Characteristics of lipids and their feeding value in swine diets

USDA-ARS?s Scientific Manuscript database

In livestock diets, energy is one of the most expensive nutritional components of feed formulation. Because lipids are a concentrated energy source, inclusion of lipids are known to affect growth rate and feed efficiency, but are also known to affect diet palatability, feed dustiness, and pellet qua...

Effect of Feed Gas Flow Rate on CO2 Absorption through Super Hydrophobic Hollow Fiber membrane Contactor

NASA Astrophysics Data System (ADS)

Kartohardjono, Sutrasno; Alexander, Kevin; Larasati, Annisa; Sihombing, Ivander Christian

2018-03-01

Carbon dioxide is pollutant in natural gas that could reduce the heating value of the natural gas and cause problem in transportation due to corrosive to the pipeline. This study aims to evaluate the effects of feed gas flow rate on CO2 absorption through super hydrophobic hollow fiber contactor. Polyethyleneglycol-300 (PEG-300) solution was used as absorbent in this study, whilst the feed gas used in the experiment was a mixture of 30% CO2 and 70% CH4. There are three super hydrophobic hollow fiber contactors sized 6 cm and 25 cm in diameter and length used in this study, which consists of 1000, 3000 and 5000 fibers, respectively. The super hydrophobic fiber membrane used is polypropylene-based with outer and inner diameter of about 525 and 235 μm, respectively. In the experiments, the feed gas was sent through the shell side of the membrane contactor, whilst the absorbent solution was pumped through the lumen fibers. The experimental results showed that the mass transfer coefficient, flux, absorption efficiency for CO2-N2 system and CO2 loading increased with the feed gas flow rate, but the absorption efficiency for CO2-N2 system decreased. The mass transfer coefficient and the flux, at the same feed gas flow rate, decreased with the number of fibers in the membrane contactor, but the CO2 absorption efficiency and the CO2 loading increased.

Efficient arsenic(V) removal from water by ligand exchange fibrous adsorbent.

PubMed

Awual, Md Rabiul; Shenashen, M A; Yaita, Tsuyoshi; Shiwaku, Hideaki; Jyo, Akinori

2012-11-01

This study is an efficient arsenic(V) removal from contaminated waters used as drinking water in adsorption process by zirconium(IV) loaded ligand exchange fibrous adsorbent. The bifunctional fibers contained both phosphonate and sulfonate groups. The bifunctional fiber was synthesised by graft polymerization of chloromethylstyrene onto polyethylene coated polypropylene fiber by means of electron irradiation graft polymerization technique and then desired phosphonate and sulfonate groups were introduced by Arbusov reaction followed by phosphorylation and sulfonation. Arsenic(V) adsorption was clarified in column methods with continuous flow operation in order to assess the arsenic(V) removal capacity in various conditions. The adsorption efficiency was evaluated in several parameters such as competing ions (chloride and sulfate), feed solution acidity, feed flow rate, feed concentration and kinetic performances at high feed flow rate of trace concentration arsenic(V). Arsenic(V) adsorption was not greatly changed when feed solutions pH at 3.0-7.0 and high breakthrough capacity was observed in strong acidic area below pH 2.2. Increasing the flow rate brings a decrease both breakthrough capacity and total adsorption. Trace level of arsenic(V) (0.015 mM) in presence of competing ions was also removed at high flow rate (750 h(-1)) with high removal efficiency. Therefore, the adsorbent is highly selective to arsenic(V) even in the presence of high concentration competing ions. The adsorbent is reversible and reusable in many cycles without any deterioration in its original performances. Therefore, Zr(IV) loaded ligand exchange adsorbent is to be an effective means to treat arsenic(V) contaminated water efficiently and able to safeguard the human health. Copyright © 2012 Elsevier Ltd. All rights reserved.

21 CFR 558.115 - Carbadox.

Code of Federal Regulations, 2010 CFR

2010-04-01

... of feed; plus oxytetracycline, 10 milligrams per pound of body weight. (i) Indications for use. For... oxytetracycline, for treatment of bacterial pneumonia caused by Pasteurella multocida susceptible to oxytetracycline; and for increased rate of weight gain and improved feed efficiency. (ii) Limitations. Feed...

Multiple-stage decisions in a marine central-place forager

PubMed Central

Friedlaender, Ari S.; Johnston, David W.; Tyson, Reny B.; Kaltenberg, Amanda; Goldbogen, Jeremy A.; Stimpert, Alison K.; Curtice, Corrie; Hazen, Elliott L.; Halpin, Patrick N.; Read, Andrew J.; Nowacek, Douglas P.

2016-01-01

Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies. PMID:27293784

A data envelope analysis to assess factors affecting technical and economic efficiency of individual broiler breeder hens.

PubMed

Romero, L F; Zuidhof, M J; Jeffrey, S R; Naeima, A; Renema, R A; Robinson, F E

2010-08-01

This study evaluated the effect of feed allocation and energetic efficiency on technical and economic efficiency of broiler breeder hens using the data envelope analysis methodology and quantified the effect of variables affecting technical efficiency. A total of 288 Ross 708 pullets were placed in individual cages at 16 wk of age and assigned to 1 of 4 feed allocation groups. Three of them had feed allocated on a group basis with divergent BW targets: standard, high (standard x 1.1), and low (standard x 0.9). The fourth group had feed allocated on an individual bird basis following the standard BW target. Birds were classified in 3 energetic efficiency categories: low, average, and high, based on estimated maintenance requirements. Technical efficiency considered saleable chicks as output and cumulative ME intake and time as inputs. Economic efficiency of feed allocation treatments was analyzed under different cost scenarios. Birds with low feed allocation exhibited a lower technical efficiency (69.4%) than standard (72.1%), which reflected a reduced egg production rate. Feed allocation of the high treatment could have been reduced by 10% with the same chick production as the standard treatment. The low treatment exhibited reduced economic efficiency at greater capital costs, whereas high had reduced economic efficiency at greater feed costs. The average energetic efficiency hens had a lower technical efficiency in the low compared with the standard feed allocation. A 1% increment in estimated maintenance requirement changed technical efficiency by -0.23%, whereas a 1% increment in ME intake had a -0.47% effect. The negative relationship between technical efficiency and ME intake was counterbalanced by a positive correlation of ME intake and egg production. The negative relationship of technical efficiency and maintenance requirements was synergized by a negative correlation of hen maintenance and egg production. Economic efficiency methodologies are effective tools to assess the economic effect of selection and flock management programs because biological, allocative, and economic factors can be independently analyzed.

77 FR 22789 - Withdrawal of Approval of Part of a New Animal Drug Application; Tiamulin

Federal Register 2010, 2011, 2012, 2013, 2014

2012-04-17

... in swine. This action is being taken at the sponsor's request because this product is no longer... feed efficiency in swine. Novartis requested voluntary withdrawal of approval of these indications for... indications for use of increased rate of weight gain and improved feed efficiency in swine are hereby...

Identification of genomic regions associated with feed efficiency in Nelore cattle.

PubMed

de Oliveira, Priscila S N; Cesar, Aline S M; do Nascimento, Michele L; Chaves, Amália S; Tizioto, Polyana C; Tullio, Rymer R; Lanna, Dante P D; Rosa, Antonio N; Sonstegard, Tad S; Mourao, Gerson B; Reecy, James M; Garrick, Dorian J; Mudadu, Maurício A; Coutinho, Luiz L; Regitano, Luciana C A

2014-09-26

Feed efficiency is jointly determined by productivity and feed requirements, both of which are economically relevant traits in beef cattle production systems. The objective of this study was to identify genes/QTLs associated with components of feed efficiency in Nelore cattle using Illumina BovineHD BeadChip (770 k SNP) genotypes from 593 Nelore steers. The traits analyzed included: average daily gain (ADG), dry matter intake (DMI), feed-conversion ratio (FCR), feed efficiency (FE), residual feed intake (RFI), maintenance efficiency (ME), efficiency of gain (EG), partial efficiency of growth (PEG) and relative growth rate (RGR). The Bayes B analysis was completed with Gensel software parameterized to fit fewer markers than animals. Genomic windows containing all the SNP loci in each 1 Mb that accounted for more than 1.0% of genetic variance were considered as QTL region. Candidate genes within windows that explained more than 1% of genetic variance were selected by putative function based on DAVID and Gene Ontology. Thirty-six QTL (1-Mb SNP window) were identified on chromosomes 1, 2, 3, 5, 6, 7, 8, 9, 10, 12, 14, 15, 16, 18, 19, 20, 21, 22, 24, 25 and 26 (UMD 3.1). The amount of genetic variance explained by individual QTL windows for feed efficiency traits ranged from 0.5% to 9.07%. Some of these QTL minimally overlapped with previously reported feed efficiency QTL for Bos taurus. The QTL regions described in this study harbor genes with biological functions related to metabolic processes, lipid and protein metabolism, generation of energy and growth. Among the positional candidate genes selected for feed efficiency are: HRH4, ALDH7A1, APOA2, LIN7C, CXADR, ADAM12 and MAP7. Some genomic regions and some positional candidate genes reported in this study have not been previously reported for feed efficiency traits in Bos indicus. Comparison with published results indicates that different QTLs and genes may be involved in the control of feed efficiency traits in this Nelore cattle population, as compared to Bos taurus cattle.

21 CFR 558.95 - Bambermycins.

Code of Federal Regulations, 2014 CFR

2014-04-01

... week after date of manufacture. (c) [Reserved] (d) Conditions of use—(1) Chickens. Use in medicated... chickens: For increased rate of weight gain and improved feed efficiency Feed continuously as the sole... International Feed No. Percent Deflorinated phosphate (20.5% calcium, 18.5% phosphorus) 6-01-080 42.50 Sodium...

Feeding rates affect growth, intestinal digestive and absorptive capabilities and endocrine functions of juvenile blunt snout bream Megalobrama amblycephala.

PubMed

Xu, Chao; Li, Xiang-Fei; Tian, Hong-Yan; Jiang, Guang-Zhen; Liu, Wen-Bin

2016-04-01

This study aimed to investigate the optimal feeding rate for juvenile blunt snout bream (average initial weight 23.74 ± 0.09 g) based on the results on growth performance, intestinal digestive and absorptive capabilities and endocrine functions. A total of 840 fish were randomly distributed into 24 cages and fed a commercial feed at six feeding rates ranging from 2.0 to 7.0% body weight (BW)/day. The results indicated that weight gain rate increased significantly (P < 0.05) as feeding rates increased from 2.0 to 5.0% BW/day, but decreased with the further increasing feeding rates (P > 0.05). Protein efficiency ratio and nitrogen and energy retention all showed a similar trend. However, feed conversion ratio increased significantly (P < 0.05) with increasing feeding rates. Feeding rates have little effects (P > 0.05) on whole-body moisture, ash and protein contents, but significantly (P < 0.05) affect both lipid and energy contents with the highest values both observed in fish fed 4.0% BW/day. In addition, moderate ration sizes (2.0-4.0% BW/day) resulted in the enhanced activities of intestinal enzymes, including lipase, protease, Na(+), K(+)-ATPase, alkaline phosphatase and creatine kinase. Furthermore, the mRNA levels of growth hormone, insulin-like growth factors-I, growth hormone receptor and neuropeptide all increased significantly (P < 0.05) as feeding rates increased from 2.0 to 5.0% and 6.0% BW/day, but decreased significantly (P < 0.05) with the further increase in feeding rates, whereas both leptin and cholecystokinin expressions showed an opposite trend. Based on the broken-line regression analysis of SGR against feeding rates, the optimal feeding rate for juvenile blunt snout bream was estimated to be 4.57% BW/day.

The relationship between different measures of feed efficiency and feeding behavior traits in Duroc pigs.

PubMed

Lu, D; Jiao, S; Tiezzi, F; Knauer, M; Huang, Y; Gray, K A; Maltecca, C

2017-08-01

Utilization of feed in livestock species consists of a wide range of biological processes, and therefore, its efficiency can be expressed in various ways, including direct measurement, such as daily feed intake, as well as indicator measures, such as feeding behavior. Measuring feed efficiency is important to the swine industry, and its accuracy can be enhanced by using automated feeding systems, which record feed intake and associated feeding behavior of individual animals. Each automated feeder space is often shared among several pigs and therefore raises concerns about social interactions among pen mates with regard to feeding behavior. The study herein used a data set of 14,901 Duroc boars with individual records on feed intake, feeding behavior, and other off-test traits. These traits were modeled with and without the random spatial effect of Pen_Room, a concatenation of room and pen, or random social interaction among pen mates. The nonheritable spatial effect of common Pen-Room was observed for traits directly measuring feed intake and accounted for up to 13% of the total phenotypic variance in the average daily feeding rate. The social interaction effect explained larger proportions of phenotypic variation in all the traits studied, with the highest being 59% for ADFI in the group of feeding behaviors, 73% for residual feed intake (RFI; RFI4 and RFI6) in the feed efficiency traits, and 69% for intramuscular fat percentage in the off-test traits. After accounting for the social interaction effect, residual BW gain and RFI and BW gain (RIG) were found to have the heritability of 0.38 and 0.18, respectively, and had strong genetic correlations with growth and off-test traits. Feeding behavior traits were found to be moderately heritable, ranging from 0.14 (ADFI) to 0.52 (average daily occupation time), and some of them were strongly correlated with feed efficiency measures; for example, there was a genetic correlation of 0.88 between ADFI and RFI6. Our work suggested that accounting for the social common pen effect was important for estimating genetic parameters of traits recorded by the automated feeding system. Residual BW gain and RIG appeared to be two robust measures of feed efficiency. Feeding behavior measures are worth further investigation as indicators of feed efficiency.

21 CFR 558.450 - Oxytetracycline.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Chickens— Oxytetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 grams per ton (g/ton) Chickens: For increased rate of weight gain and improved feed efficiency. Feed continuously; do not feed to chickens producing eggs for human consumption. 066104,048164 (ii) 100 to 200 g/ton Chickens: For control of...

21 CFR 558.450 - Oxytetracycline.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Chickens— Oxytetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 grams per ton (g/ton) Chickens: For increased rate of weight gain and improved feed efficiency. Feed continuously; do not feed to chickens producing eggs for human consumption. 066104,048164 (ii) 100 to 200 g/ton Chickens: For control of...

21 CFR 558.450 - Oxytetracycline.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Chickens— Oxytetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 grams per ton (g/ton) Chickens: For increased rate of weight gain and improved feed efficiency. Feed continuously; do not feed to chickens producing eggs for human consumption. 066104,048164 (ii) 100 to 200 g/ton Chickens: For control of...

