermediate hosts from Serbia. We also compared our generated nucleotide sequences with those reported for neighbouring European countries. Echinococcus canadensis was molecularly confirmed from pig and human hydatid isolates. E. granulosus (G1) was confirmed from sheep and cattle hydatid isolates as well as the first molecular confirmation in Serbia of E. granulosus G2 in sheep and E. granulosus G3 in sheep and cattle hydatid isolates. The Serbian E. granulosus (s.s.) parsimony network displayed 2 main haplotypes (SB02 and SB05) which together with the neutrality indices were suggestive of bottleneck and/or balancing selection. Haplotype analysis showed the presence of the common E. granulosus haplotype described from other worldwide regions. Investigation of the pairwise fixation (Fst) index suggested that Serbian populations of E. granulosus (s.s.) from sheep and cattle hosts showed moderate genetic differentiation. Six of the Serbian haplotypes (SB02-SB07) were shared with haplotypes from Bulgaria, Hungary and/or Romania. Further studies using a larger number of hydatid isolates from various locations across Serbia will provide more information on the genetic structure of E. granulosus (s.s.) within this region. Copyright © 2016 Elsevier B.V. All rights reserved.

Adaptations to climate-mediated selective pressures in sheep.

PubMed

Lv, Feng-Hua; Agha, Saif; Kantanen, Juha; Colli, Licia; Stucki, Sylvie; Kijas, James W; Joost, Stéphane; Li, Meng-Hua; Ajmone Marsan, Paolo

2014-12-01

Following domestication, sheep (Ovis aries) have become essential farmed animals across the world through adaptation to a diverse range of environments and varied production systems. Climate-mediated selective pressure has shaped phenotypic variation and has left genetic "footprints" in the genome of breeds raised in different agroecological zones. Unlike numerous studies that have searched for evidence of selection using only population genetics data, here, we conducted an integrated coanalysis of environmental data with single nucleotide polymorphism (SNP) variation. By examining 49,034 SNPs from 32 old, autochthonous sheep breeds that are adapted to a spectrum of different regional climates, we identified 230 SNPs with evidence for selection that is likely due to climate-mediated pressure. Among them, 189 (82%) showed significant correlation (P ≤ 0.05) between allele frequency and climatic variables in a larger set of native populations from a worldwide range of geographic areas and climates. Gene ontology analysis of genes colocated with significant SNPs identified 17 candidates related to GTPase regulator and peptide receptor activities in the biological processes of energy metabolism and endocrine and autoimmune regulation. We also observed high linkage disequilibrium and significant extended haplotype homozygosity for the core haplotype TBC1D12-CH1 of TBC1D12. The global frequency distribution of the core haplotype and allele OAR22_18929579-A showed an apparent geographic pattern and significant (P ≤ 0.05) correlations with climatic variation. Our results imply that adaptations to local climates have shaped the spatial distribution of some variants that are candidates to underpin adaptive variation in sheep. © The Author 2014. Published by Oxford University Press on behalf of the Society for Molecular Biology and Evolution.

Methanogens: Methane Producers of the Rumen and Mitigation Strategies

PubMed Central

Hook, Sarah E.; Wright, André-Denis G.; McBride, Brian W.

2010-01-01

Methanogens are the only known microorganisms capable of methane production, making them of interest when investigating methane abatement strategies. A number of experiments have been conducted to study the methanogen population in the rumen of cattle and sheep, as well as the relationship that methanogens have with other microorganisms. The rumen methanogen species differ depending on diet and geographical location of the host, as does methanogenesis, which can be reduced by modifying dietary composition, or by supplementation of monensin, lipids, organic acids, or plant compounds within the diet. Other methane abatement strategies that have been investigated are defaunation and vaccines. These mitigation methods target the methanogen population of the rumen directly or indirectly, resulting in varying degrees of efficacy. This paper describes the methanogens identified in the rumens of cattle and sheep, as well as a number of methane mitigation strategies that have been effective in vivo. PMID:21253540

Coxiella burnetii infections in sheep or goats: an opinionated review.

PubMed

Van den Brom, R; van Engelen, E; Roest, H I J; van der Hoek, W; Vellema, P

2015-12-14

Q fever is an almost ubiquitous zoonosis caused by Coxiella burnetii, which is able to infect several animal species, as well as humans. Cattle, sheep and goats are the primary animal reservoirs. In small ruminants, infections are mostly without clinical symptoms, however, abortions and stillbirths can occur, mainly during late pregnancy. Shedding of C. burnetii occurs in feces, milk and, mostly, in placental membranes and birth fluids. During parturition of infected small ruminants, bacteria from birth products become aerosolized. Transmission to humans mainly happens through inhalation of contaminated aerosols. In the last decade, there have been several, sometimes large, human Q fever outbreaks related to sheep and goats. In this review, we describe C. burnetii infections in sheep and goats, including both advantages and disadvantages of available laboratory techniques, as pathology, different serological tests, PCR and culture to detect C. burnetii. Moreover, worldwide prevalences of C. burnetii in small ruminants are described, as well as possibilities for treatment and prevention. Prevention of shedding and subsequent environmental contamination by vaccination of sheep and goats with a phase I vaccine are possible. In addition, compulsory surveillance of C. burnetii in small ruminant farms raises awareness and hygiene measures in farms help to decrease exposure of people to the organism. Finally, this review challenges how to contain an infection of C. burnetii in small ruminants, bearing in mind possible consequences for the human population and probable interference of veterinary strategies, human risk perception and political considerations. Copyright © 2015 Elsevier B.V. All rights reserved.

Modelling the Dynamics of Post-Vaccination Immunity Rate in a Population of Sahelian Sheep after a Vaccination Campaign against Peste des Petits Ruminants Virus

PubMed Central

Lancelot, Renaud; Lesnoff, Matthieu

2016-01-01

Background Peste des petits ruminants (PPR) is an acute infectious viral disease affecting domestic small ruminants (sheep and goats) and some wild ruminant species in Africa, the Middle East and Asia. A global PPR control strategy based on mass vaccination—in regions where PPR is endemic—was recently designed and launched by international organizations. Sahelian Africa is one of the most challenging endemic regions for PPR control. Indeed, strong seasonal and annual variations in mating, mortality and offtake rates result in a complex population dynamics which might in turn alter the population post-vaccination immunity rate (PIR), and thus be important to consider for the implementation of vaccination campaigns. Methods In a context of preventive vaccination in epidemiological units without PPR virus transmission, we developed a predictive, dynamic model based on a seasonal matrix population model to simulate PIR dynamics. This model was mostly calibrated with demographic and epidemiological parameters estimated from a long-term follow-up survey of small ruminant herds. We used it to simulate the PIR dynamics following a single PPR vaccination campaign in a Sahelian sheep population, and to assess the effects of (i) changes in offtake rate related to the Tabaski (a Muslim feast following the lunar calendar), and (ii) the date of implementation of the vaccination campaigns. Results The persistence of PIR was not influenced by the Tabaski date. Decreasing the vaccination coverage from 100 to 80% had limited effects on PIR. However, lower vaccination coverage did not provide sufficient immunity rates (PIR < 70%). As a trade-off between model predictions and other considerations like animal physiological status, and suitability for livestock farmers, we would suggest to implement vaccination campaigns in September-October. This model is a first step towards better decision support for animal health authorities. It might be adapted to other species, livestock farming systems or diseases. PMID:27603710

Correlation of Propionibacterium acnes Populations with the Presence of Triglycerides on Nonhuman Skin

PubMed Central

Webster, Guy F.; Ruggieri, Michael R.; McGinley, Kenneth J.

1981-01-01

The skins of mice, rats, rabbits, sheep, guinea pigs, and dogs were cultured for Propionibacterium acnes. Only the sebaceous regions (perianal gland) of guinea pigs harbored a significant P. acnes population. Analysis of the lipid from this region revealed a significant percentage of triglycerides, compounds lacking in the sebum of the other animals. PMID:7259157

CNVcaller: highly efficient and widely applicable software for detecting copy number variations in large populations.

PubMed

Wang, Xihong; Zheng, Zhuqing; Cai, Yudong; Chen, Ting; Li, Chao; Fu, Weiwei; Jiang, Yu

2017-12-01

The increasing amount of sequencing data available for a wide variety of species can be theoretically used for detecting copy number variations (CNVs) at the population level. However, the growing sample sizes and the divergent complexity of nonhuman genomes challenge the efficiency and robustness of current human-oriented CNV detection methods. Here, we present CNVcaller, a read-depth method for discovering CNVs in population sequencing data. The computational speed of CNVcaller was 1-2 orders of magnitude faster than CNVnator and Genome STRiP for complex genomes with thousands of unmapped scaffolds. CNV detection of 232 goats required only 1.4 days on a single compute node. Additionally, the Mendelian consistency of sheep trios indicated that CNVcaller mitigated the influence of high proportions of gaps and misassembled duplications in the nonhuman reference genome assembly. Furthermore, multiple evaluations using real sheep and human data indicated that CNVcaller achieved the best accuracy and sensitivity for detecting duplications. The fast generalized detection algorithms included in CNVcaller overcome prior computational barriers for detecting CNVs in large-scale sequencing data with complex genomic structures. Therefore, CNVcaller promotes population genetic analyses of functional CNVs in more species. © The Authors 2017. Published by Oxford University Press.

CNVcaller: highly efficient and widely applicable software for detecting copy number variations in large populations

PubMed Central

Wang, Xihong; Zheng, Zhuqing; Cai, Yudong; Chen, Ting; Li, Chao; Fu, Weiwei

2017-01-01

Abstract Background The increasing amount of sequencing data available for a wide variety of species can be theoretically used for detecting copy number variations (CNVs) at the population level. However, the growing sample sizes and the divergent complexity of nonhuman genomes challenge the efficiency and robustness of current human-oriented CNV detection methods. Results Here, we present CNVcaller, a read-depth method for discovering CNVs in population sequencing data. The computational speed of CNVcaller was 1–2 orders of magnitude faster than CNVnator and Genome STRiP for complex genomes with thousands of unmapped scaffolds. CNV detection of 232 goats required only 1.4 days on a single compute node. Additionally, the Mendelian consistency of sheep trios indicated that CNVcaller mitigated the influence of high proportions of gaps and misassembled duplications in the nonhuman reference genome assembly. Furthermore, multiple evaluations using real sheep and human data indicated that CNVcaller achieved the best accuracy and sensitivity for detecting duplications. Conclusions The fast generalized detection algorithms included in CNVcaller overcome prior computational barriers for detecting CNVs in large-scale sequencing data with complex genomic structures. Therefore, CNVcaller promotes population genetic analyses of functional CNVs in more species. PMID:29220491

MOLECULAR SURVEILLANCE FOR BARTONELLA, BORRELIA, AND RICKETTSIA SPECIES IN TICKS FROM DESERT BIGHORN SHEEP ( OVIS CANADENSIS) AND MULE DEER ( ODOCOILEUS HEMIONUS) IN SOUTHERN CALIFORNIA, USA.

PubMed

Billeter, Sarah A; Osikowicz, Lynn M; Burns, Joseph E; Konde, Lora; Gonzales, Ben J; Hu, Renjie; Kosoy, Michael Y

2018-01-01

:  Ticks (Acari: Ixodidae) were collected from 44 desert bighorn sheep ( Ovis canadensis) and 10 mule deer ( Odocoileus hemionus) in southern California, US during health inspections in 2015-16. Specimens were identified and screened by PCR analysis to determine the presence and prevalence of Bartonella, Borrelia, and Rickettsia species in ticks associated with these wild ruminants. None of the 60 Dermacentor hunteri and 15 Dermacentor albipictus ticks tested yielded positive PCR results. Additional tick specimens should be collected and tested to determine the prevalence of these confirmed or suspected tickborne pathogens within ruminant populations.

Effects of a specific blend of essential oils on apparent nutrient digestion, rumen fermentation and rumen microbial populations in sheep fed a 50:50 alfalfa hay:concentrate diet

PubMed Central

Khateri, N.; Azizi, O.; Jahani-Azizabadi, H.

2017-01-01

Objective An experiment was conducted to investigate the effects of a specific mixture of essential oils (MEO), containing thyme, clove and cinnamon EO, on rumen microbial fermentation, nutrient apparent digestibility and blood metabolites in fistulated sheep. Methods Six sheep fitted with ruminal fistulas were used in a repeated measurement design with two 24-d periods to investigate the effect of adding MEO at 0 (control), 0.8, and 1.6 mL/d on apparent nutrient digestibility, rumen fermentation characteristics, rumen microbial population and blood chemical metabolites. Animals were fed with a 50:50 alfalfa hay:concentrate diet. Results Ruminal pH, total volatile fatty acids (VFA) concentration, molar proportion of individual VFA, acetate: propionate ratio and methane production were not affected with MEO. Relative to the control, Small peptides plus amino acid nitrogen and large peptides nitrogen concentration in rumen fluid were not affected with MEO supplementation; while, rumen fluid ammonia nitrogen concentration at 0 and 6 h after morning feeding in sheep fed with 1.6 mL/d of MEO was lower (p<0.05) compared to the control and 0.8 mL/d of MEO. At 0 h after morning feeding, ammonia nitrogen concentration was higher (p<0.05) in sheep fed 0.8 mL/d of MEO relative to 1.6 mL/d and control diet. Ruminal protozoa and hyper ammonia producing (HAP) bacteria counts were not affected by addition of MEO in the diet. Relative to the control, no changes were observed in the red and white blood cells, hemoglobin, hematocrit, glucose, beta-hydroxybutyric acid, cholesterol, total protein, albumin, blood urea nitrogen and aspartate aminotransferase and alanine aminotransferase concentration. Apparent total tract digestibility of dry matter, crude proten, organic matter, and neutral detergent fiber were not influenced by MEO supplementation. Conclusion The results of the present study suggested that supplementation of MEO may have limited effects on apparent nutrient digestibility, ruminal fermentation and protozoa and HAP bacteria count, blood cells and metabolites. PMID:28249376

Taxonomy and phylogeny of Trichuris globulosa Von Linstow, 1901 from camels. A review of Trichuris species parasitizing herbivorous.

PubMed

Callejón, R; Gutiérrez-Avilés, L; Halajian, A; Zurita, A; de Rojas, M; Cutillas, C

2015-08-01

At the present work, we carried out a morph-biometrical and molecular study of Trichuris species isolated from Camelus dromedarius from Iran and from Ovis aries from South Africa comparatively with other species of Trichuris from different herbivorous hosts and geographical regions. The population from camels from Iran was identified as Trichuris globulosa. Two different morphometrically populations of Trichuris sp. from sheep from South Africa were identified: Trichuris ovis and Trichuris skrjabini. Ribosomal data did not reveal significate differences in the ITS2 sequences between T. ovis and T. globulosa to assess a specific determination. The mitochondrial data suggest that T. globulosa constitute a different genetic lineage to T. ovis. Cytochrome c-oxidase and cytochrome b partial gene sequences corroborated the existence of a different genetic lineage of T. ovis from sheep of South Africa that would be closely related to the populations of T. globulosa from camels from Iran. The cytochrome c-oxidase and cytochrome b partial gene sequences of T. globulosa have been reported for the first time. Copyright © 2015 Elsevier B.V. All rights reserved.

Field efficacy and safety of an oral formulation of the novel combination anthelmintic, derquantel-abamectin, in sheep in New Zealand

PubMed Central

Little, PR; Hodge, A; Watson, TG; Seed, JA; Maeder, SJ

2011-01-01

AIM: To evaluate the efficacy and safety of the novel anthelmintic combination, derquantel-abamectin, against gastrointestinal nematode populations in sheep, under field-use conditions. METHODS: Controlled faecal egg count reduction tests (FECRT) were conducted in New Zealand in 14 trials, covering a range of geographic locations, farming enterprises, breeds, nematode populations, and anthelmintic-resistance profiles. Enrolled animals were naturally infected with mixed populations of gastrointestinal nematodes. All trials included a group treated with derquantel-abamectin, and a negative control group. Nine trials included additional groups each treated with a single- or dual-active oral reference anthelmintic, selected from albendazole, levamisole, albendazole-levamisole, ivermectin, abamectin and moxidectin. A total of 838 animals were enrolled across all trials, and were randomly allocated to treatment groups within blocks defined by faecal nematode egg counts (FEC) pre-treatment. On Day 0 derquantel-abamectin was administered orally at 1 ml/5 kg bodyweight (2 mg/kg derquantel, 0.2 mg/ kg abamectin), and each reference anthelmintic was given at the recommended label dose. Faecal samples were collected on Day 14 (± 1 day), to determine the percentage reduction in mean FEC for each anthelmintic tested. Larval differentiation was also performed post-treatment, to estimate efficacy at the genus level. Animals were weighed on or before Day 0, and on Day 14 (± 1 day) in 13 trials. RESULTS: The efficacy of derquantel-abamectin against mixed strongyle populations was ≥99.2%, based on the percentage reduction in geometric mean FEC. Nematodirus sp. was present in six trials at a level sufficient for efficacy calculations to be conducted; in all cases, the efficacy of derquantel-abamectin was 100%. In those trials where the efficacy of at least one reference anthelmintic was <95% against strongyles and/or Nematodirus sp., derquantel-abamectin was 100% effective. In five trials, the mean gain in bodyweight was significantly greater in the derquantel-abamectin group than the negative controls. CONCLUSIONS AND CLINICAL RELEVANCE: When administered orally at 1 ml/5 kg bodyweight, derquantel-abamectin is highly effective for the treatment of gastrointestinal nematodes in sheep, including populations of strongyles and Nematodirus sp. with resistance to one or more single- or dual-active anthelmintics. Derquantel-abamectin presents sheep producers with a unique opportunity to introduce a new class of anthelmintic to their nematode control programmes, with the added benefits offered by a combination anthelmintic. PMID:20514085

The host immune response to gastrointestinal nematode infection in sheep.

PubMed

McRae, K M; Stear, M J; Good, B; Keane, O M

2015-12-01

Gastrointestinal nematode infection represents a major threat to the health, welfare and productivity of sheep populations worldwide. Infected lambs have a reduced ability to absorb nutrients from the gastrointestinal tract, resulting in morbidity and occasional mortality. The current chemo-dominant approach to nematode control is considered unsustainable due to the increasing incidence of anthelmintic resistance. In addition, there is growing consumer demand for food products from animals not subjected to chemical treatment. Future mechanisms of nematode control must rely on alternative, sustainable strategies such as vaccination or selective breeding of resistant animals. Such strategies take advantage of the host's natural immune response to nematodes. The ability to resist gastrointestinal nematode infection is considered to be dependent on the development of a protective acquired immune response, although the precise immune mechanisms involved in initiating this process remain to be fully elucidated. In this study, current knowledge on the innate and acquired host immune response to gastrointestinal nematode infection in sheep and the development of immunity is reviewed. © 2015 John Wiley & Sons Ltd.

Lack of negative effects of the biological control agent Duddingtonia flagrans on soil nematodes and other nematophagous fungi.

PubMed

Saumell, C A; Fernández, A S; Echevarria, F; Gonçalves, I; Iglesias, L; Sagües, M F; Rodríguez, E M

2016-11-01

The possible environmental effects of the massive use of Duddingtonia flagrans for controlling sheep nematodes were evaluated in two regions. Non-supplemented faeces and faeces from sheep supplemented with D. flagrans were deposited three times on pasture plots and samples were collected 7 and 14 days post-deposition. Samples were cultured in agar-water (2%) with Panagrellus spp. to recover D. flagrans and other nematophagous fungi, and soil nematodes were extracted using Baermann funnels and counted. No significant differences in the populations of soil nematodes and fungi colonizing sheep faeces (P > 0.05) were observed between supplemented and non-supplemented groups, except in one sample. The topsoil in contact with the faeces was sampled 1-4 months post-deposition, revealing that, with one exception, D. flagrans did not persist in soil beyond 2 months post-deposition. Duddingtonia flagrans does not affect faecal colonization by other fungi and soil nematodes and, once deployed on pasture, does not survive for long periods in the environment.

Sheep pox in Tunisia: Current status and perspectives.

PubMed

Ben Chehida, F; Ayari-Fakhfakh, E; Caufour, P; Amdouni, J; Nasr, J; Messaoudi, L; Haj Ammar, H; Sghaier, S; Bernard, C; Ghram, A; Cêtre-Sossah, C

2018-02-01

Sheep pox, a well-known endemic capripox infection, has significant impacts on small ruminant populations in Tunisia. It is responsible for high economic losses throughout North Africa due to its enzootic nature and to the active animal transhumance existing in some governorates in Tunisia. The aim of this review was to analyse data gathered on annual vaccination campaigns designed to control its spread by reducing the level of endemicity and to describe diagnostic and management tools adapted to the Tunisian situation. Seasonal, temporal and spatial distributions of sheep pox outbreaks, as well as related clinical features, were found. It was concluded from this review that establishing strong herd immunization through individual animal immunization, creating adequate infrastructure, increasing awareness among breeders, setting up a field-based surveillance network and improving routine diagnostic methods need to be the major components of a programme to eradicate the disease. It was also felt that cost-benefit analyses of the surveillance and control strategies used would help in controlling its persistence. © 2017 Blackwell Verlag GmbH.

Temporal dynamics of linkage disequilibrium in two populations of bighorn sheep

PubMed Central

Miller, Joshua M; Poissant, Jocelyn; Malenfant, René M; Hogg, John T; Coltman, David W

2015-01-01

Linkage disequilibrium (LD) is the nonrandom association of alleles at two markers. Patterns of LD have biological implications as well as practical ones when designing association studies or conservation programs aimed at identifying the genetic basis of fitness differences within and among populations. However, the temporal dynamics of LD in wild populations has received little empirical attention. In this study, we examined the overall extent of LD, the effect of sample size on the accuracy and precision of LD estimates, and the temporal dynamics of LD in two populations of bighorn sheep (Ovis canadensis) with different demographic histories. Using over 200 microsatellite loci, we assessed two metrics of multi-allelic LD, D′, and χ′2. We found that both populations exhibited high levels of LD, although the extent was much shorter in a native population than one that was founded via translocation, experienced a prolonged bottleneck post founding, followed by recent admixture. In addition, we observed significant variation in LD in relation to the sample size used, with small sample sizes leading to depressed estimates of the extent of LD but inflated estimates of background levels of LD. In contrast, there was not much variation in LD among yearly cross-sections within either population once sample size was accounted for. Lack of pronounced interannual variability suggests that researchers may not have to worry about interannual variation when estimating LD in a population and can instead focus on obtaining the largest sample size possible. PMID:26380673

Methods to estimate effective population size using pedigree data: Examples in dog, sheep, cattle and horse

PubMed Central

2013-01-01

Background Effective population sizes of 140 populations (including 60 dog breeds, 40 sheep breeds, 20 cattle breeds and 20 horse breeds) were computed using pedigree information and six different computation methods. Simple demographical information (number of breeding males and females), variance of progeny size, or evolution of identity by descent probabilities based on coancestry or inbreeding were used as well as identity by descent rate between two successive generations or individual identity by descent rate. Results Depending on breed and method, effective population sizes ranged from 15 to 133 056, computation method and interaction between computation method and species showing a significant effect on effective population size (P < 0.0001). On average, methods based on number of breeding males and females and variance of progeny size produced larger values (4425 and 356, respectively), than those based on identity by descent probabilities (average values between 93 and 203). Since breeding practices and genetic substructure within dog breeds increased inbreeding, methods taking into account the evolution of inbreeding produced lower effective population sizes than those taking into account evolution of coancestry. The correlation level between the simplest method (number of breeding males and females, requiring no genealogical information) and the most sophisticated one ranged from 0.44 to 0.60 according to species. Conclusions When choosing a method to compute effective population size, particular attention should be paid to the species and the specific genetic structure of the population studied. PMID:23281913

Both gas chromatography and an electronic nose reflect chemical polymorphism of juniper shrubs browsed or avoided by sheep.

PubMed

Markó, Gábor; Novák, Ildikó; Bernáth, Jeno; Altbäcker, Vilmos

2011-07-01

Chemical polymorphism may contribute to variation in browsing damage by mammalian herbivores. Earlier, we demonstrated that essential oil concentration in juniper, Juniperus communis, was negatively associated with herbivore browsing. The aim of the present study was to characterize the volatile chemical composition of browsed and non-browsed J. communis. By using either gas chromatography with flame ionization detection (GC-FID) or an electronic nose device, we could separate sheep-browsed or non-browsed juniper shrubs by their essential oil pattern and complex odor matrix. The main components of the essential oil from J. communis were monoterpenes. We distinguished three chemotypes, dominated either by α-pinene, sabinene, or δ-3-carene. Shrubs belonging to the α-pinene- or sabinene-dominated groups were browsed, whereas all individuals with the δ-3-carene chemotype were unused by the local herbivores. The electronic nose also separated the browsed and non-browsed shrubs indicating that their odor matrix could guide sheep browsing. Responses of sheep could integrate the post-ingestive effects of plant secondary metabolites with sensory experience that stems from odor-phytotoxin interactions. Chemotype diversity could increase the survival rate in the present population of J. communis as certain shrubs could benefit from relatively better chemical protection against the herbivores.

Summer habitat selection by Dall’s sheep in Wrangell-St. Elias National Park and Preserve, Alaska

USGS Publications Warehouse

Roffler, Gretchen H.; Adams, Layne G.; Hebblewhite, Mark

2017-01-01

Sexual segregation occurs frequently in sexually dimorphic species, and it may be influenced by differential habitat requirements between sexes or by social or evolutionary mechanisms that maintain separation of sexes regardless of habitat selection. Understanding the degree of sex-specific habitat specialization is important for management of wildlife populations and the design of monitoring and research programs. Using mid-summer aerial survey data for Dall’s sheep (Ovis dalli dalli) in southern Alaska during 1983–2011, we assessed differences in summer habitat selection by sex and reproductive status at the landscape scale in Wrangell-St. Elias National Park and Preserve (WRST). Males and females were highly segregated socially, as were females with and without young. Resource selection function (RSF) models containing rugged terrain, intermediate values of the normalized difference vegetation index (NDVI), and open landcover types best explained resource selection by each sex, female reproductive classes, and all sheep combined. For male and all female models, most coefficients were similar, suggesting little difference in summer habitat selection between sexes at the landscape scale. A combined RSF model therefore may be used to predict the relative probability of resource selection by Dall’s sheep in WRST regardless of sex or reproductive status.

Comparison of fermentation of diets of variable composition and microbial populations in the rumen of sheep and Rusitec fermenters. I. Digestibility, fermentation parameters, and microbial growth.

PubMed

Martínez, M E; Ranilla, M J; Tejido, M L; Ramos, S; Carro, M D

2010-08-01

Four ruminally and duodenally cannulated sheep and 8 Rusitec fermenters were used to determine the effects of forage to concentrate (F:C) ratio and type of forage in the diet on ruminal fermentation and microbial protein synthesis. The purpose of the study was to assess how closely fermenters can mimic the dietary differences found in vivo. The 4 experimental diets contained F:C ratios of 70:30 or 30:70 with either alfalfa hay or grass hay as the forage. Microbial growth was determined in both systems using (15)N as a microbial marker. Rusitec fermenters detected differences between diets similar to those observed in sheep by changing F:C ratio on pH; neutral detergent fiber digestibility; total volatile fatty acid concentrations; molar proportions of acetate, propionate, butyrate, isovalerate, and caproate; and amylase activity. In contrast, Rusitec fermenters did not reproduce the dietary differences found in sheep for NH(3)-N and lactate concentrations, dry matter (DM) digestibility, proportions of isobutyrate and valerate, carboxymethylcellulase and xylanase activities, and microbial growth and its efficiency. Regarding the effect of the type of forage in the diet, Rusitec fermenters detected differences between diets similar to those found in sheep for most determined parameters, with the exception of pH, DM digestibility, butyrate proportion, and carboxymethylcellulase activity. Minimum pH and maximal volatile fatty acid concentrations were reached at 2h and at 6 to 8h postfeeding in sheep and fermenters, respectively, indicating that feed fermentation was slower in fermenters compared with that in sheep. There were differences between systems in the magnitude of most determined parameters. In general, fermenters showed lower lactate concentrations, neutral detergent fiber digestibility, acetate:propionate ratios, and enzymatic activities. On the contrary, fermenters showed greater NH(3)-N concentrations, DM digestibility, and proportions of propionate, butyrate, isovalerate, valerate, and caproate. Values of efficiency of microbial growth were greater in fermenters compared with sheep for 70:30 diets, but they were lower for 30:70 diets. Differences between fermentation in sheep and fermenters can be mainly attributed to the lack of absorption in fermenters, differences in solid retention time, and compartmentalization in the Rusitec system. In general, the Rusitec system simulated more closely the in vivo fermentation of high-forage diets compared with high-concentrate diets. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Molecular prevalence of Chlamydia and Chlamydia-like bacteria in Tunisian domestic ruminant farms and their influencing risk factors.

PubMed

Barkallah, M; Jribi, H; Ben Slima, A; Gharbi, Y; Mallek, Z; Gautier, M; Fendri, I; Gdoura, R

2018-04-01

Chlamydia and Chlamydia-like bacteria are well known to infect several organisms and may cause a wide range of diseases, particularly in ruminants. To gain insight into the prevalence and diversity of these intracellular bacteria, we applied a pan-Chlamydiales real-time PCR to 1,134 veterinary samples taken from 130 Tunisian ruminant herds. The true adjusted animal population-level prevalence was 12.9% in cattle, against 8.7% in sheep. In addition, the true adjusted herd-level prevalence of Chlamydiae was 80% in cattle and 25.5% in sheep. Chlamydiales from three family-level lineages were detected indicating a high biodiversity of Chlamydiales in ruminant herds. Our results showed that Parachlamydia acanthamoebae could be responsible for bovine and ovine chlamydiosis in central-eastern Tunisia. Multivariable logistic regression analysis at the animal population level indicated that strata and digestive disorders variables were the important risk factors of bovine and ovine chlamydiosis. However, origin and age variables were found to be associated with bovine and ovine chlamydiosis, respectively. At the herd level, risk factors for Chlamydia positivity were as follows: abortion and herd size for cattle against breeding system, cleaning frequency, quarantine, use of disinfectant and floor type for sheep. Paying attention to these risk factors will help improvement of control programs against this harmful zoonotic disease. © 2017 Blackwell Verlag GmbH.

Flock composition, breeding strategies and farmers' traits of interest evaluation of Wollo highland sheep and their F1 crosses.

PubMed

Amare, Tadesse; Goshu, Gebeyehu; Tamir, Berhan

2018-01-01

Sheep production is a major component of the livestock sector in Ethiopia. The country owing to the large population of 30.70 million estimated numbers of sheep in the country and out of which about 72.14% are females, and 27.86% are males with diverse genetic resources. The real value of indigenous breeds was often under-estimated mostly due to their poor appearance and relatively low productivity. Developing countries in most cases opt for exotic breeds to increase animal productivity through crossbreeding or breed substitution without properly investigating the production potential of the indigenous breeds. The main objective of the research was to identify sheep flock composition and structure, farmers' traits of interest and breeding objective of Wollo highland sheep, and their F 1 crossbreed progenies. Smallholder farmers' flock synthesized from breeding ewes, breeding rams, pre-weaned ewe lambs, pre-weaned ram lambs, unproductive ewes, castrated and fattened rams, with the percentage coverage of 29.2, 13.3, 15.5, 16.5, 12.4, and 12.5%, respectively. The maximum number of flock size was 289.0 sheep per flock and higher in the third stratum. The off-take rate percentage of the three strata presented as 21.9% in 1st stratum, 12% in the 2nd stratum, and 16.4% in the 3rd stratum and higher off-take rate recorded in the first stratum. Sheep producer's traits of interest ranked by growth rate (first), body size (second) and marketing value was third rank. Communal breeding (random mating), village based controlled breeding, mixed type and private ram controlled breeding practice were comprised of 39.7, 61.7, 52 and 71.3%, respectively. The percentages of ewes per flock composition were presented as 36.5, 27.1 and 25.5%, respectively in the 3rd stratum, 2nd stratum and 3rd stratum in the order of their importance's. Genetic improvement practices at smallholder sheep producers situation was showing promising outcome with indigenous Washera F 1 crossbred lambs and which designated for weaning rate, body size, marketing age, age at first lambing, good temperament and large litter size in the order of their rank. The contemporary breeding practice tendency indicated that, reduced flock size to improve flock productivity via crossbreeding practices.

Molecular epidemiology of Mycobacterium avium subsp. paratuberculosis isolated from sheep, cattle and deer on New Zealand pastoral farms.

PubMed

Verdugo, Cristobal; Pleydell, Eve; Price-Carter, Marian; Prattley, Deborah; Collins, Desmond; de Lisle, Geoffrey; Vogue, Hinrich; Wilson, Peter; Heuer, Cord

2014-12-01

The present study aimed to describe the molecular diversity of Mycobacterium avium subsp. paratuberculosis (MAP) isolates obtained from sheep, cattle (beef and dairy) and deer farms in New Zealand. A total of 206 independent MAP isolates (15 beef cattle, 89 dairy cattle, 35 deer, 67 sheep) were sourced from 172 species-mobs (15 beef cattle, 66 dairy cattle, 31 deer, 60 sheep). Seventeen subtypes were identified, using a combination of variable number of tandem repeats (VNTR) and short sequence repeat (SSR) methods. Rarefaction analysis, analysis of molecular variance (AMOVA), Fst pairwise comparisons and proportional similarity index (PSI) were used to describe subtype population richness, genetic structure and potential associations between livestock sectors and New Zealand two main islands (North and South). The rarefaction analysis suggests a significantly higher subtype richness in dairy cattle herds when compared to the other livestock sectors. AMOVA results indicate that the main source of subtype variation is attributable to the livestock sector from which samples were sourced suggesting that subtypes are generally sector-specific. The pairwise Fst results were similar, with low Fst values for island differences within a livestock sector when compared to between sector analyses, representing a low subtype differentiation between islands. However, for a given island, potential associations were seen between dominant subtypes and specific livestock sectors. Three subtypes accounted for 76% of the isolates. The most common of these was isolated from sheep and beef cattle in the North Island, the second most frequent subtype was mainly isolated from dairy cattle (either island), while the third most common subtype was associated with deer farmed in the South Island. The PSI analysis suggests similarities in subtypes sourced from sheep and beef cattle. This contrasted with the isolates sourced from other livestock sectors, which tended to present sector-specific subtypes. Sheep and beef cattle were mainly infected with MAP Type I, while dairy cattle and deer were almost exclusively infected with MAP Type II. However, when beef cattle and deer were both present at farm level, they harboured similar subtypes. This study indicates that cross-species transmission of MAP occurs on New Zealand farms although close contact between species appears to be required, as in the case of sheep and beef cattle which are commonly grazed together in New Zealand. Copyright © 2014 Elsevier B.V. All rights reserved.

Control of the sheep blowfly in Australia and New Zealand--are we there yet?

PubMed

Sandeman, R M; Levot, G W; Heath, A C G; James, P J; Greeff, J C; Scott, M J; Batterham, P; Bowles, V M

2014-10-15

The last 50 years of research into infections in Australia and New Zealand caused by larvae of the sheep blowfly, Lucilia cuprina, have significantly advanced our understanding of this blowfly and its primary host, the sheep. However, apart from some highly effective drugs it could be argued that no new control methodologies have resulted. This review addresses the major areas of sheep blowfly research over this period describing the significant outcomes and analyses, and what is still required to produce new commercial control technologies. The use of drugs against this fly species has been very successful but resistance has developed to almost all current compounds. Integrated pest management is becoming basic to control, especially in the absence of mulesing, and has clearly benefited from computer-aided technologies. Biological control has more challenges but natural and perhaps transformed biopesticides offer possibilities for the future. Experimental vaccines have been developed but require further analysis of antigens and formulations to boost protection. Genetic technologies may provide potential for long-term control through more rapid indirect selection of sheep less prone to flystrike. Finally in the future, genetic analysis of the fly may allow suppression and perhaps eradication of blowfly populations or identification of new and more viable targets for drug and vaccine intervention. Clearly all these areas of research offer potential new controls but commercial development is perhaps inhibited by the success of current chemical insecticides and certainly requires a significant additional injection of resources. Crown Copyright © 2014. Published by Elsevier Ltd. All rights reserved.

Evaluation of fecal culture and fecal RT-PCR to detect Mycobacterium avium ssp. paratuberculosis fecal shedding in dairy goats and dairy sheep using latent class Bayesian modeling.