The effect of amino acid lysine and methionine addition on feed toward the growth and retention on mud crab (Scylla serrata)

NASA Astrophysics Data System (ADS)

Alissianto, Y. R.; Sandriani, Z. A.; Rahardja, B. S.; Agustono; Rozi

2018-04-01

High market demand of mud crab (Scylla serrata) encourages farmers to increase the production of mud crab. However, mud crab can not synthesize essential amino acids, so it is necessary to supply essential amino acids such as lysine and methionine in the diet. This study aims to determine the effect of lysine and methionine on feeds to increase growth and retention of mud crabs (Scylla serrata). In this study the amount of lysine amino acid and methionine added to the trash fish diet were: P0 (0: 0%); P1 (0.75: 0.75%); P2 (1: 1%); P3 (1.25: 1.25%); P4 (1.5: 1.5%) with the ratio of lysine and methionine 1: 1. The parameters observed in this study were Survival Rate (SR), Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Efficiency Feed (EF), protein retention and energy retention. The results of the 35-day maintenance study showed significant differences (P <0.05) against Specific Growth Rate (SGR), Feed Conversion Ratio (FCR), Efficiency Feed (EF), protein retention and no significant effect (P> 0.05) on energy retention and Survival Rate (SR) on mud crab. The best results in this study were found in P4 treatment with addition of lysine amino acids and methionine (1.5: 1.5%).

Genetic co-variance functions for live weight, feed intake, and efficiency measures in growing pigs.

PubMed

Coyne, J M; Berry, D P; Matilainen, K; Sevon-Aimonen, M-L; Mantysaari, E A; Juga, J; Serenius, T; McHugh, N

2017-09-01

The objective of the present study was to estimate genetic co-variance parameters pertaining to live weight, feed intake, and 2 efficiency traits (i.e., residual feed intake and residual daily gain) in a population of pigs over a defined growing phase using Legendre polynomial equations. The data set used consisted of 51,893 live weight records and 903,436 feed intake, residual feed intake (defined as the difference between an animal's actual feed intake and its expected feed intake), and residual daily gain (defined as the difference between an animal's actual growth rate and its expected growth rate) records from 10,201 growing pigs. Genetic co-variance parameters for all traits were estimated using random regression Legendre polynomials. Daily heritability estimates for live weight ranged from 0.25 ± 0.04 (d 73) to 0.50 ± 0.03 (d 122). Low to moderate heritability estimates were evident for feed intake, ranging from 0.07 ± 0.03 (d 66) to 0.25 ± 0.02 (d 170). The estimated heritability for residual feed intake was generally lower than those of both live weight and feed intake and ranged from 0.04 ± 0.01 (d 96) to 0.17 ± 0.02 (d 159). The heritability for feed intake and residual feed intake increased in the early stages of the test period and subsequently sharply declined, coinciding with older ages. Heritability estimates for residual daily gain ranged from 0.26 ± 0.03 (d 188) to 0.42 ± 0.03 (d 101). Genetic correlations within trait were strongest between adjacent ages but weakened as the interval between ages increased; however, the genetic correlations within all traits tended to strengthen between the extremes of the trajectory. Moderate to strong genetic correlations were evident among live weight, feed intake, and the efficiency traits, particularly in the early stage of the trial period (d 66 to 86), but weakened with age. Results from this study could be implemented into the national genetic evaluation for pigs, providing comprehensive information on the profile of growth and efficiency throughout the growing period of the animal's life, thus helping producers identify genetically superior animals.

A Burkholderia sacchari cell factory: production of poly-3-hydroxybutyrate, xylitol and xylonic acid from xylose-rich sugar mixtures.

PubMed

Raposo, Rodrigo S; de Almeida, M Catarina M D; de Oliveira, M da Conceição M A; da Fonseca, M Manuela; Cesário, M Teresa

2017-01-25

Efficient production of poly-3-hydroxybutyrate (P(3HB)) based on glucose-xylose mixtures simulating different types of lignocellulosic hydrolysate (LCH) was addressed using Burkholderia sacchari, a wild strain capable of metabolizing both sugars and producing P(3HB). Carbon catabolite repression was avoided by maintaining glucose concentration below 10g/L. Xylose concentrations above 30g/L were inhibitory for growth and production. In fed-batch cultivations, pulse size and feed addition rate were controlled in order to reach high productivities and efficient sugar consumptions. High xylose uptake and P(3HB) productivity were attained with glucose-rich mixtures (glucose/xylose ratio in the feed=1.5w/w) using high feeding rates, while with xylose-richer feeds (glucose/xylose=0.8w/w), a lower feeding rate is a robust strategy to avoid xylose build-up in the medium. Xylitol production was observed with xylose concentrations in the medium above 30-40g/L. With sugar mixtures featuring even lower glucose/xylose ratios, i.e. xylose-richer feeds (glucose/xylose=0.5), xylonic acid (a second byproduct) was produced. This is the first report of the ability of Burkholderia sacchari to produce both xylitol and xylonic acid. Copyright © 2016 Elsevier B.V. All rights reserved.

Physiological responses to digestion in low salinity in the crabs Carcinus maenas and Cancer irroratus.

PubMed

Penney, Chantelle M; Patton, Richard L; Whiteley, Nia M; Driedzic, William R; McGaw, Iain J

2016-01-01

Osmoregulation and digestion are energetically demanding, and crabs that move into low salinity environments to feed must be able to balance the demands of both processes. Achieving this balance may pose greater challenges for weak than for efficient osmoregulators. This study examined the rate of oxygen consumption (MO2) of Carcinus maenas (efficient osmoregulator) and Cancer irroratus (weak osmoregulator) as a function of feeding and hyposaline stress. The MO2 increased 2-fold in both species following feeding. The MO2 increased and remained elevated in fasted crabs during acute hyposaline exposure. When hyposaline stress occurred after feeding, C. maenas responded with an immediate summation of the MO2 associated with feeding and hyposaline stress, whereas C. irroratus reacted with a partial summation of responses in a salinity of 24‰, but were unable to sum responses in 16‰. C. irroratus exhibited longer gut transit times. This may be due to an inability to regulate osmotic water onload as efficiently as C. maenas. Mechanical digestion in crabs can account for a significant portion of SDA, and a short term interruption led to the delay in summation of metabolic demands. Although protein synthesis is reported to account for the majority of SDA, this did not appear to be the case here. Protein synthesis rates were higher in C. irroratus but neither feeding or salinity affected protein synthesis rates of either species which suggests that protein synthesis can continue in low salinity as long as substrates are available. Copyright © 2015 Elsevier Inc. All rights reserved.

Meat-type chickens have a higher efficiency of mitochondrial oxidative phosphorylation than laying-type chickens.

PubMed

Toyomizu, Masaaki; Kikusato, Motoi; Kawabata, Yusuke; Azad, Md Abul Kalam; Inui, Eriko; Amo, Taku

2011-05-01

Meat-type chickens show high feed efficiency and have a very rapid growth rate compared with laying-type chickens. To clarify whether the type-specific difference in feed conversion efficiency is involved in mitochondrial bioenergetics, modular kinetic analysis was applied to oxidative phosphorylation in skeletal muscle mitochondria of both type chickens. Mitochondria from skeletal muscle of meat-type chickens showed greater substrate oxidation and phosphorylating activities, and less proton leak than those of the laying-type, resulting in a higher efficiency of oxidative phosphorylation. Gene expression and protein content of uncoupling protein (avUCP) but not adenine nucleotide translocase (avANT) gene expression were lower in skeletal muscle mitochondria of meat-type chickens than the laying-type. The current results regarding a higher efficiency of oxidative phosphorylation and UCP content may partially support the high feed efficiency of meat-type chickens. Copyright © 2011 Elsevier Inc. All rights reserved.

Genetic variation in efficiency to deposit fat and lean meat in Norwegian Landrace and Duroc pigs.

PubMed

Martinsen, K H; Ødegård, J; Olsen, D; Meuwissen, T H E

2015-08-01

Feed costs amount to approximately 70% of the total costs in pork production, and feed efficiency is, therefore, an important trait for improving pork production efficiency. Production efficiency is generally improved by selection for high lean growth rate, reduced backfat, and low feed intake. These traits have given an effective slaughter pig but may cause problems in piglet production due to sows with limited body reserves. The aim of the present study was to develop a measure for feed efficiency that expressed the feed requirements per 1 kg deposited lean meat and fat, which is not improved by depositing less fat. Norwegian Landrace ( = 8,161) and Duroc ( = 7,202) boars from Topigs Norsvin's testing station were computed tomography scanned to determine their deposition of lean meat and fat. The trait was analyzed in a univariate animal model, where total feed intake in the test period was the dependent variable and fat and lean meat were included as random regression cofactors. These cofactors were measures for fat and lean meat efficiencies of individual boars. Estimation of fraction of total genetic variance due to lean meat or fat efficiency was calculated by the ratio between the genetic variance of the random regression cofactor and the total genetic variance in total feed intake during the test period. Genetic variance components suggested there was significant genetic variance among Norwegian Landrace and Duroc boars in efficiency for deposition of lean meat (0.23 ± 0.04 and 0.38 ± 0.06) and fat (0.26 ± 0.03 and 0.17 ± 0.03) during the test period. The fraction of the total genetic variance in feed intake explained by lean meat deposition was 12% for Norwegian Landrace and 15% for Duroc. Genetic fractions explained by fat deposition were 20% for Norwegian Landrace and 10% for Duroc. The results suggested a significant part of the total genetic variance in feed intake in the test period was explained by fat and lean meat efficiency. These new efficiency measures may give the breeders opportunities to select for animals with a genetic potential to deposit lean meat efficiently and at low feed costs in slaughter pigs rather than selecting for reduced the feed intake and backfat.

Life cycle efficiency of beef production: II. Relationship of cow efficiency ratios to traits of the dam and progeny weaned.

PubMed

Davis, M E; Rutledge, J J; Cundiff, L V; Hauser, E R

1983-10-01

Several measures of life cycle cow efficiency were calculated using weights and individual feed consumptions recorded on 160 dams of beef, dairy and beef X dairy breeding and their progeny. Ratios of output to input were used to estimate efficiency, where outputs included weaning weights of progeny plus salvage value of the dam and inputs included creep feed consumed by progeny plus feed consumed by the dam over her entire lifetime. In one approach to estimating efficiency, inputs and outputs were weighted by probabilities that were a function of the cow herd age distribution and percentage calf crop in a theoretical herd. The second approach to estimating cow efficiency involved dividing the sum of the weights by the sum of the feed consumption values, with all pieces of information being given equal weighting. Relationships among efficiency estimates and various traits of dams and progeny were examined. Weights, heights, and weight:height ratios of dams at 240 d of age were not correlated significantly with subsequent efficiency of calf production, indicating that indirect selection for lifetime cow efficiency at an early age based on these traits would be ineffective. However, females exhibiting more efficient weight gains from 240 d to first calving tended to become more efficient dams. Correlations of efficiency with weight of dam at calving and at weaning were negative and generally highly significant. Height at withers was negatively related to efficiency. Ratio of weight to height indicated that fatter dams generally were less efficient. The effect of milk production on efficiency depended upon the breed combinations involved. Dams calving for the first time at an early age and continuing to calve at short intervals were superior in efficiency. Weaning rate was closely related to life cycle efficiency. Large negative correlations between efficiency and feed consumption of dams were observed, while correlations of efficiency with progeny weights and feed consumptions in individual parities tended to be positive though nonsignificant. However, correlations of efficiency with accumulative progeny weights and feed consumptions generally were significant.

[Improving the feed conversion rate in the pig fattening industry by optimising hygienic management].

PubMed

Riedl, Antonia M; Völkel, Inger; Schlindwein, Bernhard; Czerny, Claus-Peter

2013-01-01

Considering continuously increasing forage costs, the feed conversion rate has a major impact on the economic efficiency in hog fattening. The influence of hygienic management strategies on animal health and feed efficiency was evaluated by an online-study comprising animal health management data of 202 German pig fatteners. Data analysis included a simple comparison of averages, a linear regression analysis, and a cluster analysis. Due to geographical distribution and size of premises, the random sample was not representative but yielded in significant results. The total impact of hygienic management on feed conversion was calculated to be 23.9 %. Professional performance of rodent control (beta = 0.357; p < or = 0.001), efficient insect larvae control (beta = 0.276; p = 0.008), requiring visitors to wear protective gear (beta = 0.261; p = 0.009), and immediately performed cleaning and disinfection of emptied pens (beta = 0.247; p = 0.017) were top-ranking variables. Furthermore, a significantly better fed efficiency was observed in companies reporting stables in a good state of repair or performing further preventive strategies to control animal health on herd-level (storage of fodder retain samples, health screening based on blood and faecal samples, cross-section to verify unclear death cases). For pig fatteners the benefit resulting from improved feed conversion ranged from Euro 1.15 to and Euro 2.53 per pig. Likewise optimized growth performance as a result of improved hygienic management could partly compensate increasing feed costs. The results of this online-study reveal the need to establish reliable HACCP systems on farm level.

Genetic relationships between feed efficiency in growing males and beef cow performance.

PubMed

Crowley, J J; Evans, R D; Mc Hugh, N; Kenny, D A; McGee, M; Crews, D H; Berry, D P

2011-11-01

Most studies on feed efficiency in beef cattle have focused on performance in young animals despite the contribution of the cow herd to overall profitability of beef production systems. The objective of this study was to quantify, using a large data set, the genetic covariances between feed efficiency in growing animals measured in a performance-test station, and beef cow performance including fertility, survival, calving traits, BW, maternal weaning weight, cow price, and cull cow carcass characteristics in commercial herds. Feed efficiency data were available on 2,605 purebred bulls from 1 test station. Records on cow performance were available on up to 94,936 crossbred beef cows. Genetic covariances were estimated using animal and animal-dam linear mixed models. Results showed that selection for feed efficiency, defined as feed conversion ratio (FCR) or residual BW gain (RG), improved maternal weaning weight as evidenced by the respective genetic correlations of -0.61 and 0.57. Despite residual feed intake (RFI) being phenotypically independent of BW, a negative genetic correlation existed between RFI and cow BW (-0.23; although the SE of 0.31 was large). None of the feed efficiency traits were correlated with fertility, calving difficulty, or perinatal mortality. However, genetic correlations estimated between age at first calving and FCR (-0.55 ± 0.14), Kleiber ratio (0.33 ± 0.15), RFI (-0.29 ± 0.14), residual BW gain (0.36 ± 0.15), and relative growth rate (0.37 ± 0.15) all suggest that selection for improved efficiency may delay the age at first calving, and we speculate, using information from other studies, that this may be due to a delay in the onset of puberty. Results from this study, based on the estimated genetic correlations, suggest that selection for improved feed efficiency will have no deleterious effect on cow performance traits with the exception of delaying the age at first calving.

Low nitrous oxide production through nitrifier-denitrification in intermittent-feed high-rate nitritation reactors.

PubMed

Su, Qingxian; Ma, Chun; Domingo-Félez, Carlos; Kiil, Anne Sofie; Thamdrup, Bo; Jensen, Marlene Mark; Smets, Barth F

2017-10-15

Nitrous oxide (N 2 O) production from autotrophic nitrogen conversion processes, especially nitritation systems, can be significant, requires understanding and calls for mitigation. In this study, the rates and pathways of N 2 O production were quantified in two lab-scale sequencing batch reactors operated with intermittent feeding and demonstrating long-term and high-rate nitritation. The resulting reactor biomass was highly enriched in ammonia-oxidizing bacteria, and converted ∼93 ± 14% of the oxidized ammonium to nitrite. The low DO set-point combined with intermittent feeding was sufficient to maintain high nitritation efficiency and high nitritation rates at 20-26 °C over a period of ∼300 days. Even at the high nitritation efficiencies, net N 2 O production was low (∼2% of the oxidized ammonium). Net N 2 O production rates transiently increased with a rise in pH after each feeding, suggesting a potential effect of pH on N 2 O production. In situ application of 15 N labeled substrates revealed nitrifier denitrification as the dominant pathway of N 2 O production. Our study highlights operational conditions that minimize N 2 O emission from two-stage autotrophic nitrogen removal systems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Kinetic modeling of cellulosic biomass to ethanol via simultaneous saccharification and fermentation: Part I. Accommodation of intermittent feeding and analysis of staged reactors.