PubMed

Bauman, Cathy A; Jones-Bitton, Andria; Jansen, Jocelyn; Kelton, David; Menzies, Paula

2016-09-20

The study's objective was to evaluate the ability of fecal culture (FCUL) and fecal PCR (FPCR) to identify dairy goat and dairy sheep shedding Mycobacterium avium ssp. paratuberculosis. A cross-sectional study of the small ruminant populations was performed in Ontario, Canada between October 2010 and August 2011. Twenty-nine dairy goat herds and 21 dairy sheep flocks were visited, and 20 lactating females > two years of age were randomly selected from each farm resulting in 580 goats and 397 sheep participating in the study. Feces were collected per rectum and cultured using the BD BACTEC™ MGIT™ 960 system using a standard (49 days) and an extended (240 days) incubation time, and underwent RT-PCR based on the hsp-X gene (Tetracore®). Statistical analysis was performed using a 2-test latent class Bayesian hierarchical model for each species fitted in WinBUGS. Extending the fecal culture incubation time statistically improved FCUL sensitivity from 23.1 % (95 % PI: 15.9-34.1) to 42.7 % (95 % PI: 33.0-54.5) in dairy goats and from 5.8 % (95 % PI: 2.3-12.4) to 19.0 % (95 % PI: 11.9-28.9) in dairy sheep. FPCR demonstrated statistically higher sensitivity than FCUL (49 day incubation) with a sensitivity of 31.9 % (95 % PI: 22.4-43.1) in goats and 42.6 % (95 % PI: 28.8-63.3) in sheep. Fecal culture demonstrates such low sensitivity at the standard incubation time it cannot be recommended as a screening test to detect shedding of MAP in either goats or sheep. Extending the incubation time resulted in improved sensitivity; however, it is still disappointingly low for screening purposes. Fecal PCR should be the screening test of choice in both species; however, it is important to recognize that control programs should not be based on testing alone when they demonstrate such low sensitivity.

The two populations’ cellular automata model with predation based on the Penna model

NASA Astrophysics Data System (ADS)

He, Mingfeng; Lin, Jing; Jiang, Heng; Liu, Xin

2002-09-01

In Penna's single-species asexual bit-string model of biological ageing, the Verhulst factor has too strong a restraining effect on the development of the population. Danuta Makowiec gave an improved model based on the lattice, where the restraining factor of the four neighbours take the place of the Verhulst factor. Here, we discuss the two populations’ Penna model with predation on the planar lattice of two dimensions. A cellular automata model containing movable wolves and sheep has been built. The results show that both the quantity of the wolves and the sheep fluctuate in accordance with the law that one quantity increases while the other one decreases.

Potential effects of the United States-Mexico border fence on wildlife.

PubMed

Flesch, Aaron D; Epps, Clinton W; Cain, James W; Clark, Matt; Krausman, Paul R; Morgart, John R

2010-02-01

Security infrastructure along international boundaries threatens to degrade connectivity for wildlife. To explore potential effects of a fence under construction along the U.S.-Mexico border on wildlife, we assessed movement behavior of two species with different life histories whose regional persistence may depend on transboundary movements. We used radiotelemetry to assess how vegetation and landscape structure affect flight and natal dispersal behaviors of Ferruginous Pygmy-Owls (Glaucidium brasilianum), and satellite telemetry, gene-flow estimates, and least-cost path models to assess movement behavior and interpopulation connectivity of desert bighorn sheep (Ovis canadensis mexicana). Flight height of Pygmy-Owls averaged only 1.4 m (SE 0.1) above ground, and only 23% of flights exceeded 4 m. Juvenile Pygmy-Owls dispersed at slower speeds, changed direction more, and had lower colonization success in landscapes with larger vegetation openings or higher levels of disturbance (p < or = 0.047), which suggests large vegetation gaps coupled with tall fences may limit transboundary movements. Female bighorn sheep crossed valleys up to 4.9 km wide, and microsatellite analyses indicated relatively high levels of gene flow and migration (95% CI for F(ST)=0.010-0.115, Nm = 1.9-24.8, M =10.4-15.4) between populations divided by an 11-km valley. Models of gene flow based on regional topography and movement barriers suggested that nine populations of bighorn sheep in northwestern Sonora are linked by dispersal with those in neighboring Arizona. Disruption of transboundary movement corridors by impermeable fencing would isolate some populations on the Arizona side. Connectivity for other species with similar movement abilities and spatial distributions may be affected by border development, yet mitigation strategies could address needs of wildlife and humans.

Minimising the development of anthelmintic resistance, and optimising the use of the novel anthelmintic monepantel, for the sustainable control of nematode parasites in Australian sheep grazing systems.

PubMed

Dobson, R J; Hosking, B C; Besier, R B; Love, S; Larsen, J W A; Rolfe, P F; Bailey, J N

2011-05-01

To compare the risk of different treatment scenarios on selecting for anthelmintic resistance on Australian sheep farms. A computer simulation model predicted populations of Trichostrongylus colubriformis, Haemonchus contortus or Teladorsagia (Ostertagia) circumcincta, and the frequency of anthelmintic resistance genes. Nematode populations and the progression of drug resistance for a variety of treatment options and management practices in sheep-rearing areas of Western Australia (WA), Victoria (VIC) and New South Wales (NSW) were simulated. A scoring system was devised to measure the success of each option in delaying resistance to each anthelmintic and in controlling nematode populations. The best option at all sites was combining the new anthelmintic (monepantel) with a triple mixture of benzimidazole, levamisole and abamectin (COM). The next best option was: in NSW, rotation at each treatment between monepantel, moxidectin and COM; in VIC, rotation at each treatment between monepantel and COM; and in WA, rotation at each treatment between monepantel (used in winter) and COM or moxidectin (used in summer-autumn). In WA, rapid selection for resistance occurred as a consequence of summer-autumn treatments; however, if a small percentage of adult stock were left untreated then this selection could be greatly reduced. Despite purposely assuming relatively high resistance to benzimidazole and levamisole, COM was still effective in controlling worms and delaying resistance. Because of cost constraints, it may not be feasible or profitable for producers to always use the combination of all drugs. However, the second- and third-best options still considerably slowed the development of anthelmintic resistance. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Invited review: Current state of genetic improvement in dairy sheep.

PubMed

Carta, A; Casu, Sara; Salaris, S

2009-12-01

Dairy sheep have been farmed traditionally in the Mediterranean basin in southern Europe, central Europe, eastern Europe, and in Near East countries. Currently, dairy sheep farming systems vary from extensive to intensive according to the economic relevance of the production chain and the specific environment and breed. Modern breeding programs were conceived in the 1960s. The most efficient selection scheme for local dairy sheep breeds is based on pyramidal management of the population with the breeders of nucleus flocks at the top, where pedigree and official milk recording, artificial insemination, controlled natural mating, and breeding value estimation are carried out to generate genetic progress. The genetic progress is then transferred to the commercial flocks through artificial insemination or natural-mating rams. Increasing milk yield is still the most profitable breeding objective for several breeds. Almost all milk is used for cheese production and, consequently, milk content traits are very important. Moreover, other traits are gaining interest for selection: machine milking ability and udder morphology, resistance to diseases (mastitis, internal parasites, scrapie), and traits related to the nutritional value of milk (fatty acid composition). Current breeding programs based on the traditional quantitative approach have achieved appreciable genetic gains for milk yield. In many cases, further selection goals such as milk composition, udder morphology, somatic cell count, and scrapie resistance have been implemented. However, the possibility of including other traits of selective interest is limited by high recording costs. Also, the organizational effort needed to apply the traditional quantitative approach limits the diffusion of current selection programs outside the European Mediterranean area. In this context, the application of selection schemes assisted by molecular information, to improve either traditional dairy traits or traits costly to record, seems to be attractive in dairy sheep. At the moment, the most effective strategy seems to be the strengthening of research projects aimed at finding causal mutations along the genes affecting traits of economic importance. However, genome-wide selection seems to be unfeasible in most dairy sheep breeds.

Ex-ante assessment of different vaccination-based control schedules against the peste des petits ruminants virus in sub-Saharan Africa

PubMed Central

Lancelot, Renaud; Domenech, Joseph; Lesnoff, Matthieu

2018-01-01

Background Peste des petits ruminants (PPR) is a highly contagious and widespread viral infection of small ruminants (goats and sheep), causing heavy economic losses in many developing countries. Therefore, its progressive control and global eradication by 2030 was defined as a priority by international organizations addressing animal health. The control phase of the global strategy is based on mass vaccination of small ruminant populations in endemic regions or countries. It is estimated that a 70% post-vaccination immunity rate (PVIR) is needed in a given epidemiological unit to prevent PPR virus spread. However, implementing mass vaccination is difficult and costly in smallholder farming systems with scattered livestock and limited facilities. Regarding this, controlling PPR is a special challenge in sub-Saharan Africa. In this study, we focused on this region to assess the effect of several variables of PVIR in two contrasted smallholder farming systems. Methods Using a seasonal matrix population model of PVIR, we estimated its decay in goats reared in sub-humid areas, and sheep reared in semi-arid areas, over a 4-year vaccination program. Assuming immunologically naive and PPR-free epidemiological unit, we assessed the ability of different vaccination scenarios to reach the 70% PVIR throughout the program. The tested scenarios differed in i) their overall schedule, ii) their delivery month and iii) their vaccination coverage. Results In sheep reared in semi-arid areas, the vaccination month did affect the PVIR decay though it did not in goats in humid regions. In both cases, our study highlighted i) the importance of targeting the whole eligible population at least during the two first years of the vaccination program and ii) the importance of reaching a vaccination coverage as high as 80% of this population. This study confirmed the relevance of the vaccination schedules recommended by international organizations. PMID:29351277

The effects of road transportation on physiological responses and meat quality in sheep differing in age.

PubMed

Zhong, R Z; Liu, H W; Zhou, D W; Sun, H X; Zhao, C S

2011-11-01

The aim of this study was to determine the effects of 8 h of road transportation on physiological responses and meat quality traits of sheep at 6, 12, and 24 mo of age. Seventy-two male sheep were equally divided into transported (TRANS) and nontransported (CON) treatments (n = 36), and each treatment was subdivided into 3 groups by age (n = 12). Sheep in CON groups were weighed, blood sampled, and slaughtered, whereas sheep in TRANS groups were weighed, transported, blood sampled, and slaughtered to collect meat samples. The BW of sheep in TRANS groups was reduced significantly (P < 0.001) compared with CON sheep, and older sheep lost more BW than younger animals. However, dressing percentages of TRANS sheep were significantly (P < 0.001) greater than those of CON sheep. Some meat quality variables were affected by transportation, and responses of different ages of sheep varied. Total pigment content and lipid oxidation of LM and gluteus medius of TRANS sheep increased significantly (P < 0.001) compared with CON sheep. Cooking loss of LM and gluteus medius was influenced significantly (P < 0.01) by interaction effect between transportation and age, and the values for 6-mo-old TRANS sheep were less than those of CON sheep. Serum total protein (P = 0.036), globulin (P = 0.026), triglyceride (P < 0.001), and total cholesterol concentrations (P = 0.028) of TRANS sheep decreased compared with CON sheep. Serum NEFA concentration of TRANS sheep increased in relation to CON sheep with a significant interaction (P < 0.001) between transportation and age effect. Numbers of white blood cells were influenced (P = 0.002) by an interaction effect between transportation and age, and values for 6-mo-old sheep were not influenced by transportation. Numbers of platelets were influenced (P = 0.014) by age; they decreased more in 6-mo-old sheep than in older sheep. Transportation and age had no significant effects (P > 0.05) on packed cell volume and lymphocyte number. Serum creatine kinase activities in TRANS sheep were affected (P = 0.01) by an interaction effect between transportation and age. The 2-thiobarbituric acid reactive substances in serum of TRANS sheep increased (P = 0.009) with the greatest change for 6-mo-old compared with older sheep. In conclusion, 8 h of road transportation resulted in greater heme pigment concentrations but improved meat tenderness and induced physiological responses of sheep. However, different ages of sheep showed different responses to the present transportation pattern.

Age-specific infectious period shapes dynamics of pneumonia in bighorn sheep.

PubMed

Plowright, Raina K; Manlove, Kezia R; Besser, Thomas E; Páez, David J; Andrews, Kimberly R; Matthews, Patrick E; Waits, Lisette P; Hudson, Peter J; Cassirer, E Frances

2017-10-01

Superspreading, the phenomenon where a small proportion of individuals contribute disproportionately to new infections, has profound effects on disease dynamics. Superspreading can arise through variation in contacts, infectiousness or infectious periods. The latter has received little attention, yet it drives the dynamics of many diseases of critical public health, livestock health and conservation concern. Here, we present rare evidence of variation in infectious periods underlying a superspreading phenomenon in a free-ranging wildlife system. We detected persistent infections of Mycoplasma ovipneumoniae, the primary causative agent of pneumonia in bighorn sheep (Ovis canadensis), in a small number of older individuals that were homozygous at an immunologically relevant genetic locus. Interactions among age-structure, genetic composition and infectious periods may drive feedbacks in disease dynamics that determine the magnitude of population response to infection. Accordingly, variation in initial conditions may explain divergent population responses to infection that range from recovery to catastrophic decline and extirpation. © 2017 John Wiley & Sons Ltd/CNRS.

Studies on the Feeding Habits of Lutzomyia (Lutzomyia) longipalpis (Lutz & Neiva, 1912) (Diptera: Psychodidae: Phlebotominae) Populations from Endemic Areas of American Visceral Leishmaniasis in Northeastern Brazil

PubMed Central

Afonso, Margarete Martins dos Santos; Duarte, Rosemere; Miranda, José Carlos; Caranha, Lindenbergh; Rangel, Elizabeth Ferreira

2012-01-01

The aim of this study was to identify potential blood feeding sources of L. (L.) longipalpis specimens from populations in Northeastern Brazil, endemic areas of American Visceral Leishmaniasis (AVL) and its correlation with the transmission of L. (L.) i. chagasi. The ELISA technique was applied using bird, dog, goat, opossum, equine, feline, human, sheep, and rodent antisera to analyze 609 females, resulting in an overall positivity of 60%. In all municipalities, females showed higher positivity for bird followed by dog antiserum and sand fly specimens were also positive for equine, feline, human, sheep, goat, opossum, and rodent antisera. The finding for 17 combinations of two or three types of blood in some females corroborates the opportunistic habit of this sand fly species. The results demonstrating the association between L. (L.) longipalpis and opossum suggest the need for further evaluation of the real role of this synanthropic mammal in the eco-epidemiology of AVL. PMID:22315621

Genomic estimation of additive and dominance effects and impact of accounting for dominance on accuracy of genomic evaluation in sheep populations.

PubMed

Moghaddar, N; van der Werf, J H J

2017-12-01

The objectives of this study were to estimate the additive and dominance variance component of several weight and ultrasound scanned body composition traits in purebred and combined cross-bred sheep populations based on single nucleotide polymorphism (SNP) marker genotypes and then to investigate the effect of fitting additive and dominance effects on accuracy of genomic evaluation. Additive and dominance variance components were estimated in a mixed model equation based on "average information restricted maximum likelihood" using additive and dominance (co)variances between animals calculated from 48,599 SNP marker genotypes. Genomic prediction was based on genomic best linear unbiased prediction (GBLUP), and the accuracy of prediction was assessed based on a random 10-fold cross-validation. Across different weight and scanned body composition traits, dominance variance ranged from 0.0% to 7.3% of the phenotypic variance in the purebred population and from 7.1% to 19.2% in the combined cross-bred population. In the combined cross-bred population, the range of dominance variance decreased to 3.1% and 9.9% after accounting for heterosis effects. Accounting for dominance effects significantly improved the likelihood of the fitting model in the combined cross-bred population. This study showed a substantial dominance genetic variance for weight and ultrasound scanned body composition traits particularly in cross-bred population; however, improvement in the accuracy of genomic breeding values was small and statistically not significant. Dominance variance estimates in combined cross-bred population could be overestimated if heterosis is not fitted in the model. © 2017 Blackwell Verlag GmbH.

Transmission of Mannheimia haemolytica from domestic sheep (Ovis aries) to bighorn sheep (Ovis canadensis): unequivocal demonstration with green fluorescent protein-tagged organisms.

PubMed

Lawrence, Paulraj K; Shanthalingam, Sudarvili; Dassanayake, Rohana P; Subramaniam, Renuka; Herndon, Caroline N; Knowles, Donald P; Rurangirwa, Fred R; Foreyt, William J; Wayman, Gary; Marciel, Ann Marie; Highlander, Sarah K; Srikumaran, Subramaniam

2010-07-01

Previous studies demonstrated that bighorn sheep (Ovis canadensis) died of pneumonia when commingled with domestic sheep (Ovis aries) but did not conclusively prove that the responsible pathogens were transmitted from domestic to bighorn sheep. The objective of this study was to determine, unambiguously, whether Mannheimia haemolytica can be transmitted from domestic to bighorn sheep when they commingle. Four isolates of M. haemolytica were obtained from the pharynx of two of four domestic sheep and tagged with a plasmid carrying the genes for green fluorescent protein (GFP) and ampicillin resistance (AP(R)). Four domestic sheep, colonized with the tagged bacteria, were kept about 10 m apart from four bighorn sheep for 1 mo with no clinical signs of pneumonia observed in the bighorn sheep during that period. The domestic and bighorn sheep were then allowed to have fence-line contact for 2 mo. During that period, three bighorn sheep acquired the tagged bacteria from the domestic sheep. At the end of the 2 mo of fence-line contact, the animals were allowed to commingle. All four bighorn sheep died 2 days to 9 days following commingling. The lungs from all four bighorn sheep showed gross and histopathologic lesions characteristic of M. haemolytica pneumonia. Tagged M. haemolytica were isolated from all four bighorn sheep, as confirmed by growth in ampicillin-containing culture medium, PCR-amplification of genes encoding GFP and Ap(R), and immunofluorescent staining of GFP. These results unequivocally demonstrate transmission of M. haemolytica from domestic to bighorn sheep, resulting in pneumonia and death of bighorn sheep.

Hemoprotozoa of domestic animals in France: prevalence and molecular characterization.

PubMed

Criado-Fornelio, A; Buling, A; Pingret, J L; Etievant, M; Boucraut-Baralon, C; Alongi, A; Agnone, A; Torina, A

2009-01-22

Very limited information is available on epizootiology of haematozoan infections in French domestic animals. In an attempt to address this issue, prevalence of piroplasmida was studied in carnivores and ruminants, whereas prevalence of Hepatozoon spp. was only investigated in carnivores. In total, 383 animals were included in the survey (namely 116 cats, 108 dogs, 91 sheep and 68 cows). Parasite diagnosis was carried out using molecular methods such as PCR and sequencing of the 18S rRNA gene. In addition, ruminant samples were analyzed with the reverse line blotting technique (RLB). Results of RLB and PCR plus sequencing were in total agreement. In carnivores, haematozoan prevalence was close to 1%. Two cats were infected by H. canis (1.7% prevalence) and one of them was co-infected by Cytauxzoon sp. (0.8%). This represents the first finding of both pathogens in French cats. One dog was infected by H. canis (0.9%) and another by Babesia canis vogeli (0.9%). In ruminants, haematozoan prevalence (piroplasmida) was significantly higher than in carnivores (4.8% in sheep and 8.8% in cow). Theileria ovis was found in 1 sheep, Theileria sp. in 2 sheep, Theileria buffeli in 5 cows and B. major in 1 cow. Evidence presented in this contribution indicates that haematic protozoa are not widely distributed in domestic mammal populations of France.

Molecular characterization of Fasciola species isolated from imported sheep in Taif region (Saudi Arabia).

PubMed

Shalaby, I; Gherbawy, Y; Banaja, A

2013-03-01

Accurate identification of Fasciola species, followed by biological and ecological characterization, is important with concern to the planning for field control. Because there are many variations in morphological characteristics, exact distinguishing of Fasciola species is usually difficult by simple traditional microscopic measurements and, therefore, the morphometric characterization may be insufficient for the species identification. Hence, the present work was proposed to collect 100 liver samples from 100 imported sheep from Sudan from slaughterhouses in Taif region. The samples were firstly examined macroscopically and microscopically to ensure the presence or absence of infection. The collected worms were subjected for RAPD-PCR analysis using different primers and ITS1 sequences for accurate identification. Using RAPD-PCR analysis, two primers were selected to amplify the DNA of each Fasciola. The results show that the amplification fragments were between 500 and 1500 bp and, the use of random genetic markers allowed to discriminate among the different collected species. Using Internal transcribed spacer region (ITS) sequencing, the imported sheep in Taif region consisted of 630 bps including complete ITS1, partial 18S and 5.8S and had 5 variable nucleotide positions. This is the first demonstration of the existence of both F. hepatica, F. gigantica and hybrid and/or introgressed populations of liver flukes bearing genetic material from both F. hepatica and F. gigantica in the imported sheep in Saudi Arabia by a genetic approach.

Serosurvey for Zoonotic Viral and Bacterial Pathogens Among Slaughtered Livestock in Egypt

PubMed Central

Horton, Katherine C.; Wasfy, Momtaz; Samaha, Hamed; Abdel-Rahman, Bassem; Safwat, Sameh; Abdel Fadeel, Moustafa; Mohareb, Emad; Dueger, Erica

2015-01-01

Introduction Zoonotic diseases are an important cause of human morbidity and mortality. Animal populations at locations with high risk of transmission of zoonotic pathogens offer an opportunity to study viral and bacterial pathogens of veterinary and public health concern. Methods Blood samples were collected from domestic and imported livestock slaughtered at the Muneeb abattoir in central Egypt in 2009. Samples were collected from cattle (n = 161), buffalo (n = 153), sheep (n = 174), and camels (n = 10). Samples were tested for antibodies against Leptospira spp. by a microscopy agglutination test, Coxiella burnetii by enzyme immunoassay, Brucella spp. by standard tube agglutination, and Rift Valley Fever virus (RVFV), Crimean–Congo hemorrhagic fever virus (CCHFV), sandfly fever Sicilian virus (SFSV), and sandfly fever Naples virus (SFNV) by enzyme-linked immunosorbent assay. Results Antibodies against Leptospira spp. were identified in 64 (40%) cattle, 45 (29%) buffalo, 71 (41%) sheep, and five (50%) camels; antibodies against C. burnetii in six (4%) buffalo, 14 (8%) sheep, and seven (70%) camels; and antibodies against Brucella spp. in 12 (8%) cattle, one (1%) buffalo, seven (4%) sheep, and one (10%) camel. Antibodies against RVFV were detected in two (1%) cattle and five (3%) buffalo, and antibodies against CCHFV in one (1%) cow. No antibodies against SFSV or SFNV were detected in any species. Discussion Results indicate that livestock have been exposed to a number of pathogens, although care must be taken with interpretation. It is not possible to determine whether antibodies against Leptospira spp. and RVFV in cattle and buffalo are due to prior vaccination or natural exposure. Similarly, antibodies identified in animals less than 6 months of age may be maternal antibodies transferred through colostrum rather than evidence of prior exposure. Results provide baseline evidence to indicate that surveillance within animal populations may be a useful tool to monitor the circulation of pathogens of veterinary and public health concern in Egypt. PMID:25198525

Trans-species polymorphism and selection in the MHC class II DRA genes of domestic sheep.

PubMed

Ballingall, Keith T; Rocchi, Mara S; McKeever, Declan J; Wright, Frank

2010-06-30

Highly polymorphic genes with central roles in lymphocyte mediated immune surveillance are grouped together in the major histocompatibility complex (MHC) in higher vertebrates. Generally, across vertebrate species the class II MHC DRA gene is highly conserved with only limited allelic variation. Here however, we provide evidence of trans-species polymorphism at the DRA locus in domestic sheep (Ovis aries). We describe variation at the Ovar-DRA locus that is far in excess of anything described in other vertebrate species. The divergent DRA allele (Ovar-DRA*0201) differs from the sheep reference sequences by 20 nucleotides, 12 of which appear non-synonymous. Furthermore, DRA*0201 is paired with an equally divergent DRB1 allele (Ovar-DRB1*0901), which is consistent with an independent evolutionary history for the DR sub-region within this MHC haplotype. No recombination was observed between the divergent DRA and B genes in a range of breeds and typical levels of MHC class II DR protein expression were detected at the surface of leukocyte populations obtained from animals homozygous for the DRA*0201, DRB1*0901 haplotype. Bayesian phylogenetic analysis groups Ovar-DRA*0201 with DRA sequences derived from species within the Oryx and Alcelaphus genera rather than clustering with other ovine and caprine DRA alleles. Tests for Darwinian selection identified 10 positively selected sites on the branch leading to Ovar-DRA*0201, three of which are predicted to be associated with the binding of peptide antigen. As the Ovis, Oryx and Alcelaphus genera have not shared a common ancestor for over 30 million years, the DRA*0201 and DRB1*0901 allelic pair is likely to be of ancient origin and present in the founding population from which all contemporary domestic sheep breeds are derived. The conservation of the integrity of this unusual DR allelic pair suggests some selective advantage which is likely to be associated with the presentation of pathogen antigen to T-cells and the induction of protective immunity.

Trans-Species Polymorphism and Selection in the MHC Class II DRA Genes of Domestic Sheep

PubMed Central

Ballingall, Keith T.; Rocchi, Mara S.; McKeever, Declan J.; Wright, Frank

2010-01-01

Highly polymorphic genes with central roles in lymphocyte mediated immune surveillance are grouped together in the major histocompatibility complex (MHC) in higher vertebrates. Generally, across vertebrate species the class II MHC DRA gene is highly conserved with only limited allelic variation. Here however, we provide evidence of trans-species polymorphism at the DRA locus in domestic sheep (Ovis aries). We describe variation at the Ovar-DRA locus that is far in excess of anything described in other vertebrate species. The divergent DRA allele (Ovar-DRA*0201) differs from the sheep reference sequences by 20 nucleotides, 12 of which appear non-synonymous. Furthermore, DRA*0201 is paired with an equally divergent DRB1 allele (Ovar-DRB1*0901), which is consistent with an independent evolutionary history for the DR sub-region within this MHC haplotype. No recombination was observed between the divergent DRA and B genes in a range of breeds and typical levels of MHC class II DR protein expression were detected at the surface of leukocyte populations obtained from animals homozygous for the DRA*0201, DRB1*0901 haplotype. Bayesian phylogenetic analysis groups Ovar-DRA*0201 with DRA sequences derived from species within the Oryx and Alcelaphus genera rather than clustering with other ovine and caprine DRA alleles. Tests for Darwinian selection identified 10 positively selected sites on the branch leading to Ovar-DRA*0201, three of which are predicted to be associated with the binding of peptide antigen. As the Ovis, Oryx and Alcelaphus genera have not shared a common ancestor for over 30 million years, the DRA*0201 and DRB1*0901 allelic pair is likely to be of ancient origin and present in the founding population from which all contemporary domestic sheep breeds are derived. The conservation of the integrity of this unusual DR allelic pair suggests some selective advantage which is likely to be associated with the presentation of pathogen antigen to T-cells and the induction of protective immunity. PMID:20613987

Intra-Species Genetic Diversity and Clonal Structure of Cryptosporidium parvum in Sheep Farms in a Confined Geographical Area in Northeastern Spain.

PubMed

Ramo, Ana; Monteagudo, Luis V; Del Cacho, Emilio; Sánchez-Acedo, Caridad; Quílez, Joaquín

2016-01-01

A multilocus fragment typing approach including eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene was used to investigate the intra-farm and intra-host genetic diversity of Cryptosporidium parvum in sheep farms in a confined area in northeastern Spain. Genomic DNA samples of 113 C. parvum isolates from diarrheic pre-weaned lambs collected in 49 meat-type sheep farms were analyzed. Loci exhibited various degrees of polymorphism, the finding of 7-9 alleles in the four most variable and discriminatory markers (ML2, Cgd6_5400, Cgd6_3940, and GP60) being remarkable. The combination of alleles at the twelve loci identified a total of 74 multilocus subtypes (MLTs) and provided a Hunter-Gaston discriminatory index of 0.988 (95% CI, 0.979-0.996). The finding that most MLTs (n = 64) were unique to individual farms evidenced that cryptosporidial infection is mainly transmitted within sheep flocks, with herd-to-herd transmission playing a secondary role. Limited intra- host variability was found, since only five isolates were genotypically mixed. In contrast, a significant intra-farm genetic diversity was seen, with the presence of multiple MLTs on more than a half of the farms (28/46), suggesting frequent mutations or genetic exchange through recombination. Comparison with a previous study in calves in northern Spain using the same 12-loci typing approach showed differences in the identity of major alleles at most loci, with a single MLT being shared between lambs and calves. Analysis of evolutionary descent by the algorithm eBURST indicated a high degree of genetic divergence, with over 41% MLTs appearing as singletons along with a high number of clonal complexes, most of them linking only two MLTs. Bayesian Structure analysis and F statistics also revealed the genetic remoteness of most C. parvum isolates and no ancestral population size was chosen. Linkage analysis evidenced a prevalent pattern of clonality within the parasite population.

An exploratory analysis on how geographic, socioeconomic, and environmental drivers affect the diversity of livestock breeds worldwide.

PubMed

Leroy, G; Boettcher, P; Hoffmann, I; Mottet, A; Teillard, F; Baumung, R

2016-12-01

This study investigates the relationships between various environmental and geographic, demographic, and socioeconomic factors with the diversity of livestock breeds reported within countries across the world. Statistical analyses were performed considering the numbers of breeds reported by 158 countries for 4 livestock mammalian species (cattle, sheep, goats, and pigs). Organization for Economic Cooperation and Development (OECD) countries reported more breeds than non-OECD countries in general. Strong and positive correlations were found between agricultural area, human population size, species population size, and number of breeds per country. When considering regression models, the species population size was found as the most important explanatory factor for the number of breeds reported by countries in the 4 species. Diversity of production systems in the country had a significant association with the number of breeds reported for sheep, goats, and pigs. The number of ruminant breeds was positively associated with the size of agricultural area and the diversity of land cover in the country. While demographic and cultural importance of a given species is a major factor associated with the number of livestock breeds within countries, this diversity is also connected to the variability in environmental and production conditions.

Prevalence and Identity of Taenia multiceps cysts "Coenurus cerebralis" in Sheep in Egypt.

PubMed

Amer, Said; ElKhatam, Ahmed; Fukuda, Yasuhiro; Bakr, Lamia I; Zidan, Shereif; Elsify, Ahmed; Mohamed, Mostafa A; Tada, Chika; Nakai, Yutaka

2017-12-01

Coenurosis is a parasitic disease caused by the larval stage (Coenurus cerebralis) of the canids cestode Taenia multiceps. C. cerebralis particularly infects sheep and goats, and pose a public health concerns. The present study aimed to determine the occurrence and molecular identity of C. cerebralis infecting sheep in Egypt. Infection rate was determined by postmortem inspection of heads of the cases that showed neurological manifestations. Species identification and genetic diversity were analyzed based on PCR-sequence analysis of nuclear ITS1 and mitochondrial cytochrome oxidase (COI) and nicotinamide adenine dinucleotide dehydrogenase (ND1) gene markers. Out of 3668 animals distributed in 50 herds at localities of Ashmoun and El Sadat cities, El Menoufia Province, Egypt, 420 (11.45%) sheep showed neurological disorders. Postmortem examination of these animals after slaughter at local abattoirs indicated to occurrence of C. cerebralis cysts in the brain of 111 out of 420 (26.4%), with overall infection rate 3.03% of the involved sheep population. Molecular analysis of representative samples of coenuri at ITS1 gene marker showed extensive intra- and inter-sequence diversity due to deletions/insertions in the microsatellite regions. On contrast to the nuclear gene marker, considerably low genetic diversity was seen in the analyzed mitochondrial gene markers. Phylogenetic analysis based on COI and ND1 gene sequences indicated that the generated sequences in the present study and the reference sequences in the database clustered in 4 haplogroups, with more or less similar topologies. Clustering pattern of the phylogenetic tree showed no effect for the geographic location or the host species. Copyright © 2017 Elsevier B.V. All rights reserved.

Morphometric, densitometric and mechanical properties of mandibular deciduous teeth in 5-month-old Polish Merino sheep

PubMed Central

2014-01-01

Background Caries, enamel hypoplasia, molar incisor hipomineralization, amylogenesis imperfecta, dentine dysplasia, hypophosphatasia and other dental disorders lead to tooth mineralization disturbances and structural abnormalities, decreasing masticatory organ functions. Dental disorders in sheep can lead to premature slaughter before they have attained final stage of their reproductive life and induce economic loss due to high flock replacement costs. Growth rate, health status and meat quality of sheep depends on tooth properties and quality determining in large extent efficiency of the masticatory apparatus and initial food break up. Considering lack of basic anatomical and physiological data on teeth properties in sheep, the aim of the study was to evaluate morphometric, densitometric and mechanical traits of deciduous mandibular incisor, canine and the second premolar obtained at the slaughter age of 5 months of life. Results The obtained results have shown the highest values of weight, total tooth volume, enamel volume and dentine volume in second premolar. Morphometric and mechanical parameters of incisors reached the highest values in first incisor and decreased gradually in second and third incisor, and in canine. Densitometric measurements have not revealed significant differences of the volumetric tooth mineral density in hard dental tissues between the investigated teeth. Conclusions In conclusion, proposed methodological approach is noninvasive since the deciduous teeth undergo physiological replacement with permanent teeth. Deciduous teeth can be easy collected for analyses from large animal population and may reflect mineral status and metabolism resulting from postnatal growth and development of the whole flock. In individual cases, evaluation of properties of deciduous teeth may serve for breeding selection and further reproduction of sheep possessing favorable traits of teeth and better masticatory system functions. PMID:24548814

Animal Models for Testing the DOHaD Hypothesis

EPA Science Inventory

Since the seminal work in human populations by David Barker and colleagues, several species of animals have been used in the laboratory to test the Developmental Origins of Health and Disease (DOHaD) hypothesis. Rats, mice, guinea pigs, sheep, pigs and non-human primates have bee...

Genotypic characterization and species identification of Fasciola spp. with implications regarding the isolates infecting goats in Vietnam.

PubMed

Nguyen, Thanh Giang Thi; Van De, Nguyen; Vercruysse, Jozef; Dorny, Pierre; Le, Thanh Hoa

2009-12-01

Ribosomal RNA sequences (361 or 362bp) of the second internal transcribed spacer 2 (ITS-2) and a portion of mitochondrial cox1 (423bp) for Fasciola spp. obtained from specimens collected in indigenous and hybrid goats and sheep in Vietnam were characterized for genotypic status and hybridization/introgression. Alignment of 48 ITS-2 sequences (also those from goats and sheep in this study) indicates that F. gigantica and F. hepatica differ typically from each other at seven sites whereas one of these is a distinguishing deletion (T) at the 327th position in F. gigantica relative to F. hepatica. The isolates from the mountainous goats in the North of Vietnam (Yen Bai province) showed the ITS-2 composition relatively identical to that of F. hepatica. The ITS-2 sequences from populations of Fasciola isolates in goats had probably experienced introgression/hybridization as reported previously in other ruminants and humans. All Vietnamese goat-of-origin specimens had high pairwise percentage of mitochondrial cox1 sequences to F. gigantica (97-100%), and very low identity to F. hepatica (91-93%), suggesting their maternal linkage to be traced to F. gigantica. The presence of hybrid and/or introgressed populations of liver flukes bearing genetic material from both F. hepatica and F. gigantica in the goats/sheep in Vietnam, regardless of indigenous or imported hosts, appears to be the first demonstration from a tropical country.

The elimination of echinococcosis from Iceland

PubMed Central

Beard, Trevor C.

1973-01-01

A century ago Iceland had the highest prevalence of human hydatid disease ever recorded anywhere. Since 1864 the disease has been gradually controlled, and today there is less than one new case per decade. The sheep population of about one million, over 95% of which is subject to inspection at slaughter, has yielded only 15 infected animals in the last 20 years. In most districts farm slaughtering still persists, though on a very limited scale, and farm dogs are subjected to very little control. The main credit for the remarkable control of E. granulosus is given to education, but many accidental social and environmental factors, peculiar to Iceland, contributed to the result. Of these, the most notable were the small human population and high rate of literacy; the very high dog mortality from distemper in the 19th century, which coincided with a major export trade in live sheep; the custom of feeding dogs on cooked household scraps, the risk of infection being confined to the short sheep slaughtering season and the rare occasions when a cow or pig is slaughtered; the absence of employed labour on Icelandic farms, all slaughtering being done by the owner, an educated man with middle-class values; the change in animal husbandry since 1920 towards the slaughter of 5-month-old lambs, too young to have viable cysts; and the meat subsidy, which since 1947 has led to the use of abattoirs for all but a handful of uneconomic animals kept for slaughter on the farm. PMID:4544777

Comparative analyses of the mitochondrial genome of the sheep ked Melophagus ovinus (Diptera: Hippoboscidae) from different geographical origins in China.