PubMed

Shao, Xiongjun; Lynd, Lee; Wyman, Charles; Bakker, André

2009-01-01

The model of South et al. [South et al. (1995) Enzyme Microb Technol 17(9): 797-803] for simultaneous saccharification of fermentation of cellulosic biomass is extended and modified to accommodate intermittent feeding of substrate and enzyme, cascade reactor configurations, and to be more computationally efficient. A dynamic enzyme adsorption model is found to be much more computationally efficient than the equilibrium model used previously, thus increasing the feasibility of incorporating the kinetic model in a computational fluid dynamic framework in the future. For continuous or discretely fed reactors, it is necessary to use particle conversion in conversion-dependent hydrolysis rate laws rather than reactor conversion. Whereas reactor conversion decreases due to both reaction and exit of particles from the reactor, particle conversion decreases due to reaction only. Using the modified models, it is predicted that cellulose conversion increases with decreasing feeding frequency (feedings per residence time, f). A computationally efficient strategy for modeling cascade reactors involving a modified rate constant is shown to give equivalent results relative to an exhaustive approach considering the distribution of particles in each successive fermenter.

Benefits of Group Living Include Increased Feeding Efficiency and Lower Mass Loss during Desiccation in the Social and Inbreeding Spider Stegodyphus dumicola

PubMed Central

Vanthournout, Bram; Greve, Michelle; Bruun, Anne; Bechsgaard, Jesper; Overgaard, Johannes; Bilde, Trine

2016-01-01

Group living carries a price: it inherently entails increased competition for resources and reproduction, and may also be associated with mating among relatives, which carries costs of inbreeding. Nonetheless, group living and sociality is found in many animals, and understanding the direct and indirect benefits of cooperation that override the inherent costs remains a challenge in evolutionary ecology. Individuals in groups may benefit from more efficient management of energy or water reserves, for example in the form of reduced water or heat loss from groups of animals huddling, or through reduced energy demands afforded by shared participation in tasks. We investigated the putative benefits of group living in the permanently social spider Stegodyphus dumicola by comparing the effect of group size on standard metabolic rate, lipid/protein content as a body condition measure, feeding efficiency, per capita web investment, and weight/water loss and survival during desiccation. Because energetic expenditure is temperature sensitive, some assays were performed under varying temperature conditions. We found that feeding efficiency increased with group size, and the rate of weight loss was higher in solitary individuals than in animals in groups of various sizes during desiccation. Interestingly, this was not translated into differences in survival or in standard metabolic rate. We did not detect any group size effects for other parameters, and group size effects did not co-vary with experimental temperature in a predictive manner. Both feeding efficiency and mass loss during desiccation are relevant ecological factors as the former results in lowered predator exposure time, and the latter benefits social spiders which occupy arid, hot environments. PMID:26869936

21 CFR 558.128 - Chlortetracycline.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Chickens. It is used as follows: Chlortetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 g/ton Chickens: For increased rate of weight gain and improved feed efficiency. Do not feed to chickens producing eggs for human consumption. 046573. 012286, 046573, 048164, 066104. (ii) 100 to 200 g...

21 CFR 558.128 - Chlortetracycline.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Chickens. It is used as follows: Chlortetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 g/ton Chickens: For increased rate of weight gain and improved feed efficiency. Do not feed to chickens producing eggs for human consumption. 046573. 012286, 046573, 048164, 066104. (ii) 100 to 200 g...

Anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure in a single continuously stirred tank reactor process: Limits in co-substrate ratios and organic loading rate.

PubMed

Rico, Carlos; Muñoz, Noelia; Rico, José Luis

2015-01-01

Mesophilic anaerobic co-digestion of cheese whey and the screened liquid fraction of dairy manure was investigated with the aim of determining the treatment limits in terms of the cheese whey fraction in feed and the organic loading rate. The results of a continuous stirred tank reactor that was operated with a hydraulic retention time of 15.6 days showed that the co-digestion process was possible with a cheese whey fraction as high as 85% in the feed. The efficiency of the process was similar within the range of the 15-85% cheese whey fraction. To study the effect of the increasing loading rate, the HRT was progressively shortened with the 65% cheese whey fraction in the feed. The reactor efficiency dropped as the HRT decreased but enabled a stable operation over 8.7 days of HRT. At these operating conditions, a volumetric methane production rate of 1.37 m(3) CH4 m(-3) d(-1) was achieved. Copyright © 2015 Elsevier Ltd. All rights reserved.

Use of residual feed intake in Holsteins during early lactation shows potential to improve feed efficiency through genetic selection.

PubMed

Connor, E E; Hutchison, J L; Norman, H D; Olson, K M; Van Tassell, C P; Leith, J M; Baldwin, R L

2013-08-01

Improved feed efficiency is a primary goal in dairy production to reduce feed costs and negative impacts of production on the environment. Estimates for efficiency of feed conversion to milk production based on residual feed intake (RFI) in dairy cattle are limited, primarily due to a lack of individual feed intake measurements for lactating cows. Feed intake was measured in Holstein cows during the first 90 d of lactation to estimate the heritability and repeatability of RFI, minimum test duration for evaluating RFI in early lactation, and its association with other production traits. Data were obtained from 453 lactations (214 heifers and 239 multiparous cows) from 292 individual cows from September 2007 to December 2011. Cows were housed in a free-stall barn and monitored for individual daily feed consumption using the GrowSafe 4000 System (GrowSafe Systems, Ltd., Airdrie, AB, Canada). Animals were fed a total mixed ration 3 times daily, milked twice daily, and weighed every 10 to 14 d. Milk yield was measured at each milking. Feed DM percentage was measured daily, and nutrient composition was analyzed from a weekly composite. Milk composition was analyzed weekly, alternating between morning and evening milking periods. Estimates of RFI were determined as the difference between actual energy intake and predicted intake based on a linear model with fixed effects of parity (1, 2, ≥ 3) and regressions on metabolic BW, ADG, and energy-corrected milk yield. Heritability was estimated to be moderate (0.36 ± 0.06), and repeatability was estimated at 0.56 across lactations. A test period through 53 d in milk (DIM) explained 81% of the variation provided by a test through 90 DIM. Multiple regression analysis indicated that high efficiency was associated with less time feeding per day and slower feeding rate, which may contribute to differences in RFI among cows. The heritability and repeatability of RFI suggest an opportunity to improve feed efficiency through genetic selection, which could reduce feed costs, manure output, and greenhouse gas emissions associated with dairy production.

21 CFR 558.530 - Roxarsone.

Code of Federal Regulations, 2013 CFR

2013-04-01

....60 of this chapter. (d) Conditions of use—(1) Chickens. It is used in chicken feed as follows... 45.4 Growing chickens: For increased rate of weight gain, improved feed efficiency, and improved... (ii) 22.7 to 45.4 Chlortetracycline 10 to 50 Growing chickens: As in paragraph (d)(1)(i) of this...

21 CFR 558.128 - Chlortetracycline.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Chickens. It is used as follows: Chlortetracycline amount Indications for use Limitations Sponsor (i) 10 to 50 g/ton Chickens: For increased rate of weight gain and improved feed efficiency. Do not feed to chickens producing eggs for human consumption. 054771 012286, 054771, 048164, 066104. (ii) 100 to 200 g/ton...

21 CFR 558.530 - Roxarsone.

Code of Federal Regulations, 2012 CFR

2012-04-01

....60 of this chapter. (d) Conditions of use—(1) Chickens. It is used in chicken feed as follows... 45.4 Growing chickens: For increased rate of weight gain, improved feed efficiency, and improved... (ii) 22.7 to 45.4 Chlortetracycline 10 to 50 Growing chickens: As in paragraph (d)(1)(i) of this...

21 CFR 558.500 - Ractopamine.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tom turkey feeds shall bear the following: “No increased benefit has been shown when ractopamine.... Melengestrol acetate as provided by No. 021641 in § 510.600(c) of this chapter. 021641 (3) Turkeys— Ractopamine... 13 ppm) Finishing hen turkeys: For increased rate of weight gain and improved feed efficiency when...

How to handle 'poor' foodstuffs: Acclimation of the common cockle (Cerastoderma edule) to detrital diets

NASA Astrophysics Data System (ADS)

Arambalza, Udane; Ibarrola, Irrintzi; Navarro, Enrique; Urrutxurtu, Iñaki; Urrutia, Miren B.

2018-04-01

As an approach to elucidating the "value" of detritus as a food source for bivalves, we analysed the capability of the common cockle (Cerastoderma edule) to modulate feeding and digestive rates during acclimation to low and high food rations of detrital diets with either low (Juncus maritimus) or high digestibility (Enteromorpha spp.). On acclimation day 3, feeding rates were similar in cockles fed different detrita; however, the absorption rate was higher in cockles fed Enteromorpha spp. With J. maritimus, rising food rations promoted an exponential decrease in absorption efficiency, whereas with Enteromorpha spp., absorption efficiency was only marginally reduced. During acclimation, cockles improved the rate at which both detritus were assimilated by means of increasing ingestion rates while maintaining absorption efficiency. When the time-course of digestive carbohydrase activities was monitored during acclimation to either detritus or phytoplankton (Isochrysis galbana), we found that only phytoplankton promoted the induction of cellulase activity in the digestive glands of cockles. This response in cockles fed phytoplankton promoted an increase in the digestibility of Enteromorpha spp., but had no effect on the digestibility of J. maritimus.

Analysis of key factors influencing the evaporation performances of an oriented linear cutting copper fiber sintered felt

NASA Astrophysics Data System (ADS)

Pan, Minqiang; Zhong, Yujian

2018-01-01

Porous structure can effectively enhance the heat transfer efficiency. A kind of micro vaporizer using the oriented linear cutting copper fiber sintered felt is proposed in this work. Multiple long cutting copper fibers are firstly fabricated with a multi-tooth tool and then sintered together in parallel to form uniform thickness metal fiber sintered felts that provided a characteristic of oriented microchannels. The temperature rise response and thermal conversion efficiency are experimentally investigated to evaluate the influences of porosity, surface structure, feed flow rate and input power on the evaporation characteristics. It is indicated that the temperature rise response of water is mainly affected by input power and feed flow rate. High input power and low feed flow rate present better temperature rise response of water. Porosity rather than surface structure plays an important role in the temperature rise response of water at a relatively high input power. The thermal conversion efficiency is dominated by the input power and surface structure. The oriented linear cutting copper fiber sintered felts for three kinds of porosities show better thermal conversion efficiency than that of the oriented linear copper wire sintered felt when the input power is less than 115 W. All the sintered felts have almost the same performance of thermal conversion at a high input power.

Effect of feed supplement containing earthworm meal (Lumbricus rubellus) on production performance of quail (Coturnix coturnix japonica)

NASA Astrophysics Data System (ADS)

Istiqomah, L.; Sakti, A. A.; Suryani, A. E.; Karimy, M. F.; Anggraeni, A. S.; Herdian, H.

2017-12-01

The objective of this study was to evaluate the effect of feed supplement (FS) contained earthworm meal (EWM) on production performance of laying quails. Twenty weeks-old of 360 Coturnix coturnix japonica quails were used in a Completely Randomized Design (CRD) with three dietary treatments A = CD (control without FS), B = CD + 0.250 % of FS, and C = CD + 0.375 % of FS during 6 weeks of experimental period. Each treatment in 4 equal replicates in which 30 quails were randomly allocated into 12 units of cages. Variable measured were feed intake, feed conversion ratio, feed efficiency, mortality rate, hen day production, egg weight, and egg uniformity. Data were statistically analyzed by One Way ANOVA and the differences among mean treatments are analysed using Duncan’s Multiple Range Test (DMRT). The results showed that administration of 0.375% FS based on earthworm meal, fermented rice bran, and skim milk impaired the feed conversion ratio and increased the feed efficiency. The experimental treatments did not effect on feed intake, mortality, hen day production, egg weight, and egg uniformity of quail. It is concluded that administration of feed supplement improved the growth performance of quail.

A comparison of instrumental dewatering methods for the separation and concentration of suspended sediment for subsequent trace element analysis

USGS Publications Warehouse

Horowitz, A.J.; Elrick, K.A.; Hooper, R.C.

1989-01-01

The continuous-flow centrifuges can process whole water at an influent feed rate of 41 per minute; however, when suspended sediment concentrations are low (<30 mg l-1), when small volumes of whole water are to be processed (30 to 401), or when suspended sediment mean grain size is very fine (<10 ??m), influent feed rates of 21 per minute may be more efficient. Tangential-flow filtration can be used to process samples at the rate of 11 per minute. -from Authors

High-efficiency preparation of poly(2-methacryloyloxyethyl phosphorylcholine) grafting layer on poly(ether ether ketone) by photoinduced and self-initiated graft polymerization in an aqueous solution in the presence of inorganic salt additives.

PubMed

Shiojima, Taro; Inoue, Yuuki; Kyomoto, Masayuki; Ishihara, Kazuhiko

2016-08-01

A highly efficient methodology for preparing a poly(2-methacryloyloxyethyl phosphorylcholine) (PMPC) layer on the surface of poly(ether ether ketone) (PEEK) was examined by photoinduced and self-initiated graft polymerization. To enhance the polymerization rate, we demonstrated the effects of inorganic salt additives in the feed monomer solution on thickness of grafted PMPC layer. Photoinduced polymerization occurred and the PMPC graft layer was successfully formed on the PEEK surface, regardless of inorganic salt additives. Moreover, it was clearly observed that the addition of inorganic salt enhanced the grafting thickness of PMPC layer on the surface even when the photoirradiation time was shortened. The addition of inorganic salt additives in the feed monomer solution enhanced the polymerization rate of MPC and resulted in thicker PMPC layers. In particular, we evaluated the effect of NaCl concentration and how this affected the polymerization rate and layer thickness. We considered that this phenomenon was due to the hydration of ions in the feed monomer solution and subsequent apparent increase in the MPC concentration. A PMPC layer with over 100-nm-thick, which was prepared by 5-min photoirradiation in 2.5mol/L inorganic salt aqueous solution, showed good wettability and protein adsorption resistance compared to that of untreated PEEK. Hence, we concluded that the addition of NaCl into the MPC feed solution would be a convenient and efficient method for preparing a graft layer on PEEK. Photoinduced and self-initiated graft polymerization on the PEEK surface is one of the several methodologies available for functionalization. However, in comparison with free-radical polymerization, the efficiency of polymerization at the solid-liquid interface is limited. Enhancement of the polymerization rate for grafting could solve the problem. In this study, we observed the acceleration of the polymerization rate of MPC in an aqueous solution by the addition of inorganic salt. The salt itself did not show any adverse effects on the radical polymerization; however, the apparent concentration of the monomer in feed may be increased due to the hydration of ions attributed to salt additives. We could obtain PMPC-grafted PEEK with sufficient PMPC thickness to obtain good functionality with only 5-min photoirradiation by using 2.5mol/L NaCl in the feed solution. Copyright © 2016 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Toxicity, feeding rate and growth rate response to sub-lethal concentrations of anthracene and benzo [a] pyrene in milkfish Chanos chanos (Forskkal).