PubMed

Tang, Jia-Min; Li, Fen; Cheng, Tian-Yin; Duan, De-Yong; Liu, Guo-Hua

2018-05-22

The sheep ked Melophagus ovinus is mainly found in Europe, Northwestern Africa, and Asia. Although M. ovinus is an important ectoparasite of sheep in many countries, the population genetics, molecular biology, and systematics of this ectoparasite remain poorly understood. Herein, we determined the mitochondrial (mt) genome of M. ovinus from Gansu Province, China (MOG) and compared with that of M. ovinus Xinjiang Uygur Autonomous Region, China (MOX). The mt genome sequence (15,044 bp) of M. ovinus MOG was significantly shorter (529 bp) than M. ovinus MOX. Nucleotide sequence difference in the whole mt genome except for non-coding region was 0.37% between M. ovinus MOG and MOX. For the 13 protein-coding genes, comparison revealed sequence divergences at both the nucleotide (0-1.1%) and amino acid (0-0.59%) levels between M. ovinus MOG and MOX, respectively. Interestingly, the cox1 gene of M. ovinus MOX is predicted to employ unusual mt start codons AAA, which has not been predicted previously for any parasite genome. Phylogenetic analyses showed that M. ovinus (Hippoboscoidea) is related to the superfamilies Oestroidea + Muscoidea. Our results have also indicated the paraphylies of the four families (Anthomyiidae, Calliphoridae, Muscidae, and Oestridae) and two superfamilies (Oestroidea and Muscoidea). This mt genome of M. ovinus provides useful molecular markers for studies into the population genetics, molecular biology, and systematics of this ectoparasite.

Individual gregariousness predicts behavioural synchronization in a foraging herbivore, the sheep (Ovis aries).

PubMed

Hauschildt, Verena; Gerken, Martina

2015-04-01

Diversity of animal personalities has been proposed to arise from differences in social attraction, and to enhance behavioural flexibility of a population. The present study evaluated gregariousness as a personality trait in 14 ewes kept on pasture. Gregariousness was defined based on the frequency of having a close neighbour (<3m). Highly gregarious (HG) and less gregarious (LG) animals were separated into two groups (n=7) which were reintegrated after 18 days. During direct field observations, behaviour was recorded individually every 15 min. Each session lasted 2.5h (08.30-11.00 h or 14.30-17.00 h, respectively). Behavioural synchronization was highest when the group consisted only of HG individuals (κHG=0.69, κLG=0.31; t=5.29; p<0.001), indicating that gregariousness predicted behavioural synchronization in sheep. Though sheep are generally recognized as a highly gregarious species, HG and LG individuals could be differentiated clearly and consistently. Research on animal personality might help explain social influences on behavioural synchronization. Copyright © 2015 Elsevier B.V. All rights reserved.

Low intensity, mixed livestock grazing improves the breeding abundance of a common insectivorous passerine.

PubMed

Evans, Darren M; Redpath, Stephen M; Evans, Sharon A; Elston, David A; Gardner, Charles J; Dennis, Peter; Pakeman, Robin J

2006-12-22

Livestock grazing is a major driver of ecosystem change and has been associated with significant declines in various bird species in Britain and worldwide. However, there is little experimental evidence to show how grazing affects bird populations. We manipulated livestock densities in a replicated field experiment and found that mixed sheep and cattle grazing, at low intensity, improved the breeding abundance of a common upland passerine, the meadow pipit Anthus pratensis, after two years. Plots stocked with sheep alone (at high or low density) or not stocked at all held fewer pipit territories. Despite a year-on-year decline in pairs of meadow pipits in intensively grazed plots, we found no effect of sheep number on breeding abundance. Our results support the hypothesis that mixed species of herbivores generate greater heterogeneity in vegetation structure, which modifies prey availability, resulting in a greater abundance of birds. The results of our study should inform the management of grassland areas and enhance the abundance of some bird species, particularly in areas that have seen significant shifts from mixed livestock grazing to grazing dominated by single species of animals.

Differential Susceptibility of Bighorn Sheep (Ovis canadensis) and Domestic Sheep (Ovis aries) Neutrophils to Mannheimia haemolytica Leukotoxin is not due to Differential Expression of Cell Surface CD18.

PubMed

Dassanayake, Rohana P; Shanthalingam, Sudarvili; Liu, Weiguo; Casas, Eduardo; Srikumaran, Subramaniam

2017-07-01

Bighornsheep ( Ovis canadensis ) are more susceptible to pneumonia caused by Mannheimia haemolytica than are domestic sheep ( Ovis aries ). Leukotoxin produced by M. haemolytica is the principal virulence factor involved in pneumonia pathogenesis. Although leukotoxin is cytolytic to all subsets of ruminant leukocytes, neutrophils are the most susceptible subset. Bighorn sheep neutrophils are four- to eightfold more susceptible to leukotoxin-induced cytolysis than are domestic sheep neutrophils. We hypothesized that the higher susceptibility of bighorn sheep neutrophils, in comparison to domestic sheep neutrophils, is due to higher expression of CD18, the receptor for leukotoxin on leukocytes. Our objective was to quantify CD18 expression on neutrophils of bighorn sheep and domestic sheep. Cell-surface CD18 expression on bighorn sheep and domestic sheep neutrophils was measured as antibody binding capacity of cells by flow cytometric analysis with two fluorochrome-conjugated anti-CD18 monoclonal antibodies (BAQ30A and HUH82A) and microspheres. Contrary to our expectations, CD18 expression was higher (P<0.0001) with monoclonal antibody BAQ30A and was higher (P<0.0002) as well with monoclonal antibody HUH80A on domestic sheep neutrophils in comparison to bighorn sheep neutrophils. These findings suggest that the higher in vitro susceptibility to leukotoxin of bighorn sheep neutrophils compared to domestic sheep neutrophils is not due to higher expression of the leukotoxin receptor CD18 on bighorn sheep neutrophils.

Prevalence of mange among West African Dwarf sheep and goats and associated haematological and biochemical parameters.

PubMed

Ogundiyi, Alex I; Bemji, Martha Nchang; Adebambo, Olufunmilayo A; Dipeolu, Morenike A; Onagbesan, Okanlawon M; James, Ikechwuku J; Osinowo, Olusegun A

2012-08-01

This study was carried out to assess the prevalence of mange in sheep and goats in five local government areas (LGAs) of Ogun State in South Western Nigeria. A total of 4,973 sheep and 7,902 goats of West African Dwarf breeds were sampled of which only 4 (0.08%) of sheep and 42 (0.53%) of goats were confirmed positive for mange infestation. In all the LGAs sampled, Odeda LGA had the highest concentration of sheep (39%) and goats (51%) while Abeokuta South had the least percentage of sheep (1%) and goats (1%). All the mange-infested cases in sheep were recorded in just one LGA (Ewekoro) which constituted 0.24% of the population within the location. For goats, three out of five LGAs namely: Obafemi Owode, Ewekoro and Abeokuta North had prevalence of 1.46%, 0.53% and 0.72% respectively. There was no significant (P > 0.05) difference between non-infested and infested animals in terms of packed cell volume (31.79 ± 0.87% vs. 31.41 ± 1.13%), haemoglobin (10.51 ± 0.21 g/100 ml vs. 10.28 ± 0.37 g/100 ml) and red blood cells (8.71 ± 0.29 × 10(12)/l vs. 9.40 ± 0.37 × 10(12)/l). The infested group however showed significantly (P < 0.01) higher white blood cells count (7.60 ± 0.22 × 10(9)/l) than the non-infested animals (6.81 ± 0.17 × 10(9)/l). Neutrophil, eosinophil, basophil and monocyte as well as chloride were not significantly affected by the health status of the animals. There existed significant (P < 0.01) difference between non-infested and infested animals in terms of total protein (5.42 ± 0.16 vs. 4.75 ± 0.20 g/dl), sodium (137.98 ± 1.53 vs. 128.92 ± 1.92 mEq/l) and potassium (4.04 ± 0.14 vs. 3.46 ± 0.18 mEq/l). It can be concluded from this study that the prevalence of mange mite infestation varied with location and was generally low or absent in some of the LGAs considered. Goats were particularly more susceptible to mange infestation than sheep. More concerted effort is needed to control mange in order to avoid spread since it is a contagious disease.

Conditioning food aversions to Ipomoea carnea var. Fistulosa in sheep

USDA-ARS?s Scientific Manuscript database

Ipomoea carnea is a toxic plant in Brazil that often poisons sheep. Conditioned food aversion may be a tool to reduce intoxication problems in grazing sheep. Fifteen sheep were adapted to consume I. carnea for 36 days. Subsequently sheep were randomly divided into three groups of five sheep each. ...

Survival of bighorn sheep (Ovis canadensis) commingled with domestic sheep (Ovis aries) in the absence of Mycoplasma ovipneumoniae.

PubMed

Besser, Thomas E; Cassirer, E Frances; Yamada, Catherine; Potter, Kathleen A; Herndon, Caroline; Foreyt, William J; Knowles, Donald P; Srikumaran, Subramaniam

2012-01-01

To test the hypothesis that Mycoplasma ovipneumoniae is an important agent of the bighorn sheep (Ovis canadensis) pneumonia that has previously inevitably followed experimental commingling with domestic sheep (Ovis aries), we commingled M. ovipneumoniae-free domestic and bighorn sheep (n=4 each). One bighorn sheep died with acute pneumonia 90 days after commingling, but the other three remained healthy for >100 days. This unprecedented survival rate is significantly different (P=0.002) from that of previous bighorn-domestic sheep contact studies but similar to (P>0.05) bighorn sheep survival following commingling with other ungulates. The absence of epizootic respiratory disease in this experiment supports the hypothesized role of M. ovipneumoniae as a key pathogen of epizootic pneumonia in bighorn sheep commingled with domestic sheep.

A Serological Survey of Sera from Domestic Animals on Easter Island

PubMed Central

Boulanger, P.; Gray, D. P.; Gibbs, H. C.; Murphy, D. A.

1968-01-01

Animals' sera collected on Easter Island from December 1964 to February 1965 were tested by appropriate methods for the presence of antibodies to various infections. These included, ornithosis, Q-fever, brucellosis, Johne's disease, leptospirosis, toxoplasmosis and vesicular stomatitis viruses. It appeared that the cattle and sheep were exposed to the ornithosis group of agents. The sheep were also exposed to toxoplasmosis. The low-grade reactions observed on the cattle sera with the leptospira and brucella antigens were not sufficient to indicate past infection. All sera tested with Q-fever and Johne's disease antigens gave negative reactions. The results suggested that neither strain of vesicular stomatitis virus had yet been introduced into this restricted animal population. PMID:4233830

Bighorn sheep response to road-related disturbances in Rocky Mountain National Park, Colorado

USGS Publications Warehouse

Keller, B.J.; Bender, L.C.

2007-01-01

Bighorn sheep (Ovis canadensis) use of Sheep Lakes mineral site, Rocky Mountain National Park, Colorado, USA, has decreased since 1996. Officials were concerned that human disturbance may have been contributing to this decline in use. We evaluated effects of vehicular traffic and other road-related disturbance on bighorn use of Sheep Lakes in the summers of 2002 and 2003. We found that the time and number of attempts required by bighorn to reach Sheep Lakes was positively related to the number of vehicles and people present at Sheep Lakes. Further, the number of bighorn individuals and groups attempting to visit Sheep Lakes were negatively affected by disturbance associated with the site. The number of vehicles recorded the hour before bighorn tried to access Sheep Lakes best predicted an animal's failure to cross Fall River Road and reach Sheep Lakes. We conclude that human and road-related disturbance at Sheep Lakes negatively affected bighorn use of the mineral site. Because Sheep Lakes may be important for bighorn sheep, especially for lamb production and survival, the negative influence of disturbance may compromise health and productivity of the Mummy Range bighorn sheep.

Reducing tick burdens on chicks by treating breeding female grouse with permethrin

USDA-ARS?s Scientific Manuscript database

Ticks are important arthropod vectors of diseases of human, livestock, and wildlife hosts. In the United Kingdom, the sheep tick (Ixodes ricinus) is increasingly recognized as a main limiting factor of red grouse (Lagopus lagopus) populations, a game bird of high economic value. We evaluated the e...

Genetic parameters for fecal egg counts and their relationship with body weights in Katahdin lambs

USDA-ARS?s Scientific Manuscript database

Reliance on anthelminthic drugs to control internal parasites in sheep is no longer sustainable because of the development of resistance to these drugs in parasite populations. Genetic selection may offer an alternative long-term solution, as differences in parasite resistance exist both within and ...

The Northern Territories: Case Study in Japanese-Soviet Relations.

DTIC Science & Technology

1982-06-01

types ( watermelons and tomatoes) due to the relatively warm climatic conditions. Pigs, sheep, and horses populate most all settlements, and dairy...reluctantly accepted these restrictions because of its depend- ence on fish as its primary source of protein , but in doing so has given de facto recognition to

Efficacy of compound X (Bedoukian Research) on reducing fecal egg count in lambs

USDA-ARS?s Scientific Manuscript database

Gastrointestinal nematode (GIN) parasites are a major constraint to profitable sheep production. Due to long-term use of anthelmintics, GIN populations have developed resistance to those available. The objective of this study was to determine the efficacy of a proprietary compound developed by Bedou...

Fire's effects on wildlife habitat - symposium proceedings; 1984 March 21; Missoula, MT

Treesearch

James E. Lotan; James K. Brown

1985-01-01

A compilation of 11 papers in which authorities discuss the impacts of fire on wildlife habitat and wildlife populations. Presentations cover bobwhite quail, nongame birds, white-tailed deer, bighorn and Stone's sheep; and the response to burning of curlleaf cercocarpus, aspen, evergreen ceanothus, and antelope bitterbrush.

Art Education in the Australian Outback.

ERIC Educational Resources Information Center

Duncam, Paul

1994-01-01

Examines the art education classes conducted via radio and correspondence by the Longreach School of Distance Education in Queensland, Australia. Consisting mostly of cattle and sheep ranches, Queensland is marked by vast distances and low population. Considers the ways that this isolation has shaped the character of distance visual arts…

Changes in concentrations of lysergol in urine and prolactin in plasma, rectal temperature and respiration rate in sheep selected for resistance or susceptibility to ryegrass staggers and fed ergovaline.

PubMed

Gooneratne, S R; Scannell, M; Wellby, M; Fletcher, L

2011-09-01

To determine the effects of feeding ryegrass seed containing ergovaline to sheep selected for resistance or susceptibility to ryegrass staggers on concentration of lysergol (a metabolite of ergovaline) in urine, prolactin in plasma, rectal temperature and respiration rate. Two experiments were carried out using 12 Romney crossbred ewe lambs aged 9 months, comprising animals resistant (n=4), susceptible (n=4) or outcross (n=4) to ryegrass staggers. In Experiment 1, sheep were given either a single (Part A) or six (Part B) feed (s) of endophyte-infected seed containing ergovaline at 30 mg/kg dry matter (DM), at 42 μg ergovaline/kg bodyweight (BW), to simulate acute and chronic exposure to ergovaline, respectively. The concentration and excretion of lysergol in urine and concentration of prolactin in plasma were measured over 3 and 12 days, for Parts A and B respectively. In Experiment 2, after a recovery period of 7 days, the same sheep were fed with ergovaline at 67 μg/kg of BW for 7 days. Soon after the seventh feed the sheep were moved to a hothouse at 36.5°C and 60% humidity, and 3 h later their rectal temperatures and respiration rates were measured. The concentration of lysergol and excretion in urine increased to a peak between 6 and 9 h after exposure to ergovaline whereas the concentration of prolactin in plasma was markedly reduced. Differences in concentration and rate of excretion of lysergol in urine between animals resistant, outcross and susceptible to ryegrass staggers were not significant (p>0.1). The animals resistant to ryegrass staggers had a lower rectal temperature (p<0.05) and a faster respiration rate than the outcross and susceptible groups when exposed to high ambient temperature and high humidity. This study showed that excretion of lysergol in urine increased with each exposure of sheep to ergovaline. Animals genetically resistant to ryegrass staggers exhibited a lower rectal temperature and a faster respiration rate than those susceptible, demonstrating the possible cross resistance of sheep to ergovaline in a population originally selected for resistance to ryegrass staggers. Hence potential exists to select animals resistant to ryegrass staggers that are also resistant to ergovaline.

Experimental Transmission of Bighorn Sheep Sinus Tumors to Bighorn Sheep (Ovis canadensis canadensis) and Domestic Sheep.

PubMed

Fox, K A; Wootton, S; Marolf, A; Rouse, N; LeVan, I; Spraker, T; Miller, M; Quackenbush, S

2016-11-01

Bighorn sheep sinus tumors are a recently described disease affecting the paranasal sinuses of Rocky Mountain bighorn sheep (Ovis canadensis canadensis). Several features of this disease suggest an infectious cause, although a specific etiologic agent has not been identified. To test the hypothesis that bighorn sheep sinus tumors are caused by an infectious agent, we inoculated 4 bighorn sheep lambs and 4 domestic sheep lambs intranasally with a cell-free filtrate derived from a naturally occurring bighorn sheep sinus tumor; we held 1 individual of each species as a control. Within 18 months after inoculation, all 4 inoculated domestic sheep (100%) and 1 of the 4 inoculated bighorn sheep (25%) developed tumors within the ethmoid sinuses or nasal conchae, with features similar to naturally occurring bighorn sheep sinus tumors. Neither of the uninoculated sheep developed tumors. Histologically, the experimentally transmitted tumors were composed of stellate to spindle cells embedded within a myxoid matrix, with marked bone production. Tumor cells stained positively with vimentin, S100, alpha smooth muscle actin, and osteocalcin, suggesting origin from a multipotent mesenchymal cell. A periosteal origin for these tumors is suspected. Immunohistochemical staining for the envelope protein of JSRV (with cross-reactivity to ENTV) was equivocal, and PCR assays specific for these agents were negative. © The Author(s) 2016.

West Nile Virus Infection in Sheep.

PubMed

Rimoldi, G; Mete, A; Adaska, J M; Anderson, M L; Symmes, K P; Diab, S

2017-01-01

West Nile virus (WNV) infection has been detected in many species of birds and mammals, but scant information is available about the disease in small ruminants. West Nile virus was diagnosed in 6 sheep with neurological signs and encephalitis, in California between 2002 and 2014. All sheep had severe lymphoplasmacytic meningoencephalitis. Lymphoplasmacytic myelitis was also detected in 2 sheep where the spinal cord was examined. Brain tissue was positive for WNV detected by polymerase chain reaction in 6 of 6 sheep and by immunohistochemistry (IHC) in 5 of 6 sheep. Viral antigen was not detected by IHC in extraneural tissues in the 3 sheep examined. West Nile virus RNA was sequenced from 2 of 6 sheep, and each one clusters closely with WNV isolated from mosquito pools from nearby locations at similar times. West Nile virus was the most common cause of viral encephalitis in sheep diagnosed at this laboratory between 2002 and 2014, accounting for 6 of 9 sheep.

Allergy to goat and sheep cheese with tolerance to cow's milk and its derivatives.

PubMed

Viñas, M; Carnés, J; López-Matas, M A; Hernández, N; Castillo, M J; Ibero, M

2014-01-01

We present two adult and three paediatric patients who had allergic reactions after cheese ingestion and subsequently tolerated cow's milk derivatives. The objective of this study was to determine possible cross-reactivity between different types of cheese. Skin tests were performed to cow's milk fractions, and prick-prick tests for goat, sheep and cow cheese. Specific IgE to the fractions of cow's milk and cow, sheep and goat cheese was analysed. The protein profile of cow, sheep and goat cheese extracts was determined by SDS-PAGE and the allergenic profile by immunoblot. Cross-reactivity was investigated by immunoblot inhibition. Skin tests were positive for casein in the patients. The prick-prick tests were positive for the three cheeses in patients 1 and 4, for goat and sheep cheese in patients 2 and 3, and for sheep cheese in patient 5. The specific IgE test was positive in patients 1, 3 and 4 for goat and sheep cheese, and negative in patients 2 and 5. Serum 3 and 4 clearly recognised goat and sheep cheese extracts. Goat casein was almost completely inhibited with sheep casein and partially inhibited with goat and sheep serum proteins, while there was no inhibition with cow cheese. Sheep casein was totally inhibited with sheep serum proteins. Sheep casein was inhibited with goat and cow caseins, suggesting cross-reactivity among the three types of cheese. We showed sensitisation to goat and sheep cheese in two patients, and only to sheep cheese in another two of the studied patients. Copyright © 2012 SEICAP. Published by Elsevier Espana. All rights reserved.

21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 21 Food and Drugs 2 2012-04-01 2012-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION..., sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (a) Description. (1) Roquefort cheese...

21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

Code of Federal Regulations, 2014 CFR

2014-04-01

... 21 Food and Drugs 2 2014-04-01 2014-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION..., sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (a) Description. (1) Roquefort cheese...

21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 21 Food and Drugs 2 2013-04-01 2013-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION..., sheep's milk blue-mold, and blue-mold cheese from sheep's milk. (a) Description. (1) Roquefort cheese...

Non-overlapping distributions of feral sheep (Ovis aries) and Stout Iguanas (Cyclura pinguis) on Guana Island, British Virgin Islands

USGS Publications Warehouse

Skipper, Ben R.; Grisham, Blake A.; Kalyvaki, Maria; McGaughey, Kathleen; Mougey, Krista; Navarrete, Laura; Rondeau, Renée; Boal, Clint W.; Perry, Gad

2013-01-01

Stout Iguanas (Cyclura pinguis) remain one of the most critically endangered reptiles in the world. Factors contributing to that status include habitat loss, predation by introduced species, and competition with introduced herbivores. On Guana Island, British Virgin Islands, the presence of feral sheep (Ovis aries) has been a hypothesized detriment to iguanas. Using motion sensitive cameras, we documented the distribution of feral sheep on Guana Island in 2010. We also quantified the impact of feral sheep on ground vegetation by comparing plant abundance at longterm sheep exclosures and areas where sheep were absent to areas where sheep were present. Finally, we compared sheep distribution to iguana distribution on the island. The co-occurrence of sheep and Stout Iguanas was less than expected, indicating possible competition. Although we detected no difference in vegetative cover between areas where sheep were present and absent, the long-term exclosures showed that the exclusion of sheep allowed the abundance of many plant species to increase. Our data support the hypothesis that feral sheep are altering the abundance of ground-level vegetation and limiting iguana distribution on the island.

Effect of Entodinium caudatum on starch intake and glycogen formation by Eudiplodinium maggii in the rumen and reticulum.

PubMed

Bełżecki, Grzegorz; McEwan, Neil R; Kowalik, Barbara; Michałowski, Tadeusz; Miltko, Renata

2017-02-01

This study aimed to quantify the engulfed starch and reserve α-glucans (glycogen) in the cells of the ciliates Eudiplodinium maggii, as well the α-glucans in defaunated and selectively faunated sheep. The content of starch inside the cell of ciliates varied from 21 to 183mg/g protozoal DM relative to the rumen fauna composition whereas, the glycogen fluctuated between 17 and 126mg/g dry matter (DM) of this ciliate species. Establishment of the population Entodinium caudatum in the rumen of sheep already faunated with E. maggii caused a drop in both types of quantified carbohydrates. The content of α-glucans in the rumen of defaunated sheep varied from 4.4 to 19.9mg/g DM and increased to 7.4-29.9 or 11.8-33.9mg/g DM of rumen contents in the presence of only E. maggii or E. maggii and E. caudatum, respectively. The lowest content of the carbohydrates was always found just before feeding and the highest at 4h thereafter. The α-glucans in the reticulum varied 7.5-40.1, 14.3-76.8 or 21.9-106.1mg/g DM of reticulum content for defaunated, monofaunated or bifaunated sheep, respectively. The results indicated that both ciliate species engulf starch granules and convert the digestion products to the glycogen, diminishing the pool of starch available for amylolytic bacteria. Copyright © 2016 Elsevier GmbH. All rights reserved.

Technical note: Protozoa-specific antibodies raised in sheep plasma bind to their target protozoa in the rumen.

PubMed

Williams, Y J; Rea, S M; Popovski, S; Skillman, L C; Wright, A-D G

2014-12-01

Binding of IgG antibodies to Entodinium spp. in the rumen of sheep (Ovis aries) was investigated by adding IgG, purified from plasma, directly into the rumen. Plasma IgG was sourced from sheep that had or had not been immunized with a vaccine containing whole fixed Entodinium spp. cells. Ruminal fluid was sampled approximately 2 h after each antibody dosing. Binding of protozoa by a specific antibody was detected using an indirect fluorescent antibody test. An antibody titer in the ruminal fluid was determined by ELISA, and the concentration of ruminal fluid ammonia-N and ruminal pH were also determined. Entodinium spp. and total protozoa from IgG-infused sheep were enumerated by microscopic counts. Two-hourly additions of IgG maintained a low antibody titer in the rumen for 12 h and the binding of the antibody to the rumen protozoa was demonstrated. Increased ammonia-N concentrations and altered ruminal fluid pH patterns indicated that additional fermentation of protein was occurring in the rumen after addition of IgG. No reduction in numbers of Entodinium spp. was observed (P>0.05). Although binding of antibodies to protozoa has been demonstrated in the rumen, it is unclear how much cell death occurred. On the balance of probability, it would appear that the antibody was degraded or partially degraded, and the impact of this on protozoal populations and the measurement of a specific titer is also unclear.

Range Management Affects Native Ungulate Populations in Península Valdés, a World Natural Heritage

PubMed Central

Nabte, Marcela J.; Marino, Andrea I.; Rodríguez, María Victoria; Monjeau, Adrián; Saba, Sergio L.

2013-01-01

Sheep rearing is the main productive activity in Patagonian rangelands, where guanacos are the only native ungulate. Ranchers perceive a decrease in range carrying capacity as guanaco numbers increase, therefore guanaco conservation within private lands becomes a considerable challenge. This issue is particularly evident in the World Natural Heritage Península Valdés (PV), where there is a need to harmonize livestock production and biodiversity conservation. While sheep rearing prevails as the primary land use in the area, some ecotourism initiatives have been implemented to complement livestock production. In order to study how land use affected guanaco distribution, we characterized PV's ranches in terms of land subdivision, primary productivity, stocking-rate and management type, and assess how these variables affected guanaco encounter rates. Smaller ranches were composed of smaller paddocks (mean size 4.8 km2), which showed higher values of the remote-sensing derived Enhance Vegetation Index (EVI) (mean 0.14) and held higher sheep densities (mean 108.0 sheep/km2), while larger management units (mean size 23.8 km2), showed lower EVI values (mean 0.12) and lower stocking-rates (mean 36.7 sheep/km2). This pattern suggests that primary productivity has been a decisive factor to determine the minimal paddock size set by ranchers in PV, apparently precluding excessive land-subdivision in less productive areas. Guanaco encounter rate, expressed as number of guanacos per travelled kilometre, was inversely related to EVI and stocking-rate. However, land subdivision was the better predictor of guanaco encounter-rate within only sheep ranches, finding more guanacos per kilometre as paddock size increased. In contrast, in ranches where ecotourism was implemented as a complementary activity, guanaco encounter-rates were greater, regardless of paddock size. Our results suggest that the implementation of an additional activity by which landowners derive benefits from wildlife has prompted a beneficial outcome for guanacos, presumably through a decrease in harassment intensity. Finally, we propose possible mechanisms by which land subdivision may affect guanaco distribution and potential alternatives for the inclusion of wildlife conservation in a context of extensive livestock production. PMID:23390546

Range management affects native ungulate populations in Península Valdés, a World Natural Heritage.

PubMed

Nabte, Marcela J; Marino, Andrea I; Rodríguez, María Victoria; Monjeau, Adrián; Saba, Sergio L

2013-01-01

Sheep rearing is the main productive activity in Patagonian rangelands, where guanacos are the only native ungulate. Ranchers perceive a decrease in range carrying capacity as guanaco numbers increase, therefore guanaco conservation within private lands becomes a considerable challenge. This issue is particularly evident in the World Natural Heritage Península Valdés (PV), where there is a need to harmonize livestock production and biodiversity conservation. While sheep rearing prevails as the primary land use in the area, some ecotourism initiatives have been implemented to complement livestock production. In order to study how land use affected guanaco distribution, we characterized PV's ranches in terms of land subdivision, primary productivity, stocking-rate and management type, and assess how these variables affected guanaco encounter rates. Smaller ranches were composed of smaller paddocks (mean size 4.8 km(2)), which showed higher values of the remote-sensing derived Enhance Vegetation Index (EVI) (mean 0.14) and held higher sheep densities (mean 108.0 sheep/km(2)), while larger management units (mean size 23.8 km(2)), showed lower EVI values (mean 0.12) and lower stocking-rates (mean 36.7 sheep/km(2)). This pattern suggests that primary productivity has been a decisive factor to determine the minimal paddock size set by ranchers in PV, apparently precluding excessive land-subdivision in less productive areas. Guanaco encounter rate, expressed as number of guanacos per travelled kilometre, was inversely related to EVI and stocking-rate. However, land subdivision was the better predictor of guanaco encounter-rate within only sheep ranches, finding more guanacos per kilometre as paddock size increased. In contrast, in ranches where ecotourism was implemented as a complementary activity, guanaco encounter-rates were greater, regardless of paddock size. Our results suggest that the implementation of an additional activity by which landowners derive benefits from wildlife has prompted a beneficial outcome for guanacos, presumably through a decrease in harassment intensity. Finally, we propose possible mechanisms by which land subdivision may affect guanaco distribution and potential alternatives for the inclusion of wildlife conservation in a context of extensive livestock production.

76 FR 3026 - Fluazinam; Pesticide Tolerances

Federal Register 2010, 2011, 2012, 2013, 2014

2011-01-19

...: Cattle, fat; cattle, kidney; cattle, liver; cattle, meat; cattle, meat byproducts; goat, fat; goat, kidney; goat, liver; goat, meat; goat, meat byproducts; horse, fat; horse, kidney; horse, liver; horse, meat; horse, meat byproducts; milk; sheep, fat; sheep, kidney; sheep, liver; sheep, meat; and sheep...

Evidence of Bovine viral diarrhea virus Infection in Three Species of Sympatric Wild Ungulates in Nevada: Life History Strategies May Maintain Endemic Infections in Wild Populations

PubMed Central

Wolff, Peregrine L.; Schroeder, Cody; McAdoo, Caleb; Cox, Mike; Nelson, Danielle D.; Evermann, James F.; Ridpath, Julia F.

2016-01-01

Evidence for bovine viral diarrhea virus (BVDV) infection was detected in 2009–2010 while investigating a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis, canadensis), and sympatric mountain goats (Oreamnos americanum) in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 was 81% (N = 32) in the bighorns and 100% (N = 3) in the mountain goats. Serosurveillance from 2011 to 2015 of surviving bighorns and mountain goats as well as sympatric mule deer (Odocoileus hemionus), indicated a prevalence of 72% (N = 45), 45% (N = 51), and 51% (N = 342) respectively. All species had antibody titers to BVDV1 and BVDV2. BVDV1 was isolated in cell culture from three bighorn sheep and a mountain goat kid. BVDV2 was isolated from two mule deer. Six deer (N = 96) sampled in 2013 were positive for BVDV by antigen-capture ELISA on a single ear notch. Wild ungulates and cattle concurrently graze public and private lands in these two mountain ranges, thus providing potential for interspecies viral transmission. Like cattle, mule deer, mountain goats, and bighorn sheep can be infected with BVDV and can develop clinical disease including immunosuppression. Winter migration patterns that increase densities and species interaction during the first and second trimester of gestation may contribute to the long term maintenance of the virus in these wild ungulates. More studies are needed to determine the population level impacts of BVDV infection on these three species. PMID:27014215

Successive sheep grazing reduces population density of Brandt's voles in steppe grassland by altering food resources: a large manipulative experiment.

PubMed

Li, Guoliang; Yin, Baofa; Wan, Xinrong; Wei, Wanhong; Wang, Guiming; Krebs, Charles J; Zhang, Zhibin

2016-01-01

Livestock grazing has shaped grassland ecosystems around the world. Previous studies indicated grazing showed various impacts on small rodents; however, most studies were conducted over 1-2 years without controlling for confounding factors such as immigration/emigration and predation in rodents. Brandt's voles (Lasiopodomys brandtii) are generally recognized as pests because of food overlap with domestic herbivores, but are also important for biodiversity conservation because they provide nests or food to many birds. Fully understanding the ecological relationship between domestic herbivores and small mammals is essential to making ecosystem management decisions. To address these needs, we carried out a field experiment during the period 2010-2013 to assess the effects of sheep grazing on vegetation and the population density of Brandt's voles along a gradient of three grazing intensities by using 12 large-scale enclosures. Responses of Brandt's voles to livestock grazing varied with grazing intensity and year. As compared to the control group, sheep grazing had no effect on vole abundance in the first year but an overall negative effect on vole abundance in the following 3 years. Successive grazing caused decreases in survival and male body mass of voles, but had no significant effect on fecundity. Negative effects of grazing were associated with a grazing-induced deterioration in both food quantity (reflected by biomass and cover of less-preferred plants), and food quality (measured by tannin and total phenol content). Our findings highlight the urgent need for more flexible management of yearly rotational grazing to optimize livestock production while maintaining species diversity and ecosystem health.

Serological Evidence for the Circulation of Rift Valley Fever Virus in Domestic Small Ruminants in Southern Gabon.

PubMed

Maganga, Gael Darren; Abessolo Ndong, Andre Lea; Mikala Okouyi, Clency Sylde; Makiala Mandanda, Sheila; N'Dilimabaka, Nadine; Pinto, Anais; Agossou, Ernest; Cossic, Brieuc; Akue, Jean-Paul; Leroy, Eric Maurice

2017-06-01

Rift Valley fever (RVF) is a zoonotic disease, which caused several epidemics in humans in many countries of Africa. Using an inhibition enzyme-linked immunosorbent assay (ELISA), real-time reverse transcription PCR, and nested one-step reverse transcription PCR, we conducted a cross-sectional study in populations of sheep and goats from the Mongo County in 2014 to determine the circulation of the Rift Valley fever virus (RVFV) in small ruminants from this area. From a total of 201 small ruminants (95 sheep and 106 goats), the overall IgG seroprevalence against the RVFV was 6.47% (13/201). No RVFV RNA was detected in the animal plasmas. Logistic regression analysis showed that age, species, sex, and locality were not the significant risk factors. The findings of this study highlight the risk of RVF for domestic ruminants bred in this region and for the human rural population living in contact with these animals and they emphasize the need to develop adequate control measures to limit this threat.

Lentiviral diseases of sheep and goats: chronic pneumonia leukoencephalomyelitis and arthritis.

PubMed

Narayan, O; Cork, L C

1985-01-01

This review describes the pathogenesis of a slowly progressive disease complex caused by naturally occurring nononcogenic retroviruses in sheep and goats. In nature, infections are usually clinically silent, but disease may manifest itself after prolonged incubation periods. Clinically, this is seen as dyspnea, progressive paralysis, and/or progressive arthritis. In all organs the basic lesion is inflammatory with infiltration and proliferation of lymphocytes, plasma cells, and macrophages. Other organ-specific pathologic changes such as primary demyelination in the central nervous system and degeneration of cartilaginous structures in joints accompany inflammation. The viruses infect tissue-specific macrophage populations in vivo. Viral replication in these cells is restricted to minimal levels but continues indefinitely in the animal as a result of either failure to induce specific neutralizing antibodies or antigenic drift when neutralizing antibodies develop. Consistent low-grade viral replication sets the pace for disease by providing continuous antigenic stimulation for the inflammatory cellular immune response or antibodies that localize in the target tissues. These cells and immune complexes may have adverse effects on indigenous cell populations.

Genetic selection for temperament affects behaviour and the secretion of adrenal and reproductive hormones in sheep subjected to stress.

PubMed

Hawken, P A R; Luckins, N; Tilbrook, A; Fiol, C; Martin, G B; Blache, D

2013-01-01

We investigated the effect of genetic selection for temperament on the way that stressors affect the behaviour and the adrenal and reproductive axes of sheep. We tested three hypotheses: (i) isolation would increase cortisol secretion and decrease luteinising hormone (LH) secretion more in nervous sheep than in calm sheep; (ii) isolation combined with simulated human presence would increase cortisol secretion and decrease LH secretion more in nervous sheep than in calm sheep and (iii) isolation combined with stressors that were not specific to the selection process (i.e. non-selection stressors) would increase cortisol secretion and decrease LH secretion equally in calm and nervous sheep. Isolation alone increased cortisol secretion and decreased LH secretion in nervous sheep but not in calm sheep. Compared to calm sheep, nervous sheep were more agitated during the first 2 h of isolation but not during the second 2 h of isolation. Exposure to non-selection stressors increased cortisol secretion, decreased LH pulse amplitude and the mean plasma concentrations of LH in both calm and nervous sheep. We conclude that genetic selection for temperament affects the behavioural expression of the stress response and the secretion of adrenal and reproductive hormones during isolation, but has less impact on their reactivity to non-selection stressors.

Detecting signatures of selection within the Tibetan sheep mitochondrial genome.

PubMed

Niu, Lili; Chen, Xiaoyong; Xiao, Ping; Zhao, Qianjun; Zhou, Jingxuan; Hu, Jiangtao; Sun, Hongxin; Guo, Jiazhong; Li, Li; Wang, Linjie; Zhang, Hongping; Zhong, Tao

2017-11-01

Tibetan sheep, a Chinese indigenous breed, are mainly distributed in plateau and mountain-valley areas at a terrestrial elevation between 2260 and 4100 m. The herd is genetically distinct from the other domestic sheep and undergoes acclimatization to adapt to the hypoxic environment. To date, whether the mitochondrial DNA modification of Tibetan sheep shares the same feature as the other domestic breed remains unknown. In this study, we compared the whole mitogenome sequences from 32 Tibetan sheep, 22 domestic sheep and 24 commercial sheep to identify the selection signatures of hypoxic-tolerant in Tibetan sheep. Nucleotide diversity analysis using the sliding window method showed that the highest level of nucleotide diversity was observed in the control region with a peak value of π = 0.05215, while the lowest π value was detected in the tRNAs region. qPCR results showed that the relative mtDNA copy number in Tibetan sheep was significantly lower than that in Suffolk sheep. None of the mutations in 12S rRNA were fixed in Tibetan sheep, which indicated that there has been less artificial selection in this herd than the other domestic and commercial breeds. Although one site (1277G) might undergo the purifying selection, it was not identified as the breed-specific allele in Tibetan sheep. We proposed that nature selection was the main drive during the domestication of Tibetan sheep and single mutation (or locus) could not reveal the signature of selection as for the high diversity in the mitogenome of Tibetan sheep.

Density of wild prey modulates lynx kill rates on free-ranging domestic sheep.

PubMed

Odden, John; Nilsen, Erlend B; Linnell, John D C

2013-01-01

Understanding the factors shaping the dynamics of carnivore-livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed.

Density of Wild Prey Modulates Lynx Kill Rates on Free-Ranging Domestic Sheep

PubMed Central

Odden, John; Nilsen, Erlend B.; Linnell, John D. C.

2013-01-01

Understanding the factors shaping the dynamics of carnivore–livestock conflicts is vital to facilitate large carnivore conservation in multi-use landscapes. We investigated how the density of their main wild prey, roe deer Capreolus capreolus, modulates individual Eurasian lynx Lynx lynx kill rates on free-ranging domestic sheep Ovis aries across a range of sheep and roe deer densities. Lynx kill rates on free-ranging domestic sheep were collected in south-eastern Norway from 1995 to 2011 along a gradient of different livestock and wild prey densities using VHF and GPS telemetry. We used zero-inflated negative binomial (ZINB) models including lynx sex, sheep density and an index of roe deer density as explanatory variables to model observed kill rates on sheep, and ranked the models based on their AICc values. The model including the effects of lynx sex and sheep density in the zero-inflation model and the effect of lynx sex and roe deer density in the negative binomial part received most support. Irrespective of sheep density and sex, we found the lowest sheep kill rates in areas with high densities of roe deer. As roe deer density decreased, males killed sheep at higher rates, and this pattern held for both high and low sheep densities. Similarly, females killed sheep at higher rates in areas with high densities of sheep and low densities of roe deer. However, when sheep densities were low females rarely killed sheep irrespective of roe deer density. Our quantification of depredation rates can be the first step towards establishing fairer compensation systems based on more accurate and area specific estimation of losses. This study demonstrates how we can use ecological theory to predict where losses of sheep will be greatest, and can be used to identify areas where mitigation measures are most likely to be needed. PMID:24278123

Response of Lucilia sericata (Diptera: Calliphoridae) to Screwworm Oviposition Attractant

USDA-ARS?s Scientific Manuscript database

The sheep blow fly, Lucilia sericata Meigen (Diptera: Calliphoridae), causes sheep myiasis in various parts of the world. The females are attracted to sheep, following various olfactory cues emanating from the sheep's body, and oviposit on suitable substrates on sheep ultimately causing myiasis. Ear...

Multiplex-touchdown PCR assay for the detection and genotyping of Helicobacter pylori from artificially contaminated sheep milk.

PubMed

Quaglia, N C; Normanno, G; Dambrosio, A; Celano, G V; Parisi, A; Firinu, A; Buonavoglia, C

2005-10-01

Helicobacter pylori (Hp) is an organism commonly present worldwide in the human population, sometimes causing serious illnesses such as duodenal and gastric ulcers, adenocarcinoma of the stomach, and low-grade B-cell mucosa-associated lymphoid tissue lymphoma of the stomach. This article describes a multiplex-touchdown PCR method for the identification and genotyping (vacA-s1/m1, sl/m2, and s2/m2-and cagA genes) of Hp directly from sheep milk artificially contaminated with Hp strains from human gastric biopsies and with Hp ATCC 43504. The strains from humans carried sl/m2 cagA+ and s2/m2 cagA allelic combinations, while the ATCC strains carried an sl/ml cagA+ allelic combination. The technique showed a sensitivity of 15 CFU/ml for species identification and of 1,500 CFU/ml for the detection of genes encoding for VacA and CagA. It has proven to be specific and rapid, and the authors suggest that it be used as a rapid screening method to ensure that sheep milk is uncontaminated with this organism.

The distribution of runs of homozygosity and selection signatures in six commercial meat sheep breeds

PubMed Central

Purfield, Deirdre C.; McParland, Sinead; Wall, Eamon; Berry, Donagh P.

2017-01-01

Domestication and the subsequent selection of animals for either economic or morphological features can leave a variety of imprints on the genome of a population. Genomic regions subjected to high selective pressures often show reduced genetic diversity and frequent runs of homozygosity (ROH). Therefore, the objective of the present study was to use 42,182 autosomal SNPs to identify genomic regions in 3,191 sheep from six commercial breeds subjected to selection pressure and to quantify the genetic diversity within each breed using ROH. In addition, the historical effective population size of each breed was also estimated and, in conjunction with ROH, was used to elucidate the demographic history of the six breeds. ROH were common in the autosomes of animals in the present study, but the observed breed differences in patterns of ROH length and burden suggested differences in breed effective population size and recent management. ROH provided a sufficient predictor of the pedigree inbreeding coefficient, with an estimated correlation between both measures of 0.62. Genomic regions under putative selection were identified using two complementary algorithms; the fixation index and hapFLK. The identified regions under putative selection included candidate genes associated with skin pigmentation, body size and muscle formation; such characteristics are often sought after in modern-day breeding programs. These regions of selection frequently overlapped with high ROH regions both within and across breeds. Multiple yet uncharacterised genes also resided within putative regions of selection. This further substantiates the need for a more comprehensive annotation of the sheep genome as these uncharacterised genes may contribute to traits of interest in the animal sciences. Despite this, the regions identified as under putative selection in the current study provide an insight into the mechanisms leading to breed differentiation and genetic variation in meat production. PMID:28463982

An evaluation of alternative selection indexes for a non-linear profit trait approaching its economic optimum.

PubMed

Martin-Collado, D; Byrne, T J; Visser, B; Amer, P R

2016-12-01

This study used simulation to evaluate the performance of alternative selection index configurations in the context of a breeding programme where a trait with a non-linear economic value is approaching an economic optimum. The simulation used a simple population structure that approximately mimics selection in dual purpose sheep flocks in New Zealand (NZ). In the NZ dual purpose sheep population, number of lambs born is a genetic trait that is approaching an economic optimum, while genetically correlated growth traits have linear economic values and are not approaching any optimum. The predominant view among theoretical livestock geneticists is that the optimal approach to select for nonlinear profit traits is to use a linear selection index and to update it regularly. However, there are some nonlinear index approaches that have not been evaluated. This study assessed the efficiency of the following four alternative selection index approaches in terms of genetic progress relative to each other: (i) a linear index, (ii) a linear index updated regularly, (iii) a nonlinear (quadratic) index, and (iv) a NLF index (nonlinear index below the optimum and then flat). The NLF approach does not reward or penalize animals for additional genetic merit beyond the trait optimum. It was found to be at least comparable in efficiency to the approach of regularly updating the linear index with short (15 year) and long (30 year) time frames. The relative efficiency of this approach was slightly reduced when the current average value of the nonlinear trait was close to the optimum. Finally, practical issues of industry application of indexes are considered and some potential practical benefits of efficient deployment of a NLF index in highly heterogeneous industries (breeds, flocks and production environments) such as in the NZ dual purpose sheep population are discussed. © 2016 Blackwell Verlag GmbH.

[The dose estimation to the population as a result of radioactive contamination of the Semipalatinsk Test area].

PubMed

Spiridonova, S I; Mukusheva, M K; Shubina, O A; Solomatin, V M; Epifanova, I E

2008-01-01

The results are presented from estimation of spatial distribution of 137Cs and 90Sr contamination densities in the areas of horses and sheep grazing within the Semipalatinsk Test Site. Dose burdens to various cohorts of the population living within the STS and consuming contaminated animal products are predicted. Doses of shepherds in the most contaminated pasture areas have been found to exceed the accepted limit (1 mSv/y). The conclusion is made about the need for further studies on the risk assessment of the STS population exposure above the accepted limits.

Facilities, breed and experience affect ease of sheep handling: the livestock transporter's perspective.

PubMed

Burnard, C L; Pitchford, W S; Hocking Edwards, J E; Hazel, S J

2015-08-01

An understanding of the perceived importance of a variety of factors affecting the ease of handling of sheep and the interactions between these factors is valuable in improving profitability and welfare of the livestock. Many factors may contribute to animal behaviour during handling, and traditionally these factors have been assessed in isolation under experimental conditions. A human social component to this phenomenon also exists. The aim of this study was to gain a deeper understanding of the importance of a variety of factors affecting ease of handling, and the interactions between these from the perspective of the livestock transporter. Qualitative interviews were used to investigate the factors affecting sheep behaviour during handling. Interview transcripts underwent thematic analysis. Livestock transporters discussed the effects of attitudes and behaviours towards sheep, helpers, facilities, distractions, environment, dogs and a variety of sheep factors including breed, preparation, experience and sex on sheep behaviour during handling. Transporters demonstrated care and empathy and stated that patience and experience were key factors determining how a person might deal with difficult sheep. Livestock transporters strongly believed facilities (ramps and yards) had the greatest impact, followed by sheep experience (naivety of the sheep to handling and transport) and breed. Transporters also discussed the effects of distractions, time of day, weather, dogs, other people, sheep preparation, body condition and sheep sex on ease of handling. The concept of individual sheep temperament was indirectly expressed.

Survival of bighorn sheep (Ovis canadensis) commingled with domestic sheep (Ovis aries) in the absence of mycoplasma ovipneumoniae.

USDA-ARS?s Scientific Manuscript database

To test the hypothesis that Mycoplasma ovipneumoniae is an important agent of the bighorn sheep (Ovis canadensis) pneumonia that has previously inevitably followed experimental commingling with domestic sheep (Ovis aries), we commingled M. ovipneumoniae–free domestic and bighorn sheep (n=4 each). On...

Cystic echinococcosis in slaughtered sheep in Sardinia (Italy).

PubMed

Scala, A; Garippa, G; Varcasia, A; Tranquillo, V M; Genchi, C

2006-01-15

Of 771 regularly slaughtered Sardinian breed sheep, 580 (75%) were found infected with Echinococcus granulosus hydatid cysts. Seventy-nine sheep (10.3%) had at least 1 fertile cyst. The prevalence of sheep infected with purulent/caseous cysts, calcified cysts and sterile cysts was 13, 59 and 28%, respectively. The age of sheep was positively associated with the probability of infection that increased 1.15 fold for each further year of age. Fertile cysts were found in the lungs of 46 sheep (6%) and in the liver of 13 sheep (1.7%), and in the lung and the liver of 20 sheep (2.6%). Most fertile cysts were found in the lungs (314) and most sheep were infected with less than 10 cysts. When analyzed by a mixed-effect logistic model, the probability to find fertile cysts in the lungs was three times higher compared to the liver and it increased with the age of the sheep (rho = 0.70, p < 0.001). Of 4072 collected cysts, 532 were fertile, 178 purulent/caseous, 2339 calcified and 1023 sterile.

Extensive Variation and Sub-Structuring in Lineage A mtDNA in Indian Sheep: Genetic Evidence for Domestication of Sheep in India

PubMed Central

Singh, Sachin; Kumar Jr, Satish; Kolte, Atul P.; Kumar, Satish

2013-01-01

Previous studies on mitochondrial DNA analysis of sheep from different regions of the world have revealed the presence of two major- A and B, and three minor- C, D and E maternal lineages. Lineage A is more frequent in Asia and lineage B is more abundant in regions other than Asia. We have analyzed mitochondrial DNA sequences of 330 sheep from 12 different breeds of India. Neighbor-joining analysis revealed lineage A, B and C in Indian sheep. Surprisingly, multidimensional scaling plot based on FST values of control region of mtDNA sequences showed significant breed differentiation in contrast to poor geographical structuring reported earlier in this species. The breed differentiation in Indian sheep was essentially due to variable contribution of two major lineages to different breeds, and sub- structuring of lineage A, possibly the latter resulting from genetic drift. Nucleotide diversity of this lineage was higher in Indian sheep (0.014 ± 0.007) as compared to that of sheep from other regions of the world (0.009 ± 0.005 to 0.01 ± 0.005). Reduced median network analysis of control region and cytochrome b gene sequences of Indian sheep when analyzed along with available published sequences of sheep from other regions of the world showed that several haplotypes of lineage A were exclusive to Indian sheep. Given the high nucleotide diversity in Indian sheep and the poor sharing of lineage A haplotypes between Indian and non-Indian sheep, we propose that lineage A sheep has also been domesticated in the east of Near East, possibly in Indian sub-continent. Finally, our data provide support that lineage B and additional lineage A haplotypes of sheep might have been introduced to Indian sub-continent from Near East, probably by ancient sea trade route. PMID:24244282

The structure, dynamics and movement patterns of the Australian sheep industry.

PubMed

East, I J; Foreman, I

2011-12-01

To describe the structure of Australia's sheep industries and the movement of sheep to enable examination of the potential for animal movements to spread disease between farms. The structure, size, marketing and movement patterns of Australian sheep farms was determined through (i) review of data published by the Australian Bureau of Statistics and Australian Bureau of Agricultural and Resource Economics, (ii) interviews with producers and saleyard managers and (iii) expert opinion. Twelve geographic regions are described, based on the type and extent of sheep farming in each region. Five production sectors were identified within the Australian sheep industry, with the proportion of each varying between the geographic regions. Over the past 20 years, the industry has decreased in size and contracted from the northern and central areas of Australia. Movement of sheep onto the majority (79%) of properties was limited to the introduction of less than 50 stud rams annually, although cross-bred- and wether-based farms introduced up to 2000 sheep annually; 75% of sheep movements occurred over distances less than 200 km, but stud rams moved up to 500 km. An increasing percentage of movements off farms was direct to abattoirs and over 80% of sheep sold through saleyards were purchased by abattoirs. The majority of Australian sheep farms operate as self-replacing enterprises and introduce few stock. In addition, most sheep movements occur over distances of less than 200 km and therefore sheep movements within Australia have only a limited potential to spread disease over larger distances. © 2011 The Authors. Australian Veterinary Journal © 2011 Australian Veterinary Association.

Propofol Pharmacokinetics and Estimation of Fetal Propofol Exposure during Mid-Gestational Fetal Surgery: A Maternal-Fetal Sheep Model

PubMed Central

Niu, Jing; Venkatasubramanian, Raja; Vinks, Alexander A.; Sadhasivam, Senthilkumar

2016-01-01

Background Measuring fetal drug concentrations is extremely difficult in humans. We conducted a study in pregnant sheep to simultaneously describe maternal and fetal concentrations of propofol, a common intravenous anesthetic agent used in humans. Compared to inhalational anesthesia, propofol supplemented anesthesia lowered the dose of desflurane required to provide adequate uterine relaxation during open fetal surgery. This resulted in better intraoperative fetal cardiac outcome. This study describes maternal and fetal propofol pharmacokinetics (PK) using a chronically instrumented maternal-fetal sheep model. Methods Fetal and maternal blood samples were simultaneously collected from eight mid-gestational pregnant ewes during general anesthesia with propofol, remifentanil and desflurane. Nonlinear mixed-effects modeling was performed by using NONMEM software. Total body weight, gestational age and hemodynamic parameters were tested in the covariate analysis. The final model was validated by bootstrapping and visual predictive check. Results A total of 160 propofol samples were collected. A 2-compartment maternal PK model with a third fetal compartment appropriately described the data. Mean population parameter estimates for maternal propofol clearance and central volume of distribution were 4.17 L/min and 37.7 L, respectively, in a typical ewe with a median heart rate of 135 beats/min. Increase in maternal heart rate significantly correlated with increase in propofol clearance. The estimated population maternal-fetal inter-compartment clearance was 0.0138 L/min and the volume of distribution of propofol in the fetus was 0.144 L. Fetal propofol clearance was found to be almost negligible compared to maternal clearance and could not be robustly estimated. Conclusions For the first time, a maternal-fetal PK model of propofol in pregnant ewes was successfully developed. This study narrows the gap in our knowledge in maternal-fetal PK model in human. Our study confirms that maternal heart rate has an important influence on the pharmacokinetics of propofol during pregnancy. Much lower propofol concentration in the fetus compared to maternal concentrations explain limited placental transfer in in-vivo paired model, and less direct fetal cardiac depression we observed earlier with propofol supplemented inhalational anesthesia compared to higher dose inhalational anesthesia in humans and sheep. PMID:26752560

A bioinformatic pipeline for identifying informative SNP panels for parentage assignment from RADseq data.

PubMed

Andrews, Kimberly R; Adams, Jennifer R; Cassirer, E Frances; Plowright, Raina K; Gardner, Colby; Dwire, Maggie; Hohenlohe, Paul A; Waits, Lisette P

2018-06-05

The development of high-throughput sequencing technologies is dramatically increasing the use of single nucleotide polymorphisms (SNPs) across the field of genetics, but most parentage studies of wild populations still rely on microsatellites. We developed a bioinformatic pipeline for identifying SNP panels that are informative for parentage analysis from restriction site-associated DNA sequencing (RADseq) data. This pipeline includes options for analysis with or without a reference genome, and provides methods to maximize genotyping accuracy and select sets of unlinked loci that have high statistical power. We test this pipeline on small populations of Mexican gray wolf and bighorn sheep, for which parentage analyses are expected to be challenging due to low genetic diversity and the presence of many closely related individuals. We compare the results of parentage analysis across SNP panels generated with or without the use of a reference genome, and between SNPs and microsatellites. For Mexican gray wolf, we conducted parentage analyses for 30 pups from a single cohort where samples were available from 64% of possible mothers and 53% of possible fathers, and the accuracy of parentage assignments could be estimated because true identities of parents were known a priori based on field data. For bighorn sheep, we conducted maternity analyses for 39 lambs from five cohorts where 77% of possible mothers were sampled, but true identities of parents were unknown. Analyses with and without a reference genome produced SNP panels with >95% parentage assignment accuracy for Mexican gray wolf, outperforming microsatellites at 78% accuracy. Maternity assignments were completely consistent across all SNP panels for the bighorn sheep, and were 74.4% consistent with assignments from microsatellites. Accuracy and consistency of parentage analysis were not reduced when using as few as 284 SNPs for Mexican gray wolf and 142 SNPs for bighorn sheep, indicating our pipeline can be used to develop SNP genotyping assays for parentage analysis with relatively small numbers of loci. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Intra-Species Genetic Diversity and Clonal Structure of Cryptosporidium parvum in Sheep Farms in a Confined Geographical Area in Northeastern Spain

PubMed Central

Ramo, Ana; Monteagudo, Luis V.; Del Cacho, Emilio; Sánchez-Acedo, Caridad

2016-01-01

A multilocus fragment typing approach including eleven variable-number tandem-repeat (VNTR) loci and the GP60 gene was used to investigate the intra-farm and intra-host genetic diversity of Cryptosporidium parvum in sheep farms in a confined area in northeastern Spain. Genomic DNA samples of 113 C. parvum isolates from diarrheic pre-weaned lambs collected in 49 meat-type sheep farms were analyzed. Loci exhibited various degrees of polymorphism, the finding of 7–9 alleles in the four most variable and discriminatory markers (ML2, Cgd6_5400, Cgd6_3940, and GP60) being remarkable. The combination of alleles at the twelve loci identified a total of 74 multilocus subtypes (MLTs) and provided a Hunter-Gaston discriminatory index of 0.988 (95% CI, 0.979−0.996). The finding that most MLTs (n = 64) were unique to individual farms evidenced that cryptosporidial infection is mainly transmitted within sheep flocks, with herd-to-herd transmission playing a secondary role. Limited intra- host variability was found, since only five isolates were genotypically mixed. In contrast, a significant intra-farm genetic diversity was seen, with the presence of multiple MLTs on more than a half of the farms (28/46), suggesting frequent mutations or genetic exchange through recombination. Comparison with a previous study in calves in northern Spain using the same 12-loci typing approach showed differences in the identity of major alleles at most loci, with a single MLT being shared between lambs and calves. Analysis of evolutionary descent by the algorithm eBURST indicated a high degree of genetic divergence, with over 41% MLTs appearing as singletons along with a high number of clonal complexes, most of them linking only two MLTs. Bayesian Structure analysis and F statistics also revealed the genetic remoteness of most C. parvum isolates and no ancestral population size was chosen. Linkage analysis evidenced a prevalent pattern of clonality within the parasite population. PMID:27176718

Semen variables of sheep (Ovis aries) experimentally infected with Toxoplasma gondii.

PubMed

Lopes, W D Z; Costa, A J; Souza, F A; Rodrigues, J D F; Costa, G H N; Soares, V E; Silva, G S

2009-04-01

The influence of Toxoplasma gondii on semen variables and sperm morphology of sheep was evaluated in eight reproductive males distributed into three experimental groups: GI, three sheep inoculated with 2.0x10(5) of P strain oocytes; GII, three sheep infected with 1.0x10(6) of RH strain tachyzoites and; GIII two control sheep. Clinical (rectal temperature, cardiac and respiratory frequencies), parasite and serology exams (IIF) were realized. Sperm variables (volume, motility, vigor and concentration) and semen morphology for each sheep were also evaluated. Thus, semen and blood collections were assessed on post-inoculation days (PIDs)-1,3,5,7,11,14 and weekly thereafter up to PID 70. Clinical alterations were observed (hypothermia and anorexia) in infected sheep from groups GI and GII. Parasitic outbreaks were detected in five sheep. All the infected sheep produced antibodies against T. gondii from PID 5 onwards, reaching a peak of 4096 and 8192 for group GI and GII sheep, respectively. Differences (P<0.05) were observed regarding the ejaculate volume between the inoculated groups (oocytes and tachyzoites) and control. Even though experimental toxoplasmic infection resulted in clinical symptomology in the inoculated sheep, the minimal alterations in sperm pathologies could not be directly attributed to T. gondii.

Cystic echinococcosis amongst small ruminants and humans in central Ethiopia.

PubMed

Assefa, Habtamu; Mulate, Belay; Nazir, Shahid; Alemayehu, Alula

2015-08-21

This study was conducted to determine the prevalence of cystic echinococcosis (CE) in small ruminants and humans in Addis Ababa, central Ethiopia. A cross-sectional study involving systematic random sampling was conducted to estimate the prevalence of CE in 512 small ruminants (262 sheep and 250 goats) slaughtered at Addis Ababa Abattoir Enterprise between October 2011 and March 2012. Hydatid cysts were identified macroscopically during postmortem examination and their fertility and viability were determined. CE was observed in 21 (8.02%) sheep and 17 (6.80%) goats. In sheep 13 (4.96%) of the lungs, 10 (3.81%) livers and 1 (0.381%) heart were found to be infected with hydatid cysts. Involvement of lung and liver in goats was found to be 10 (4.0%) and 8 (3.2%) respectively, with no cysts recorded in the heart. Of the total of 77 and 47 cysts encountered in sheep and goats, 33 (42.85%) and 15 (31.91%) respectively were fertile. Viability of protoscoleces from fertile cysts in sheep (29 [87.87%]) was higher than in goats (6 [40.0%]). For humans, retrospective analysis covering five years of case reports at two major hospitals in Addis Ababa between January 2008 and December 2012 showed that of the total of 25 840 patients admitted for ultrasound examination, 27 CE cases were registered, a prevalence of 0.1% and mean annual incidence rate of approximately 0.18 cases per 100 000 population. Liver was the major organ affected in humans (81.5% in affected patients) followed by spleen (11.1%) and kidney (7.4%). Logistic regression analysis showed that prevalence of CE varied significantly in relation to host age in the small ruminants (OR = 3.93, P < 0.05) as well as in humans (95% CI, R = 4.8). This epidemiological study confirms the importance of CE in small ruminants and humans in central Ethiopia, emphasising the need for integrated approaches to controlling this neglected preventable disease.

The altitudinal mobility of wild sheep at the Epigravettian site of Kalavan 1 (Lesser Caucasus, Armenia): Evidence from a sequential isotopic analysis in tooth enamel.

PubMed

Tornero, Carlos; Balasse, Marie; Bălăşescu, Adrian; Chataigner, Christine; Gasparyan, Boris; Montoya, Cyril

2016-08-01

Kalavan 1 is an Epigravettian hunting campsite in the Aregunyats mountain chain in northeastern Armenia (Lesser Caucasus). The site lies at an elevation of 1640 m in a bottleneck that controls the descent into the Barepat Valley from the alpine meadows above. The lithic and faunal assemblages show evidence of the production of hunting weapons, the hunting and targeting of wild sheep (Ovis orientalis), and the constitution of animal product reserves. A seasonal occupation of the site was proposed within a model of occupation by Epigravettian hunter-gatherers that involved a search for obsidian resources in high altitude sources from the spring to the summer and settling at Kalavan 1 at the end of summer or during autumn to coincide with the migration of wild herds from the alpine meadows to the valley. A key parameter of this model is wild sheep ethology, with a specifically seasonal vertical mobility, based on observations from contemporary mouflon populations from the surrounding areas. In this study, the vertical mobility of Paleolithic wild sheep was directly investigated through sequential isotope analysis (δ(18)O, δ(13)C) in teeth. A marked seasonality of birth is suggested that reflects a physiological adaptation to the strong environmental constraints of this mountainous region. Most importantly, a recurrent altitudinal mobility was demonstrated on a seasonal basis, which confirms that wild sheep migrated from lowland areas that they occupied in the winter and then moved to higher altitude meadows during the summer. Last, low inter-individual variability in the stable isotope sequences favors a hypothesis of accumulation for these faunal remains over a short time period. Overall, this new dataset strengthens the previous interpretations for Kalavan 1 and contributes to an understanding of the pattern of occupation of mountain territories by Epigravettian communities. Copyright © 2016 Elsevier Ltd. All rights reserved.

Measurement of phenotypic resilience to gastro-intestinal nematodes in Merino sheep and association with resistance and production variables.

PubMed

Kelly, Gareth A; Kahn, Lewis P; Walkden-Brown, Stephen W

2013-03-31

A cross-over experiment was conducted to compare six different phenotypic measures of resilience to gastro-intestinal nematodes (predominantly Haemonchus contortus) in Merino sheep and their association with resistance and production levels. On each of six farms, 120 ewes born in 2006 and 120 older mixed age ewes were selected at shearing in 2007. Of these, 60 in each mob were serially treated with long-acting anthelmintics to suppress worm populations. The other 60 ewes were managed according to management practices employed on the farm (infected, INF). At shearing in 2008, the experimental sheep had their anthelmintic treatments switched. The experiment concluded at shearing in 2009. Measures of resilience were greasy fleece weight (GFW), live weight gain (LWG) and haematocrit (HCT) when infected and the difference in these variables between infected and suppressed. Resistance was determined from multiple faecal worm egg counts (WEC) when infected. Measures of resilience based on GFW, LWG and HCT were moderately correlated with each other (r=0.25-0.50) suggesting that they represent different traits. Correlations between a measure in infected animals, and the difference in the same measurement between infected and uninfected animals were higher (r=-0.37 to -0.82), indicating that measurement during infection is an adequate measure of resilience. WEC was negatively correlated with LWG and HCT during infection but not GFW. Correlations with resilience measures based on difference between infected and uninfected were positive. Surviving infected sheep were found to have higher haematocrit (HCT), and lower WEC in summer and autumn than sheep that died following the measurement. These results show that measurement of performance traits while infected is a reasonable approximation of measurement of resilience based on the difference in performance between infected and non-infected. They also show that resilience to worm infection is not a single trait, but rather a suite of moderately correlated traits. Copyright © 2012 Elsevier B.V. All rights reserved.

Prevalence of anthelmintic resistance on Lithuanian sheep farms assessed by in vitro methods.

PubMed

Kupčinskas, Tomas; Stadalienė, Inga; Šarkūnas, Mindaugas; Riškevičienė, Vita; Várady, Marian; Höglund, Johan; Petkevičius, Saulius

2015-12-16

This study examines the prevalence of drug resistance in gastrointestinal nematodes to macrocyclic lactones (ML) and benzimidazoles (BZ) in Lithuanian sheep using sensitive and precise in vitro methods. The survey was conducted from August 2013 to November 2014. Thirty-three farms with sheep previously treated with BZ and ivermectin (IVM) were included in the study. On 12 farms where only BZ were used, egg hatch discrimination dose testing (EHDDT) was conducted to detect anthelmintic resistance (AR) to BZ. On eight farms where only ML were used, micro agar larval development testing (MALDT) was conducted to detect AR to ivermectin (IVM). On the remaining 13 farms, where both classes of drugs were used, EHDDT and MALDT were both applied to detect multidrug resistance to BZ and IVM. BZ-resistant gastrointestinal nematodes were found on all 25 farms with a previous history of BZ use. High levels of resistance (>40 % of hatching) were recorded on 36 % of these farms, and low levels (<20 % of hatching) on 40 % of farms. IVM-resistant populations were found on 13 out of 21 sheep farms using this drug. Of these 13 farms with AR to IVM, low levels of resistance (<30 % development) were recorded on 84.6 % of farms and high levels (>30 % development) on 15.4 % of farms. No resistance to IVM was recorded on 38.1 % of farms. Multi-drug resistance was detected on five farms out of 13 (38.5 %) using both classes of drugs. The present study demonstrates the existence of AR to BZ and ML on Lithuanian sheep farms thus confirming results in a previous in vivo study. Cases of multi-drug resistance were recorded in the present study and require further consideration. An appropriate strategy for anthelmintic treatment, measures to prevent gastrointestinal nematode infection and a better understanding of the management practices associated with resistance may slow down further development of AR.

MRI-determined lumbar muscle morphometry in man and sheep: potential biomechanical implications for ovine model to human spine translation.

PubMed

Valentin, Stephanie; Licka, Theresia F; Elliott, James

2015-10-01

The sheep is a commonly used animal model for human lumbar spine surgery, but only in vitro investigations comparing the human and ovine spine exist. Spinal musculature has previously not been compared between man and sheep. This additional knowledge could further indicate to what extent these species are biomechanically similar. Therefore, the purpose of the study was to investigate spinal muscle morphometric properties using magnetic resonance imaging (MRI) in different age groups of healthy human participants and sheep in vivo. Healthy human participants (n = 24) and sheep (n = 17) of different age groups underwent T1-weighted MRI of the lumbar spine. Regions of interest of the muscles erector spinae (ES), multifidus (M) and psoas (PS) were identified. The ratio of flexor to extensor volume, ratio of M to ES volume, and muscle fat relative to an area of intermuscular fat were calculated. Sheep M to ES ratio was significantly smaller than in the human participants (sheep 0.16 ± 0.02; human 0.37 ± 0.05; P < 0.001), although flexor to extensor ratio was not significantly different between species (human 0.39 ± 0.08; sheep 0.43 ± 0.05; P = 0.06). Age did not influence any muscle ratio outcome. Sheep had significantly greater extensor muscle fat compared with the human participants (M left human 40.64%, sheep 53.81%; M right human 39.17%, sheep 51.33%; ES left human 40.86%, sheep 51.29%; ES right human 35.93%, sheep 44.38%; all median values; all P < 0.001), although PS did not show any significant between-species differences (PS left human 36.89%, sheep 33.67%; PS right human 32.78%, sheep 30.09%; P < 0.05). The apparent differences in the size and shape of sheep and human lumbar spine muscles may indicate dissimilar biomechanical and functional demands, which is an important consideration when translating to human surgical models. © 2015 Anatomical Society.

9 CFR 51.27 - Identification of goats, sheep, and horses to be destroyed.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Identification of goats, sheep, and... DISEASES ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.27 Identification of goats, sheep, and horses to be destroyed. The claimant must ensure that any goats, sheep, and...

9 CFR 51.27 - Identification of goats, sheep, and horses to be destroyed.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Identification of goats, sheep, and... DISEASES ANIMALS DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.27 Identification of goats, sheep, and horses to be destroyed. The claimant must ensure that any goats, sheep, and...

Changes in bone structure of Corriedale sheep with inherited rickets: a peripheral quantitative computed tomography assessment.

PubMed

Dittmer, Keren E; Firth, Elwyn C; Thompson, Keith G; Marshall, Jonathan C; Blair, Hugh T

2011-03-01

An inherited skeletal disease with gross and microscopic features of rickets has been diagnosed in Corriedale sheep in New Zealand. The aim of this study was to quantify the changes present in tibia from sheep with inherited rickets using peripheral quantitative computed tomography. In affected sheep, scans in the proximal tibia, where metaphysis becomes diaphysis, showed significantly greater trabecular bone mineral content (BMC) and bone mineral density (BMD). The sheep with inherited rickets had significantly greater BMC and bone area in the mid-diaphysis of the proximal tibia compared to control sheep. However, BMD in the mid-diaphysis was significantly less in affected sheep than in controls, due to the greater cortical area and lower voxel density values in affected sheep. From this it was concluded that the increased strain on under-mineralised bone in sheep with inherited rickets led to increased bone mass in an attempt to improve bone strength. Copyright © 2010 Elsevier Ltd. All rights reserved.

Transfer of single dose of intravitreal injection of ranibizumab and bevacizumab into milk of sheep

PubMed Central

Cakmak Argun, Tugba; Yalcin Tok, Ozlem; Tok, Levent; Yilmaz, Gulsen; Meric Yilmaz, Fatma; Gunes, Alime; Argun, Mehmet; Butuner, Osman

2017-01-01

AIM To investigate whether single-dose intravitreal injections of bevacizumab and ranibizumab transfer into milk. METHODS This study included lactating 12 sheep and a single 3-month old suckling lamb of each sheep. Two groups consisting of 6 sheep and their lambs were constituted; the ranibizumab group and the bevacizumab group before the administration of intravitreal injections, blood and milk samples were obtained from all sheep and, following the injections, blood and milk samples of all sheep and blood samples of all lambs were collected at regular time points. Serum and milk concentrations of bevacizumab and ranibizumab were measured using an enzyme-linked immunosorbent assay (ELISA) kit. The limit of determination was 0.9 ng/mL for bevacizumab and 0.62 ng/mL for ranibizumab. RESULTS At 6h after intravitreal injections, bevacizumab concentration was above the limit of determination in the blood of all sheep. At 3wk, when the study was terminated, bevacizumab concentrations were high in 4 sheep. Even though bevacizumab concentrations in milk showed fluctuations, the drug transferred into the milk of all sheep at detectable concentrations. Ranibizumab drug concentrations in the blood and milk of sheep and those in the blood of lambs were below the limit of determination by the ELISA kit. CONCLUSION This sheep model study demonstrate that intravitreal injection of ranibizumab, which did not transfer into the milk of sheep and suckling lambs, is safer than bevacizumab during lactation period. PMID:28730108

Chromosomal Distribution of Endogenous Jaagsiekte Sheep Retrovirus Proviral Sequences in the Sheep Genome

PubMed Central

Carlson, Jonathan; Lyon, Monique; Bishop, Jeanette; Vaiman, Anne; Cribiu, Edmond; Mornex, Jean-François; Brown, Susan; Knudson, Dennis; DeMartini, James; Leroux, Caroline

2003-01-01

A family of endogenous retroviruses (enJSRV) closely related to Jaagsiekte sheep retrovirus (JSRV) is ubiquitous in domestic and wild sheep and goats. Southern blot hybridization studies indicate that there is little active replication or movement of the enJSRV proviruses in these species. Two approaches were used to investigate the distribution of proviral loci in the sheep genome. Fluorescence in situ hybridization (FISH) to metaphase chromosome spreads using viral DNA probes was used to detect loci on chromosomes. Hybridization signals were reproducibly detected on seven sheep chromosomes and eight goat chromosomes in seven cell lines. In addition, a panel of 30 sheep-hamster hybrid cell lines, each of which carries one or more sheep chromosomes and which collectively contain the whole sheep genome, was examined for enJSRV sequences. DNA from each of the lines was used as a template for PCR with JSRV gag-specific primers. A PCR product was amplified from 27 of the hybrid lines, indicating that JSRV gag sequences are found on at least 15 of the 28 sheep chromosomes, including those identified by FISH. Thus, enJSRV proviruses are essentially randomly distributed among the chromosomes of sheep and goats. FISH and/or Southern blot hybridization on DNA from several of the sheep-hamster hybrid cell lines suggests that loci containing multiple copies of enJSRV are present on chromosomes 6 and 9. The origin and functional significance of these arrays is not known. PMID:12915578

ANALYSIS OF RISK FROM EXPOSURE TO ALDICARB USING IMMUNE RESPONSE OF NONUNIFORM POPULATIONS OF MICE

EPA Science Inventory

The immunomodulation response of mice to low levels of aldicarb in drinking water was investigated in four series of studies. he splenic plaque forming cell (PFC) response to red sheep cells were measured for treatment levels of 0.01 to 1000 ppb (ug/kg). ased on their beginning a...