PubMed

Palanikumar, L; Kumaraguru, A K; Ramakritinan, C M; Anand, M

2013-01-01

The feeding rate, growth rate and gross conversion efficiency were studied in milkfish Chanos chanos for 28 days of exposure to sub-lethal concentrations of anthracene (1.00, 2.00, 3.00, 6.00 and 12.0 μg l(-1)) and benzo [a] pyrene (0.30, 0.70, 1.40, 2.80 and 5.60 μg l(-1)) under continuous flow through bioassays. Based on survival and growth data, No Observed Effect Concentration; Lowest Observed Effect Concentration were estimated after 28 days, the values for anthracene were 2.03 and 3.09 μg l(-1), and the values for benzo [a] pyrene were 0.82 and 1.46 μg l(-1), respectively. Anthracene and benzo [a] pyrene exposure caused reduction in feeding and growth rate.

Pretreatment solution recycling and high-concentration output for economical production of bioethanol.

PubMed

Han, Minhee; Moon, Se-Kwon; Choi, Gi-Wook

2014-11-01

The purpose of this study was to enhance the economic efficiency of producing bioethanol. Pretreatment solution recycling is expected to increase economic efficiency by reducing the cost of pretreatment and the amount of wastewater. In addition, the production of high-concentration bioethanol could increase economic efficiency by reducing the energy cost of distillation. The pretreatment conditions were 95 °C, 0.72 M NaOH, 80 rpm twin-screw speed, and flow rate of 90 mL/min at 18 g/min of raw biomass feeding for pretreatment solution recycling. The pretreatment with NaOH solution recycling was conducted five times. All of the components and the pretreatment efficiency were similar, despite reuse. In addition, we developed a continuous biomass feeding system for production of high-concentration bioethanol. Using this reactor, the bioethanol productivity was investigated using various pretreated biomass feeding rates in a simultaneous saccharification and fermentation (SSF) process. The maximum ethanol concentration, yield, and productivity were 74.5 g/L, 89.5%, and 1.4 g/L h, respectively, at a pretreated biomass loading of approximately 25% (w/v) with an enzyme dosage of 30 FPU g/cellulose. The results presented here constitute an important contribution toward the production of bioethanol from Miscanthus.

Thermophilic methane production from cattle waste.

PubMed Central

Varel, V H; Isaacson, H R; Bryant, M P

1977-01-01

Methane production from waste of cattle fed a finishing diet was investigated, using four 3-liter-working volume anaerobic digestors at 60 degrees C. At 55 degrees C a start-up culture, in which waste was the only source of bacteria, was generated within 8 days and readily adapted to 60 degrees C, where efficiency of methanogenesis was greater. Increasing the temperature from 60 to 65 degrees C tended to drastically lower efficiency. When feed concentrations of volatile solids (VS, organic matter) were increased in steps of 2% after holding for 1 months at a given concentration, the maximum concentrations for efficient fermentation were 8.2, 10.0, 11.6, and 11.6% for the retention times (RT) of 3, 6, 9, and 12 days, respectively. The VS destructions for these and lower feed concentrations were 31 to 37, 36 to 40, 47 to 49 and 51 to 53% for the 3-, 6-, 9-, and 12-day RT digestors, respectively, and the corresponding methane production rates were about 0.16, 0.18, 0.20, and 0.22 liters/day per g of VS in the feed. Gas contained 52 to 57% methane. At the above RT and feed concentrations, alkalinity rose to 5,000 to 7,700 mg of CaCo3 per liter (pH to 7.5 to 7.8), NH3 plus NH4+ to 64 to 90 mM, and total volatile acids to 850 to 2,050 mg/liter as acetate. The 3-day RT digestor was quite stable up to 8.2% feed VS and at this feed concentration produced methane at the very high rate of 4.5 liters/day per liter of digestor. Increasing the percentage of feed VS beyond those values indicated above resulted in greatly decreased organic matter destruction and methane production, variable decrease in pH, and increased alkalinity, ammonia, and total volatile acid concentrations, with propionate being the first to accumulate in large amounts. In a second experiment with another lot of waste, the results were similar. These studies indicate that loading rates can be much higher than those previously thought useful for maximizing methanogenesis from cattle waste. PMID:557954

Cellular automata simulation of topological effects on the dynamics of feed-forward motifs

PubMed Central

Apte, Advait A; Cain, John W; Bonchev, Danail G; Fong, Stephen S

2008-01-01

Background Feed-forward motifs are important functional modules in biological and other complex networks. The functionality of feed-forward motifs and other network motifs is largely dictated by the connectivity of the individual network components. While studies on the dynamics of motifs and networks are usually devoted to the temporal or spatial description of processes, this study focuses on the relationship between the specific architecture and the overall rate of the processes of the feed-forward family of motifs, including double and triple feed-forward loops. The search for the most efficient network architecture could be of particular interest for regulatory or signaling pathways in biology, as well as in computational and communication systems. Results Feed-forward motif dynamics were studied using cellular automata and compared with differential equation modeling. The number of cellular automata iterations needed for a 100% conversion of a substrate into a target product was used as an inverse measure of the transformation rate. Several basic topological patterns were identified that order the specific feed-forward constructions according to the rate of dynamics they enable. At the same number of network nodes and constant other parameters, the bi-parallel and tri-parallel motifs provide higher network efficacy than single feed-forward motifs. Additionally, a topological property of isodynamicity was identified for feed-forward motifs where different network architectures resulted in the same overall rate of the target production. Conclusion It was shown for classes of structural motifs with feed-forward architecture that network topology affects the overall rate of a process in a quantitatively predictable manner. These fundamental results can be used as a basis for simulating larger networks as combinations of smaller network modules with implications on studying synthetic gene circuits, small regulatory systems, and eventually dynamic whole-cell models. PMID:18304325

Weather influences feed intake and feed efficiency in a temperate climate.

PubMed

Hill, Davina L; Wall, Eileen

2017-03-01

A key goal for livestock science is to ensure that food production meets the needs of an increasing global population. Climate change may heighten this challenge through increases in mean temperatures and in the intensity, duration, and spatial distribution of extreme weather events, such as heat waves. Under high ambient temperatures, livestock are expected to decrease dry matter intake (DMI) to reduce their metabolic heat production. High yielding dairy cows require high DMI to support their levels of milk production, but this may increase susceptibility to heat stress. Here, we tested how feed intake and the rate of converting dry matter to milk (feed efficiency, FE) vary in response to natural fluctuations in weather conditions in a housed experimental herd of lactating Holstein Friesians in the United Kingdom. Cows belonged to 2 lines: those selected for high genetic merit for milk traits (select) and those at the UK average (control). We predicted that (1) feed intake and FE would vary with an index of temperature and humidity (THI), wind speed, and the number of hours of sunshine, and that (2) the effects of (1) would depend on the cows' genetic merit. Animals received a mixed ration, available ad libitum, from automatic feed measurement gates. Using >73,000 daily feed intake and FE records from 328 cows over 8 yr, we found that select cows produced more fat- and protein-corrected milk, and had higher DMI and FE than controls. Cows of both lines decreased DMI and fat- and protein-corrected milk but, importantly, increased FE as THI increased. This suggests that improvements in the efficiency of converting feed to milk may partially offset the costs of reduced milk yield owing to a warmer climate, at least under conditions of mild heat stress. The rate of increase in FE with THI was steeper in select cows than in controls, which raises the possibility that select cows use more effective coping tactics. This is, to our knowledge, the first longitudinal study on the effects of weather on FE. Understanding how weather influences feed intake and efficiency can help us to develop management and selection practices that optimize productivity under unfavorable weather conditions. This will be an important aspect of climate resilience in future. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Factors affecting beef cattle producer perspectives on feed efficiency.

PubMed

Wulfhorst, J D; Ahola, J K; Kane, S L; Keenan, L D; Hill, R A

2010-11-01

To establish the basis for implementation of a producer education program, a social assessment of the willingness and barriers to adoption of a measure of feed efficiency in beef cattle [residual feed intake (RFI)] was conducted. A 35-question mailed survey was sent to 1,888 producers acquired from the stratified random sample of the Idaho Cattle Association member list (n = 488), Red Angus Association of America member list (n = 2,208), and Red Angus Association of America bull buyer list (n = 5,325). The adjusted response rate for the survey was 49.9%. Of the survey respondents, 58.7% were commercial cow/calf producers and 41.3% were seedstock producers or operated a combination seedstock/commercial operation. Commercial operations had an average of 223 ± 17 cows and 13 ± 3 bulls, whereas seedstock herds (including combination herds) had slightly fewer cows (206 ± 24) and more bulls (23 ± 6). Both commercial and seedstock operators indicated that calving ease/birth weight was the most important trait used to evaluate genetic merit of breeding bulls. Only 3.8 and 4.8% of commercial and seedstock producers indicated that feed efficiency was the most important characteristic used for bull selection. Binary logistic regression models were used to predict willingness of seedstock producers to begin collecting data for the calculation of RFI on their bulls, or to predict willingness of commercial producers to begin selecting bulls based on RFI data. In response, 49.1% of commercial producers and 43.6% of seedstock producers indicated they were willing to adopt RFI as a measure of feed efficiency. These data indicate that feed efficiency was one of the traits that producers consider important; those who perceive feed efficiency as important tended to be actively involved in data collection on their herds, underpinning the notion that objective assessment was valued and used by some. Additional data collection in a future social assessment will continue to elaborate the proportion of producers who perceive feed efficiency as an increasingly important decision and management tool for beef production.

Protein requirements of bobwhite chicks for survival, growth and efficiency of feed utilization

USGS Publications Warehouse

Nestler, R.B.; Bailey, W.W.; McClure, H.E.

1942-01-01

During the summer and fall of 1939 four experiments were conducted at the Patuxent Research Refuge, Bowie, Maryland, to determine the protein requirements of bobwhite chicks. A total of 816 chicks were used to compare six levels of protein, namely, 22,24,26, 28, 30, and 32 per cent.....From the three standpoints of survival, rate of growth, and efficiency of feed utilization for the first ten weeks of life, the 28 per cent level of protein gave the best results. During the ninth and tenth weeks, the highest efficiency of feed utilization was obtained on the 22 per cent level. The results indicate that after the birds have reached about twothirds of their mature weight, the difference in efficiency between a diet containing 28 per cent of protein and one containing 22 per cent may be small enough to justify, in the interest of economy, the use of a diet containing the lower percentage of protein.

Effects of by-product feed-based silage on feeding, rumination, and excretion in growing Hanwoo heifers.

PubMed

Kim, Young-Il; Lee, Sang Moo; Lee, Youn Hee; Lee, Myeon; Choi, Do Young; Kwak, Wan Sup

2015-01-01

This study investigated the effects of feeding by-product feed (BF)-based silage on the behavior of growing Hanwoo heifers. Twelve Hanwoo heifers (13.2 months-old, 315 kg body weight; four heifers per pen) were assigned to three diets: a rice straw (RS) diet (concentrate mix and free access to RS), a RS and BF-based silage (RSBFS) diet (concentrate mix and free access to RS and BF-based silage), and a BF-based silage (BFS) diet (concentrate mix and free access to BF-based silage). Behavior was recorded for 5 days using camcorders. Compared to the RS group, the BFS group showed 21.7% higher dry matter intake, shorter feeding, rumination, and chewing times, as well as longer resting time (p < 0.05). Although all groups exhibited similar drinking, urination, and defecation frequencies, the BFS group exhibited higher feeding rates, rumination efficiency, and chewing efficiency than the RS group (p < 0.05). Compared to the BFS group, the RSBFS group showed higher peNDF8.0 intake (15.2% vs. 25.0% dry matter intake), longer feeding and sitting times, lower defecation frequency (p < 0.05), and similar rumination efficiency. In conclusion, complete replacement of conventional RS with BF-based silage reduced rumination and chewing activity in growing Hanwoo heifers, and BF-based silage feeding with large-particle straw is an effective approach in improving heifer behavior.

Challenges in measuring feed efficiency

USDA-ARS?s Scientific Manuscript database

The term feed efficiency is vague, and is defined differently by people. Historically, feed efficiency has been defined as the feed:gain (F:G) ratio or the inverse (G:F). Indexes have been developed to rank animals for feed efficiency. These indexes include residual feed intake (RFI) and residual...

Breeding and mass scale rearing of clownfish Amphiprion percula: feeding and rearing in brackishwater

NASA Astrophysics Data System (ADS)

Dhaneesh, Kottila Veettil; Ajith Kumar, Thipramalai Thankappan; Swagat, Ghosh; Balasubramanian, Thangavel

2012-07-01

Breeding and mass scale larval rearing of clownfish Amphiprion percula is very limited in brackishwater. We designed an indoor program of A. percula culture in brackishwater with a salinity of 24±1, during which the impacts of feed type, water temperature, and light intensity, on the efficiency of its reproduction, were revealed. The fish were accommodated along with sea anemones in fibre glass tanks to determine the influence of brooder diet on breeding efficiency. Higher reproductive efficiency [number of eggs laid (276 ± 22.3 eggs)] was observed when fish were fed live Acetes sp. rather than clam (204 ± 16.4 eggs), trash fish (155 ± 12 eggs) and formulated feed (110 ± 10 eggs). The spawning rate was increased during September and October (water temperature, 28.74 ± 0.55°C) on average of 2.4 spawning per month; and low spawning rate was in January (water temperature, 24.55 ± 0.45°C) on average of 1 spawning per month. Among three light intensities (100, 500, and 900 lx) set to evaluate larval survival rate, larvae showed the highest survival rate (65.5%) at 900 lx. The breeding method specifically in brackishwater developed in the present study is a new approach, will help the people from the regions of estuary and backwater to enhance their livelihood and it will lead to reduce the exploitation from the wild habitat.

Effects of a dietary complex of humic and fulvic acids (FeedMAX 15) on the health and production of feedlot cattle destined for the Australian domestic market.

PubMed

Cusack, P M V

2008-01-01

To examine the effects of a dietary humic and fulvic acid complex, FeedMAX 15, on the health, growth rate, feed conversion ratio, and carcase characteristics of feedlot cattle. Cattle, in eight pens of 125 animals each, were fed either a diet containing a humic and fulvic acid complex (FeedMAX 15, FeedMAX Industries, Toowoomba, Queensland) or the same diet without the additive. Control or FeedMAX 15 diets were allocated to each pen at random. Individual cattle were allocated alternately to control or treatment pens based on order of presentation. Comparisons of disease incidence, mortality, feed intake, growth rate, feed conversion ratio, fat depth, dressing percentage, meat colour, fat colour and marbling were made at the conclusion of the feeding period. No differences were found between cattle fed FeedMAX 15 and cattle not fed the additive in entry body weight (P = 0.99), exit body weight (P = 0.91), dressing percentage (P = 0.66), P8 fat depth (P = 0.57), meat colour (P = 0.67), marbling (P = 0.70), all diseases (P = 0.64), bovine respiratory disease (P = 0.91), or mortalities (P = 1.0). Cattle fed FeedMAX 15 reached the market specifications for body weight and fat depth in fewer mean days (P = 0.0001), had a greater average daily gain (P = 0.05), a lower feed conversion ratio (P = 0.05) and whiter fat (P < 0.0001). Feeding the humic and fulvic acid complex, FeedMAX 15, at 0.055 g per kg body weight per day, can increase growth rate and feed conversion efficiency in feedlot cattle.