Characterization of bovine ruminal and equine cecal microbial populations enriched for enhanced nitro-toxin metabolizing activity

USDA-ARS?s Scientific Manuscript database

The phytochemicals 3-nitro-1-propionic acid (NPA) and 3-nitro-1-propanol (NPOH) are produced by a wide variety of leguminous plants, including over 150 different species and varieties of Astragalus. These compounds are toxic to naive grazing animals, but can be safely fed to cattle and sheep that h...

Peste des Petits Ruminants Virus in Vulnerable Wild Small Ruminants, Iran, 2014-2016.

PubMed

Marashi, Mahmoud; Masoudi, Siamak; Moghadam, Majid Kharazian; Modirrousta, Hossein; Marashi, Mahyar; Parvizifar, Masoumeh; Dargi, Majid; Saljooghian, Mahyar; Homan, Farbod; Hoffmann, Bernd; Schulz, Claudia; Starick, Elke; Beer, Martin; Fereidouni, Sasan

2017-04-01

In 2014-2016, >1,000 wild goats and sheep in 4 northern and central provinces of Iran died from peste des petits ruminants virus (PPRV) infection. Partial nucleoprotein sequencing of PPRV from 3 animals showed a close relationship to lineage 4 strains from China. Control measures are needed to preserve vulnerable ruminant populations.

Comparison of internal transcribed spacers and intergenic spacer regions of five common Iranian sheep bursate nematodes.

PubMed

Nabavi, Reza; Conneely, Brendan; McCarthy, Elaine; Good, Barbara; Shayan, Parviz; DE Waal, Theo

2014-09-01

Accurate identification of sheep nematodes is a critical point in epidemiological studies and monitoring of drug resistance in flocks. However, due to a close morphological similarity between the eggs and larval stages of many of these nematodes, such identification is not a trivial task. There are a number of studies showing that molecular targets in ribosomal DNA (Internal transcribed spacer 1, 2 and Intergenic spacer) are suitable for accurate identification of sheep bursate nematodes. The objective of present study was to compare the ITS1, ITS2 and IGS regions of Iranian common bursate nematodes in order to choose best target for specific identification methods. The first and second internal transcribed spacers (ITS1and ITS2) and intergenic spacer (IGS) of the ribosomal DNA (rDNA) of 5 common Iranian bursate nematodes of sheep were sequenced. The sequences of some non-Iranian isolates were used for comparison in order to evaluate the variation in sequence homology between geographically different nematode populations. Comparison of the ITS1 and ITS2 sequences of Iranian nematodes showed greatest similarity among Teladorsagia circumcincta and Marshallagia marshalli of 94% and 88%, respectively. While Trichostrongylus colubriformis and M. marshalli showed the highest homology (99%) in the IGS sequences. Comparison of the spacer sequences of Iranian with non-Iranian isolates showed significantly higher variation in Haemonchus contortus compared to the other species. Both the ITS1 and ITS2 sequences are convenient targets to have species-specific identification of Iranian bursate nematodes. On the other hand the IGS region may be a less suitable molecular target.

Molecular characterization of Echinococcus granulosus isolated from sheep in Palestine.

PubMed

Adwan, Ghaleb; Adwan, Kamel; Bdir, Sami; Abuseir, Sameh

2013-06-01

A total of twenty-three Echinococcus granulosus hydatid cysts were collected from infected sheep slaughtered in Nablus abattoir, Nablus - Palestine. Protoscoleces or germinal membranes were used for DNA extraction followed by PCR amplification. Amplified products were analyzed the presence of a fragment of 444bp of the mitochondrial cytochrome c oxidase subunit 1 (cox1) gene followed by nucleotide sequencing. Overall, 21 hydatid cysts were positive compared to a negative control. The partial sequences of cox1 gene of E. granulosus strains indicated that the sheep in Palestine were infected with genotype 1 (G1), genotype 2 (G2) and genotype 3 (G3). The prevalence of these genotypes was (14/21) 66.7%, (4/21) 19.0% and (3/21) 14.3% for G1, G2 and G3, respectively. Our results showed that twelve strains of G1 belonged to the common haplotype EG01 which is the major haplotype in all the geographic populations. Phylogenetic analysis also showed that two sequences of G1 genotype which have GenBank accession No. KC109657 and KC109659 were corresponding to G1.4 micro-variants. Only the sequence of GenBank accession No. KC109652 identified in our study as G2 was found to have complete identity to the original sequence described for the cox1 gene (GenBank accession No. M84662). It is concluded that G1 genotype is the predominant genotype in sheep in Palestine. Therefore, these findings should be taken into consideration in developing prevention strategies and control programs for hydatidosis in Palestine. Copyright © 2013 Elsevier Inc. All rights reserved.

9 CFR 71.20 - Approval of livestock facilities.

Code of Federal Regulations, 2010 CFR

2010-01-01

... manufacturer for fly control. (17) Sheep and goats: —This facility will handle breeding sheep or goats... sheep that are not also designated high-risk animals or to sheep or goats designated under 9 CFR part 79... maintained by the facility for a period of 2 years, or for a period of 5 years in the case of sheep or goats...

9 CFR 79.2 - Identification of sheep and goats in interstate commerce.

Code of Federal Regulations, 2010 CFR

2010-01-01

... goats; the breed or cross if known; the name, street address, including city and State, or the township... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Identification of sheep and goats in... SCRAPIE IN SHEEP AND GOATS § 79.2 Identification of sheep and goats in interstate commerce. (a) No sheep...

9 CFR 71.20 - Approval of livestock facilities.

Code of Federal Regulations, 2011 CFR

2011-01-01

... manufacturer for fly control. (17) Sheep and goats: —This facility will handle breeding sheep or goats... sheep that are not also designated high-risk animals or to sheep or goats designated under 9 CFR part 79... maintained by the facility for a period of 2 years, or for a period of 5 years in the case of sheep or goats...

9 CFR 79.2 - Identification of sheep and goats in interstate commerce.

Code of Federal Regulations, 2011 CFR

2011-01-01

... goats; the breed or cross if known; the name, street address, including city and State, or the township... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Identification of sheep and goats in... SCRAPIE IN SHEEP AND GOATS § 79.2 Identification of sheep and goats in interstate commerce. (a) No sheep...

Mitochondrial DNA variation of domestic sheep (Ovis aries) in Kenya.

PubMed

Resende, Adriana; Gonçalves, Joana; Muigai, Anne W T; Pereira, Filipe

2016-06-01

The history of domestic sheep (Ovis aries) in Africa remains largely unknown. After being first introduced from the Near East, sheep gradually spread through the African continent with pastoral societies. The eastern part of Africa was important either for the first diffusion of sheep southward or for putative secondary introductions from the Arabian Peninsula or southern Asia. We analysed mitochondrial DNA control region sequences of 91 domestic sheep from Kenya and found a high diversity of matrilines from the widespread haplogroup B, whereas only a single individual from haplogroup A was detected. Our phylogeography analyses of more than 500 available mitochondrial DNA sequences also identified ancestral haplotypes that were probably first introduced in Africa and are now widely distributed. Moreover, we found no evidence of an admixture between East and West African sheep. The presence of shared haplotypes in eastern and ancient southern African sheep suggests the possible southward movement of sheep along the eastern part of Africa. Finally, we found no evidence of an extensive introduction of sheep from southern Asia into Africa via the Indian Ocean trade. The overall findings on the phylogeography of East African domestic sheep set the grounds for understanding the origin and subsequent movements of sheep in Africa. The richness of maternal lineages in Kenyan breeds is of prime importance for future conservation and breeding programmes. © 2016 Stichting International Foundation for Animal Genetics.

9 CFR 51.28 - Moving goats, sheep, and horses to be destroyed.

Code of Federal Regulations, 2013 CFR

2013-01-01

... DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.28 Moving goats, sheep, and horses to be destroyed. Goats, sheep, and horses to be destroyed because of brucellosis must be...

9 CFR 51.28 - Moving goats, sheep, and horses to be destroyed.

Code of Federal Regulations, 2012 CFR

2012-01-01

... DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.28 Moving goats, sheep, and horses to be destroyed. Goats, sheep, and horses to be destroyed because of brucellosis must be...

9 CFR 51.28 - Moving goats, sheep, and horses to be destroyed.

Code of Federal Regulations, 2014 CFR

2014-01-01

... DESTROYED BECAUSE OF BRUCELLOSIS Indemnity for Sheep, Goats, and Horses § 51.28 Moving goats, sheep, and horses to be destroyed. Goats, sheep, and horses to be destroyed because of brucellosis must be...

[The epidemiology and etiology research of Tibetan sheep plague in Qinghai plateau].

PubMed

Wei, Baiqing; Xiong, Haoming; Yang, Xiaoyan; Yang, Yonghai; Qi, Meiying; Jin, Juan; Xin, Youquan; Li, Xiang; Yang, Hanqing; Han, Xiumin; Dai, Ruixia

2015-03-01

To identify the epidemiology and etiology characteristics of Tibetan sheep plague in Qinghai plateau. The background materials of Qinghai Tibetan sheep plague found during 1975 to 2009 were summarized, the regional, time and interpersonal distribution, infection routes, ecological factors for the spread were used to analyze; followed by choosing 14 Yersinia pestis strains isolated from such sheep for biochemical test, toxicity test, virulence factors identification, plasmid analysis, and DFR genotype. From 1975 to 2009, 14 Yersinia pestis strains were isolated from Tibetan sheep in Qinghai province. Tibetan sheep, as the infection source, had caused 10 cases of human plague, 25 plague patients, and 13 cases of death. All of the initial cases were infected due to eating Tibetan sheep died of plague; followed by cases due to contact of plague patients, while all the initial cases were bubonic plague. Cases of bubonic plague developed into secondary pneumonic plague and septicemia plague were most popular and with high mortality. Most of the Tibetan sheep plague and human plague occurred in Gannan ecological zone in southern Gansu province, which was closely related to its unique ecological and geographical landscape. Tibetan sheep plague coincided with human plague caused by Tibetan sheep, especially noteworthy was that November (a time for marmots to start their dormancy) witnesses the number of Yersinia pestis strains isolated from Tibetan sheep and human plague cases caused by Tibetan sheep. This constituted the underlying cause that the epidemic time of Tibetan sheep plague lags obviously behind that of the Marmot plague. It was confirmed in the study that all the 14 strains were of Qinghai-Tibet Plateau ecotype, with virulence factors evaluation and toxicity test demonstrating strains as velogenic. As found in the (Different Region) DFR genotyping, the strains isolated from Yushu county and Zhiduo county were genomovar 5, the two strain isolated from Nangqian county were genomovar 5 and genomovar 7, while those isolated Delingha region were genomovar 8. Tibetan sheep were vulnerable to plague infection, hence causing human plague as the infectious source. The Yersinia pestis strains isolated from Tibetan sheep plague carried pathogen characteristics of Qinghai-Tibet plateau plague, developing many new characteristics of such plague.

High occurrence of mitochondrial heteroplasmy in nepalese indigenous sheep (Ovis aries) compared to chinese sheep.

PubMed

Gorkhali, Neena Amatya; Jiang, Lin; Shrestha, Bhola Shankar; He, Xiao-Hong; Junzhao, Qian; Han, Jian-Lin; Ma, Yue-Hui

2016-07-01

Heteroplasmy due to length polymorphism with tandem repeats in mtDNAs within individual was hardly studied in domestic animals. In the present study, we identified intra-individual length variation in the control region of mtDNAs in Nepalese sheep by molecular cloning and sequencing techniques. We observed one to four tandem repeats of a 75-bp nucleotide sequences in the mtDNA control region in 45% of the total Nepalese sheep sampled in contrast to the Chinese sheep, indicating that the heteroplasmy is specific to Nepalese sheep. The high rate of heteroplasmy in Nepalese sheep could be a resultant of the mtDNA mutation and independent segregation at intra-individual level or a strand slippage and mispairing during the replication.

Sarcoptic mange and cheetah conservation in Masai Mara (Kenya): epidemiological study in a wildlife/livestock system.

PubMed

Gakuya, Francis; Ombui, Jackson; Maingi, Ndichu; Muchemi, Gerald; Ogara, William; Soriguer, Ramón C; Alasaad, Samer

2012-10-01

The sanitary control of threatened wild animals is of pivotal interest for their conservation. This task, however, is highly complex in wildlife/livestock systems. In this paper we report findings from a 2-year cross-sectional study of the epidemiology and attempted control of a Sarcoptes mite infestation in the threatened cheetah population in Masai Mara (Kenya), and discuss its interaction with sympatric wild (lion, wildebeest and Thomson's gazelle) and domestic (dog, cattle and sheep) animals. Sarcoptes scabiei was isolated from cheetahs, Thomson's gazelles, wildebeests, lions, cattle, goats and dogs; Psoroptes ovis, on the other hand, was only isolated from sheep. The prevalence study revealed 12·77% infection rates in cheetahs, 4·7% in dogs, 0·8% in Thomson's gazelles, 0·8% in sheep, 0·09% in cattle, and 0·09% in goats, while it opportunistically affected lions and wildebeest. Our study revealed that prevalence of Sarcoptes mite in cheetah population was not associated with the studied geographical blocks, animal sex or the presence of affected domestic animals. Cheetah infection with S. scabiei was associated with the climatic conditions (dry more than wet season) and the balancing between the total number of Thomson's gazelles and the prevalence of infected individuals. Apparently the high prevalence of mangy gazelles has a negative effect on cheetah; this negative effect was reduced when the number of healthy gazelles was increased. Treatment with injectable ivermectin of the clinically affected wild and domestic animals during the first year of this study was associated with much lower incidence of sarcoptic mange during the second year.

A stereotaxic, population-averaged T1w ovine brain atlas including cerebral morphology and tissue volumes

PubMed Central

Nitzsche, Björn; Frey, Stephen; Collins, Louis D.; Seeger, Johannes; Lobsien, Donald; Dreyer, Antje; Kirsten, Holger; Stoffel, Michael H.; Fonov, Vladimir S.; Boltze, Johannes

2015-01-01

Standard stereotaxic reference systems play a key role in human brain studies. Stereotaxic coordinate systems have also been developed for experimental animals including non-human primates, dogs, and rodents. However, they are lacking for other species being relevant in experimental neuroscience including sheep. Here, we present a spatial, unbiased ovine brain template with tissue probability maps (TPM) that offer a detailed stereotaxic reference frame for anatomical features and localization of brain areas, thereby enabling inter-individual and cross-study comparability. Three-dimensional data sets from healthy adult Merino sheep (Ovis orientalis aries, 12 ewes and 26 neutered rams) were acquired on a 1.5 T Philips MRI using a T1w sequence. Data were averaged by linear and non-linear registration algorithms. Moreover, animals were subjected to detailed brain volume analysis including examinations with respect to body weight (BW), age, and sex. The created T1w brain template provides an appropriate population-averaged ovine brain anatomy in a spatial standard coordinate system. Additionally, TPM for gray (GM) and white (WM) matter as well as cerebrospinal fluid (CSF) classification enabled automatic prior-based tissue segmentation using statistical parametric mapping (SPM). Overall, a positive correlation of GM volume and BW explained about 15% of the variance of GM while a positive correlation between WM and age was found. Absolute tissue volume differences were not detected, indeed ewes showed significantly more GM per bodyweight as compared to neutered rams. The created framework including spatial brain template and TPM represent a useful tool for unbiased automatic image preprocessing and morphological characterization in sheep. Therefore, the reported results may serve as a starting point for further experimental and/or translational research aiming at in vivo analysis in this species. PMID:26089780

Microstructure and mechanical properties of sheep horn.

PubMed

Zhu, Bing; Zhang, Ming; Zhao, Jian

2016-07-01

The sheep horn presents outstanding mechanical properties of impact resistance and energy absorption, which suits the need of the vehicle bumper design, but the mechanism behind this phenomenon is less investigated. The microstructure and mechanical properties of the sheep horn of Small Tailed Han Sheep (Ovis aries) living in northeast China were investigated in this article. The effect of sampling position and orientation of the sheep horn sheath on mechanical properties were researched by tensile and compression tests. Meanwhile, the surface morphology and microstructure of the sheep horn were observed using scanning electron microscopy (SEM). The formation mechanism of the mechanical properties of the sheep horn was investigated by biological coupling analysis. The analytical results indicated that the outstanding mechanical properties of the sheep horn are determined by configuration, structure, surface morphology and material coupling elements. These biological coupling elements make the sheep horn possess super characteristics of crashworthiness and energy absorption through the internal coupling mechanism. We suppose that these findings would make a difference in vehicle bumper design. Microsc. Res. Tech. 79:664-674, 2016. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

Translational neurophysiology in sheep: measuring sleep and neurological dysfunction in CLN5 Batten disease affected sheep

PubMed Central

Perentos, Nicholas; Martins, Amadeu Q.; Watson, Thomas C.; Bartsch, Ullrich; Mitchell, Nadia L.; Palmer, David N.; Jones, Matthew W.

2015-01-01

Creating valid mouse models of slowly progressing human neurological diseases is challenging, not least because the short lifespan of rodents confounds realistic modelling of disease time course. With their large brains and long lives, sheep offer significant advantages for translational studies of human disease. Here we used normal and CLN5 Batten disease affected sheep to demonstrate the use of the species for studying neurological function in a model of human disease. We show that electroencephalography can be used in sheep, and that longitudinal recordings spanning many months are possible. This is the first time such an electroencephalography study has been performed in sheep. We characterized sleep in sheep, quantifying characteristic vigilance states and neurophysiological hallmarks such as sleep spindles. Mild sleep abnormalities and abnormal epileptiform waveforms were found in the electroencephalographies of Batten disease affected sheep. These abnormalities resemble the epileptiform activity seen in children with Batten disease and demonstrate the translational relevance of both the technique and the model. Given that both spontaneous and engineered sheep models of human neurodegenerative diseases already exist, sheep constitute a powerful species in which longitudinal in vivo studies can be conducted. This will advance our understanding of normal brain function and improve our capacity for translational research into neurological disorders. PMID:25724202

Investigation of border disease and bovine virus diarrhoea in sheep from 76 mixed cattle and sheep farms in eastern Switzerland.

PubMed

Braun, U; Bachofen, C; Schenk, B; Hässig, M; Peterhans, E

2013-05-01

The purpose of this study was to examine the occurrence of sheep persistently infected with Border disease virus (BDV) on 76 mixed cattle and sheep farms and whether seroconversion to BDV infection occurred in cattle of these farms. Seroprevalence of BDV and bovine viral disease virus (BVDV) infection in sheep was also investigated. Quantitative RT-PCR for pestivirus detection and an ELISA to detect pestivirus antibodies were used in 2'384 and 2'291 ovine blood samples, respectively. Another 27 seropositive sheep from ten flocks underwent serum neutralization testing to differentiate between BDV and BVDV antibodies. A BDV titre that was at least four times higher than the BVDV titre was interpreted as the result of BDV infection. Titres against BVDV were interpreted in an analogous fashion. All examined sheep were pestivirus-negative, 310 sheep were seropositive, 119 had an indeterminate titre and 1'862 were seronegative. The flock seroprevalence ranged from 0.0 to 73.9 %. Three of the 27 flocks that underwent serum neutralization testing were interpreted as BDV-infected because of 6 sheep with higher BDV titres, and 6 flocks were interpreted as BVDV-infected because of 14 sheep with higher BVDV titres.

Patterns of faecal nematode egg shedding after treatment of sheep with a long-acting formulation of moxidectin.

PubMed

Crilly, James Patrick; Jennings, Amy; Sargison, Neil

2015-09-15

Much of the current information on the effects of long-acting anthelmintics on nematode populations derives either from research farms or mathematical models. A survey was performed with the aim of establishing how moxidectin is currently being used on sheep farms in the south-east of Scotland. A study was undertaken on a subsection of the surveyed farms to examine the effects of long-acting moxidectin treatments in both spring and autumn on faecal nematode egg output. The survey showed that whole flock treatments of injectable 2% moxidectin were used to control sheep scab on 21% of farms. Injectable 2% moxidectin and oral moxidectin were used to control the periparturient rise in faecal nematode egg shedding by ewes on 13% and 55% of farms respectively. The effects of injectable 2% moxidectin treatment on faecal nematode egg shedding post-treatment in both the autumn and spring were investigated by faecal nematode egg counts at the time of treatment and at 2-weekly interval thereafter on eight and six farms in the autumn and spring, respectively. Faecal egg shedding recommenced at 8 weeks (autumn) and 4 weeks (spring) post-treatment. Counts increased to a peak and then declined. The mean (95% confidence interval) peak counts post-treatment were 2.8 (0.6, 5.1), 3.6 (1.7, 5.5) and 53.5 (25.1, 82.0) eggs per gram (EPG) for autumn-treated ewes, autumn-treated lambs and spring-treated ewes respectively. The spring treated sheep showed a statistically significantly earlier return to faecal egg shedding (p=0.0125, p=0.0342) compared to both other groups, statistically significantly higher peak in egg counts than the autumn treated sheep (p<0.001) and a statistically significantly longer period of positive egg counts (p=0.0148). There was no statistically significant difference in the timing of the peak FECs between autumn and spring (p=0.211). The FECs of all groups of sheep treated with an injectable long-acting formulation of moxidectin became positive earlier than would be expected from the period of persistence given on the datasheet, but post-treatment FECs were very low compared to pre-treatment counts. Copyright © 2015 Elsevier B.V. All rights reserved.

Skin transcriptome profiles associated with coat color in sheep

PubMed Central

2013-01-01

Background Previous molecular genetic studies of physiology and pigmentation of sheep skin have focused primarily on a limited number of genes and proteins. To identify additional genes that may play important roles in coat color regulation, Illumina sequencing technology was used to catalog global gene expression profiles in skin of sheep with white versus black coat color. Results There were 90,006 and 74,533 unigenes assembled from the reads obtained from white and black sheep skin, respectively. Genes encoding for the ribosomal proteins and keratin associated proteins were most highly expressed. A total of 2,235 known genes were differentially expressed in black versus white sheep skin, with 479 genes up-regulated and 1,756 genes down-regulated. A total of 845 novel genes were differentially expressed in black versus white sheep skin, consisting of 107 genes which were up-regulated (including 2 highly expressed genes exclusively expressed in black sheep skin) and 738 genes that were down-regulated. There was also a total of 49 known coat color genes expressed in sheep skin, from which 13 genes showed higher expression in black sheep skin. Many of these up-regulated genes, such as DCT, MATP, TYR and TYRP1, are members of the components of melanosomes and their precursor ontology category. Conclusion The white and black sheep skin transcriptome profiles obtained provide a valuable resource for future research to understand the network of gene expression controlling skin physiology and melanogenesis in sheep. PMID:23758853

Predicting population survival under future climate change: density dependence, drought and extraction in an insular bighorn sheep.

PubMed

Colchero, Fernando; Medellin, Rodrigo A; Clark, James S; Lee, Raymond; Katul, Gabriel G

2009-05-01

1. Our understanding of the interplay between density dependence, climatic perturbations, and conservation practices on the dynamics of small populations is still limited. This can result in uninformed strategies that put endangered populations at risk. Moreover, the data available for a large number of populations in such circumstances are sparse and mined with missing data. Under the current climate change scenarios, it is essential to develop appropriate inferential methods that can make use of such data sets. 2. We studied a population of desert bighorn sheep introduced to Tiburon Island, Mexico in 1975 and subjected to irregular extractions for the last 10 years. The unique attributes of this population are absence of predation and disease, thereby permitting us to explore the combined effect of density dependence, environmental variability and extraction in a 'controlled setting.' Using a combination of nonlinear discrete models with long-term field data, we constructed three basic Bayesian state space models with increasing density dependence (DD), and the same three models with the addition of summer drought effects. 3. We subsequently used Monte Carlo simulations to evaluate the combined effect of drought, DD, and increasing extractions on the probability of population survival under two climate change scenarios (based on the Intergovernmental Panel on Climate Change predictions): (i) increase in drought variability; and (ii) increase in mean drought severity. 4. The population grew from 16 individuals introduced in 1975 to close to 700 by 1993. Our results show that the population's growth was dominated by DD, with drought having a secondary but still relevant effect on its dynamics. 5. Our predictions suggest that under climate change scenario (i), extraction dominates the fate of the population, while for scenario (ii), an increase in mean drought affects the population's probability of survival in an equivalent magnitude as extractions. Thus, for the long-term survival of the population, our results stress that a more variable environment is less threatening than one in which the mean conditions become harsher. Current climate change scenarios and their underlying uncertainty make studies such as this one crucial for understanding the dynamics of ungulate populations and their conservation.

Novel self-expandable, stent-based transcatheter pulmonic valve: a preclinical animal study.

PubMed

Kim, Gi Beom; Lim, Hong-Gook; Kim, Yong Jin; Choi, Eun Young; Kwon, Bo Sang; Jeong, Saeromi

2014-04-15

Because transcatheter implantation of pulmonary valve is indicated for limited-size dysfunctional right ventricular outflow tract only as a balloon-expandable stent, we investigated the feasibility of a large-diameter self-expandable valved stent and the durability of the valve after >6 months. We made a nitinol-wire-based, self-expandable valved stent with leaflets made from porcine pericardium. The porcine pericardium was treated with α-galactosidase, glutaraldehyde, and glycine after decellularization. After cutting the inguinal or cervical area, we implanted a valved stent in 12 sheep through the femoral or jugular vein by using an 18-Fr delivery catheter, controlling the catheter handles and hook block under fluoroscopic and echocardiographic guidance. The mean body weight of sheep was 43.9 kg. We successfully implanted valved stents (diameter: 24 mm in 7 sheep, 26 mm in 5 sheep) in good position in 8 sheep, in the main pulmonary artery (PA) in 2 sheep, and in the right ventricular outlet tract (RVOT) in 2 sheep. We sacrificed 8 sheep (6 sheep in good position, 1 sheep in the main PA, and 1 sheep in the RVOT) after >6 months. Five of the 6 sheep implanted in good position showed well-preserved valve morphology at the time of sacrifice. Histologic findings after routine sacrifice showed well-maintained collagen wave structure and no visible calcification in all explanted valve leaflets. Transcatheter implantation of a nitinol-wire-based, self-expandable valved stent in the pulmonic valve was feasible, and stents implanted in good position showed well-preserved valve leaflets with functional competence in the mid-term results. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Genetically similar strains of Escherichia coli O157:H7 isolated from sheep, cattle and human patients.

PubMed

Söderlund, Robert; Hedenström, Ingela; Nilsson, Anna; Eriksson, Erik; Aspán, Anna

2012-10-24

Comparatively little is known about the prevalence or the molecular characteristics of the zoonotic pathogen E. coli O157:H7 in the sheep reservoir. To investigate this and determine the host specificity of subclones of the bacterium, we have conducted a slaughterhouse prevalence study in sheep and compared the collected isolates to O157:H7 previously isolated from cattle and human patients. Verotoxin-producing O157:H7 was found in 11/597 (1.8%) of samples from sheep in Swedish slaughterhouses, 9/492 faecal (1.8%) and 2/105 ear samples (1.9%). All positive sheep were < 6 months old. Pulsed field gel electrophoresis typing revealed exact matches between isolates from the sheep prevalence study and human patients as well as between isolates from sheep and cattle. In one case, matching isolates were found in sheep, cattle, and a human patient in the same municipality. Identical PFGE profiles generally corresponded to similar but non-identical multi-locus VNTR profiles. In one sheep sample, SNP-typing found the highly virulent clade 8 variant of O157:H7. The virulence gene profiles of sheep isolates from the prevalence study and three sheep farms linked to cases of human illness were investigated by PCR detection (eaeA, hlyA, cdtV-B, vtx1), and partial sequencing of vtx2. The observed profiles were similar to those of cattle strains investigated previously. The same pathogenic subtypes of VTEC O157:H7, including the highly virulent clade 8, appear to be present in both sheep and cattle in Sweden, suggesting strains can circulate freely between ruminant reservoirs.

Selective propagation of mouse-passaged scrapie prions with long incubation period from a mixed prion population using GT1-7 cells

PubMed Central

Masujin, Kentaro; Okada, Hiroyuki; Ushiki-Kaku, Yuko; Matsuura, Yuichi; Yokoyama, Takashi

2017-01-01

In our previous study, we demonstrated the propagation of mouse-passaged scrapie isolates with long incubation periods (L-type) derived from natural Japanese sheep scrapie cases in murine hypothalamic GT1-7 cells, along with disease-associated prion protein (PrPSc) accumulation. We here analyzed the susceptibility of GT1-7 cells to scrapie prions by exposure to infected mouse brains at different passages, following interspecies transmission. Wild-type mice challenged with a natural sheep scrapie case (Kanagawa) exhibited heterogeneity of transmitted scrapie prions in early passages, and this mixed population converged upon one with a short incubation period (S-type) following subsequent passages. However, when GT1-7 cells were challenged with these heterologous samples, L-type prions became dominant. This study demonstrated that the susceptibility of GT1-7 cells to L-type prions was at least 105 times higher than that to S-type prions and that L-type prion-specific biological characteristics remained unchanged after serial passages in GT1-7 cells. This suggests that a GT1-7 cell culture model would be more useful for the economical and stable amplification of L-type prions at the laboratory level. Furthermore, this cell culture model might be used to selectively propagate L-type scrapie prions from a mixed prion population. PMID:28636656

Selective propagation of mouse-passaged scrapie prions with long incubation period from a mixed prion population using GT1-7 cells.

PubMed

Miyazawa, Kohtaro; Masujin, Kentaro; Okada, Hiroyuki; Ushiki-Kaku, Yuko; Matsuura, Yuichi; Yokoyama, Takashi

2017-01-01

In our previous study, we demonstrated the propagation of mouse-passaged scrapie isolates with long incubation periods (L-type) derived from natural Japanese sheep scrapie cases in murine hypothalamic GT1-7 cells, along with disease-associated prion protein (PrPSc) accumulation. We here analyzed the susceptibility of GT1-7 cells to scrapie prions by exposure to infected mouse brains at different passages, following interspecies transmission. Wild-type mice challenged with a natural sheep scrapie case (Kanagawa) exhibited heterogeneity of transmitted scrapie prions in early passages, and this mixed population converged upon one with a short incubation period (S-type) following subsequent passages. However, when GT1-7 cells were challenged with these heterologous samples, L-type prions became dominant. This study demonstrated that the susceptibility of GT1-7 cells to L-type prions was at least 105 times higher than that to S-type prions and that L-type prion-specific biological characteristics remained unchanged after serial passages in GT1-7 cells. This suggests that a GT1-7 cell culture model would be more useful for the economical and stable amplification of L-type prions at the laboratory level. Furthermore, this cell culture model might be used to selectively propagate L-type scrapie prions from a mixed prion population.

The effect of Slit homolog 2 (SLIT2) on populations of preantral follicles in cultured cortical tissue from pig ovaries

USDA-ARS?s Scientific Manuscript database

SLIT guidance ligands are secreted glycoproteins involved in organogenesis. SLIT proteins and their receptor have been linked to ovarian development in fetal sheep and luteal function in adult humans. In pigs, SLIT proteins have been associated with age at puberty (GWAS) and as a major node in genom...

Evidence of bovine viral diarrhea virus infection in three species of sympatric wild ungulates in Nevada: Life history strategies may maintain endemic infections in wild populations

USDA-ARS?s Scientific Manuscript database

Evidence for bovine viral diarrhea virus (BVDV) infection was detected in 2009-10 during a pneumonia die-off in Rocky Mountain bighorn sheep (Ovis canadensis canadensis), and sympatric mountain goats (Oreamnos americanum) in adjacent mountain ranges in Elko County, Nevada. Seroprevalence to BVDV-1 ...

On Counting Sheep: The Self-Medication and Coping Strategies of University Students Suffering from Primary Insomnia

ERIC Educational Resources Information Center

Cockcroft, K.; Grasko, D.; Fridjhon, P.

2006-01-01

A factor that affects university students' academic performance is the quantity and quality of their sleep. There is a high rate of insomnia in the general population, but the prevalence of sleep difficulties among university students has not been extensively studied. The current study found that 23 per cent of the researched student population…

Defined bacterial populations in the rumens of gnotobiotic lambs.

PubMed

Lysons, R J; Alexander, T J; Wellstead, P D; Hobson, P N; Mann, S O; Stewart, C S

1976-06-01

Five gnotobiotic lambs were fed on sterile diets until they were killed at 13 to 21 weeks of age. They were dosed orally with different combinations of 11 species of rumen bacteria. The biochemical reactions of each of the bacteria inoculated had been determined in pure culture in vitro, and they were chosen to perform the main reactions known to be associated with digestion in the normal mature rumen. Two of the bacteria could not be reisolated, but the remainder had established readily in the rumen, forming stable, mixed, defined populations. The total numbers of bacteria in the rumen, and the viable counts of most of the individual species were comparable to those of normal sheep. The concentration of volatile fatty acids was lower, however, and in four of the lambs there was a higher proportion of butyric acid and a lower proportion of propionic acid than in normal sheep. Cellulolytic, ureolytic, and methanogenic activities appeared to be taking place and lactate-utilizing bacteria appeared to reverse the accumulation of lactate which resulted from the activity of lactate-producing bacteria. Some of the bacteria also established at high levels in the caecum.

Bovine herpesvirus-1 (BHV-1), bovine leukemia virus (BLV) and bovine viral diarrhea virus (BVDV) infections in Algerian dromedary camels (Camelus dromaderius).

PubMed

Saidi, Radhwane; Bessas, Amina; Bitam, Idir; Ergün, Yaşar; Ataseven, Veysel Soydal

2018-03-01

This study was performed to investigate the presence of bovine herpesvirus-1 (BHV-1), bovine leukemia virus (BLV) and bovine viral diarrhea virus (BVDV) infections in dromedary camels (Camelus dromaderius) kept in mixed herds with sheep and goats in Algeria, since the prevalence of BHV-1, BVDV, and BLV infections among dromedary camels in Algeria is unknown. Totally, 111 camel sera were collected from two provinces (Laghouat and Ghardaia) in Algeria. The sera were analyzed for BHV-1 specific antibodies, BVDV specific antibodies and BVDV antigen using the ELISA, and BLV nucleic acid using PCR. The seropositivity rate was 9.0% for BVDV-specific antibody, although 41.4% of camels tested were positive for BVDV antigen. Moreover, there was no evidence of BHV-1 and BLV infections. The results indicated that camels might represent an important source for BVDV infection in all ruminants, including cattle, sheep, and goats bred in mixed herds in Algeria, since they had a higher BVDV prevalence rates. Therefore, the prevention and control measures for BVDV infection should put in place in camel populations to limit the spread of BVDV infection to ruminant populations in Algeria.

T and B lymphocyte function in response to a protein-free diet.

PubMed Central

Carlomagno, M A; Alito, A E; Almiron, D I; Gimeno, A

1982-01-01

Groups of female adult rats were fed either isocaloric protein-free or 18% protein diets for various intervals. Four days before sacrifice, the animals were immunized either with sheep erythrocytes or with a trinitrophenyl-lipopolysaccharide (TNP-LPS) conjugate. Spleen lymphoid cell populations, spleen plaque-forming cells, and serum hemolysins were measured. A persistent diminution, proportional to the duration of protein deprivation, was observed in all parameters studied after immunization with the T-dependent antigen, sheep erythrocytes. The immune dysfunction was more pronounced for hemolysin titers, which became undetectable after 15 days of protein-free diet. The response of the protein-free group to the T-independent antigen (TNP-LPS) after 15 days of diet was only 34% of the control. When a T-cell lymphokine, macrophage migration inhibitory factor, was measured, a normal response was observed in the protein-free group. Feeding a normal diet rapidly restored the spleen plaque-forming cell populations to 60% of normal after 4 days and to 100% after 6 days. Protein starvation influenced the production of antibodies more than it did the number of antibody-forming cells. The nutritional impairment of immunoglobulin synthesis appears to be reversible. PMID:6216214

The impact of malnutrition and other causes of losses of adult sheep in 12 flocks during drought.

PubMed

Bush, R D; Toribio, J-A L M L; Windsor, P A

2006-07-01

To establish the range and cost of losses in Merino flocks in southern New South Wales during drought conditions by determining the cause of death, morbidity or wasting in adult sheep. Pathological studies were performed on 392 dead or moribund adult sheep from 12 Ovine Johne's disease (OJD)-infected flocks during 2002 and a further 58 sheep culled due to wasting from one of these flocks in 2003. Flocks ranged between 3,500 and 20,000 sheep. The most likely cause of death, morbidity or wasting was determined following consideration of the environment in which the animal was found, clinical and gross pathological findings, plus histopathology of tissues collected during necropsy. A most likely cause of death, morbidity or wasting was determined for 362 sheep in 2002 and 58 sheep in 2003. OJD contributed to the death of 250 sheep in 2002, and wasting of 48 sheep in 2003. Of the sheep that died or were euthanased due to other causes, malnutrition was a contributing factor in the death of 70 sheep (63%) in 2002 and 2 sheep (20%) in 2003. Losses were not evenly distributed across flocks, with 57% of mortalities caused by malnutrition in 2002 occurring in one flock. Malnutrition accounted for 18% of the annual cost of all deaths among adult sheep in 2002 with an average cost of $16,882 per farm. Losses not attributed to malnutrition included a range of infectious and non-infectious disorders. These included balanoposthitis, clostridial enterotoxaemia, cutaneous myiasis, endoparasitism, enteritis, intestinal adenocarcinoma, misadventure, peritonitis, periparturient death of ewes, photosensitisation, pneumonia, post-shearing stress and squamous cell carcinoma of the perineum. Almost one third of mortalities in OJD-infected flocks during drought were unrelated to OJD and could be reduced by improving nutritional and disease management practices. The importance of close supervision of the flock is highlighted so that early management intervention can be instituted, including the culling of cases of welfare concern.