The effectiveness of crude papain enzyme supplement for tilapia’s (Oreochromis niloticus) growth at the floating nets of Cirata Reservoir

NASA Astrophysics Data System (ADS)

Rostika, R.; Sunarto; Sugiyanto, H. N.; Dewanti, L. P.

2018-03-01

Papain is an enzyme capable of hydrolyzing protease into a more simple elements i.e. the peptide to amino acids. The enzyme in the feed can increase the absorption of protein and digestion rate in the digestive tract of fish. This research examined the effective level of enzyme papain to increase the Feed Utilization Efficiency (FUE), Protein Efficiency Ratio (PER) and Average Daily Gain (ADG). This research used Completely Randomized Design (CRD) with five treatments i.e. treatment A (control), treatment B (1.5 %), treatment C (2.25 %), treatment D (3 %) and treatment E (3.75 %) in triplicate. Tilapia (Oreochromis niloticus) with the average initial weight of 17 g, and initial total lenght of 8–10 cm was fed three times daily at feeding rate of 5 % of the total body weight. The results showed that supplementation of papain in the feed significantly increased the activity of protease, FUE, PER and ADG. The optimal dose of the enzyme papain at 3.75 % was able to increase 48.31 % of FUE, 2.13 % of PER and 2.07 % of ADG.

The effects of increasing amounts of milk replacer powder added to whole milk on passage rate, nutrient digestibility, ruminal development, and body composition in dairy calves.

PubMed

Azevedo, R A; Machado, F S; Campos, M M; Lopes, D R G; Costa, S F; Mantovani, H C; Lopes, F C F; Marcondes, M I; Pereira, L G R; Tomich, T R; Coelho, S G

2016-11-01

The aim of this study was to evaluate the effects on feed intake, calf performance, feed efficiency, fecal score, passage rate, apparent nutrient digestibility, development of rumen and other organs, and body composition of increasing the total solids content of liquid feed (whole milk) by adding increasing amounts of milk replacer powder during the preweaning period. Crossbred Holstein-Gyr calves (n=32) were assigned to 1 of 4 treatments (n=8 per group), which consisted of different total solids concentrations: 12.5, 15.0, 17.5, and 20.0% of liquid feed. Calves received 6 L of liquid per day, divided into 2 equal meals (0800 and 1600 h) and provided in buckets, from 5 to 55d of age. Starter and water were provided ad libitum during the entire experiment. At 56d of age, animals were killed. Laboratory analysis determined that the actual total solids contents of the liquid feed were 13.5, 16.1, 18.2, and 20.4%, for the proposed 12.5, 15.0, 17.5, and 20.0% total solids treatments, respectively. The osmolality of liquid feed treatments was 265 to 533 mOsm/L. Fecal score was similar among treatments, except for wk 2 and 7. Intake of liquid feed was similar among treatments from 6wk of age. During wk 4, 5, and 6, we detected a linear decrease in starter intake. After wk 7, we observed greater starter intake for calves fed approximately 16.1% total solids. Water intake, feed efficiency, and withers height were similar among treatments. Increasing concentrations of total solids in liquid feed quadratically affected average daily gain, final body weight, and empty body weight. We observed a greater average daily gain for calves fed approximately 20.4% total solids. Passage rate, nutrient digestibility, development of pre-stomachs and intestine, and body composition were similar among treatments. Increasing the concentration of total solids in liquid feed up to 20.4% reduced starter intake between 4 and 6wk of life, but increased average daily gain. It did not affect passage rate, nutrient digestibility, ruminal and organ development, or body composition in calves during the preweaning period, indicating that this strategy may be a viable alternative for feeding without increasing the total volume of liquid feed provided to dairy calves. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Grinding efficiency of abutment tooth with both dentin and core composite resin on axial plane.

PubMed

Miho, Otoaki; Sato, Toru; Matsukubo, Takashi

2015-01-01

The purpose of this study was to evaluate grinding efficiency in abutment teeth comprising both dentin and core composite resin in the axial plane. Grinding was performed over 5 runs at two loads (0.5 or 0.25 N) and two feed rates (1 or 2 mm/sec). The grinding surface was observed with a 3-D laser microscope. Tomographic images of the grinding surfaces captured perpendicular to the feed direction were also analyzed. Using a non-ground surface as a reference, areas comprising only dentin, both dentin and core composite resin, or only core composite resin were analyzed to determine the angle of the grinding surface. Composite resins were subjected to the Vickers hardness test and scanning electron microscopy. Data were statistically analyzed using a one-way analysis of variance and multiple comparison tests. Multiple regression analysis was performed for load, feed rate, and Vickers hardness of the build-up material depending on number of runs. When grinding was performed at a constant load and feed rate, a greater grinding angle was observed in areas comprising both dentin and composite resin or only composite resin than in areas consisting of dentin alone. A correlation was found between machinability and load or feed rate in areas comprising both dentin and composite resin or composite resin alone, with a particularly high correlation being observed between machinability and load. These results suggest that great caution should be exercised in a clinical setting when the boundary between the dentin and composite resin is to be ground, as the angle of the grinding surface changes when the rotating diamond point begins grinding the composite resin.

Factors influencing bird foraging preferences among conspecific fruit trees

USGS Publications Warehouse

Foster, M.S.

1990-01-01

The rates at which birds visit fruiting individuals of Allophylus edulis (Sapindaceae) differ substantially among trees. Such avian feeding preferences are well-known, but usually involve fruits and trees of different species. Factors controlling avian preferences for particular trees in a population of conspecifics are generally undocumented. To address this issue, I attempted to correlate rates at which individual birds and species fed in trees of Allophylus with 27 fruit or plant characteristics. Birds that swallow fruits whole were considered separately from those that feed in other ways. Plant characters were selected on the basis of their potential influence on feeding efficiency or predation risk, assuming that birds would select feeding trees so as to maximize the net rate of energy or nutrient intake and to minimize predation. Correlations were found between feeding visits by some groups of birds and percent water in the pulp, milligrams of mineral ash in the pulp, and crop size. No character was correlated with feeding visits by all groups of birds in both years of the study. The correlations with water and mineral ash are unexplained and may be artifacts. The correlation with crop size may represent a tactic to minimize predation.

Effect of The Phytase Enzyme Addition in The Artificial Feed on Digestibility of Feed, Feed Conversion Ratio and Growth of Gift Tilapia Saline Fish (Oreochromis niloticus) Nursery Stadia I

NASA Astrophysics Data System (ADS)

Rachmawati, Diana; Samidjan, Istiyanto; Elfitasari, Tita

2018-02-01

The purpose of this study was to determine the effect of adding the phytase enzyme in the artificial feed on digestibility of feed, feed conversion ratio and growth of gift tilapia saline fish (Oreochromis niloticus) nursery stadia I. The fish samples in this study used gift tilapia saline fish (O. niloticus) with an average weight of 0,62 ± 0,008 g/fish and the stocking density of 1 fish1 L. Experimental method used in this study was completely randomized design with 4 treatments and 3 repetitions. The treatments were by adding phytase enzyme in artificial feed with the different level of doses those were A (0 FTU kg1 feed), B (500 FTU kg1 feed), C (1000 FTU kg1 feed) and D (1500 FTU kg1 feed). The results show that the addition of phytase enzyme was significantly (P<0.01) affected on apparent digestibility coefficient of protein (ADCP), apparent digestibility coefficient of Phospor (ADCF), feed conversion ratio (FCR), protein efficiency ratio (PER), and relative growth rate (RGR), on the other hand it insignificantly (P>0.05) affected on Survival Rate (SR) of gift tilapia saline fish. The optimum doses of phytase enzyme on RGR, FCR, PER, ADCP and ADCF of gift tilapia saline fish ranged from 1060 to 1100 FTU kg-1 feed.

Evaluating the process parameters of the dry coating process using a 2(5-1) factorial design.

PubMed

Kablitz, Caroline Désirée; Urbanetz, Nora Anne

2013-02-01

A recent development of coating technology is dry coating, where polymer powder and liquid plasticizer are layered on the cores without using organic solvents or water. Several studies evaluating the process were introduced in literature, however, little information about the critical process parameters (CPPs) is given. Aim of the study was the investigation and optimization of CPPs with respect to one of the critical quality attributes (CQAs), the coating efficiency of the dry coating process in a rotary fluid bed. Theophylline pellets were coated with hydroxypropyl methylcellulose acetate succinate as enteric film former and triethyl citrate and acetylated monoglyceride as plasticizer. A 2(5-1) design of experiments (DOEs) was created investigating five independent process parameters namely coating temperature, curing temperature, feeding/spraying rate, air flow and rotor speed. The results were evaluated by multilinear regression using the software Modde(®) 7. It is shown, that generally, low feeding/spraying rates and low rotor speeds increase coating efficiency. High coating temperatures enhance coating efficiency, whereas medium curing temperatures have been found to be optimum in terms of coating efficiency. This study provides a scientific base for the design of efficient dry coating processes with respect to coating efficiency.

Methods and consequences of including feed intake and efficiency in genetic selection for multiple-trait merit.

PubMed

Barwick, Stephen A; Henzell, Anthony L; Walmsley, Brad J; Johnston, David J; Banks, Robert G

2018-05-04

Methods are presented for including feed intake and efficiency in genetic selection for multiple-trait merit when commercial production is from any combination of pasture or concentrates. Consequences for the production system and for individual animals are illustrated with a beef cattle example. Residual feed intake at pasture (RFI-p), residual feed intake in the feedlot (RFI-f), and cow condition score are additional traits of the breeding objective. Feed requirement change is costed in the economic values of other objective traits. Selection responses are examined when feed costs are ignored, partially or fully included in the breeding objective, and when net feed intake (NFI) EBVs are added to the index. When all feed cost was included and NFI EBVs were in the index, selection (with selection intensity, i = 1) increased production system $ net return by 6.0%, $ per unit of product by 5.2%, $ per unit of feed by 6.6%, total product by 0.7% and product per unit of feed by 1.3%. There was little change in production system total feed. When feed cost was ignored, selection decreased production system $ net return, $ per unit of product, and $ per unit of feed. At the individual trait level, when feed was fully included there were increases in weaning weight-direct (0.8 kg), feedlot entry weight (1.4 kg), dressing % (0.04%), carcass meat % (0.36%), carcase fat depth (0.12 mm), carcass marbling score (0.02 score), cow condition score (0.01 score), calving ease-direct (0.97%), calving ease-maternal (0.22%) and cow weaning rate (1.3%), and decreases in weaning weight-maternal (-0.9 kg), RFI-p (-0.09 kg DM/d), RFI-f (-0.11 kg DM/d), sale weight (-1.6 kg) and cow weight (-8.7 kg). Gains were evident over a range of feed price. Selection for $ net return also increased $ net return per unit of feed, suggesting that $ net return per unit area would increase in grazing industries. Feed cost for trait change was the source of a major genotype × environment interaction affecting animal rankings. Where industry production environments vary, and feed cost for trait change varies with the environment, we recommend that industry indexes be derived for more than one level of feed cost. Cow condition score did not decline while biological and economic efficiency of the production system and individual animal were improving, suggesting that efficiency can be improved under multiple-trait selection without compromising breeding cow welfare.

Dietary uptake of Cu sorbed to hydrous iron oxide is linked to cellular toxicity and feeding inhibition in a benthic grazer

USGS Publications Warehouse

Cain, Daniel J.; Croteau, Marie-Noele; Fuller, Christopher C.; Ringwood, Amy H.

2016-01-01

Whereas feeding inhibition caused by exposure to contaminants has been extensively documented, the underlying mechanism(s) are less well understood. For this study, the behavior of several key feeding processes, including ingestion rate and assimilation efficiency, that affect the dietary uptake of Cu were evaluated in the benthic grazer Lymnaea stagnalis following 4–5 h exposures to Cu adsorbed to synthetic hydrous ferric oxide (Cu–HFO). The particles were mixed with a cultured alga to create algal mats with Cu exposures spanning nearly 3 orders of magnitude at variable or constant Fe concentrations, thereby allowing first order and interactive effects of Cu and Fe to be evaluated. Results showed that Cu influx rates and ingestion rates decreased as Cu exposures of the algal mat mixture exceeded 104 nmol/g. Ingestion rate appeared to exert primary control on the Cu influx rate. Lysosomal destabilization rates increased directly with Cu influx rates. At the highest Cu exposure where the incidence of lysosomal membrane damage was greatest (51%), the ingestion rate was suppressed 80%. The findings suggested that feeding inhibition was a stress response emanating from excessive uptake of dietary Cu and cellular toxicity.

Lethal/sublethal responses of Daphnia magna to acute norfloxacin contamination and changes in phytoplankton-zooplankton interactions induced by this antibiotic

NASA Astrophysics Data System (ADS)

Pan, Ying; Yan, Shi-Wei; Li, Ruo-Zhu; Hu, Yi-Wen; Chang, Xue-Xiu

2017-01-01

Although the well-known antibiotic norfloxacin (NOR) is recognized as an important environmental pollutant, little is known about its impacts on ecological processes, particularly on species interactions. In this paper, we quantified Daphnia magna (Crustacea, Cladocera) responses in mortality rate at lethal NOR concentrations (0, 25, 50, 100, 200, 300 and 400 mg L-1), and in heartbeat rate, swimming behavior and feeding rate (on the green alga Chlorella pyrenoidosa) at sublethal NOR concentrations (0, 25, 50 and 100 mg L-1) to determine the effects of this antibiotic in plankton systems. In 96-h-long lethal experiment, mortality rates of D. magna increased significantly with increasing NOR concentration and exposure time. In sublethal experiments, heartbeat rate decreased, while time ratio of vertical to horizontal swimming (TVH) and the duration of quiescence increased in D. magna individuals exposed to increasing NOR concentrations after 4 and 12 h of exposure. These collectively led to decreases in both average swimming ability and feeding rate, consistent with the positive relationship between average swimming ability and feeding rate. Overall, results indicate that, by affecting zooplankton heartbeat rate and behavior, NOR decreased feeding efficiency of D. magna even at low doses, therefore, it might seriously compromise ecosystem health and function.

Effects of varying dietary carbohydrate levels on growth performance, body composition and liver histology of Malaysian mahseer fingerlings (Tor tambroides).