Complete Mitochondrial Genome Sequences of Chinese Indigenous Sheep with Different Tail Types and an Analysis of Phylogenetic Evolution in Domestic Sheep.

PubMed

Fan, Hongying; Zhao, Fuping; Zhu, Caiye; Li, Fadi; Liu, Jidong; Zhang, Li; Wei, Caihong; Du, Lixin

2016-05-01

China has a long history of sheep (Ovis aries [O. aries]) breeding and an abundance of sheep genetic resources. Knowledge of the complete O. aries mitogenome should facilitate the study of the evolutionary history of the species. Therefore, the complete mitogenome of O. aries was sequenced and annotated. In order to characterize the mitogenomes of 3 Chinese sheep breeds (Altay sheep [AL], Shandong large-tailed sheep [SD], and small-tailed Hulun Buir sheep [sHL]), 19 sets of primers were employed to amplify contiguous, overlapping segments of the complete mitochondrial DNA (mtDNA) sequence of each breed. The sizes of the complete mitochondrial genomes of the sHL, AL, and SD breeds were 16,617 bp, 16,613 bp, and 16,613 bp, respectively. The mitochondrial genomes were deposited in the GenBank database with accession numbers KP702285 (AL sheep), KP981378 (SD sheep), and KP981380 (sHL sheep) respectively. The organization of the 3 analyzed sheep mitochondrial genomes was similar, with each consisting of 22 tRNA genes, 2 rRNA genes (12S rRNA and 16S rRNA), 13 protein-coding genes, and 1 control region (D-loop). The NADH dehydrogenase subunit 6 (ND6) and 8 tRNA genes were encoded on the light strand, whereas the rest of the mitochondrial genes were encoded on the heavy strand. The nucleotide skewness of the coding strands of the 3 analyzed mitogenomes was biased toward A and T. We constructed a phylogenetic tree using the complete mitogenomes of each type of sheep to allow us to understand the genetic relationships between Chinese breeds of O. aries and those developed and utilized in other countries. Our findings provide important information regarding the O. aries mitogenome and the evolutionary history of O. aries inside and outside China. In addition, our results provide a foundation for further exploration of the taxonomic status of O. aries.

Complete Mitochondrial Genome Sequences of Chinese Indigenous Sheep with Different Tail Types and an Analysis of Phylogenetic Evolution in Domestic Sheep

PubMed Central

Fan, Hongying; Zhao, Fuping; Zhu, Caiye; Li, Fadi; Liu, Jidong; Zhang, Li; Wei, Caihong; Du, Lixin

2016-01-01

China has a long history of sheep (Ovis aries [O. aries]) breeding and an abundance of sheep genetic resources. Knowledge of the complete O. aries mitogenome should facilitate the study of the evolutionary history of the species. Therefore, the complete mitogenome of O. aries was sequenced and annotated. In order to characterize the mitogenomes of 3 Chinese sheep breeds (Altay sheep [AL], Shandong large-tailed sheep [SD], and small-tailed Hulun Buir sheep [sHL]), 19 sets of primers were employed to amplify contiguous, overlapping segments of the complete mitochondrial DNA (mtDNA) sequence of each breed. The sizes of the complete mitochondrial genomes of the sHL, AL, and SD breeds were 16,617 bp, 16,613 bp, and 16,613 bp, respectively. The mitochondrial genomes were deposited in the GenBank database with accession numbers KP702285 (AL sheep), KP981378 (SD sheep), and KP981380 (sHL sheep) respectively. The organization of the 3 analyzed sheep mitochondrial genomes was similar, with each consisting of 22 tRNA genes, 2 rRNA genes (12S rRNA and 16S rRNA), 13 protein-coding genes, and 1 control region (D-loop). The NADH dehydrogenase subunit 6 (ND6) and 8 tRNA genes were encoded on the light strand, whereas the rest of the mitochondrial genes were encoded on the heavy strand. The nucleotide skewness of the coding strands of the 3 analyzed mitogenomes was biased toward A and T. We constructed a phylogenetic tree using the complete mitogenomes of each type of sheep to allow us to understand the genetic relationships between Chinese breeds of O. aries and those developed and utilized in other countries. Our findings provide important information regarding the O. aries mitogenome and the evolutionary history of O. aries inside and outside China. In addition, our results provide a foundation for further exploration of the taxonomic status of O. aries. PMID:26954183

Gastrolobium spp. poisoning in sheep: A case report

USDA-ARS?s Scientific Manuscript database

This report describes the history and investigation of a suspected plant poisoning event in Western Australia where fifteen sheep died. One of the poisoned sheep was necropsied and gross and microscopic pathology of the poisoned sheep is described. Monofluoroacetate was detected in rumen contents ...

The seroprevalence of Toxoplasma gondii in Ontario sheep flocks

PubMed Central

Waltner-Toews, David; Mondesire, Roy; Menzies, Paula

1991-01-01

In a random sample of 103 sheep farms in Ontario, 99% of the farms had some sheep serologically positive for Toxoplasma gondii, based on an enzymelinked immunosorbent assay (ELISA). The percent of sheep affected within farms ranged from 3.8% to 97.8%, with an average flock prevalence of 57.6%. When farm management variables were considered in a multivariate analysis, significantly lower rates of serologically positive sheep were associated with neutering of female cats and clipping of ewes' perineums before lambing; significantly higher prevalence rates were found on farms where sheep were purchased from other flocks, pigs were raised on the same farm, sheep shared pasture with other animals, flowing water was available at pasture, and pastured replacements had access to housing. As well, in univariate analyses, higher prevalence was positively associated with an increasing number of cat litters born over the previous two years and offering creep feed or forage to lambs, and inversely with the amount of labor expended on sheep rearing. PMID:17423914

Effect of alternate and simultaneous grazing on endoparasite infection in sheep and cattle.

PubMed

Brito, Daiana Lima; Dallago, Bruno Stéfano Lima; Louvandini, Helder; dos Santos, Viviane Rodrigues Verdolin; Torres, Sonia Emília Figueirêdo de Araújo; Gomes, Edgard Franco; do Amarante, Alessandro Francisco Talamini; de Melo, Cristiano Barros; McManus, Concepta Margaret

2013-01-01

This experiment was carried out on 8 ha of Panicum maximum cv. Tanzania pastures, with rotational grazing consisting of 7 days of occupation and 21 days of rest. Four treatments were evaluated: cattle grazing alone (BOV), sheep grazing alone (OVI), cattle and sheep grazing simultaneously (SIM) and cattle grazing followed by sheep (alternate - ALT). Twenty heifers and 30 male Santa Inês lambs were used. Fecal egg count (FEC) and fecal cultures were carried out. Blood was also collected to examine red and white cell series, total plasma protein (TPP), albumin and hemoglobin. FEC and estimated nematode pathogenicity index in sheep were lower in the SIM treatment. The Haemonchus spp. proportion was higher in isolated grazing systems. For sheep, mixed grazing was shown to reduce endoparasite infection, and SIM was better than ALT. For cattle, no difference between grazing systems was seen. Therefore, simultaneous grazing (sheep and cattle) may be a tool for reducing the need for anthelmintic treatments in sheep.

Spinal Motion and Muscle Activity during Active Trunk Movements – Comparing Sheep and Humans Adopting Upright and Quadrupedal Postures

PubMed Central

Valentin, Stephanie; Licka, Theresia F.

2016-01-01

Sheep are used as models for the human spine, yet comparative in vivo data necessary for validation is limited. The purpose of this study was therefore to compare spinal motion and trunk muscle activity during active trunk movements in sheep and humans. Three-dimensional kinematic data as well as surface electromyography (sEMG) of spinal flexion and extension was compared in twenty-four humans in upright (UR) and 4-point kneeling (KN) postures and in 17 Austrian mountain sheep. Kinematic markers were attached over the sacrum, posterior iliac spines, and spinous and transverse processes of T5, T8, T11, L2 and L5 in humans and over the sacrum, tuber sacrale, T5, T8, T12, L3 and L7 in sheep. The activity of erector spinae (ES), rectus abdominis (RA), obliquus externus (OE), and obliquus internus (OI) were collected. Maximum sEMG (MOE) was identified for each muscle and trial, and reported as a percentage (MOE%) of the overall maximally observed sEMG from all trials. Spinal range of motion was significantly smaller in sheep compared to humans (UR / KN) during flexion (sheep: 6–11°; humans 12–34°) and extension (sheep: 4°; humans: 11–17°). During extension, MOE% of ES was greater in sheep (median: 77.37%) than UR humans (24.89%), and MOE% of OE and OI was greater in sheep (OE 76.20%; OI 67.31%) than KN humans (OE 21.45%; OI 19.34%), while MOE% of RA was lower in sheep (21.71%) than UR humans (82.69%). During flexion, MOE% of RA was greater in sheep (83.09%) than humans (KN 47.42%; UR 41.38%), and MOE% of ES in sheep (45.73%) was greater than KN humans (14.45%), but smaller than UR humans (72.36%). The differences in human and sheep spinal motion and muscle activity suggest that caution is warranted when ovine data are used to infer human spine biomechanics. PMID:26741136

Codon 141 polymorphisms of the ovine prion protein gene affect the phenotype of classical scrapie transmitted from goats to sheep.

PubMed

Konold, Timm; Phelan, Laura J; Donnachie, Ben R; Chaplin, Melanie J; Cawthraw, Saira; González, Lorenzo

2017-05-04

A study to investigate transmission of classical scrapie via goat milk was carried out in sheep: firstly, lambs were challenged orally with goat scrapie brain homogenate to confirm transmission of scrapie from goats to sheep. In the second study phase, milk from scrapie-infected goats was fed to lambs. Lambs were selected according to their prion protein gene (PRNP) genotype, which was either VRQ/VRQ or ARQ/ARQ, with or without additional polymorphisms at codon 141 (FF 141 , LF 141 or LL 141 ) of the ovine PRNP. This report describes the clinical, pathological and molecular phenotype of goat scrapie in those sheep that progressed to clinical end-stage. Ten sheep (six VRQ/VRQ and four ARQ/ARQ, of which three FF 141 and one LL 141 ) challenged with one of two scrapie brain homogenates, and six pairs of sheep (ARQ, of which five LL 141 and seven LF 141 ) fed milk from six different goats, developed clinical disease, which was characterised by a pruritic (all VRQ/VRQ and LL 141 sheep) or a non-pruritic form (all LF 141 and FF 141 sheep). Immunohistochemical (IHC) examination revealed that the pattern of intra- and extracellular accumulation of disease-associated prion protein in the brain was also dependent on PRNP polymorphisms at codon 141, which was similar in VRQ and LL 141 sheep but different from LF 141 and FF 141 sheep. The influence of codon 141 was also seen in discriminatory Western blot (WB), with LF 141 and FF 141 sheep showing a bovine spongiform encephalopathy-like profile (diminished reactivity with P4 antibody) on brain tissue. However, discriminatory WB in lymphoid tissues, and IHC pattern and profile both in lymphoid and brain tissue was consistent with classical scrapie in all sheep. This study provided further evidence that the clinical presentation and the pathological and molecular phenotypes of scrapie in sheep are influenced by PRNP polymorphisms, particularly at codon 141. Differences in the truncation of disease-associated prion protein between LL 141 sheep and those carrying the F 141 allele may be responsible for these observations.

Spinal Motion and Muscle Activity during Active Trunk Movements - Comparing Sheep and Humans Adopting Upright and Quadrupedal Postures.

PubMed

Valentin, Stephanie; Licka, Theresia F

2016-01-01

Sheep are used as models for the human spine, yet comparative in vivo data necessary for validation is limited. The purpose of this study was therefore to compare spinal motion and trunk muscle activity during active trunk movements in sheep and humans. Three-dimensional kinematic data as well as surface electromyography (sEMG) of spinal flexion and extension was compared in twenty-four humans in upright (UR) and 4-point kneeling (KN) postures and in 17 Austrian mountain sheep. Kinematic markers were attached over the sacrum, posterior iliac spines, and spinous and transverse processes of T5, T8, T11, L2 and L5 in humans and over the sacrum, tuber sacrale, T5, T8, T12, L3 and L7 in sheep. The activity of erector spinae (ES), rectus abdominis (RA), obliquus externus (OE), and obliquus internus (OI) were collected. Maximum sEMG (MOE) was identified for each muscle and trial, and reported as a percentage (MOE%) of the overall maximally observed sEMG from all trials. Spinal range of motion was significantly smaller in sheep compared to humans (UR / KN) during flexion (sheep: 6-11°; humans 12-34°) and extension (sheep: 4°; humans: 11-17°). During extension, MOE% of ES was greater in sheep (median: 77.37%) than UR humans (24.89%), and MOE% of OE and OI was greater in sheep (OE 76.20%; OI 67.31%) than KN humans (OE 21.45%; OI 19.34%), while MOE% of RA was lower in sheep (21.71%) than UR humans (82.69%). During flexion, MOE% of RA was greater in sheep (83.09%) than humans (KN 47.42%; UR 41.38%), and MOE% of ES in sheep (45.73%) was greater than KN humans (14.45%), but smaller than UR humans (72.36%). The differences in human and sheep spinal motion and muscle activity suggest that caution is warranted when ovine data are used to infer human spine biomechanics.

Effects of shade on welfare and meat quality of grazing sheep under high ambient temperature.

PubMed

Liu, H W; Cao, Y; Zhou, D W

2012-12-01

This study was conducted to evaluate the effects of providing shade on growth performance, welfare, and meat quality of grazing sheep under high ambient temperature. A total of 120 healthy male Ujumqin wool sheep (a local breed; BW = 18.7 ± 1.27 kg; 14 wk old) were randomly and equally divided into shaded and unshaded treatments with 3 pens per treatment. Sheep were grazed on an unshaded pastureland from 0600 to 1000 h and 1400 to 1800 h. During other times, sheep were confined in shaded or unshaded pens. Body weight was recorded on d 1 and 42 of the experiment. Rectal temperature and respiration rate were recorded on d 7, 14, 21, 28, 35, and 42. At end of the trial, sheep were blood sampled and slaughtered to collect meat samples. Respiration rate was greater (P < 0.05) in the unshaded sheep than shaded sheep on d 14, 21, 28, 35, and 42 of the trial whereas no significant differences were found on d 7. Moreover, no differences were observed in final BW, ADG, or rectal temperature throughout the trial. The pH at 24 h postmortem (pH(24)) and cooking loss were greater (P < 0.01) in unshaded than shaded sheep. On the contrary, lightness (L*), redness (a*) and yellowness (b*) values at 24 h postmortem were lower (P < 0.05) in unshaded versus shaded sheep. The sheep in the unshaded group had a greater (P < 0.05) cortisol concentration compared with the shaded group. Sheep in the shaded group had lower creatine kinase activity (P < 0.01) as well as observed for glucose (P < 0.05), triiodothyronine (P < 0.01), and thyroxine (P < 0.05) concentrations and white blood cell count (P < 0.05). Compared with the unshaded group, sheep in the shaded group had a greater lymphocytes (LYM) count (P < 0.05). In contrast, the opposite was true for neutrophils (NEU) count (P < 0.01) and NEU:LYM ratio (P < 0.01). In conclusion, the shade cloth, although not enhancing ADG, improved meat quality traits and certain stress parameters in grazing sheep reared under high ambient temperature.

Whole Genome Sequencing demonstrates that Geographic Variation of Escherichia coli O157 Genotypes Dominates Host Association.

PubMed

Strachan, Norval J C; Rotariu, Ovidiu; Lopes, Bruno; MacRae, Marion; Fairley, Susan; Laing, Chad; Gannon, Victor; Allison, Lesley J; Hanson, Mary F; Dallman, Tim; Ashton, Philip; Franz, Eelco; van Hoek, Angela H A M; French, Nigel P; George, Tessy; Biggs, Patrick J; Forbes, Ken J

2015-10-07

Genetic variation in an infectious disease pathogen can be driven by ecological niche dissimilarities arising from different host species and different geographical locations. Whole genome sequencing was used to compare E. coli O157 isolates from host reservoirs (cattle and sheep) from Scotland and to compare genetic variation of isolates (human, animal, environmental/food) obtained from Scotland, New Zealand, Netherlands, Canada and the USA. Nei's genetic distance calculated from core genome single nucleotide polymorphisms (SNPs) demonstrated that the animal isolates were from the same population. Investigation of the Shiga toxin bacteriophage and their insertion sites (SBI typing) revealed that cattle and sheep isolates had statistically indistinguishable rarefaction profiles, diversity and genotypes. In contrast, isolates from different countries exhibited significant differences in Nei's genetic distance and SBI typing. Hence, after successful international transmission, which has occurred on multiple occasions, local genetic variation occurs, resulting in a global patchwork of continental and trans-continental phylogeographic clades. These findings are important for three reasons: first, understanding transmission and evolution of infectious diseases associated with multiple host reservoirs and multi-geographic locations; second, highlighting the relevance of the sheep reservoir when considering farm based interventions; and third, improving our understanding of why human disease incidence varies across the world.

gamma. -irradiated sewage solids in diets for sheep: nutritive evaluations and long-term assessments of possible toxicants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sanson, D.W.

1983-01-01

Air-dried solids from primary (undigested) sewage sludge were collected at Las Cruces, New Mexico (a non-industrial town with population about 50,000). Bagged sewage solids were ..gamma..-irradiated (1 megarad dosage) to kill parasites and pathogenic organisms and evaluated as prospective feedstuffs for sheep. Pelleted, complete diets for gestating-lactating fine-wool ewes and for their growing-finishing lambs were formulated to be isonitrogenous with either 3.5% cottonseed meal (conventional diet) or 7% sewage solids (experimental diet). Digestibility of organic matter and crude protein, and biological value of nitrogen, did not differ (P > .05) between diets, as determined with wethers. Wether lambs fed tomore » slaughter with conventional or experimental diets did not differ (P > .05) in rate of gain, carcass characteristics, element concentrations in blood and serum chemistry profiles, although liver Cu and kidney Pb levels were increased (P < .05) about 1.6-fold by sewage solids. Element contents of spleen and muscles did not differ (P > .05) due to diets. These studies confirm previous research at New Mexico State University which indicates that dried solids from municipal (primary) sludge provide nutritive benefits to sheep with risks of toxicity and heavy metal accumulation that appear tolerable where managed properly.« less

In vivo bubble nucleation probability in sheep brain tissue.

PubMed

Gateau, J; Aubry, J-F; Chauvet, D; Boch, A-L; Fink, M; Tanter, M

2011-11-21

Gas nuclei exist naturally in living bodies. Their activation initiates cavitation activity, and is possible using short ultrasonic excitations of high amplitude. However, little is known about the nuclei population in vivo, and therefore about the rarefaction pressure required to form bubbles in tissue. A novel method dedicated to in vivo investigations was used here that combines passive and active cavitation detection with a multi-element linear ultrasound probe (4-7 MHz). Experiments were performed in vivo on the brain of trepanated sheep. Bubble nucleation was induced using a focused single-element transducer (central frequency 660 kHz, f-number = 1) driven by a high power (up to 5 kW) electric burst of two cycles. Successive passive recording and ultrafast active imaging were shown to allow detection of a single nucleation event in brain tissue in vivo. Experiments carried out on eight sheep allowed statistical studies of the bubble nucleation process. The nucleation probability was evaluated as a function of the peak negative pressure. No nucleation event could be detected with a peak negative pressure weaker than -12.7 MPa, i.e. one order of magnitude higher than the recommendations based on the mechanical index. Below this threshold, bubble nucleation in vivo in brain tissues is a random phenomenon.

Long-term effects of grazing and topography on extra-radical hyphae of arbuscular mycorrhizal fungi in semi-arid grasslands.

PubMed

Ren, Haiyan; Gui, Weiyang; Bai, Yongfei; Stein, Claudia; Rodrigues, Jorge L M; Wilson, Gail W T; Cobb, Adam B; Zhang, Yingjun; Yang, Gaowen

2018-02-01

Grazing and topography have drastic effects on plant communities and soil properties. These effects are thought to influence arbuscular mycorrhizal (AM) fungi. However, the simultaneous impacts of grazing pressure (sheep ha -1 ) and topography on plant and soil factors and their relationship to the production of extra-radical AM hyphae are not well understood. Our 10-year study assessed relationships between grazing, plant species richness, aboveground plant productivity, soil nutrients, edaphic properties, and AM hyphal length density (HLD) in different topographic areas (flat or sloped). We found HLD linearly declined with increasing grazing pressure (1.5-9.0 sheep ha -1 ) in sloped areas, but HLD was greatest at moderate grazing pressure (4.5 sheep ha -1 ) in flat areas. Structural equation modeling indicates grazing reduces HLD by altering soil nutrient dynamics in sloped areas, but non-linearly influences HLD through plant community and edaphic changes in flat areas. Our findings highlight how topography influences key plant and soil factors, thus regulating the effects of grazing pressure on extra-radical hyphal production of AM fungi in grasslands. Understanding how grazing and topography influence AM fungi in semi-arid grasslands is vital, as globally, severe human population pressure and increasing demand for food aggravate the grazing intensity in grasslands.

Bartonella melophagi in blood of domestic sheep (Ovis aries) and sheep keds (Melophagus ovinus) from the southwestern US: Cultures, genetic characterization, and ecological connections.

PubMed

Kosoy, Michael; Bai, Ying; Enscore, Russell; Rizzo, Maria Rosales; Bender, Scott; Popov, Vsevolod; Albayrak, Levent; Fofanov, Yuriy; Chomel, Bruno

2016-07-15

Bartonella melophagi sp. nov. was isolated from domestic sheep blood and from sheep keds (Melophagus ovinus) from the southwestern United States. The sequence analyses of the reference strain performed by six molecular markers consistently demonstrated that B. melophagi relates to but differ from other Bartonella species isolated from domestic and wild ruminants. Presence of 183 genes specific for B. melophagi, being absent in genomes of other Bartonella species associated with ruminants also supports the separation of this bacterial species from species of other ruminants. Bartonella DNA was detected in all investigated sheep keds; however, culturing of these bacteria from sheep blood rejects a speculation that B. melophagi is an obligatory endosymbiont. Instead, the results support the hypothesis that the domestic sheep is a natural host reservoir for B. melophagi and the sheep ked its main vector. This bacterium was not isolated from the blood of bighorn sheep and domestic goats belonging to the same subfamily Caprinae. B. melophagi has also been shown to be zoonotic and needs to be investigated further. Published by Elsevier B.V.

Bloat in sheep (Ovis aries).

PubMed

Colvin, H W; Backus, R C

1988-01-01

1. Most of the field studies on bloat are conducted with cattle and most of the laboratory experiments seeking to explain the various parameters associated with bloat are done with sheep. 2. Based on grazing behaviour, it would be expected that sheep might bloat more severely than cattle because they selectively choose to eat leaves over stems and chew what they ingest more frequently than cattle. Furthermore, sheep appear to select legumes over grasses because the legumes can be eaten more rapidly. However, because they are selective, sheep eat more slowly than cattle. Despite a higher bloat expectation, bloating in sheep is reported to be less of a problem than in cattle. 3. Although frothing of rumen ingesta was described earlier in cattle as the cause of acute legume bloat, experiments with frothy bloat in sheep preceded those in cattle. 4. Anti-frothing agents were used in sheep before cattle to treat acute legume bloat. 5. Experiments devoted to the study of eructation in ruminants were carried out on sheep, then cattle. 6. Convincing evidence that rumen motility does not cease during acute legume bloat was gathered using sheep. 7. Although the transected tracheal technique for the determination of the volume of eructated gas was developed with cattle, the pathway of eructated gas was confirmed with sheep. 8. All the current evidence accumulated from experiments with sheep supports the hypothesis that death due to legume bloat is caused by acute neural, respiratory, and cardiovascular insult resulting from the effect of the distended rumen on thoracic viscera, diaphragm, intercostal muscles, and the abdominal vena cava. 9. Experiments with sheep and cattle being fed scabrous and nonscabrous diets similar in chemical composition show that sheep are more resistant than cattle to the increase in intrarumen pressure, decline in rumen contraction amplitude, and decrease in rumen contraction frequency caused by nonscabrous diets. 10. The sequence of events in the reticulorumen during primary and secondary contractions previously described following visual and palpation experiments with cattle was confirmed by the use of myoelectrodes implanted in the various sacs of the reticulorumen of sheep. 11. Elevated intrarumen pressure is associated with an increase in the frequency of primary (mixing) and secondary (eructation) contractions (more secondaries than primaries).(ABSTRACT TRUNCATED AT 400 WORDS)

Pruritus is a common feature in sheep infected with the BSE agent

PubMed Central

Konold, Timm; Bone, Gemma; Vidal-Diez, Alberto; Tortosa, Raul; Davis, Andrew; Dexter, Glenda; Hill, Peter; Jeffrey, Martin; Simmons, Marion M; Chaplin, Melanie J; Bellworthy, Susan J; Berthelin-Baker, Christine

2008-01-01

Background The variability in the clinical or pathological presentation of transmissible spongiform encephalopathies (TSEs) in sheep, such as scrapie and bovine spongiform encephalopathy (BSE), has been attributed to prion protein genotype, strain, breed, clinical duration, dose, route and type of inoculum and the age at infection. The study aimed to describe the clinical signs in sheep infected with the BSE agent throughout its clinical course to determine whether the clinical signs were as variable as described for classical scrapie in sheep. The clinical signs were compared to BSE-negative sheep to assess if disease-specific clinical markers exist. Results Forty-seven (34%) of 139 sheep, which comprised 123 challenged sheep and 16 undosed controls, were positive for BSE. Affected sheep belonged to five different breeds and three different genotypes (ARQ/ARQ, VRQ/VRQ and AHQ/AHQ). None of the controls or BSE exposed sheep with ARR alleles were positive. Pruritus was present in 41 (87%) BSE positive sheep; the remaining six were judged to be pre-clinically infected. Testing of the response to scratching along the dorsum of a sheep proved to be a good indicator of clinical disease with a test sensitivity of 85% and specificity of 98% and usually coincided with weight loss. Clinical signs that were displayed significantly earlier in BSE positive cases compared to negative cases were behavioural changes, pruritic behaviour, a positive scratch test, alopecia, skin lesions, teeth grinding, tremor, ataxia, loss of weight and loss of body condition. The frequency and severity of each specific clinical sign usually increased with the progression of disease over a period of 16–20 weeks. Conclusion Our results suggest that BSE in sheep presents with relatively uniform clinical signs, with pruritus of increased severity and abnormalities in behaviour or movement as the disease progressed. Based on the studied sheep, these clinical features appear to be independent of breed, affected genotype, dose, route of inoculation and whether BSE was passed into sheep from cattle or from other sheep, suggesting that the clinical phenotype of BSE is influenced by the TSE strain more than by other factors. The clinical phenotype of BSE in the genotypes and breed studied was indistinguishable from that described for classical scrapie cases. PMID:18445253

Genetic testing for TMEM154 mutations associated with lentivirus susceptibility in sheep

USDA-ARS?s Scientific Manuscript database

Ovine lentiviruses cause incurable, progressive, lymphoproliferative diseases that affect millions of sheep worldwide. Genetic variation in the ovine transmembrane protein 154 gene (TMEM154) has been recently associated with lentivirus infections in U.S. sheep. Sheep with the two most common TMEM1...

Role of PRNP S127 allele in experimental goat infection with classical caprine scrapie

USDA-ARS?s Scientific Manuscript database

Classical scrapie is a transmissible spongiform encephalopathy that affects domestic goats and sheep. Experimental inoculation studies in sheep confirmed that classical caprine scrapie can readily transmit to sheep. Therefore, even if current scrapie eradication measures are successful in sheep, goa...

Determinants of sheep prices in the highlands of northeastern Ethiopia: implication for sheep value chain development.

PubMed

Kassa, Beneberu Teferra; Haile, Anteneh Girma; Essa, John Abdu

2011-12-01

In order to assess and identify the determinants of sheep price and price variation across time, a time series data were collected from four selected markets in North Shewa, Northeastern Ethiopia on weekly market day basis for a period of 2 years. Data on animal characteristics and purpose of buying were collected on a weekly basis from randomly selected 15-25 animals, and a total of 7,976 transactions were recorded. A general linear model technique was used to identify factors influencing sheep price, and the results showed that sheep price (liveweight sheep price per kilogram taken as a dependent variable) is affected by animal characteristics such as weight, sex, age, condition, season, and color. Most of the markets' purpose for which the animal was purchased did not affect significantly the price per kilogram. This may be due to the similarity of the markets in terms of buyer's purpose. The results suggest that there will be benefit from coordinated fattening, breeding, and marketing programs to take the highest advantage from the preferred animals' characteristics and selected festival markets. Finally, the study recommends for a coordinated action to enhance the benefit generated for all participant actors in the sheep value chain through raising sheep productivity, improving the capacity of sheep producers and agribusiness entrepreneurs to access and use latest knowledge and technologies; and strengthening linkages among actors in the sheep value chain.

Gene identification and analysis of transcripts differentially regulated in fracture healing by EST sequencing in the domestic sheep.

PubMed

Hecht, Jochen; Kuhl, Heiner; Haas, Stefan A; Bauer, Sebastian; Poustka, Albert J; Lienau, Jasmin; Schell, Hanna; Stiege, Asita C; Seitz, Volkhard; Reinhardt, Richard; Duda, Georg N; Mundlos, Stefan; Robinson, Peter N

2006-07-05

The sheep is an important model animal for testing novel fracture treatments and other medical applications. Despite these medical uses and the well known economic and cultural importance of the sheep, relatively little research has been performed into sheep genetics, and DNA sequences are available for only a small number of sheep genes. In this work we have sequenced over 47 thousand expressed sequence tags (ESTs) from libraries developed from healing bone in a sheep model of fracture healing. These ESTs were clustered with the previously available 10 thousand sheep ESTs to a total of 19087 contigs with an average length of 603 nucleotides. We used the newly identified sequences to develop RT-PCR assays for 78 sheep genes and measured differential expression during the course of fracture healing between days 7 and 42 postfracture. All genes showed significant shifts at one or more time points. 23 of the genes were differentially expressed between postfracture days 7 and 10, which could reflect an important role for these genes for the initiation of osteogenesis. The sequences we have identified in this work are a valuable resource for future studies on musculoskeletal healing and regeneration using sheep and represent an important head-start for genomic sequencing projects for Ovis aries, with partial or complete sequences being made available for over 5,800 previously unsequenced sheep genes.

Coxiella burnetii seroprevalence and risk factors on commercial sheep farms in The Netherlands.

PubMed

Schimmer, B; de Lange, M M A; Hautvast, J L A; Vellema, P; van Duynhoven, Y T H P

2014-07-05

Coxiella burnetii seroprevalence was assessed on Dutch dairy and non-dairy sheep farms using ELISA. Risk factors for seropositivity on non-dairy sheep farms were identified at farm and sheep level by univariate and multivariate multilevel analyses. Based on 953 dairy and 5671 non-dairy serum samples, sheep seroprevalences were 18.7 per cent and 2.0 per cent, respectively, and 78.6 per cent and 30.5 per cent at farm level. Significant risk factors for non-dairy sheep farms were farm location in the south of the country, sheep kept on marginal grounds, one or several supply addresses for ewes during 2007-2009 and wearing farm boots and/or outfit by professional visitors. On sheep level, risk factors included among others farm location in the south of the country, lamb breeding as main farm purpose, goat density within 10 km farm radius, use of windbreak curtain or windshields, and presence of ≥6 stillborn lambs in 2009. Farm location in the south of the country and goat density suggests that infected goats have played a role in the transmission to non-dairy sheep. Other risk factors suggest introduction of the bacterium through sheep supply and professional visitors. Biosecurity measures should be strengthened, including avoiding infection during handling of stillborn lambs and birth products in the lambing period. British Veterinary Association.

Comparison of Prion Allele Frequency found in Suffolk and Targhee Sheep

USDA-ARS?s Scientific Manuscript database

Scrapie is a class of Transmissible Spongiform Encephalopathy that affects sheep and goats. The objective of this study was to compare genotypic and allelic frequencies among USSES Targhee and Suffolk sheep. A total of 122 sheep were genotyped for codon 171 with allele specific primers in 2 separate...

Spontaneous poisoning by Prosopis juliflora (Leguminosae) in sheep

USDA-ARS?s Scientific Manuscript database

The aim of this paper is to describe the first report of clinical, epidemiological and pathological aspects of spontaneous poisoning by Prosopis juliflora in sheep. Of a total of 500 sheep at risk, two adult male sheep were affected; one died spontaneously and the other animal was examined, euthaniz...

75 FR 27361 - Notice of Public Meeting, Whiskey Mountain Bighorn Sheep Range Locatable Mineral Withdrawal...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-05-14

...] Notice of Public Meeting, Whiskey Mountain Bighorn Sheep Range Locatable Mineral Withdrawal Extension, WY...) will hold a public meeting in conjunction with the Whiskey Mountain Bighorn Sheep Range Locatable... of Proposed Withdrawal Extension for the Whiskey Mountain Bighorn Sheep Winter Range, which was...

Seroprevalence of Toxoplasma gondii infection in domestic sheep in Durango State, Mexico

USDA-ARS?s Scientific Manuscript database

The seroprevalence of Toxoplasma gondii infection in sheep in northern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples from 511 sheep from 8 farms in Durango State, Mexico using the modified agglutination test (MAT). Sheep were raised in 3 geographical regions, i....

Sheep Production Occupations. Skills and Competencies.

ERIC Educational Resources Information Center

Sabol, Joe

This report summarizes the findings of a national study to determine what skills and competencies are needed by beginning employees on sheep ranches and farms, lamb feedlots, and in the sheep shearing industry. The research procedure, which involved determining from the sheep industry the competencies needed by beginning employees in the thirteen…

PrP genotype frequencies and risk evaluation for scrapie in dairy sheep breeds from southern Italy.

PubMed

Martemucci, Giovanni; Iamartino, Daniela; Blasi, Michele; D'Alessandro, Angela Gabriella

2015-12-01

Concerns regarding scrapie in sheep breeding have increased in the last few decades. The present study was carried out in dairy sheep breeds from southern Italy. In order to find breeding animals resistant to scrapie, the PrP genes of 1,205 animals from entire flocks of dairy native Apulian Leccese and Altamurana breeds, and Sicilian Comisana breed, were analysed for polymorphisms at codons 136, 154, and 171 related to scrapie resistance/susceptibility. The Altamurana breed was considered as two populations (Alt-Cav and Alt-Cra-Zoe), based on presumed cross-breeding. A total of five alleles and ten different genotypes were found. The ARQ allele was predominant for all breeds followed by ARR, the most resistant allele to scrapie, which was highly prevalent in Comisana (50%) and in native Alt-Cav (42.4%). The VRQ allele, associated with the highest susceptibility to scrapie, was detected at not negligeable levels in allocthonous Comisana (3.5%), at a low frequency (0.2%) in native Leccese and Alt-Cra-Zoe, while it was absent in Alt-Cav. The frequencies of PrP genotypes with a very low susceptibility risk to scrapie (R1) was higher in Comisana and Alt-Cav. The most susceptible genotype, ARQ/VRQ, was found only in Comisana. Within the Altamurana breed, there were notable differences between Alt-Cav and Alt-Cra-Zoe sheep. The Alt-Cav was characterised by the absence of VRQ and AHQ alleles and by the higher frequency of the ARR/ARR genotype (18.7%). Breeding programs, mainly in endangered breeds such as Altamurana, should be conducted gradually, combining resistance to scrapie, maintenance of genetic variability, and production. Copyright © 2015 Elsevier B.V. All rights reserved.

Brucella melitensis infection in sheep: present and future.