PubMed

Ishak, Sairatul Dahlianis; Kamarudin, Mohd Salleh; Ramezani-Fard, Ehsan; Saad, Che Roos; Yusof, Yus Aniza

2016-07-01

We investigated the effects of four iso-nitrogenous (40% crude protein) and iso-caloric (17.6 kJ g(-1)) diets with different dietary carbohydrate levels (15%, 20%, 25% and 30%) on the growth performance, feed utilization efficiency, body composition and liver histology of Malaysian mahseer (Tor tambroides) fingerlings in a 10-week feeding trial. Fish (initial weight of 0.8?0.1 g; initial total length 4.2?0.1 cm) were fed twice daily at 4% body mass. Dietary carbohydrate level had significant effects (P<0.05) on weight gain, SGR (specific growth rate), FCR (feed conversion rate), PER (protein efficiency rate), survival percentage and all nutrient retention values (PRV, LRV, CRV, ERV). Protein, carbohydrate and gross energy composition of the fish body were also significantly differed (P<0.05) among treatments. Liver histology showed mild hepatic steatosis and hypertrophy for fishes receiving a higher dietary carbohydrate inclusion. In general, treatments with 20% and 25% dietary carbohydrate levels produced better growth results compared to the rest of the treatments. Using a second-order polynomial regression analysis model, the optimal dietary carbohydrate level of 23.4% was estimated for mahseer fingerlings. ?

Control of particle size by feed composition in the nanolatexes produced via monomer-starved semicontinuous emulsion copolymerization.

PubMed

Sajjadi, Shahriar

2015-05-01

Conventional batch and semicontinuous emulsion copolymerizations often produce large particles whose size cannot be easily correlated with the comonomer feed compositions, and are to some degree susceptible to composition drift. In contrast, we found that copolymer nanolatexes made via semicontinuous monomer-starved emulsion copolymerizations are featured with an average nanoparticle size being controlled by the feed composition, a high conversion achieved, and a high degree of particle composition uniformity. This was achieved because the rate of particle growth, during nucleation, was controlled by the rate of comonomer addition, and the copolymer composition, surfactant parking area on the particles, and nucleation efficiency determined by the comonomer feed composition. Two model systems, methyl methacrylate/styrene and vinyl acetate/butyl acrylate, with significant differences in water solubility were studied. Monomers were added to the aqueous solution of sodium dodecylsulfate and potassium persulfate at a low rate to achieve high instantaneous conversions. Copyright © 2015 Elsevier Inc. All rights reserved.

The use of food wastes as feed ingredients for culturing grass carp (Ctenopharyngodon idellus) in Hong Kong.

PubMed

Choi, W M; Lam, C L; Mo, W Y; Wong, M H

2016-04-01

Different types of food wastes, e.g., meats, bones, cereals, fruits, and vegetables, were collected from hotels in Hong Kong, mixed in different ratio, and processed into feed pellets (food wastes (FWs) A, B, and C) for feeding trials in aquaculture species. Grass carp fed with cereal-dominant feed (FW A) showed the best growth (in terms of specific growth rate, relative weight gain, and protein efficiency ratio), among all food waste feeds. However, the growth rates of food waste groups especially the meat product-contained feeds (FW B and FW C) were lower than the commercial feed, Jinfeng(®) 613 formulation (control). The results indicated that grass carp utilized plant proteins better than animal proteins and preferred carbohydrate as a major energy source than lipid. The high-lipid content in feed containing meat products was also a possible reason for hindering growth and resulted high body lipid. It is suggested that lipid should be removed in the preparation of food waste feed or further investigations by implementing supplements, e.g., enzymes in feed to enhance lipid or protein utilization by fish. This utilization of food waste could be an effective and practical way to deal with these wastes in this densely populated city.

Variable feeding behavior in Orchestoidea tuberculata (Nicolet 1849): Exploring the relative importance of macroalgal traits

NASA Astrophysics Data System (ADS)

Duarte, Cristian; Acuña, Karin; Navarro, Jorge M.; Gómez, Iván; Jaramillo, Eduardo; Quijón, Pedro

2014-03-01

The feeding behavior of algal consumers inhabiting sandy beaches and the consequences of this behavior on their performance are poorly understood. Food quality has been shown to influence the food preference of algal consumers. However, food preference can often be altered or subordinated to habitat choice. This study analyzes the feeding behavior (preference and consumption rate), absorption efficiency and growth rates of the talitrid amphipod Orchestoidea tuberculata (Nicolet, 1849) in relation to the nutritional characteristics of two of the most common macroalgae stranded in the Chilean north-central region. Our experiments show that these amphipods prefer Macrocystis integrifolia over Lessonia nigrescens when presented with fresh fragments of both algae simultaneously. However, this preference did not match the performance of the amphipods when reared on diets of a single algal species: in that growth rates were not different. These results suggest that M. integrifolia is not a superior food item compared to L. nigrescens. The lower content of proteins and total organic matter found in M. integrifolia supports this interpretation. The preference of the amphipods for L. nigrescens over M. integrifolia when dry powdered algae of each species were provided (artificial food), suggested that some aspect of the physical structure of these two algae determined food preference. When the amphipods were maintained with each of the algal species in no choice experiments, they consumed 2 times more M. integrifolia, but showed higher absorption efficiency on L. nigrescens. These results suggest that food quantity and not absorption efficiency was used to compensate for the lower nutritional quality of M. integrifolia. The feeding behavior documented in this study differs significantly from that observed in populations of the same species inhabiting southern Chile, cautioning against generalizing results obtained even within a single species. Our results suggest that physical features rather than chemical characteristics of the food drive feeding preferences, including the potential (indirect) roles played by the fronds of these seaweeds as refuges against competition and desiccation.

Mist characterization in drilling 1018 steel

NASA Astrophysics Data System (ADS)

Cole, Ian

Minimum quantity lubrication replaces the traditional method of flood cooling with small amounts of high-efficient lubrication. Limited studies have been performed to determine the characteristics of mist produced during MQL. This study investigated the mist concentration levels produced while drilling 1018 steel using a vegetable based lubricant. ANOVA was performed to determine whether speed and feed rates or their interactions have a significant effect on mist concentration levels and particle diameter. It was observed that the concentration levels obtained under all four speed and feed rate combinations studied exceeded the current OSHA and NIOSH standards.

Macrofaunal involvement in the sublittoral decay of kelp debris: the polychaete Platynereis dumerilii (Audouin and Milne-Edwards) (Annelida: Polychaeta)

NASA Astrophysics Data System (ADS)

Bedford, A. P.; Moore, P. G.

1985-02-01

Platynereis dumerilii is found in large numbers in parchment-like tubes attached to sublittoral accumulations of detached maroalgae (principally Laminaria saccharina) in Kames Bay, Isle of Cumbrae and Lochranza, Isle of Arran. Its rôle in weed decomposition has been examined by comparing its responses (behavioural choice, growth rates, absorption efficiencies of both carbon and protein, gut retention times and rate of faecal output) to fresh and rotting weed. Worms grew significantly on either diet, with older individuals gaining more weight than small individuals. Animals of a standard size (derived from measurements of maximum bite size) feeding on fresh weed, however, grew significantly faster than those feeding on rotting weed. The former had a significantly higher protein absorption efficiency which was linearly related to protein content of ingested weed. This was not so on rotting weed. Organic carbon absorption efficiencies did not differ significantly between the two groups, neither did gut retention times nor rates of faecal output. Given a choice, Platynereis chooses to build its tube, and to feed, on fresh kelp—a strategem which ensures both maximum scope for occupancy before fronds decay and a superabundance of preferred food. Platynereis feeds around its tube entrance, recropping small areas for 2-3 days, prior to switching to another area nearby. Ciliate population densities on Platynereis faeces are much lower than on either homogenized or intact weed, associated with their lower, nutritional value (at first). Platynereis bubes act to bind kelp fronds together stabilizing the faecal input to infaunal detritivores. Platynereis is an example of a detritivore which exploits the detrital substratum directly.

A method for predicting optimized processing parameters for surfacing

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

Dupont, J.N.; Marder, A.R.

1994-12-31

Welding is used extensively for surfacing applications. To operate a surfacing process efficiently, the variables must be optimized to produce low levels of dilution with the substrate while maintaining high deposition rates. An equation for dilution in terms of the welding variables, thermal efficiency factors, and thermophysical properties of the overlay and substrate was developed by balancing energy and mass terms across the welding arc. To test the validity of the resultant dilution equation, the PAW, GTAW, GMAW, and SAW processes were used to deposit austenitic stainless steel onto carbon steel over a wide range of parameters. Arc efficiency measurementsmore » were conducted using a Seebeck arc welding calorimeter. Melting efficiency was determined based on knowledge of the arc efficiency. Dilution was determined for each set of processing parameters using a quantitative image analysis system. The pertinent equations indicate dilution is a function of arc power (corrected for arc efficiency), filler metal feed rate, melting efficiency, and thermophysical properties of the overlay and substrate. With the aid of the dilution equation, the effect of processing parameters on dilution is presented by a new processing diagram. A new method is proposed for determining dilution from welding variables. Dilution is shown to depend on the arc power, filler metal feed rate, arc and melting efficiency, and the thermophysical properties of the overlay and substrate. Calculated dilution levels were compared with measured values over a large range of processing parameters and good agreement was obtained. The results have been applied to generate a processing diagram which can be used to: (1) predict the maximum deposition rate for a given arc power while maintaining adequate fusion with the substrate, and (2) predict the resultant level of dilution with the substrate.« less

Genetic and Phenotypic Parameter Estimates for Feed Intake and Other Traits in Growing Beef Cattle

USDA-ARS?s Scientific Manuscript database

Intake and feed efficiency were moderately heritable; however, residual feed intake was more heritable than intake and feed efficiency. Adjusting residual feed intake and feed efficiency for carcass fatness had little effect on heritability and correlations with remaining traits. Flight speed was ...

40 CFR 761.71 - High efficiency boilers.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid... percent when PCBs are being burned. (iv) The mineral oil dielectric fluid does not comprise more than 10 percent (on a volume basis) of the total fuel feed rate. (v) The mineral oil dielectric fluid is not fed...

40 CFR 761.71 - High efficiency boilers.

Code of Federal Regulations, 2010 CFR

2010-07-01

... PROHIBITIONS Storage and Disposal § 761.71 High efficiency boilers. (a) To burn mineral oil dielectric fluid... percent when PCBs are being burned. (iv) The mineral oil dielectric fluid does not comprise more than 10 percent (on a volume basis) of the total fuel feed rate. (v) The mineral oil dielectric fluid is not fed...

Growth and energy budget of juvenile lenok Brachymystax lenok in relation to ration level

NASA Astrophysics Data System (ADS)

Liu, Yang; Li, Zhongjie; Zhang, Tanglin; Yuan, Jing; Mou, Zhenbo; Liu, Jiashou

2015-03-01

We evaluated the effect of ration level (RL) on the growth and energy budget of lenok Brachymystax lenok. Juvenile lenok (initial mean body weight 3.06±0.13 g) were fed for 21 d at five different ration levels: starvation, 2%, 3%, 4% bwd (body weight per day, based on initial mean values), and apparent satiation. Feed consumption, apparent digestibility, and growth were directly measured. Specific growth rates in terms of wet weight, dry weight, protein, and energy increased logarithmically with an increase in ration levels. The relationship between specific growth rate in terms of wet weight (SGRw, %/d) and RL (%) was characterized by a decelerating curve: SGRw=-1.417+3.166ln(RL+1). The apparent digestibility coefficients of energy exhibited a decreasing pattern with increasing ration level, and there was a significant difference among different RLs. Body composition was significantly affected by ration size. The relationship between feed efficiency rate in terms of energy (FERe) and RL was: FERe=-14.167+23.793RL-3.367(RL)2, and the maximum FERe was observed at a 3.53% ration. The maintenance requirement for energy of juvenile lenok was 105.39 kJ BW (kg)-0.80/d, the utilization efficiency of DE for growth was 0.496. The energy budget equation at satiation was: 100IE=29.03FE+5.78(ZE+UE)+39.56 HE+25.63 RE, where IE is feed energy, FE is fecal energy, ZE+UE is excretory energy, HE is heat production, and RE is recovered energy. Our results suggest that the most suitable feeding rate for juvenile lenok aquaculture for wet weight growth is 2.89% bwd, whereas for energy growth, the suggested rate is 3.53% bwd at this growth stage.

Stover removal effects on continuous corn yield and nitrogen use efficiency under irrigation

USDA-ARS?s Scientific Manuscript database

Corn (Zea mays L.) residue or stover is harvested as supplemental feed for livestock and is a primary feedstock for cellulosic biofuels. Limited information is available on corn residue removal effects on grain yield under different nitrogen (N) fertilizer rates, irrigation rates and amelioration pr...

Thermodynamic Analysis on of Skid-Mounted Coal-bed Methane Liquefaction Device using Cryogenic Turbo-Expander

NASA Astrophysics Data System (ADS)

Chen, Shuangtao; Niu, Lu; Zeng, Qiang; Li, Xiaojiang; Lou, Fang; Chen, Liang; Hou, Yu

2017-12-01

Coal-bed methane (CBM) reserves are rich in Sinkiang of China, and liquefaction is a critical step for the CBM exploration and utilization. Different from other CBM gas fields in China, CBM distribution in Sinkiang is widespread but scattered, and the pressure, flow-rate and nitrogen content of CBM feed vary significantly. The skid-mounted liquefaction device is suggested as an efficient and economical way to recover methane. Turbo-expander is one of the most important parts which generates the cooling capacity for the cryogenic liquefaction system. Using turbo-expander, more cooling capacity and higher liquefied fraction can be achieved. In this study, skid-mounted CBM liquefaction processes based on Claude cycle are established. Cryogenic turbo-expander with high expansion ratio is employed to improve the efficiency of CBM liquefaction process. The unit power consumption per liquefaction mole flow-rate for CBM feed gas is used as the object function for process optimization, compressor discharge pressure, flow ratio of feed gas to turbo-expander and nitrogen friction are analyzed, and optimum operation range of the liquefaction processes are obtained.

Thermal Catalytic Syngas Cleanup for High-Efficiency Waste-to-Energy Converters

DTIC Science & Technology

2015-12-01

characteristics for a full-scale WEC based on the collected experimental data. 20 RESULTS AND DISCUSSION Task 1 – Tar-Cracking Reactor...prepared to show the effect of reaching the target throughput rate of 50 lb/hr on conversion efficiency. In scaling up the experimental results , the...Midmoisture Full Moisture Fuel Feed Rate, kg/hr 22.3 22.3 22.3 Results Using the Experimental Recuperator Effectiveness Fuel Energy In, kWth 160 136 121

Improving residual feed intake of mule progeny of Muscovy ducks: genetic parameters and responses to selection with emphasis on carcass composition and fatty liver quality.