PubMed

Garin-Bastuji, B; Blasco, J M; Grayon, M; Verger, J M

1998-01-01

Sheep brucellosis, a zoonosis mainly due to B. melitensis (biovar 1, 2 or 3), remains widespread world-wide. Pathologically and epidemiologically, the disease is very similar to B. abortus infection in cattle. The live B. melitensis Rev 1 strain is currently considered as the best vaccine available for the control of sheep brucellosis, especially when used at the standard dose by the conjunctival route. Used exhaustively in whole-flock vaccination programmes, it induces a great decrease in the prevalence in both sheep and human populations. The expensive test-and-slaughter strategy should be restricted to the lowest infected areas. Whenever possible, Brucella spp. should be isolated by culture using adequate selective media from uterine discharges, aborted fetuses, udder secretions or selected tissues, such as lymph nodes, testes or epididymides. Species and biovar identification is routinely based on cultural criteria, on lysis by phages and on simple biochemical and serological tests. The recently developed polymerase chain reaction methods provide additional means of detection and identification. Despite the high degree of DNA homology within the genus Brucella, several methods, including PCR-RFLP and Southern blot, have been developed which allow, to a certain extent, the differentiation between Brucella species and some of their biovars. While several ELISA tests have been developed recently, the rose bengal plate agglutination and complement fixation tests, based on the detection of anti-S-LPS antibody, are still recommended for screening flocks and individuals. However, these tests sometimes lack specificity or sensitivity. For pooled samples, there are no useful tests such as the milk ring test in cattle. The brucellin allergic skin test can be used as a screening or complementary test in unvaccinated flocks, provided that a purified, lipopolysaccharide (LPS)-free and standardized antigen preparation is used.

Reliable molecular differentiation of Trichuris ovis and Trichuris discolor from sheep (Ovis orientalis aries) and roe deer (Capreolus capreolus) and morphological characterisation of their females: morphology does not work sufficiently.

PubMed

Vejl, Pavel; Nechybová, Stanislava; Peřinková, Pavla; Melounová, Martina; Sedláková, Vladimíra; Vašek, Jakub; Čílová, Daniela; Rylková, Kateřina; Jankovská, Ivana; Vadlejch, Jaroslav; Langrová, Iva

2017-08-01

The main aim of the study was to evaluate associations between morphological variability of Trichuris females from sheep and roe deer and their rDNA polymorphism in whipworm populations from the Czech Republic. The results introduced the use of new molecular markers based on the internal transcribed spacer (ITS)1-5.8S RNA-ITS2 region polymorphisms, as useful tools for the unambiguous differentiation of congeners Trichuris ovis and Trichuris discolor. These markers revealed both parasites in roe deer and in sheep; however, T. ovis females predominated in sheep while T. discolor females occurred mostly in roe deer. Additional analysis of ITS1-5.8 rRNA-ITS2 discovered the genetic uniformity of the analysed T. discolor but high haplotype variation of T. ovis. Simultaneously, molecularly designated female individuals of both species were categorised into four morphotypes (MT) on the basis of morphology of genital pore area. MT1 and MT4 (vulvar opening on everted vaginal appendage/on visible cuticular bulge) occurred only in T. ovis, MT2 (uneverted vagina-vulvar opening without any elevation) was identified only in T. discolor and MT3 (transient type of vulvar opening on a small swelling) was observed in both species. Statistical analysis of biometric data confirmed that morphology of vulva is not a reliable marker for the species determination. On the basis of the ITS1-5.8S RNA-ITS2 region variability, we carried out a phylogenetic analysis (maximum likelihood method, Hasegawa-Kishino-Yano model) which showed that T. ovis haplotypes from the Czech Republic and Ireland and T. discolor haplotypes from the Czech Republic, Spain, Iran and Japan are sister OTUs.

Polymorphisms in the HSP90AA1 5' flanking region are associated with scrapie incubation period in sheep.

PubMed

Marcos-Carcavilla, Ane; Moreno, Carole; Serrano, Magdalena; Laurent, Pascal; Cribiu, Edmond P; Andréoletti, Olivier; Ruesche, Julien; Weisbecker, Jean-Louis; Calvo, Jorge H; Moazami-Goudarzi, Katayoun

2010-07-01

Susceptibility to scrapie is mainly controlled by point mutations at the PRNP locus. However, additional quantitative trait loci (QTL) have been identified across the genome including a region in OAR18. The gene which encodes the inducible form of the cytoplasmic Hsp90 chaperone (HSP90AA1) maps within this region and seems to be associated with the resistance/susceptibility to scrapie in sheep. Here, we have analyzed several polymorphisms which were previously described in the ovine HSP90AA1 5' flanking region and in intron 10 in two naturally scrapie infected Romanov sheep populations. First, we have studied 58 ARQ/VRQ animals pertaining to the sire family where the QTL influencing scrapie incubation period in OAR18 was detected. We have found a significant association between polymorphisms localized at -660 and -528 in the HSP90AA1 5' flanking region and the scrapie incubation period. These two polymorphisms have also been studied in a second sample constituted by 62 VRQ/VRQ sheep showing an extreme incubation period. Results are concordant with the first dataset. Finally, we have studied the HSP90AA1 expression in scrapie and control animals (N = 41) with different HSP90AA1 genotypes by real time PCR on blood samples. The HSP90AA1 expression rate was equivalent in CC(-600)AA(-528) and CG(-600)AG(-528) scrapie resistant animals (ARR/ARR) and was higher in their CC(-600)AA(-528) than in their CG(-600)AG(-528) scrapie susceptible counterparts (VRQ/VRQ). Our results support the hypothesis that the ovine HSP90AA1 gene acts as a modulator of scrapie susceptibility, contributing to the observed differences in the incubation period of scrapie infected animals with the same PRNP genotype.

Discrepant epidemiological patterns between classical and atypical scrapie in sheep flocks under French TSE control measures.

PubMed

Fediaevsky, Alexandre; Gasqui, Patrick; Calavas, Didier; Ducrot, Christian

2010-09-01

The occurrence of secondary cases of atypical and classical scrapie was examined in 340 outbreaks of atypical and 296 of classical sheep scrapie detected in France during active surveillance programmes between 2002 and 2007. The prevalence of atypical scrapie in these flocks was 0.05% under selective culling and 0.07% under intensified monitoring i.e. not significantly different from that detected during active surveillance of the general population (P>0.5), whereas these figures were much higher for classical scrapie (3.67% and 0.25%, respectively, P<10(-5)). In addition the number of atypical scrapie cases per outbreak did not indicate clustering. The results suggest that atypical scrapie occurs spontaneously or is not particularly contagious, and that the control measures in force allowed appropriate control of classical scrapie but were not more efficient than active surveillance in detecting cases of atypical scrapie. Copyright 2009 Elsevier Ltd. All rights reserved.

A Review of Hypothesized Determinants Associated with Bighorn Sheep (Ovis canadensis) Die-Offs

PubMed Central

Miller, David S.; Hoberg, Eric; Weiser, Glen; Aune, Keith; Atkinson, Mark; Kimberling, Cleon

2012-01-01

Multiple determinants have been hypothesized to cause or favor disease outbreaks among free-ranging bighorn sheep (Ovis canadensis) populations. This paper considered direct and indirect causes of mortality, as well as potential interactions among proposed environmental, host, and agent determinants of disease. A clear, invariant relationship between a single agent and field outbreaks has not yet been documented, in part due to methodological limitations and practical challenges associated with developing rigorous study designs. Therefore, although there is a need to develop predictive models for outbreaks and validated mitigation strategies, uncertainty remains as to whether outbreaks are due to endemic or recently introduced agents. Consequently, absence of established and universal explanations for outbreaks contributes to conflict among wildlife and livestock stakeholders over land use and management practices. This example illustrates the challenge of developing comprehensive models for understanding and managing wildlife diseases in complex biological and sociological environments. PMID:22567546

The effects of tissue processing on markers for T and B cells from solid tissues.

PubMed

Millard, P R; Rabin, B S; Whiteside, T L; Hubbard, J D

1977-03-01

Suspensions of lymphoid cells from tissues have been used for the determination of the quantitative relationship between the T and B cell populations. The distribution of the lymphocytes within a given tissue, however, cannot be demonstrated once such a suspension has been prepared. Various methods of characterizing lymphocytes within tissues were evaluated. The method of tissue preparation can alter the capability of detecting the lymphocyte markers. Fluorescein-labeled anti-immunoglobulin sera reacted equally well with lymphocytes in tissue regardless of the method of tissue preparation. Complement-coated sheep erythrocytes were less effective in detecting lymphocyte markers in tissue sections than in cell suspensions. Quantitative assays of lymphocytes could be done in suspensions only. Unaltered sheep erythrocytes did not bind to T lymphocytes in tissue. T lymphocytes could be identified in tissue sections, however, by the use of anti-human T cell serum.

Prevention of thiopental and thiopental/halothane cardiac sensitization to epinephrine in the sheep.

PubMed Central

Rezakhani, A; Edjtehadi, M; Szabuniewicz, M

1977-01-01

The effects of epinephrine (5 microgram/kg of body weight) on ten unanesthetized sheep were experimentally tested: all sheep displayed serious arrhythmias. Sheep anesthetized with thiopental and thiopental/halothane combination displayed cardiac arrhythmias of the order of 10% and 20% respectively. Challenge injections of epinephrine (5 microgram/kg of body weight) to ten sheep anesthetized with thiopental, and to the same number of animals after 45 minutes of anesthesia with thiopental/halothane, produced serious arrhythmias. However, following preanesthetic treatment with acepromazine maleate (0.5 mg/kg) to 15 sheep, serious arrhythmias were prevented in all of them when they were given arrhythmic doses of epinephrine. Images Fig. 2. PMID:922556

Potential disease agents in domestic goats and relevance to bighorn sheep (Ovis canadensis) management

PubMed Central

Weiser, Glen C.

2017-01-01

Domestic goats are raised for meat, milk and hair production, in herds for rangeland weed control, and as pack animals. Domestic sheep, goats and wild bighorn sheep are all susceptible to a multifactorial pneumonia. We sampled 43 herd goats from 7 herds and 48 pack goats from 11 herds for viral and bacterial serology, parasitology, and Pasteurellaceae microbiology. The goats in this study were in generally good health, although most goats did harbor various pathogens and parasites including several bacteria, specifically Pasteurellaceae, which have been associated with pneumonia in free-ranging bighorn sheep. It is not known if domestic goats can transmit the Pasteurellaceae or other pathogens found in this study readily to wild bighorn sheep. However, due the possibility of transmission, domestic goats in areas in or near bighorn sheep habitat should be managed to minimize the risk of spreading disease agents to bighorn sheep. PMID:28282407

Potential disease agents in domestic goats and relevance to bighorn sheep (Ovis canadensis) management.

PubMed

Drew, Mark L; Weiser, Glen C

2017-01-01

Domestic goats are raised for meat, milk and hair production, in herds for rangeland weed control, and as pack animals. Domestic sheep, goats and wild bighorn sheep are all susceptible to a multifactorial pneumonia. We sampled 43 herd goats from 7 herds and 48 pack goats from 11 herds for viral and bacterial serology, parasitology, and Pasteurellaceae microbiology. The goats in this study were in generally good health, although most goats did harbor various pathogens and parasites including several bacteria, specifically Pasteurellaceae, which have been associated with pneumonia in free-ranging bighorn sheep. It is not known if domestic goats can transmit the Pasteurellaceae or other pathogens found in this study readily to wild bighorn sheep. However, due the possibility of transmission, domestic goats in areas in or near bighorn sheep habitat should be managed to minimize the risk of spreading disease agents to bighorn sheep.

Whole genome structural analysis of Caribbean hair sheep reveals quantitative link to West African ancestry

USDA-ARS?s Scientific Manuscript database

Hair sheep of Caribbean origin have become an important part of the U.S. sheep industry. Lack of wool eliminates a number of health concerns and drastically reduces the cost of production. More importantly, Caribbean hair sheep demonstrate robust performance even in the presence of drug resistant ga...

9 CFR 113.45 - Sheep safety test.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Sheep safety test. 113.45 Section 113.45 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Procedures § 113.45 Sheep safety test. The sheep safety test provided in this section shall be conducted when...

21 CFR 133.183 - Romano cheese.

Code of Federal Regulations, 2014 CFR

2014-04-01

... Products § 133.183 Romano cheese. (a) Romano cheese is the food prepared from cow's milk or sheep's milk or... purposes of this section, the word “milk” means cow's milk or goat's milk or sheep's milk or mixtures of... of sheep's milk) the corresponding products from sheep's milk; water in a quantity sufficient to...

21 CFR 133.183 - Romano cheese.

Code of Federal Regulations, 2012 CFR

2012-04-01

... Products § 133.183 Romano cheese. (a) Romano cheese is the food prepared from cow's milk or sheep's milk or... purposes of this section, the word “milk” means cow's milk or goat's milk or sheep's milk or mixtures of... of sheep's milk) the corresponding products from sheep's milk; water in a quantity sufficient to...

21 CFR 133.183 - Romano cheese.

Code of Federal Regulations, 2013 CFR

2013-04-01

... Products § 133.183 Romano cheese. (a) Romano cheese is the food prepared from cow's milk or sheep's milk or... purposes of this section, the word “milk” means cow's milk or goat's milk or sheep's milk or mixtures of... of sheep's milk) the corresponding products from sheep's milk; water in a quantity sufficient to...

Physiological and behavioural responses of sheep to simulated sea transport motions

USDA-ARS?s Scientific Manuscript database

The motion of ships can cause discomfort and stress in humans, but little is known about the impact on sheep welfare, despite many sheep travelling long distances by ship during live export. We tested whether exposing sheep to roll (side to side movement), heave (up and down movement) and pitch (fro...

9 CFR 93.435 - Sheep and goats.

Code of Federal Regulations, 2011 CFR

2011-01-01

... 9 Animals and Animal Products 1 2011-01-01 2011-01-01 false Sheep and goats. 93.435 Section 93.435... CONVEYANCE AND SHIPPING CONTAINERS Ruminants Additional General Provisions § 93.435 Sheep and goats. (a) Except as provided in paragraph (b) of this section, all sheep and goats imported into the United States...

21 CFR 500.65 - Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of...

Code of Federal Regulations, 2013 CFR

2013-04-01

... containers for emergency treatment of anaphylactoid shock in cattle, horses, sheep, and swine. 500.65 Section... cattle, horses, sheep, and swine. (a) Anaphylactoid reactions in cattle, horses, sheep, and swine occur... treating anaphylactoid shock. Usual Dosage: Cattle, horses, sheep, and swine—1 cubic centimeter per 100...

21 CFR 500.65 - Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of...

Code of Federal Regulations, 2014 CFR

2014-04-01

... containers for emergency treatment of anaphylactoid shock in cattle, horses, sheep, and swine. 500.65 Section... cattle, horses, sheep, and swine. (a) Anaphylactoid reactions in cattle, horses, sheep, and swine occur... treating anaphylactoid shock. Usual Dosage: Cattle, horses, sheep, and swine—1 cubic centimeter per 100...

21 CFR 500.65 - Epinephrine injection 1:1,000 in 10-milliliter containers for emergency treatment of...

Code of Federal Regulations, 2012 CFR

2012-04-01

... containers for emergency treatment of anaphylactoid shock in cattle, horses, sheep, and swine. 500.65 Section... cattle, horses, sheep, and swine. (a) Anaphylactoid reactions in cattle, horses, sheep, and swine occur... treating anaphylactoid shock. Usual Dosage: Cattle, horses, sheep, and swine—1 cubic centimeter per 100...

9 CFR 93.435 - Sheep and goats.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Sheep and goats. 93.435 Section 93.435... CONVEYANCE AND SHIPPING CONTAINERS Ruminants Additional General Provisions § 93.435 Sheep and goats. (a) Except as provided in paragraph (b) of this section, all sheep and goats imported into the United States...

9 CFR 113.45 - Sheep safety test.

Code of Federal Regulations, 2010 CFR

2010-01-01

... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false Sheep safety test. 113.45 Section 113.45 Animals and Animal Products ANIMAL AND PLANT HEALTH INSPECTION SERVICE, DEPARTMENT OF AGRICULTURE... Procedures § 113.45 Sheep safety test. The sheep safety test provided in this section shall be conducted when...

75 FR 31743 - Notice of Request for Extension of Approval of an Information Collection; Brucellosis in Sheep...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-06-04

... Collection; Brucellosis in Sheep, Goats, and Horses; Payment of Indemnity AGENCY: Animal and Plant Health... collection associated with regulations for the payment of indemnity for sheep, goats, and horses destroyed... INFORMATION CONTACT: For information on regulations for the payment of indemnity for sheep, goats, and horses...

Sheep skeletal muscle transcriptome analysis reveals muscle growth regulatory lncRNAs.

PubMed

Chao, Tianle; Ji, Zhibin; Hou, Lei; Wang, Jin; Zhang, Chunlan; Wang, Guizhi; Wang, Jianmin

2018-01-01

As widely distributed domestic animals, sheep are an important species and the source of mutton. In this study, we aimed to evaluate the regulatory lncRNAs associated with muscle growth and development between high production mutton sheep (Dorper sheep and Qianhua Mutton Merino sheep) and low production mutton sheep (Small-tailed Han sheep). In total, 39 lncRNAs were found to be differentially expressed. Using co-expression analysis and functional annotation, 1,206 co-expression interactions were found between 32 lncRNAs and 369 genes, and 29 of these lncRNAs were found to be associated with muscle development, metabolism, cell proliferation and apoptosis. lncRNA-mRNA interactions revealed 6 lncRNAs as hub lncRNAs. Moreover, three lncRNAs and their associated co-expressed genes were demonstrated by cis-regulatory gene analyses, and we also found a potential regulatory relationship between the pseudogene lncRNA LOC101121401 and its parent gene FTH1. This study provides a genome-wide resolution of lncRNA and mRNA regulation in muscles from mutton sheep.

Comparative Pharmacokinetics of Cefquinome (Cobactan 2.5%) following Repeated Intramuscular Administrations in Sheep and Goats

PubMed Central

El-Hewaity, Mohamed; Abd El Latif, Amera

2014-01-01

The comparative pharmacokinetic profile of cefquinome was studied in sheep and goats following repeated intramuscular (IM) administrations of 2 mg/kg body weight. Cefquinome concentrations in serum were determined by microbiological assay technique using Micrococcus luteus (ATCC 9341) as test organism. Following intramuscular injection of cefquinome in sheep and goats, the disposition curves were best described by two-compartment open model in both sheep and goats. The pharmacokinetics of cefquinome did not differ significantly between sheep and goats; similar intramuscular dose rate of cefquinome should therefore be applicable to both species. On comparing the data of serum levels of repeated intramuscular injections with first intramuscular injection, it was revealed that repeated intramuscular injections of cefquinome have cumulative effect in both species sheep and goats. The in vitro serum protein-binding tendency was 15.65% in sheep and 14.42% in goats. The serum concentrations of cefquinome along 24 h after injection in this study were exceeding the MICs of different susceptible microorganisms responsible for serious disease problems. These findings indicate successful use of cefquinome in sheep and goats. PMID:26464946

Seroprevalence and Risk Factors of Chlamydia abortus Infection in Tibetan Sheep in Gansu Province, Northwest China

PubMed Central

Qin, Si-Yuan; Yin, Ming-Yang; Cong, Wei; Zhou, Dong-Hui; Zhang, Xiao-Xuan; Zhao, Quan; Zhu, Xing-Quan; Zhou, Ji-Zhang; Qian, Ai-Dong

2014-01-01

Chlamydia abortus, an important pathogen in a variety of animals, is associated with abortion in sheep. In the present study, 1732 blood samples, collected from Tibetan sheep between June 2013 and April 2014, were examined by the indirect hemagglutination (IHA) test, aiming to evaluate the seroprevalence and risk factors of C. abortus infection in Tibetan sheep. 323 of 1732 (18.65%) samples were seropositive for C. abortus antibodies at the cut-off of 1 : 16. A multivariate logistic regression analysis was used to evaluate the risk factors associated with seroprevalence, which could provide foundation to prevent and control C. abortus infection in Tibetan sheep. Gender of Tibetan sheep was left out of the final model because it is not significant in the logistic regression analysis (P > 0.05). Region, season, and age were considered as major risk factors associated with C. abortus infection in Tibetan sheep. Our study revealed a widespread and high prevalence of C. abortus infection in Tibetan sheep in Gansu province, northwest China, with higher exposure risk in different seasons and ages and distinct geographical distribution. PMID:25401129

Sheep skeletal muscle transcriptome analysis reveals muscle growth regulatory lncRNAs

PubMed Central

Chao, Tianle; Ji, Zhibin; Hou, Lei; Wang, Jin; Zhang, Chunlan

2018-01-01

As widely distributed domestic animals, sheep are an important species and the source of mutton. In this study, we aimed to evaluate the regulatory lncRNAs associated with muscle growth and development between high production mutton sheep (Dorper sheep and Qianhua Mutton Merino sheep) and low production mutton sheep (Small-tailed Han sheep). In total, 39 lncRNAs were found to be differentially expressed. Using co-expression analysis and functional annotation, 1,206 co-expression interactions were found between 32 lncRNAs and 369 genes, and 29 of these lncRNAs were found to be associated with muscle development, metabolism, cell proliferation and apoptosis. lncRNA–mRNA interactions revealed 6 lncRNAs as hub lncRNAs. Moreover, three lncRNAs and their associated co-expressed genes were demonstrated by cis-regulatory gene analyses, and we also found a potential regulatory relationship between the pseudogene lncRNA LOC101121401 and its parent gene FTH1. This study provides a genome-wide resolution of lncRNA and mRNA regulation in muscles from mutton sheep. PMID:29666768

Bacterial and Protozoal Communities and Fatty Acid Profile in the Rumen of Sheep Fed a Diet Containing Added Tannins ▿

PubMed Central

Vasta, Valentina; Yáñez-Ruiz, David R.; Mele, Marcello; Serra, Andrea; Luciano, Giuseppe; Lanza, Massimiliano; Biondi, Luisa; Priolo, Alessandro

2010-01-01

This study evaluated the effects of tannins on ruminal biohydrogenation (BH) due to shifts in the ruminal microbial environment in sheep. Thirteen lambs (45 days of age) were assigned to two dietary treatments: seven lambs were fed a barley-based concentrate (control group) while the other six lambs received the same concentrate with supplemental quebracho tannins (9.57% of dry matter). At 122 days of age, the lambs were slaughtered, and the ruminal contents were subjected to fatty acid analysis and sampled to quantify populations of Butyrivibrio fibrisolvens, which converts C18:2 c9-c12 (linoleic acid [LA]) to C18:2 c9-t11 (rumenic acid [RA]) and then RA to C18:1 t11 (vaccenic acid [VA]); we also sampled for Butyrivibrio proteoclasticus, which converts VA to C18:0 (stearic acid [SA]). Tannins increased (P < 0.005) VA in the rumen compared to the tannin-free diet. The concentration of SA was not affected by tannins. The SA/VA ratio was lower (P < 0.005) for the tannin-fed lambs than for the controls, suggesting that the last step of the BH process was inhibited by tannins. The B. proteoclasticus population was lower (−30.6%; P < 0.1), and B. fibrisolvens and protozoan populations were higher (+107% and +56.1%, respectively; P < 0.05) in the rumen of lambs fed the tannin-supplemented diet than in controls. These results suggest that quebracho tannins altered BH by changing ruminal microbial populations. PMID:20173064

Bacterial and protozoal communities and fatty acid profile in the rumen of sheep fed a diet containing added tannins.

PubMed

Vasta, Valentina; Yáñez-Ruiz, David R; Mele, Marcello; Serra, Andrea; Luciano, Giuseppe; Lanza, Massimiliano; Biondi, Luisa; Priolo, Alessandro

2010-04-01

This study evaluated the effects of tannins on ruminal biohydrogenation (BH) due to shifts in the ruminal microbial environment in sheep. Thirteen lambs (45 days of age) were assigned to two dietary treatments: seven lambs were fed a barley-based concentrate (control group) while the other six lambs received the same concentrate with supplemental quebracho tannins (9.57% of dry matter). At 122 days of age, the lambs were slaughtered, and the ruminal contents were subjected to fatty acid analysis and sampled to quantify populations of Butyrivibrio fibrisolvens, which converts C(18:2) c9-c12 (linoleic acid [LA]) to C(18:2) c9-t11 (rumenic acid [RA]) and then RA to C(18:1) t11 (vaccenic acid [VA]); we also sampled for Butyrivibrio proteoclasticus, which converts VA to C(18:0) (stearic acid [SA]). Tannins increased (P < 0.005) VA in the rumen compared to the tannin-free diet. The concentration of SA was not affected by tannins. The SA/VA ratio was lower (P < 0.005) for the tannin-fed lambs than for the controls, suggesting that the last step of the BH process was inhibited by tannins. The B. proteoclasticus population was lower (-30.6%; P < 0.1), and B. fibrisolvens and protozoan populations were higher (+107% and +56.1%, respectively; P < 0.05) in the rumen of lambs fed the tannin-supplemented diet than in controls. These results suggest that quebracho tannins altered BH by changing ruminal microbial populations.

A field trial of production and financial consequences of helminthosis control in sheep production in Ethiopia.

PubMed

Tibbo, M; Aragaw, K; Philipsson, J; Malmfors, B; Näsholm, A; Ayalew, W; Rege, J E O

2008-04-17

We used a partial-budget analysis to evaluate profitability of different management strategies of three genotypes of sheep in a 2 x 2 x 3 factorial experiment conducted at Debre Berhan research station in the central highlands of Ethiopia. This involved two anthelmintic-treatment levels (treated vs. non-treated), two supplementary nutrition levels (protein-energy supplementation yes/no) and three genotypes: indigenous Menz (n=40), 50% Awassi x 50% Menz crosses (n=38) and 75% Awassi x 25% Menz crosses (n=31). All sheep were exposed to natural sub-clinical helminthosis challenge. Supplemented sheep were offered a concentrate mix daily on an individual basis. Anthelmintic-treated sheep were drenched with fenbendazole against nematodes and with triclabendazole against trematodes. Data were collected during the experimental period (for 10 months from approximately 1 year of age) on feed intake, live weight, eggs per gram (EPG) of faeces, packed-cell volume (PCV), wool weight, and adult-worm burden. Actual market input and output prices were recorded. Supplemented sheep had significantly higher marginal profit (MP) per sheep than non-supplemented sheep (ETB 33 vs. 4). Likewise, anthelmintic treated sheep performed significantly better than their non-treated contemporaries (MP=ETB 28 vs. 8). The 75% Awassi crosses were least profitable.

The welfare risks and impacts of heat stress on sheep shipped from Australia to the Middle East.

PubMed

Phillips, Clive

2016-12-01

This review considers the welfare issues confronting sheep due to heat stress on board ships undertaking long distance voyages. Sheep engage in behavioural and physiologic mechanisms to attempt to mitigate heat stress, but the evidence from Australian shipments from 2005 to 2014 is that mortality approximately doubles when sheep are transported from Australia in winter to the Middle East in summer. Much of this increase has been attributed to salmonellosis and inanition, but this may have been mistaken for, or exacerbated by, heat stress. The Australian government's estimate of the heat stress threshold of sheep is substantially higher than that observed under simulated live export conditions, which leads to an underestimate of the importance of heat stress in sheep on voyages where mortality is high. Improved temperature monitoring on ships and the creation of both a robust model of the impact of increased temperatures on sheep morbidity and mortality, and a heat stress scale for sheep would assist in understanding and addressing this welfare concern. The high risk to sheep exported from Australia during summer in the Middle East is sufficient to warrant consideration of restriction of trade during this period. Copyright © 2016 Elsevier Ltd. All rights reserved.

Characterizing CH4, CO2 and N2O emission from barn feeding Tibetan sheep in Tibetan alpine pastoral area in cold season

NASA Astrophysics Data System (ADS)

Xu, Tianwei; Zhao, Na; Hu, Linyong; Xu, Shixiao; Liu, Hongjin; Ma, Li; Zhao, Xinquan

2017-05-01

Herein, methane (CH4), carbon dioxide (CO2) and nitrous oxide (N2O) emission from different aged barn feeding Tibetan sheep were characterized using a respiration chamber in combination with gas chromatograph method in cold season of 2013. This work was based on measuring the increase of gas concentration inside respiration chamber by the means of gas chromatograph. Results indicated that diurnal CH4 emission patterns for barn feeding Tibetan sheep were driven by feeding schedule, diurnal CO2 emission patterns were relatively stable with two slight emission peaks, diurnal N2O emission patterns were driven by the variation of temperature inside chamber. Diurnal CH4 emission rates were 17.65, 19.49 and 21.06 g sheep-1 d-1 for yearling, two-year and three-year barn feeding Tibetan sheep, account for 6.15%, 5.76% and 5.45% of their daily gross energy intakes, respectively. Diurnal CO2 emission rates were 526.88, 588.43 and 640.66 g sheep-1 d-1 for yearling, two-year and three-year barn feeding Tibetan sheep, respectively. Diurnal N2O emission rates were 1.64, 1.25 and 1.05 mg sheep-1 d-1 for yearling, two-year and three-year barn feeding Tibetan sheep, respectively. Three-year barn feeding Tibetan sheep released more CO2-eq on per unit BW and BW0.75 gain basis.

Identification and Classification of New Transcripts in Dorper and Small-Tailed Han Sheep Skeletal Muscle Transcriptomes.

PubMed

Chao, Tianle; Wang, Guizhi; Wang, Jianmin; Liu, Zhaohua; Ji, Zhibin; Hou, Lei; Zhang, Chunlan

2016-01-01

High-throughput mRNA sequencing enables the discovery of new transcripts and additional parts of incompletely annotated transcripts. Compared with the human and cow genomes, the reference annotation level of the sheep genome is still low. An investigation of new transcripts in sheep skeletal muscle will improve our understanding of muscle development. Therefore, applying high-throughput sequencing, two cDNA libraries from the biceps brachii of small-tailed Han sheep and Dorper sheep were constructed, and whole-transcriptome analysis was performed to determine the unknown transcript catalogue of this tissue. In this study, 40,129 transcripts were finally mapped to the sheep genome. Among them, 3,467 transcripts were determined to be unannotated in the current reference sheep genome and were defined as new transcripts. Based on protein-coding capacity prediction and comparative analysis of sequence similarity, 246 transcripts were classified as portions of unannotated genes or incompletely annotated genes. Another 1,520 transcripts were predicted with high confidence to be long non-coding RNAs. Our analysis also revealed 334 new transcripts that displayed specific expression in ruminants and uncovered a number of new transcripts without intergenus homology but with specific expression in sheep skeletal muscle. The results confirmed a complex transcript pattern of coding and non-coding RNA in sheep skeletal muscle. This study provided important information concerning the sheep genome and transcriptome annotation, which could provide a basis for further study.

Net energy and protein requirements for pregnancy differ between goats and sheep.

PubMed

Härter, C J; Ellis, J L; France, J; Resende, K T; Teixeira, I A M A

2016-06-01

Current feeding systems for goats estimate the energy and protein requirements for pregnancy using data from sheep. The objective of this study was to predict the NE and net protein requirements for pregnancy in goats carrying single and twin fetuses and to compare these requirements with those of sheep. Data were compiled from 2 studies with dairy goats and 3 studies with sheep. These studies measured the energy content (EC) and protein content (PC) of the gravid uterus and of the mammary gland using the comparative slaughter technique. The current study was performed as a meta-analysis using an exponential model, comparing species (sheep versus goats) and litter size (single versus twin) from 50 to 140 d of pregnancy. Total EC and total PC in the gravid uterus were similar in goats and sheep carrying a single fetus. Energy and protein contents of the gravid uterus of sheep carrying twins were, on average, 29% greater than that of goats with twins from 80 to 140 d of pregnancy. During pregnancy, EC and PC of the mammary gland in goats carrying singles and twins were, on average, greater than those of sheep by 9 and 24%, respectively, for EC and by 25% for PC for both litter sizes. In conclusion, the gravid uterus and the mammary gland of goats and sheep require different amounts of energy and protein. Sheep carrying twins have the greatest daily NE and net protein requirements for pregnancy followed by goats carrying twins and both species carrying a single fetus. Therefore, it is inappropriate to adopt data from sheep to predict the net pregnancy requirements of goats, and the results found in this study could be relevant to the nutritional management of dairy goats.

Expression of CYP2A6, KIF12, and SULT1C1 in liver of sheep with divergent sheepmeat flavour and odour

NASA Astrophysics Data System (ADS)

Listyarini, K.; Jakaria; Furqon, A.; Sumantri, C.; Uddin, M. J.; Gunawan, A.

2018-05-01

The aim of this study was to investigate the expression of some of the key enzymes involved in liver sample of sheep with high and low sheepmeat flavour and odour. The study was conducted with Indonesian Javanese fat tailed sheep. Sheep having a fat branched chain fatty acids 4-methylnonanoic (MNA) greater and less than 215 μg g-1 and 229 will be defined as low and sheep meat odour, respectively. For the flavour, sheep having a fat skatole level less than 0.25 μg g-1 and greater than 0.25 μg g-1 will be defined as low and high flavour samples, respectively. The enzymes investigated were cytochrome P450 2A13 (CYP2A6), kinesin-like protein KIF12 (KIF12), and sulfotransferase 1C1 (SULT1C1). Expression of CYP2A6 in liver had differ between animals with high and low sheep meat flavour. Expression of CYP2A6, which catalyses the first stage of oxidation degradation, was increased in high sheep meat flavour and odour (P > 0.05). Similar pattern, the expression of SULT1C1, which catalyse the second stage of conjugation steroid catabolism, was increase in high sheep meat flavour and odour (P > 0.05). In contrast, the expression of KIF12 was decreased in high sheep meat flavour and odour animals. It is suggested that accumulation sheep meat flavour and odour in liver tissue of Indonesian Javanese fat tailed might be related to a high rate of oxidation in metabolic stage I and conjugation degradation in metabolic stage II.

Relationship between thoracic auscultation and lung pathology detected by ultrasonography in sheep.

PubMed

Scott, Phil; Collie, Dave; McGorum, Bruce; Sargison, Neil

2010-10-01

The utility of routine auscultation to detect and characterise the nature of a range of superficial lung and pleural pathologies in domestic sheep was assessed using ultrasonographic examination to indicate and localise pathologies pre-mortem. Necropsy examination was then used to fully characterise the nature and extent of the lesions. Auscultation recordings were made from 10 normal sheep with no clinical evidence of respiratory disease and with absence of significant superficial lung pathology, which was confirmed initially by ultrasound examination and subsequently at necropsy examination. A further two sheep with endotoxaemia and 30 sheep with well-defined lung lesions were also examined. Increased audibility of normal lung sounds in 4/10 normal sheep was associated with tachypnoea as a consequence of handling and transport during hot weather and was also observed in the two sheep with endotoxaemia. Moderate to severe coarse crackles detected in all advanced cases of ovine pulmonary adenocarcinoma (n=16) were audible over an area larger than the lesion distribution identified during ultrasound examination, and confirmed later at necropsy. Auscultation did not detect abnormal sounds in any of the five sheep with focal pleural abscesses (up to 10 cm diameter). Unilateral pyothorax caused attenuation of sounds relative to the contra-lateral normal lung in all three sheep with this condition. Marked fibrinous pleurisy caused attenuation of sounds relative to normal areas of lung in six sheep. No sounds resembling the description of pleural frictions rubs were heard in the sheep with marked fibrinous pleurisy (n=6) or associated with focal pleural abscesses (n=5). Routine interpretation of auscultated sound did not allow the presence of superficial lung pathology or its distribution to be accurately defined in the respiratory diseases represented in this study. Copyright © 2009 Elsevier Ltd. All rights reserved.

Seroprevalence and correlates of Toxoplasma gondii infection in domestic sheep in Michoacán State, Mexico.

PubMed

Alvarado-Esquivel, Cosme; Silva-Aguilar, Dante; Villena, Isabelle; Dubey, Jitender P

2013-11-01

Toxoplasma gondii infection in sheep is of public health and economic importance. Seroprevalence of T. gondii infection and correlates were determined in 405 sheep from 7 farms in 4 geographical regions in Michoacán State, Mexico using the modified agglutination test (MAT). General sheep and environmental characteristics were obtained by a questionnaire. All sheep were raised in semi-extensive conditions in temperate climate. Antibodies to T. gondii were found in 121 (29.9%) of the 405 sheep with MAT titers of 1:25 in 46, 1:50 in 20, 1:100 in 7, 1:200 in 5, 1:400 in 7, 1:800 in 11, 1:1600 in 5, and 1:3200 or higher in 20. Seropositivity did not vary significantly with age, sex or breed. In contrast, seroprevalence varied among farms, geographic region, municipality, altitude, mean annual temperature, and mean annual rainfall. The median seroprevalence in farms was 32.6% (range 7.1-71.4%). Sheep raised in farms at ≥1900 m above sea level had a higher seroprevalence (44.1%) than those in farms at lower sea level (16.3%). Sheep raised in municipalities with ≤17.7 °C mean annual temperature had a higher seroprevalence (37.2%) than those in municipalities with higher mean annual temperature (14.1%). Sheep raised in a municipality with 600 mm of mean annual rainfall had a higher seroprevalence (71.4%) than municipalities with higher mean annual rainfall (29.1%). This is the first report on the seroprevalence and correlates of T. gondii infection in sheep in Michoacán State, Mexico. The role of environmental characteristics for T. gondii infection in sheep deserves further research. Copyright © 2013 Elsevier B.V. All rights reserved.

Anthelmintic utilisation practices and prevalence of gastrointestinal helminth infections in sheep kept in the urban and peri-urban areas of Bishoftu Town.