PubMed

Drouilhet, L; Basso, B; Bernadet, M-D; Cornuez, A; Bodin, L; David, I; Gilbert, H; Marie-Etancelin, C

2014-10-01

In France, about 95% of the fatty liver production comes from mule ducks, an infertile hybrid cross between female common ducks (Anas platyrhynchos) and Muscovy drakes (Cairina moschata). As a hybrid, genetic improvement of the performance of mule ducks is achieved by selection of the parental populations. Feed represents two-thirds of the total costs of duck production; thus, the breeders' main concern is to improve the birds' feed efficiency without impairing their capacity to be overfed after the growing period. To obtain insight into this economically important trait, we designed a divergent selection experiment for Muscovy sires on the basis of the residual feed intake (RFI) of their male mule progeny. Residual feed intake represents the fraction of feed intake that cannot be explained by maintenance and production requirements. Data comprised records from generations 0 to 2 with 227 Muscovy sires of 2,016 mule ducks. Growth and fat deposition were measured individually for all mule ducks. Half-sib mule ducks were placed together in 1 small pen, and the feed consumption was recorded for each pen; all half-sibs therefore had the same feed intake estimates. Heritability of RFI was high (0.83 ± 0.42), and after 2 generations of selection, the differences between lines in terms of RFI (contrast of 9.13 g/d, representing 0.76 phenotypic standard deviation; P < 0.0001) and feed conversion ratio (contrast of 0.08, representing 0.28 phenotypic standard deviation; P = 0.0003) were marked. In regard to carcass traits, the low-RFI line (high-efficiency animals) had heavier legs (476 vs. 463 g; P < 0.0001) and magret muscles (268 vs. 262 g; P = 0.001) than the high-RFI line (low-efficiency animals). No differences were observed for either the liver weight or the melting rate between the 2 lines (P > 0.46). Selection on RFI thus improves the feed efficiency of animals without impairing their capacity to produce fatty liver.

Liquid-phase membrane extraction of targeted pesticides from manufacturing wastewaters in a hollow fibre contactor with feed-stream recycle.

PubMed

Đorđević, Jelena; Vladisavljević, Goran T; Trtić-Petrović, Tatjana

2017-01-01

A two-phase membrane extraction in a hollow fibre contactor with feed-stream recycle was applied to remove selected pesticides (tebufenozide, linuron, imidacloprid, acetamiprid and dimethoate) from their mixed aqueous solutions. The contactor consisted of 50 polypropylene hollow fibres impregnated with 5% tri-n-octylphosphine oxide in di-n-hexyl ether. For low-polar pesticides with log P ≥ 2 (tebufenozide and linuron), the maximum removal efficiency increased linearly from 85% to 96% with increasing the feed flow rate. The maximum removal efficiencies of more polar pesticides were significantly higher under feed recirculation (86%) than in a continuous single-pass operation (30%). It was found from the Wilson's plot that the mass transfer resistance of the liquid membrane can be neglected for low-polar pesticides. The pesticide removals from commercial formulations were similar to those from pure pesticide solutions, indicating that built-in adjuvants did not affect the extraction process.

Efficiency of organic acid preparations for the elimination of naturally occurring Salmonella in feed material.

PubMed

Axmann, Sonja; Kolar, Veronika; Adler, Andreas; Strnad, Irmengard

2017-11-01

Salmonella can enter animal stocks via feedstuffs, thus posing not only an infection risk for animals, but also threatening to contaminate food of animal origin and finally humans. Salmonella contamination in feedstuffs is still a recurring and serious issue in animal production (especially for the poultry sector), and is regularly detected upon self-monitoring by feed companies (self-checks) and official inspections authorities. Operators within the feed chain in certain cases need to use hygienic condition enhancers, such as organic acids, to improve the quality of feed for animal nutrition, providing additional guarantees for the protection of animal and public health. The present study investigated the efficiencies of five organic acid preparations. The acid products were added to three different feed materials contaminated with Salmonella (contamination occurred by recontamination in the course of the production process) at seven different inclusion rates (1-7%) and analysed after 1, 2, and 7 days' exposure time using culture method (tenfold analysis). A reliable standard was established for defining a successful decontamination under the prevailing test conditions: 10 Salmonella-negative results out of 10 tested samples (0/10: i.e. 0 positive samples and 10 negative samples). The results demonstrated that the tested preparations showed significant differences with regard to the reduction in Salmonella contamination. At an inclusion rate of 7% of the feed materials, two out of five acid preparations showed an insufficient, very small, decontamination effect, whereas two others had a relatively large partial effect. Reliable decontamination was demonstrated only for one acid preparation, however, subject to the use of the highest acid concentration.

Toxicity of dietary Heliotropium dolosum seed to broiler chickens.

PubMed

Eröksüz, Y; Eröksüz, H; Ozer, H; Canatan, H; Yaman, I; Cevik, A

2001-12-01

Five groups of 20 female broiler chicks were fed different levels of dehulled Heliotropium dolosum seed (w/w%; 0.0, 1.0, 3.0, 5.0 or 10.0%) from 10 to 52 d of age. In all doses the seed caused decreases in daily feed intake, weight gain, and feed efficiency, and biochemical findings, severity of pathologic changes, and mortality rate increased in a dose-dependent manner. Acute toxicity was observed in livers of chicks fed 10% seed. Other test groups had chronic changes. Livers had massive to submassive necrosis, hepatic megalocytosis, bile duct proliferation, fatty change, and periportal fibrosis. Biochemical evaluations revealed hypoalbuminemia, hypoprotienemia and increased ALP activity and billuribin. The seed of Heliotropium dolosum produced biochemical and specific pathologic changes in broiler chicks, as well as decreased food intake and feed efficiency. Higher seed levels induced more pronounced changes.

A review of feed efficiency in swine: biology and application.

PubMed

Patience, John F; Rossoni-Serão, Mariana C; Gutiérrez, Néstor A

2015-01-01

Feed efficiency represents the cumulative efficiency with which the pig utilizes dietary nutrients for maintenance, lean gain and lipid accretion. It is closely linked with energy metabolism, as the oxidation of carbon-containing components in the feed drive all metabolic processes. While much is known about nutrient utilization and tissue metabolism, blending these subjects into a discussion on feed efficiency has proven to be difficult. For example, while increasing dietary energy concentration will almost certainly increase feed efficiency, the correlation between dietary energy concentration and feed efficiency is surprisingly low. This is likely due to the plethora of non-dietary factors that impact feed efficiency, such as the environment and health as well as individual variation in maintenance requirements, body composition and body weight. Nonetheless, a deeper understanding of feed efficiency is critical at many levels. To individual farms, it impacts profitability. To the pork industry, it represents its competitive position against other protein sources. To food economists, it means less demand on global feed resources. There are environmental and other societal implications as well. Interestingly, feed efficiency is not always reported simply as a ratio of body weight gain to feed consumed. This review will explain why this arithmetic calculation, as simple as it initially seems, and as universally applied as it is in science and commerce, can often be misleading due to errors inherent in recording of both weight gain and feed intake. This review discusses the importance of feed efficiency, the manner in which it can be measured and reported, its basis in biology and approaches to its improvement. It concludes with a summary of findings and recommendations for future efforts.

Divergent selection for residual feed intake affects the transcriptomic and proteomic profiles of pig skeletal muscle.

PubMed

Vincent, A; Louveau, I; Gondret, F; Tréfeu, C; Gilbert, H; Lefaucheur, L

2015-06-01

Improving feed efficiency is a relevant strategy to reduce feed cost and environmental waste in livestock production. Selection experiments on residual feed intake (RFI), a measure of feed efficiency, previously indicated that low RFI was associated with lower feed intake, similar growth rate, and greater lean meat content compared with high RFI. To gain insights into the molecular mechanisms underlying these differences, 24 Large White females from 2 lines divergently selected for RFI were examined. Pigs from a low-RFI ("efficient") and high-RFI ("inefficient") line were individually fed ad libitum from 67 d of age (27 kg BW) to slaughter at 115 kg BW (n = 8 per group). Additional pigs of the high-RFI line were feed restricted to the daily feed intake of the ad libitum low-RFI pigs (n = 8) to investigate the impact of selection independently of feed intake. Global gene and protein expression profiles were assessed in the LM collected at slaughter. The analyses involved a porcine commercial microarray and 2-dimensional gel electrophoresis. About 1,000 probes were differentially expressed (P < 0.01) between RFI lines. Only 10% of those probes were also affected by feed restriction. Gene functional classification indicated a greater expression of genes involved in protein synthesis and a lower expression of genes associated with mitochondrial energy metabolism in the low-RFI pigs compared with the high-RFI pigs. At the protein level, 11 unique identified proteins exhibited a differential abundance (P < 0.05) between RFI lines. Differentially expressed proteins were generally not significantly affected by feed restriction. Mitochondrial oxidative proteins such as aconitase hydratase, ATP synthase subunit α, and creatine kinase S-type had a lower abundance in the low-RFI pigs, whereas fructose-biphosphate aldolase A and glyceraldehyde-3-phosphate dehydrogenase, 2 proteins involved in glycolysis, had a greater abundance in those pigs compared with high-RFI pigs. Antioxidant proteins such as superoxide dismutase and glutathione peroxidase 3 at the mRNA level and peroxiredoxin-6 at the protein level were also less expressed in LM of the most efficient pigs, likely related to lower oxidative molecule production. Collectively, both the transcriptomic and proteomic approaches revealed a lower oxidative metabolism in muscle of the low-RFI pigs and all these modifications were largely independent of differences in feed intake.

Impact of amino acid and CP restriction from 20 to 140 kg BW on performance and dynamics in empty body protein and lipid deposition of entire male, castrated and female pigs.

PubMed

Ruiz-Ascacibar, I; Stoll, P; Kreuzer, M; Boillat, V; Spring, P; Bee, G

2017-03-01

Breeding leaner pigs during the last decades may have changed pig's empty body (EB) composition, a key trait for elaborating feeding recommendations. This research aimed to provide new experimental data on changes in the chemical composition of the EB of pigs from 20 to 140 kg BW. In addition, the impact of a reduction in the dietary CP associated with lower lysine, methionine+cystine, threonine and tryptophan levels was determined. In total, 48 males, castrates and females weighing 20 kg BW were allocated either to a control grower-finisher diet formulated according to current Swiss feeding recommendations, or a low CP grower-finisher diet (80% of control). Feed intake was monitored and pigs were weighed weekly. The chemical composition of EB (blood, hairs and hoofs, offals, bile, carcass) was determined at 20, 40, 60, 80, 100, 120 and 140 kg BW on four pigs per gender and diet (eight pigs per gender at 20 kg). The five fractions were weighed and samples were analysed for dry matter, protein, fat and energy. Nutrient deposition rates and N efficiency were calculated by using the 20 kg BW category as reference. Analysis revealed an accurate feed optimisation for the aforementioned essential amino acids (EAA), whereas digestible isoleucine content in the low CP diet was at 70% of the control diet. Despite similar feed intake, daily gain and feed efficiency were impaired (P<0.01) from 20 to 100 kg BW in the low CP compared with the control pigs. In the same growth period, castrates had the greatest feed intake but, together with females, displayed the lowest (P<0.01) feed efficiency. Protein deposition was reduced (P<0.01) by up to 31% with low CP diet and was lower (P<0.01) in castrates and females than males at 100 kg BW. The greatest fat deposition rates were found with low CP diet and castrates. N efficiency improved (P<0.05) by 10% with the low CP diet from 100 to 140 kg. The males displayed the greatest (P<0.05) N efficiency. These findings suggest that the CP content of finisher II diets could be reduced to 102, 102 and 104 g/kg for females, castrates and males, respectively, without a negative impact on protein deposition or growth. It remains unclear whether the negative effects found in the BW range from 20 to 100 kg on the EB deposition were due to the 20% reduction of the dietary CP and the five limiting EAA or to other EAA via an unbalanced EAA profile.

Thermophilic biogasification of biomass

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

Ghosh, S.; Klass, D.L.; Edwards, V.H.

1980-01-01

Secondary sewage effluent- and fresh-water-grown water hyacinths (Eichhornia crassipes), Coastal Bermuda grass (Cynodon dactylon), and a hyacinth-grass-municipal solid waste-sludge (biomass-waste) blend were used as test feeds to develop a fast thermophilic biomass- digestion process. For the pure biomass feeds thermophilic digestion has no apparent advantage over mesophilic digestion, but the reverse is true for the biomass-waste blend. Alkaline pretreatment of the feed improved thermophilic digester performance substantially. For a given plant feed load, the reactor volume, culture-heating requirements, and CH4 production rate for thermophilic digestion of the pretreated biomass-waste feed were 18,46, and 135% of those for conventional mesophilic digestion.more » For a biomass-waste feed the respective volatile solids reduction and energy recovery efficiencies were 46 and 49% for thermophilic and 36 and 43% for mesophilic digestions.« less

Production of Dissolved Organic Matter During Doliolid Feeding

NASA Astrophysics Data System (ADS)

Castellane, N. J.; Paffenhofer, G. A.; Stubbins, A.

2016-02-01

The biological carbon pump (BCP) draws carbon dioxide out of the atmosphere and buries it at the seafloor. The efficiency of the BCP is determined in part by the sinking rates of particulate organic carbon (POC) from ocean surface waters. Zooplankton can package POC into fecal pellets with higher sinking rates than their food source (e.g. phytoplankton), increasing the efficiency of the BCP. However, dissolved organic carbon (DOC) is also produced as zooplankton ingest and egest food, reducing the efficiency of BCP. The pelagic tunicate Dolioletta gegenbauri (doliolid) is a gelatinous zooplankton found at high concentrations in shelf waters, including our study site: the South Atlantic Bight. Doliolids are efficient grazers capable of stripping large quantities of phytoplankton from the water column. To determine the balance between pellet formation and DOC production during feeding, doliolids (6-7 mm gonozooids) were placed in natural seawater amended with a live phytoplankton food source and incubated on a plankton wheel. Dissolved organic matter (DOM) released directly to the water as well as the water soluble fraction of pellet organic matter were quantified and optically characterized. Colored dissolved organic matter (CDOM) absorbance and fluorescence spectra revealed that doliolid feeding produces DOM with optical properties that are commonly indicative of newly produced, highly biolabile DOM of microbial origin. Based upon these optical characteristics, doliolid-produced DOM is expected to be highly bio-labile in the environment and therefore rapidly degraded by surface ocean microbes shunting phytoplankton-derived organic carbon out of the BCP and back to dissolved inorganic carbon.

Effects of brown fish meal replacement with fermented soybean meal on growth performance, feed efficiency and enzyme activities of Chinese soft-shelled turtle, Pelodiscus sinensis

NASA Astrophysics Data System (ADS)

Zou, Yurong; Ai, Qinghui; Mai, Kangsen; Zhang, Wenbing; Zhang, Yanjiao; Xu, Wei

2012-06-01

A 120-day feeding experiment was conducted to investigate the effects of partial replacement of brown fish meal (BFM) by fermented soybean meal (FSBM) in diets of Chinese soft-shelled turtle ( Pelodiscus sinensis). The turtles (initial mean body weight, (115.52 ± 1.05) g) were fed with three experimental diets, in which 0%, 4.72% and 9.44% BFM protein was replaced by 0%, 3% and 6% FSBM, respectively. Results showed that the feeding rate (FR), specific growth rate (SGR) and feed efficiency ratio (FER) of turtles fed with the diet containing 3% FSBM were not significantly different from the control group (0% FSBM) ( P > 0.05). However, FR, SGR and FER of turtles fed with the diet containing 6% FSBM were significantly lower than those of the control group ( P < 0.05). No significant differences were observed in the activities of serum glutamic-oxalacetic transaminase and glutamic-pyruvic transaminase among dietary treatments ( P > 0.05). However, the uric acid concentration in turtles fed with the diet containing 3% or 6% FSBM was significantly lower than that in the control group ( P < 0.05). There were no significant differences in the activities of lysozyme, alkaline phosphatase and total superoxide dismutase among dietary treatments ( P > 0.05). The results suggested that FSBM could replace 4.72% BFM protein in turtle diets without exerting adverse effects on turtle growth, feed utilization and measured immune parameters.