PubMed

Datiko, Jallale; Terefe, Getachew; Bekele, Jemere

2013-02-01

Assessment of the anthelmintic (AH) utilisation practices and estimation of the prevalence of gastrointestinal helminth infections in sheep were carried out from November 2010 to April 2011 in urban and peri-urban areas of Bishoftu Town, central Ethiopia. A structured questionnaire was employed to assess the AH utilisation practices in sheep of 310 owners/households, while floatation and sedimentation techniques were used to study the prevalence of helminth infections. Faecal examinations revealed that 53.9 % of sheep harboured gastrointestinal helminth infections with a high frequency due to strongyles (77.3 %). The questionnaire survey revealed that sources of AH for sheep were government and private veterinary clinics for 98.5 % of urban and 65.4 % peri-urban respondents. In peri-urban areas, AH were also purchased from open markets and illegal dealers. Albendazole was the most common (75.5 %) drug used in sheep followed by ivermectin (18.7 %) and tetramisole (5.8 %). The criteria for selecting AH were: prescription by veterinarians (51.6 %), efficacy (31.9 %), price (12.3 %) and arbitrary reasons (4.2 %). Treatment frequency was minimal with 51.3, 32.3 and 15.8 % of the owners treating their sheep once, twice and less than once per year, respectively. Treatments mainly depended on manifestations of general (45.8 %) and digestive (23.3 %) symptoms. Irrespective of the body weight of the sheep, albendazole was the only drug reported to be given at half bolus/sheep (14.1 %). Owing to this practice, albendazole faces the risk of reduced efficacy or AH resistance due to its wide spread utilisation, handling by untrained personnel and suspected underdosage, which altogether support the perception of sheep owners on its lower effect on the performance of treated sheep.

Sheep production and marketing system in southern Ethiopia: the case of Awassazuria district.

PubMed

Tadesse, Estefanos; Negesse, Tegene; Abebe, Girma

2015-10-01

A survey was conducted in Awassazuria district of southern Ethiopia to characterize sheep production system. A structured questionnaire was used to collect data. Using purposive sampling, a total of 120 households from the district were included in the survey. Collected data were analyzed using descriptive statistics. Result indicated that Kajima neighbourhood has more (p<0.05) grazing land than the others. Communal grazing, roadside grazing, enset (false banana, Ensete ventricosum), banana leaf and private grazing land were major feed resources for sheep. Lake Awassa and tap water were permanent water sources. Watering frequency of sheep varies from once a day to once in 4 days. Sheep are primarily kept to generate income and equilibrate benefit and risk and for home consumption. The criteria used by the households for purchase and sale of sheep are physical characteristics (coat colour, horn and tail) (46.7 %), body conformation (35 %), age (10.8 %) and known local ecotype (7.5 %). The reasons of slaughter of sheep include festival (55 %), childbirth (18.3 %), wedding (12.5 %), mutton for home (9 %), circumcision (5 %) and for guest (1.7 %). Farmers fatten sheep for New Year (60 %), Easter (30.8 %), Christmas and Arefa (Eid al-Adha celebration (Feast of the Sacrifice); <10 %). The reasons for expansion of sheep flock in the future were market price, high market demand, immediate return, ease of management, equilibrium between benefits and risks and suitability for home consumption, ranked in decreasing order of importance. The sheep production in southern Ethiopia is constrained by shortage of grazing land (23.3 %), recurrent drought (17.5 %), disease and parasite (15 %), marketing (10.8 %), water shortage (9 %) and other constraints including predators and lack of input, capital and lack of extension service. The presence of diversified and environmentally adaptable sheep breeds, high demand of mutton in the Awassa town and presence of nutritious and unutilized feed resources like fish meal and poultry litter were some of the opportunities for sheep production in the area.

Oxidant/antioxidant status in lambs and sheep with liver and lung cystic echinococcosis diagnosed by ultrasonography and necropsy.

PubMed

Sagkan-Ozturk, A; Durgut, R; Ozturk, O H

2015-03-15

The aim of this study was to evaluate total antioxidant capacity (TAC), total oxidant status (TOS), and oxidative stress index (OSI) in sheep and lambs with cyctic eccinocoocosis (CE) diagnosed by ultrasonography and necropsy findings. A total of 9 sheep and 17 lambs with CE were used in this study and the findings were compared to those of 6 healthy control sheep. Ultrasonography were used for the diagnosis of CE in sheep and lambs, and necropsy was performed to check the presence of cysts in liver and lungs. Serum TOS and TAC were measured by a novel colorimetric method. The TOS-to-TAC ratios were also calculated as OSI values. Serum biochemical profiles were determined by conventional measurement methods as well. The mean values for TOS, TAC and OSI were significantly (p<0.001) lower in sheep and lambs with CE when compared with those of the control sheep, and they were also significantly lower in lambs with CE in comparison to the mean values obtained in sheep with CE. The levels of serum albumin, total cholesterol, creatinine, and triglycerides in lambs with CE were found out to decrease significantly (p<0.001) when compared with those of both sheep with EC and the control group. There were no significant differences between the groups in terms of other serum parameters. In addition, when clinically and some biochemical values were evaluated, CE was found to be more severe in lambs than in sheep. It was concluded that although common diagnostic cyst detection is performed by postmortem examination, ultrasonography could successfully be used in conjunction with serum biochemical profile detection and serum TOS, TAC and OSI measurements for diagnosis of cysts in liver and lungs of severely infected living sheep and lambs. Serum albumin, total cholesterol, creatinine, total protein and triglycerides might be used as indicators in sheep and particularly in lambs for the diagnosis of CE. Copyright © 2015 Elsevier B.V. All rights reserved.

Molecular identification of Theileria and Babesia in sheep and goats in the Black Sea Region in Turkey.

PubMed

Aydin, Mehmet Fatih; Aktas, Munir; Dumanli, Nazir

2013-08-01

This study was carried out to investigate presence and distribution of Theileria and Babesia species via microscopic examination and reverse line blotting (RLB) techniques in sheep and goats in the Black Sea region of Turkey. For this purpose, 1,128 blood samples (869 sheep and 259 goats) were collected by active surveillance from sheep and goats in different provinces of various cities in the region in the years 2010 and 2011. Smears were prepared from the blood samples, stained with Giemsa, and examined under the light microscope for Theileria and Babesia piroplasms. The genomic DNAs were extracted from blood samples. The length of 360-430-bp fragment in the variable V4 region of 18S SSU rRNA gene of Theileria and Babesia species was amplified using the gDNAs. The polymerase chain reaction products were hybridized to the membrane-connected species-specific probes. A total of 38 animals (3.37%) including 34 sheep (3.91%) and 4 goats (1.54%) were found to be positive for Theileria spp. piroplasms in microscopic examination of smears while Babesia spp. piroplasm could not detected. Infection rates were 34.64% in sheep, 10.04% in goats, and totally 28.99% for Theileria ovis while 0.58% in sheep and totally 0.44% for Babesia ovis. However, Theileria sp. OT3 was detected in 2.65% of sheep and 2.04% of all animals; besides Theileria sp., MK had 0.58% prevalence in sheep and 0.77% in goats, with a total 0.62% with RLB. Although T. ovis and Theileria sp. MK were determined in both sheep and goats, B. ovis and Theileria sp. OT3 were observed only in the sheep. These results provide the first detailed molecular data for sheep and goat theileriosis and babesiosis in the region.

Genomic selection signatures in sheep from the Western Pyrenees.

PubMed

Ruiz-Larrañaga, Otsanda; Langa, Jorge; Rendo, Fernando; Manzano, Carmen; Iriondo, Mikel; Estonba, Andone

2018-03-22

The current large spectrum of sheep phenotypic diversity results from the combined product of sheep selection for different production traits such as wool, milk and meat, and its natural adaptation to new environments. In this study, we scanned the genome of 25 Sasi Ardi and 75 Latxa sheep from the Western Pyrenees for three types of regions under selection: (1) regions underlying local adaptation of Sasi Ardi semi-feral sheep, (2) regions related to a long traditional dairy selection pressure in Latxa sheep, and (3) regions experiencing the specific effect of the modern genetic improvement program established for the Latxa breed during the last three decades. Thirty-two selected candidate regions including 147 annotated genes were detected by using three statistical parameters: pooled heterozygosity H, Tajima's D, and Wright's fixation index F st . For Sasi Ardi sheep, chromosomes Ovis aries (OAR)4, 6, and 22 showed the strongest signals and harbored several candidate genes related to energy metabolism and morphology (BBS9, ELOVL3 and LDB1), immunity (NFKB2), and reproduction (H2AFZ). The major genomic difference between Sasi Ardi and Latxa sheep was on OAR6, which is known to affect milk production, with highly selected regions around the ABCG2, SPP1, LAP3, NCAPG, LCORL, and MEPE genes in Latxa sheep. The effect of the modern genetic improvement program on Latxa sheep was also evident on OAR15, on which several olfactory genes are located. We also detected several genes involved in reproduction such as ESR1 and ZNF366 that were affected by this selection program. Natural and artificial selection have shaped the genome of both Sasi Ardi and Latxa sheep. Our results suggest that Sasi Ardi traits related to energy metabolism, morphological, reproductive, and immunological features have been under positive selection to adapt this semi-feral sheep to its particular environment. The highly selected Latxa sheep for dairy production showed clear signatures of selection in genomic regions related to milk production. Furthermore, our data indicate that the selection criteria applied in the modern genetic improvement program affect immunity and reproduction traits.

Biological and clinical responses of west African sheep to Crimean-Congo haemorrhagic fever virus experimental infection.

PubMed

Gonzalez, J P; Camicas, J L; Cornet, J P; Wilson, M L

1998-01-01

West African sheep appear to play a central role as virus hosts in the maintenance cycle of Crimean-Congo haemorrhagic fever (CCHF) virus in endemic areas and also because of their role as a principal host of the CCHF virus tick vector. In an effort to clarify CCHF epidemiological significance in sheep, we studied the biological and clinical aspects of sheep experimentally infected with CCHF virus. West African sheep breeds were infected either by intraperitoneal inoculation or by infestation with experimentally CCHF-virus-infected ticks (Hyalomma truncatum). A total of 17 sheep including controls as well as 5 lambs from their progeny were monitored. A moderate but constant fever was observed (39.7 degrees C +/- 0.3) which correlates with the viraemia. Virus was reisolated from blood samples taken from day 3 to day 9 postinfection (p.i.) at a mean titre of 3.3 log LD50/ml. The virus was detected for a period of time of 7 days in non-immune sheep and for less than 4 days in previously immunized sheep. In non-immune sheep, antibody detected by ELISA showed an IgM response on day 7 p.i., followed by an IgG response one day later. Five infected sheep, surveyed for liver and kidney biological markers, showed hepatic dysfunction with a moderate serum aspartate transferase rise to 210 U/l. Out of four sheep tested for blood markers, two showed an abnormal blood cell count, with marked neutrophilia of up to 63% lasting for two weeks. Infected pregnant ewes produced antibodies in their milk at a significant titre (1:1,000), and antibodies were recovered in the sera of nursing lambs from their first meal to 50 days after birth. These findings are discussed; they demonstrate that, in spite of a high turnover of local sheep herds (median age of 3 years) and long-term CCHF antibody persistence (> 3 years), sheep can be infected and efficiently transmit the virus at least once in a lifetime.

Quantitating PrP polymorphisms present in prions from heterozygous scrapie-infected sheep

USDA-ARS?s Scientific Manuscript database

Scrapie is a prion (PrPSc) disease of sheep. The incubation period of sheep scrapie is strongly influenced by polymorphisms at positions 136, 154, and 171 of a sheep’s normal cellular prion protein (PrPC). Chymotrypsin was used to digest sheep recombinant PrP to identify a set of characteristic pept...

Lack of prion accumulation in lymphoid tissues of PRNP ARQ/ARR sheep intracranially inoculated with the agent of scrapie

USDA-ARS?s Scientific Manuscript database

Sheep scrapie is a transmissible spongiform encephalopathy that can be transmitted horizontally. The prion protein gene (PRNP) profoundly influences the susceptibility of sheep to the scrapie agent and the tissue levels and distribution of PrPSc in affected sheep. The purpose of this study was to co...

40 CFR 180.557 - Tetraconazole; tolerances for residues.

Code of Federal Regulations, 2011 CFR

2011-07-01

..., oil 0.10 Pecan 0.04 Poultry, fat 0.05 Poultry, meat 0.01 Poultry meat byproducts 0.01 Sheep, fat 0.02 Sheep, liver 0.20 Sheep, meat 0.01 Sheep, meat byproducts (except liver) 0.01 Soybean, refined oil 0.80 Soybean, seed 0.15 (b) Section 18 emergency exemptions. [Reserved] (c) Tolerances with regional...

Transmission of mannheimia haemolytica from domestic sheep (ovis aries) to bighorn sheep (ovis canadensis) : Unequivocal demonstration with green fluorescent protien-tagged organisms

USDA-ARS?s Scientific Manuscript database

Previous studies have demonstrated that bighorn sheep (BHS) die of pneumonia when they commingle with domestic sheep (DS). However, these studies did not conclusively prove the transmission of pathogens from DS to BHS. The objective of this study was to determine unambiguously whether Mannheimia hae...

Differences in leukocyte differentiation molecule abundances on domestic sheep (Ovis aries) and bighorn sheep (Ovis canadensis) neutrophils identified by flow cytometry

USDA-ARS?s Scientific Manuscript database

Although both domestic sheep (DS) and bighorn sheep (BHS) are affected by similar respiratory bacterial pathogens, experimental and field data indicate BHS are more susceptible to pneumonia. Cross-reactive monoclonal antibodies (mAbs) for use in flow cytometry (FC) are valuable reagents for interspe...

Variant discovery in the sheep milk transcriptome using RNA sequencing.

PubMed

Suárez-Vega, Aroa; Gutiérrez-Gil, Beatriz; Klopp, Christophe; Tosser-Klopp, Gwenola; Arranz, Juan José

2017-02-15

The identification of genetic variation underlying desired phenotypes is one of the main challenges of current livestock genetic research. High-throughput transcriptome sequencing (RNA-Seq) offers new opportunities for the detection of transcriptome variants (SNPs and short indels) in different tissues and species. In this study, we used RNA-Seq on Milk Sheep Somatic Cells (MSCs) with the goal of characterizing the genetic variation within the coding regions of the milk transcriptome in Churra and Assaf sheep, two common dairy sheep breeds farmed in Spain. A total of 216,637 variants were detected in the MSCs transcriptome of the eight ewes analyzed. Among them, a total of 57,795 variants were detected in the regions harboring Quantitative Trait Loci (QTL) for milk yield, protein percentage and fat percentage, of which 21.44% were novel variants. Among the total variants detected, 561 (2.52%) and 1,649 (7.42%) were predicted to produce high or moderate impact changes in the corresponding transcriptional unit, respectively. In the functional enrichment analysis of the genes positioned within selected QTL regions harboring novel relevant functional variants (high and moderate impact), the KEGG pathway with the highest enrichment was "protein processing in endoplasmic reticulum". Additionally, a total of 504 and 1,063 variants were identified in the genes encoding principal milk proteins and molecules involved in the lipid metabolism, respectively. Of these variants, 20 mutations were found to have putative relevant effects on the encoded proteins. We present herein the first transcriptomic approach aimed at identifying genetic variants of the genes expressed in the lactating mammary gland of sheep. Through the transcriptome analysis of variability within regions harboring QTL for milk yield, protein percentage and fat percentage, we have found several pathways and genes that harbor mutations that could affect dairy production traits. Moreover, remarkable variants were also found in candidate genes coding for major milk proteins and proteins related to milk fat metabolism. Several of the SNPs found in this study could be included as suitable markers in genotyping platforms or custom SNP arrays to perform association analyses in commercial populations and apply genomic selection protocols in the dairy production industry.

Nutritional enhancement of sheep meat fatty acid profile for human health and wellbeing.

PubMed

Chikwanha, Obert C; Vahmani, Payam; Muchenje, Voster; Dugan, Michael E R; Mapiye, Cletos

2018-02-01

Dietary fatty acids (FA) consumed by sheep, like other ruminants, can undergo biohydrogenation resulting in high proportions of saturated FA (SFA) in meat. Biohydrogenation is typically less extensive in sheep than cattle, and consequently, sheep meat can contain higher proportions of omega (n)-3 polyunsaturated FA (PUFA), and PUFA biohydrogenation intermediates (PUFA-BHI) including conjugated linoleic acid (CLA) and trans-monounsaturated FAs (t-MUFA). Sheep meat is also noted for having characteristically higher contents of branched chain FA (BCFA). From a human health and wellness perspective, some SFA and trans-MUFA have been found to negatively affect blood lipid profiles, and are associated with increased risk of cardiovascular disease (CVD). On the other hand, n-3 PUFA, BCFA and some PUFA-BHI may have many potential beneficial effects on human health and wellbeing. In particular, vaccenic acid (VA), rumenic acid (RA) and BCFA may have potential for protecting against cancer and inflammatory disorders among other human health benefits. Several innovative strategies have been evaluated for their potential to enrich sheep meat with FA which may have human health benefits. To this end, dietary manipulation has been found to be the most effective strategy of improving the FA profile of sheep meat. However, there is a missing link between the FA profile of sheep meat, human consumption patterns of sheep FA and chronic diseases. The current review provides an overview of the nutritional strategies used to enhance the FA profile of sheep meat for human consumption. Copyright © 2017 Elsevier Ltd. All rights reserved.

Pasteurellaceae isolated from bighorn sheep (Ovis canadensis) from Idaho, Oregon, and Wyoming.

PubMed

Miller, David S; Weiser, Glen C; Ward, Alton C S; Drew, Mark L; Chapman, Phillip L

2012-07-01

To elucidate the species and biovariants of Pasteurellaceae isolated from clinically normal bighorn sheep (Ovis canadensis) or bighorn sheep with evidence of respiratory disease. 675 Pasteurellaceae isolates from 290 free-ranging bighorn sheep in Idaho, Oregon and Wyoming. Nasal and oropharyngeal swab specimens were inoculated onto selective and nonselective blood agar media. Representatives of each colony type were classified via a biovariant scheme. The association of respective β-hemolytic isolates with respiratory disease was evaluated via χ(2) analyses. Bacterial isolates belonged to 4 species: Histophilus somni, Mannheimia haemolytica, Pasteurella multocida, and Bibersteinia (Pasteurella) trehalosi. Within the latter 3 species, 112 subspecies, biotypes, and biovariants were identified. Bibersteinia trehalosi 2 and B trehalosi 2B constituted 345 of 675 (51%) isolates. Most (597/618 [97%]) isolates from adult sheep were from clinically normal animals, whereas most (47/57 [82%]) isolates from lambs were from animals with evidence of respiratory disease. Twenty-two Pasteurellaceae biovariants were isolated from sheep with respiratory disease; 17 of these biovariants were also isolated from clinically normal sheep. The ability of isolates to cause β-hemolysis on blood agar was associated with respiratory disease in adult bighorn sheep (OR, 2.59; 95% confidence interval, 1.10 to 6.07). Bighorn lambs appeared more susceptible to respiratory disease caused by Pasteurellaceae than did adult sheep. β-Hemolytic Pasteurellaceae isolates were more likely to be associated with respiratory disease than were non-β-hemolytic isolates in adult sheep. Identification of Pasteurellaceae with the greatest pathogenic potential will require studies to estimate the risk of disease from specific biovariants.

Parasites of domestic and wild animals in South Africa. XLII. Helminths of sheep on four farms in the Eastern Cape Province.

PubMed

Horak, I G

2003-09-01

At monthly intervals for periods ranging from 9 to 25 consecutive months between three and four Merino yearling-sheep and two Merino lambs on three farms in Eastern Cape Thornveld, and two Dorper yearling-sheep on a farm in Valley Bushveld were slaughtered and examined for helminths. The Merino sheep were infected with 15 nematode species, of which Haemonchus contortus, Nematodirus spathiger and Trichostrongylus spp. were the most numerous, and with four cestode species. The Dorper sheep were infected with 17 nematode species, of which Trichostrongylus rugafus and N. spathiger were the most numerous, and with two cestode species. Haemonchus contortus was most numerous in older sheep during the summer months and exhibited no tendency to over-winter as arrested fourth stage larvae. The largest numbers of N. spathiger were present in sheep on the most coastally located of the farms during autumn and winter; on a farm further inland during spring; and on an inland farm in Valley Bushveld during spring and summer. As Merino lambs progressed from birth to 9 months of age a larger proportion of their dwindling burdens of N. spathiger was present as fourth stage larvae. Dorper sheep in Valley Bushveld harboured most Teladorsagia circumcincta in May and from October to January. Trichostrongylus rugatus was most numerous in Merino sheep on one of the Thornveld farms during September, whereas all Trichostrongylus spp., including T. rugatus, were most numerous in Dorper sheep on the Valley Bushveld farm during January.

Genome-wide analysis reveals signatures of selection for important traits in domestic sheep from different ecoregions.

PubMed

Liu, Zhaohua; Ji, Zhibin; Wang, Guizhi; Chao, Tianle; Hou, Lei; Wang, Jianmin

2016-11-03

Throughout a long period of adaptation and selection, sheep have thrived in a diverse range of ecological environments. Mongolian sheep is the common ancestor of the Chinese short fat-tailed sheep. Migration to different ecoregions leads to changes in selection pressures and results in microevolution. Mongolian sheep and its subspecies differ in a number of important traits, especially reproductive traits. Genome-wide intraspecific variation is required to dissect the genetic basis of these traits. This research resequenced 3 short fat-tailed sheep breeds with a 43.2-fold coverage of the sheep genome. We report more than 17 million single nucleotide polymorphisms and 2.9 million indels and identify 143 genomic regions with reduced pooled heterozygosity or increased genetic distance to each other breed that represent likely targets for selection during the migration. These regions harbor genes related to developmental processes, cellular processes, multicellular organismal processes, biological regulation, metabolic processes, reproduction, localization, growth and various components of the stress responses. Furthermore, we examined the haplotype diversity of 3 genomic regions involved in reproduction and found significant differences in TSHR and PRL gene regions among 8 sheep breeds. Our results provide useful genomic information for identifying genes or causal mutations associated with important economic traits in sheep and for understanding the genetic basis of adaptation to different ecological environments.

Seroprevalence of Toxoplasma gondii in domestic sheep in Oaxaca State, Mexico.

PubMed

Alvarado-Esquivel, C; Estrada-Malacón, M A; Reyes-Hernández, S O; Pérez-Ramírez, J A; Trujillo-López, J I; Villena, I; Dubey, J P

2013-02-01

The seroprevalence of Toxoplasma gondii infection in sheep in southern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples of 429 sheep from 4 farms in 2 geographical regions in Oaxaca State, Mexico, using the modified agglutination test (MAT); 99 (23.1%) of the 429 sheep had positive MAT titers: 1:25 in 35, 1:50 in 18, 1:100 in 7, 1:200 in 1, 1:400 in 3, 1:800 in 10, 1:1,600 in 5, and 1:3,200, or higher, in 20. Seroprevalence of T. gondii infection varied with management, breed of sheep, and location. It was significantly higher in sheep raised under semi-intensive (grazed on cultivated pasture and hay) conditions than in those raised under semi-extensive conditions (grazed on communal natural grass land). The seroprevalence of T. gondii infection was significantly higher in mixed-breed sheep than in pure breeds. Sheep raised in temperate climate in municipalities at 1,560-1,600 m above sea level (Central Valley region) had a significantly higher seroprevalence of T. gondii infection than those raised in semiarid and warm-humid climates in municipalities at 1,020-1,080 m of altitude (Cañada region) (29.8% vs. 7.1%, respectively). This is the first report of T. gondii infection in sheep in Oaxaca State, Mexico.

21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE...

21 CFR 133.184 - Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk.

Code of Federal Regulations, 2011 CFR

2011-04-01

... 21 Food and Drugs 2 2011-04-01 2011-04-01 false Roquefort cheese, sheep's milk blue-mold, and blue-mold cheese from sheep's milk. 133.184 Section 133.184 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) FOOD FOR HUMAN CONSUMPTION CHEESES AND RELATED CHEESE...

Examining relationships between production and gastrointestinal nematode (GIN) measures in organic and conventionally reared Katahdin lambs

USDA-ARS?s Scientific Manuscript database

Katahdin sheep numbers are growing in the Southeastern US. It is a breed committed to the sheep industry’s goal of eradicating Scrapie by selecting for sheep with RR or QR at codon 171. Gastrointestinal nematodes remain a threat to the health and well-being of sheep due to widespread anthelmintic r...

Differential susceptibility of bighorn sheep (Ovis Canadensis) and domestic sheep (Ovis Aries) neutrophils to Mannheimia Haemolytica Leukotoxin is not due to differential expression of cell surface CD18

USDA-ARS?s Scientific Manuscript database

Bighorn sheep (BHS) are more susceptible to pneumonia caused by Mannheimia haemolytica than domestic sheep (DS). Leukotoxin produced by M. haemolytica is the principal virulence factor involved in pneumonia pathogenesis. Although leukotoxin is cytolytic to all subsets of ruminant leukocytes, neutrop...

Toxoplasma gondii and Neospora caninum seroprevalence in dairy sheep and goats mixed stock farming.

PubMed

Diakoua, Anastasia; Anastasia, Diakou; Papadopoulos, Elias; Elias, Papadopoulos; Panousis, Nikolaos; Nikolaos, Panousis; Karatzias, Charilaos; Charilaos, Karatzias; Giadinis, Nektarios; Nektarios, Giadinis

2013-12-06

Toxoplasma and Neospora infections are important causes of abortions and economic losses in animal production. Mixed stock farming of sheep and goats is a common practice in Mediterranean countries and could serve as a suitable model for the evaluation of differences between the two animal species regarding parasitic infections. In order to investigate the seroprevalence of T. gondii and N. caninum among flocks of small ruminants in Greece and to evaluate any prevalence difference between sheep and goats kept in mixed flocks, 833 sera samples (458 sheep and 375 goats) from 50 mixed flocks in different areas of the country were examined by ELISA for the detection of specific antibodies. Specific IgG against T. gondii were detected in 53.71% and 61.3% and against N. caninum in 16.8% and 6.9% of the sheep and goats, respectively. Goats had higher Toxoplasma seroprevalence than sheep (p<0.05), while sheep had higher Neospora seroprevalence than goats (p<0.05). The present study is the first report world wide, on the seroprevalence of T. gondii and N. caninum in sheep and goats that are kept together in mixed flocks. Copyright © 2013 Elsevier B.V. All rights reserved.

Seroprevalence of Toxoplasma gondii infection in domestic sheep in Durango State, Mexico.

PubMed

Alvarado-Esquivel, C; García-Machado, C; Alvarado-Esquivel, D; Vitela-Corrales, J; Villena, I; Dubey, J P

2012-04-01

The seroprevalence of Toxoplasma gondii infection in sheep (Ovis aries) in northern Mexico is largely unknown. Antibodies to T. gondii were determined in serum samples from 511 sheep from 8 farms in Durango State, Mexico, using the modified agglutination test (MAT). Sheep were raised in 3 geographical regions, i.e., mountainous (n  =  68), semi-desert (n  =  132), and valley (n  =  311). Overall, T. gondii antibodies were found in 77 (15.1%) of 511 sheep, with MAT titers of 1∶25 in 27, 1∶50 in 10, 1∶100 in 11, 1∶200 in 11, 1∶400 in 8, 1∶800 in 3, 1∶1,600 in 4, and 1∶3,200 in 3. The seroprevalence of T. gondii infection increased significantly with age, indicating post-natal transmission. In contrast, gender, breed, flock size, and geographic region did not significantly influence the seroprevalence. Seropositive sheep were found in 7 of 8 farms sampled. This is the first report of T. gondii infection in sheep in Durango State, Mexico. Results indicate that infected sheep are probably an important source of T. gondii infection for humans in Durango State.

The reindeer abomasal nematode (Ostertagia gruehneri) is naturally transmitted to sheep when sharing pastures.

PubMed

Manninen, Saana-Maaria; Thamsborg, Stig M; Laaksonen, Sauli; Oksanen, Antti

2014-11-01

The increasing number of sheep (Ovis aries) in northern Finland, often alternately corralled with winter-fed reindeer (Rangifer tarandus tarandus), creates potential for cross-infection of gastrointestinal nematodes. The aim of this study was to elucidate this possibility with 43 animals. Eleven reindeer and 8 sheep had shared a corral by turns, reindeer during winters, and sheep in summers. Another 12 reindeer had no known contact with sheep. Twelve sheep had no close contact to other ruminants. Both reindeer groups were free-ranging during summers. During slaughter in September to November, 2003, abomasa and parts of intestines were collected. Gastrointestinal nematodes were counted and identified. The species found were the following: in reindeer, Ostertagia gruehneri/Ostertagia arctica, Mazamastrongylus dagestanica, Nematodirus tarandi, Nematodirella longissimespiculata and Bunostomum trigonocephalum; in sheep, Teladorsagia circumcincta/Teladorsagia trifurcata, O. gruehneri/O. arctica, Nematodirus filicollis and N. spathiger. In the sheep sharing corral with reindeer, the only abomasal nematode species found was O. gruehneri, a reindeer parasite. The generation interval of O. gruehneri in Finnish reindeer appears to be shorter than in Canadian Arctic caribou, where complete larval inhibition leading to only one generation yearly has been reported.

[Helminth burden of slaughter sheep in Upper Bavaria. 1: Species spectrum, infestation extent and infestation intensity].

PubMed

Rehbein, S; Kollmannsberger, M; Visser, M; Winter, R

1996-05-01

The helminth fauna of 136 slaughtered sheep (99 lambs < 1 year, and 37 sheep > or = 1 year) from Upper Bavaria, Germany, was examined. In all 2 species of trematodes, 3 species of cestodes and 24 species of nematodes were found. All the animals harboured gastrointestinal nematodes, 9 of them liver flukes, 33 Moniezia spp., 19 Cysticercus tenuicollis, and one sheep Setaria sp. Lungworms were not seen. The most prevalent species were Cooperia curticei (74.3%), Trichuris ovis (69.1%), Ostertagia circumcincta (68.4%), Oesophagostomum venulosum (63.2%) and Chabertia ovina (61.8%). The highest mean wormburden was seen in Cooperia curticei (12471) followed by Trichostrongylus axei (1856), Trichostrongylus colubriformis (1752), Nematodirus filicollis (1551) and Nematodirus battus (1238). In both lambs and older sheep the small intestine harboured the highest wormburden followed by abomasum and large intestine. The total nematode counts were much higher in lambs than in older sheep. The lambs harboured more intestinal nematodes than older sheep but fewer abomasal worms.

"Ménage à Trois": the evolutionary interplay between JSRV, enJSRVs and domestic sheep.

PubMed

Armezzani, Alessia; Varela, Mariana; Spencer, Thomas E; Palmarini, Massimo; Arnaud, Frédérick

2014-12-09

Sheep betaretroviruses represent a fascinating model to study the complex evolutionary interplay between host and pathogen in natural settings. In infected sheep, the exogenous and pathogenic Jaagsiekte sheep retrovirus (JSRV) coexists with a variety of highly related endogenous JSRVs, referred to as enJSRVs. During evolution, some of them were co-opted by the host as they fulfilled important biological functions, including placental development and protection against related exogenous retroviruses. In particular, two enJSRV loci, enJS56A1 and enJSRV-20, were positively selected during sheep domestication due to their ability to interfere with the replication of related competent retroviruses. Interestingly, viruses escaping these transdominant enJSRVs have recently emerged, probably less than 200 years ago. Overall, these findings suggest that in sheep the process of endogenization is still ongoing and, therefore, the evolutionary interplay between endogenous and exogenous sheep betaretroviruses and their host has not yet reached an equilibrium.

“Ménage à Trois”: The Evolutionary Interplay between JSRV, enJSRVs and Domestic Sheep

PubMed Central

Armezzani, Alessia; Varela, Mariana; Spencer, Thomas E.; Palmarini, Massimo; Arnaud, Frédérick

2014-01-01

Sheep betaretroviruses represent a fascinating model to study the complex evolutionary interplay between host and pathogen in natural settings. In infected sheep, the exogenous and pathogenic Jaagsiekte sheep retrovirus (JSRV) coexists with a variety of highly related endogenous JSRVs, referred to as enJSRVs. During evolution, some of them were co-opted by the host as they fulfilled important biological functions, including placental development and protection against related exogenous retroviruses. In particular, two enJSRV loci, enJS56A1 and enJSRV-20, were positively selected during sheep domestication due to their ability to interfere with the replication of related competent retroviruses. Interestingly, viruses escaping these transdominant enJSRVs have recently emerged, probably less than 200 years ago. Overall, these findings suggest that in sheep the process of endogenization is still ongoing and, therefore, the evolutionary interplay between endogenous and exogenous sheep betaretroviruses and their host has not yet reached an equilibrium. PMID:25502326

Desert bighorn sheep mortality due to presumptive type C botulism in California

USGS Publications Warehouse

Swift, P.K.; Wehausen, J.D.; Ernest, H.B.; Singer, R.S.; Pauli, A.M.; Kinde, H.; Rocke, T.E.; Bleich, V.C.

2000-01-01

During a routine telemetry flight of the Mojave Desert (California, USA) in August 1995, mortality signals were detected from two of 12 radio-collared female desert bighorn sheep (Ovis canadensis) in the vicinity of Old Dad Peak in San Bernardino County (California). A series of field investigations determined that at least 45 bighorn sheep had died near two artificial water catchments (guzzlers), including 13 bighorn sheep which had presumably drowned in a guzzler tank. Samples from water contaminated by decomposing bighorn sheep carcasses and hemolyzed blood from a fresh bighorn sheep carcass were tested for the presence of pesticides, heavy metals, strychnine, blue-green algae, Clostridium botulinum toxin, ethylene glycol, nitrates, nitrites, sodium, and salts. Mouse bioassay and enzyme-linked immunosorbent assay detected type C botulinum toxin in the hemolyzed blood and in fly larvae and pupae. This, coupled with negative results from other analyses, led us to conclude that type C botulinum poisoning was most likely responsible for the mortality of bighorn sheep outside the guzzler tank.

The Effect of Crude Protein Content on Meat and Fat Production in Sheep

NASA Astrophysics Data System (ADS)

Mawati, S.; Restitrisnani, V.; Soedarsono

2018-02-01

This study was undertaken to evaluate the effect of crude protein (CP) content on meat protein and fat production in sheep. Twenty four male thin tail sheep aged 6-7 months with average body weight of 13±1.56 kg were used in this study. The sheep were fed 10-14% CP. Sheep with the average body weight amount 16.75 kg were slaughter after 4 months rising. Parameters observed in this study were carcass weight, meat weight and fat weight of thin tail sheep. The data were analyzed using correlation analysis. The result of this study showed that CP content on diet had weak and negative correlation with meat production (r = -0.06) (y = -0.148x + 62.54) but had weak and possitive correlation with fat production (r = 0.3) (y = 0.807x2 -18.40x + 119.1). Based on the result, it can be concluded that the optimum CP content for sheep is 12.5% CP.

Endogenous Retroviral Insertions Indicate a Secondary Introduction of Domestic Sheep Lineages to the Caucasus and Central Asia between the Bronze and Iron Age

PubMed Central

Schroeder, Oskar; Benecke, Norbert; Frölich, Kai; Peng, Zuogang; Kaniuth, Kai; Sverchkov, Leonid; Reinhold, Sabine; Belinskiy, Andrey; Ludwig, Arne

2017-01-01

Sheep were one of the first livestock species domesticated by humans. After initial domestication in the Middle East they were spread across Eurasia. The modern distribution of endogenous Jaagsiekte sheep retrovirus insertions in domestic sheep breeds suggests that over the course of millennia, successive introductions of improved lineages and selection for wool quality occurred in the Mediterranean region and most of Asia. Here we present a novel ancient DNA approach using data of endogenous retroviral insertions in Bronze and Iron Age domestic sheep from the Caucasus and Pamir mountain areas. Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia. PMID:28632161

Endogenous Retroviral Insertions Indicate a Secondary Introduction of Domestic Sheep Lineages to the Caucasus and Central Asia between the Bronze and Iron Age.

PubMed

Schroeder, Oskar; Benecke, Norbert; Frölich, Kai; Peng, Zuogang; Kaniuth, Kai; Sverchkov, Leonid; Reinhold, Sabine; Belinskiy, Andrey; Ludwig, Arne

2017-06-20

Sheep were one of the first livestock species domesticated by humans. After initial domestication in the Middle East they were spread across Eurasia. The modern distribution of endogenous Jaagsiekte sheep retrovirus insertions in domestic sheep breeds suggests that over the course of millennia, successive introductions of improved lineages and selection for wool quality occurred in the Mediterranean region and most of Asia. Here we present a novel ancient DNA approach using data of endogenous retroviral insertions in Bronze and Iron Age domestic sheep from the Caucasus and Pamir mountain areas. Our findings support a secondary introduction of wool sheep from the Middle East between the Late Bronze Age and Iron Age into most areas of Eurasia.