Jejunal feeding tubes can be efficiently and independently placed by intensive care unit teams.

PubMed

Welpe, Pascal; Frutiger, Adrian; Vanek, Patrik; Kleger, Gian-Reto

2010-01-01

Nutrition support is an important therapeutic measure in critically ill patients. Several studies have shown that the enteral route is preferable to the parenteral route. Insertion of a feeding tube beyond the ligament of Treitz combined with continuous gastric drainage will reduce regurgitation and probably also the rate of nosocomial pneumonia. This study was conducted to assess the safety, success rate, and time required to establish jejunal nutrition by the fluoroscopy-guided technique in intensive care unit (ICU) patients. This was a prospective observational study in the ICUs of a 300-bed and a 600-bed community hospital. Indications were large gastric residuals during attempted gastric feeding, severe acute pancreatitis, or recurrent aspiration. Feeding tubes were introduced by the ICU staff at bedside under fluoroscopic guidance (a senior ICU physician and a resident or a registered ICU nurse). The correct jejunal position was documented by the application of a radiopaque contrast medium through the tube. After confirmation of the correct position, jejunal tube feeding was immediately started. The insertion procedure in 38 patients lasted a median of 17 minutes. The median time from decision to place the tube until start of enteral feeding was 141 minutes. The success rate was 84.2%. No adverse events were observed. Fluoroscopic placement of a jejunal feeding tube at the bedside is fast, is safe, and has a high success rate when performed by well-trained ICU staff. Using this method makes the ICU team more self-sufficient when critically ill patients require enteral nutrition and no gastroenterologist is available.

Effect of Dietary Types on Feed Intakes, Growth Performance and Economic Benefit in Tibetan sheep and Yaks on the Qinghai-Tibet Plateau during Cold Season

PubMed Central

Xu, Shixiao; Hu, Linyong; Zhao, Na; Liu, Zhe; Ma, Li; Liu, Hongjin; Zhao, Xinquan

2017-01-01

Pastoralists on the Tibetan alpine rangeland suffered great economic loss in cold season, due to serious live-weight loss of domestic livestock under traditional grazing management. This study aimed to evaluate the effect of dietary types (crude protein levels) on feed intakes, growth performance and economic returns of local Tibetan sheep and yaks during cold season. Twenty-four yearling Tibetan sheep (25.29±3.95 kg LW) and twenty two-year-old yaks (100.62±4.55 kg LW) with familiar body conditions were randomly assigned to four groups, fed oats hay (OH), oats silage (OS), total mixed ration (TMR) and traditionally grazed on the local cool-season pasture (TG), respectively, over a 135-day experiment. Daily dry matter intake was determined; all animals were weighed at the beginning and every 15 days of the 135-day experiment. Then, the total live-weight gain, average daily live-weight gain, gain rate, feed efficiency and net economic benefit were calculated. Results indicated that feed and nutrient intakes (DMI, DMI/kg LW, DMI/kg LW0.75 and CPI) of TMR, OH and OS were higher than TG (P < 0.05). Grazing animals suffered serious live-weight loss, while TMR, OS and OH significantly (P < 0.05) improved total live-weight gain and gain rate in both Tibetan sheep and yaks during the entire experiment. TMR worked better in animal performance and feed efficiency, obtained the highest breeding profit in both Tibetan sheep and yaks among four treatments (P < 0.05). When expressed on net economic benefit, TMR shared the highest net economic benefit in Tibetan sheep, OH shared the highest net economic benefit in yaks, but, no significant difference of net economic benefit in yaks fed TMR and OH diets was determined (P > 0.05). Results indicated that TMR was a reasonable diet in promoting feed intakes, animal performance, feed efficiency and economic returns in domestic livestock, which should be considered by local herdsmen to increase their breeding profit during cold season. PMID:28056054

Effect of Dietary Types on Feed Intakes, Growth Performance and Economic Benefit in Tibetan sheep and Yaks on the Qinghai-Tibet Plateau during Cold Season.

PubMed

Xu, Tianwei; Xu, Shixiao; Hu, Linyong; Zhao, Na; Liu, Zhe; Ma, Li; Liu, Hongjin; Zhao, Xinquan

2017-01-01

Pastoralists on the Tibetan alpine rangeland suffered great economic loss in cold season, due to serious live-weight loss of domestic livestock under traditional grazing management. This study aimed to evaluate the effect of dietary types (crude protein levels) on feed intakes, growth performance and economic returns of local Tibetan sheep and yaks during cold season. Twenty-four yearling Tibetan sheep (25.29±3.95 kg LW) and twenty two-year-old yaks (100.62±4.55 kg LW) with familiar body conditions were randomly assigned to four groups, fed oats hay (OH), oats silage (OS), total mixed ration (TMR) and traditionally grazed on the local cool-season pasture (TG), respectively, over a 135-day experiment. Daily dry matter intake was determined; all animals were weighed at the beginning and every 15 days of the 135-day experiment. Then, the total live-weight gain, average daily live-weight gain, gain rate, feed efficiency and net economic benefit were calculated. Results indicated that feed and nutrient intakes (DMI, DMI/kg LW, DMI/kg LW0.75 and CPI) of TMR, OH and OS were higher than TG (P < 0.05). Grazing animals suffered serious live-weight loss, while TMR, OS and OH significantly (P < 0.05) improved total live-weight gain and gain rate in both Tibetan sheep and yaks during the entire experiment. TMR worked better in animal performance and feed efficiency, obtained the highest breeding profit in both Tibetan sheep and yaks among four treatments (P < 0.05). When expressed on net economic benefit, TMR shared the highest net economic benefit in Tibetan sheep, OH shared the highest net economic benefit in yaks, but, no significant difference of net economic benefit in yaks fed TMR and OH diets was determined (P > 0.05). Results indicated that TMR was a reasonable diet in promoting feed intakes, animal performance, feed efficiency and economic returns in domestic livestock, which should be considered by local herdsmen to increase their breeding profit during cold season.

Effects of feeding strategy on milk production, reproduction, pasture utilization, and economics of autumn-calving dairy cows in eastern North Carolina.

PubMed

Vibart, R E; Washburn, S P; Green, J T; Benson, G A; Williams, C M; Pacheco, D; Lopez-Villalobos, N

2012-02-01

A balance among stocking rate (SR), pasture management, and supplementary feeding is required to optimize overall farm performance and profitability in pasture-based dairying. Beginning in September 2003, a seasonal, autumn-calving, pasture-based farming system was established to address the effects of feeding strategy (FS; i.e., a unique combination of stocking and supplementation rate) on productive, reproductive, and economic performance of lactating herds over 3 yr. Eighty lactating cows (1/3 Holsteins, 1/3 Jerseys, and 1/3 crosses of those breeds) were randomly assigned to either a lesser stocking, lesser supplementation group [LSR; 2.2 cows/ha, 6.3 kg of dry matter (DM) of a corn-based concentrate consumed daily, n=40] or a greater stocking, greater supplementation group (HSR; 3.3 cows/ha, 9.2 kg of DM of a corn-based concentrate consumed daily, n=40). Pasture/forage crop rotations included annual ryegrass and sorghum-Sudan (50%), annual ryegrass and bermudagrass (20%), and a tall fescue-white clover pasture (30%). Pre- and postgrazing herbage mass values and grazing intervals (3,347±255.8 kg of DM/ha, 1,861±160.6 kg of DM/ha, 23.6±1.9 d) did not differ between FS. The nutritive value of fresh and conserved forages was similar between feeding strategies, except for acid detergent fiber in freshly grazed bermudagrass (29.6 vs. 26.3% of DM for LSR and HSR, respectively). Cows on HSR tended to spend more time on an adjacent feeding area where conserved forages were offered (85 vs. 61 d/yr) as opposed to grazing paddocks (204 vs. 228 d/yr). Lactation performance was greater for HSR; cows on HSR produced 10.8% more milk fat and 6.3% more milk protein than cows on LSR. Holstein cows produced the greatest amounts of mature-equivalent milk, but did not differ from crossbred cows in terms of energy-corrected milk, and mature-equivalent fat and protein yields. Reproductive efficiency did not differ among feeding strategy, but breed differences were observed; conception rates at first and all services, as well as pregnancy rates, were greater for Jersey and crossbred cows compared with Holsteins. The greater stocking rate required additional supplemental concentrate and time away from grazing paddocks, but reproductive efficiency was similar and overall lactation performance was greater. The greater stocking rate resulted in increased productivity and greater income over feed costs per unit of land. Copyright © 2012 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Growth performance, feed digestibility, body composition, and feeding behavior of high- and low-residual feed intake fat-tailed lambs under moderate feed restriction.

PubMed

Rajaei Sharifabadi, H; Naserian, A A; Valizadeh, R; Nassiry, M R; Bottje, W G; Redden, R R

2016-08-01

Two experiments were conducted to evaluate the effect of moderate feed restriction on productivity of lambs classified on the basis of phenotypic expression of residual feed intake (RFI). In Exp. 1, 58 fat-tailed Kurdi ram lambs (32.1 ± 4.2 kg BW) were individually fed, ad libitum, a pelleted diet (35% alfalfa hay and 65% concentrate). Feed intake and ADG were determined for a 6-wk period and 3 feed efficiency measures including RFI, G:F, and partial efficiency of maintenance (PEM) were calculated. The lambs were sorted based on RFI and the 16 highest RFI (RFI ≥ mean + 0.5 SD) and 16 lowest RFI (RFI ≤ mean - 0.5 SD) lambs were subjected to body composition (BC) and DM digestibility (DMD) analysis. Feeding behavior traits (FB) were also evaluated for 24 h using a regular 5-min interval observation method. The high- and low-RFI lambs (14 lambs/RFI group) so classified in Exp. 1 were used in Exp. 2. Half of the lambs in each RFI group were randomly selected to be fed ad libitum or 85% of ad libitum (restricted feeding), which resulted in 4 experimental groups: 1) ad libitum high-RFI, 2) feed restricted high-RFI, 3) ad libitum low-RFI, and 4) feed restricted low-RFI. The lambs were fed the same diet as Exp. 1, and growth efficiency during a 6-wk test period as well as BC, DMD, and FB were also determined in Exp. 2. In Exp. 1, the low-RFI lambs consumed 14% ( < 0.01) less feed than high-RFI lambs. Differences were also observed between high- and low-RFI groups for G:F ( = 0.01), RFI ( < 0.01), and PEM ( < 0.01) in Exp. 1, but no differences were detected between high- and low-RFI lambs for ADG ( = 0.79), DMD ( = 0.42), BC ( > 0.72), and FB ( > 0.24). In Exp.2, the restriction feeding regime negatively affected ADG ( < 0.01) and G:F ( = 0.02) in low-RFI lambs, whereas G:F ( = 0.02) and PEM ( < 0.01) were improved in high-RFI lambs under the feed restriction condition. No effects of feed restriction on DMD ( = 0.87) and BC ( > 0.05) were observed. The lambs fed at the restricted level of intake presented a greater time ( < 0.01) and rate ( = 0.01) of eating than those fed ad libitum. Although bunk visits and feeding events were decreased ( < 0.01) with feed restriction, no interaction ( > 0.05) was detected between RFI phenotype and feeding regime for FB. In summary, feeding high-RFI lambs at 85% of ad libitum level improved G:F with no effect on ADG, whereas growth performance was reduced by feeding low-RFI lambs at 85% of ad libitum. However, these changes in feed efficiency were not related to DMD, BC, or FB.

Dry matter intake and feed efficiency profiles of 3 genotypes of Holstein-Friesian within pasture-based systems of milk production.

PubMed

Coleman, J; Berry, D P; Pierce, K M; Brennan, A; Horan, B

2010-09-01

The primary objective of the study was to quantify the effect of genetic improvement using the Irish total merit index (Economic Breeding Index) on dry matter intake and feed efficiency across lactation and to quantify the variation in performance among alternative definitions of feed efficiency. Three genotypes of Holstein-Friesian dairy cattle were established from within the Moorepark dairy research herd: 1) low Economic Breeding Index North American Holstein-Friesian representative of the Irish national average dairy cow, 2) high genetic merit North American Holstein-Friesian, and 3) high genetic merit New Zealand Holstein-Friesian. Animals from within each genotype were randomly allocated to 1 of 2 possible intensive pasture-based feed systems: 1) the Moorepark pasture system (2.64 cows/ha and 500 kg of concentrate supplement per cow per lactation) and 2) a high output per hectare pasture system (2.85 cows/ha and 1,200 kg of concentrate supplement per cow per lactation). A total of 128 and 140 spring-calving dairy cows were used during the years 2007 and 2008, respectively. Each group had an individual farmlet of 17 paddocks, and all groups were managed similarly throughout the study. The effects of genotype, feed system, and the interaction between genotype and feed system on dry matter intake, milk production, body weight, body condition score, and different definitions of feed efficiency were studied using mixed models with factorial arrangements of genotypes and feed systems accounting for the repeated cow records across years. No significant genotype-by-feed-system interactions were observed for any of the variables measured. Results showed that aggressive selection using the Irish Economic Breeding Index had no effect on dry matter intake across lactation when managed on intensive pasture-based systems of milk production, although the ranking of genotypes for feed efficiency differed depending on the definition of feed efficiency used. Performance of animals grouped on alternative definitions of feed efficiency showed that conventional definitions such as feed conversion efficiency or residual feed intake may be inappropriate measures of efficiency for lactating dairy cows. An alternative definition, residual solids production, is proposed. This definition of feed efficiency identifies animals that produce greater volumes of milk solids at similar levels of feed intake without excessive body tissue mobilization and with improved fertility performance. The results also suggest that although there are differences in feed efficiency between strains of Holstein-Friesian, there is also variation within genotypes so that improvements in feed efficiency can be realized if the appropriate definition of feed efficiency is incorporated into breeding programs. Copyright (c) 2010 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Feed Efficiency: An Assessment of Current Knowledge from a Voluntary Subsample of the Swine Industry

ERIC Educational Resources Information Center

Flohr, Josh R.; Tokach, Mike D.; DeRouchey, Joel M.; Goodband, Robert D.; Dritz, Steve S.; Nelssen, Jim L.; Patience, John F.

2014-01-01

A voluntary sample of pork producers and advisers to the swine industry were surveyed about feed efficiency. The questionnaire was designed to accomplish three objectives: (a) determine the level of knowledge related to feed efficiency topics, (b) identify production practices used that influence feed efficiency, and (c) identify information gaps…

Infant sleep and feeding patterns are associated with maternal sleep, stress, and depressed mood in women with a history of major depressive disorder (MDD).

PubMed

Sharkey, Katherine M; Iko, Ijeoma N; Machan, Jason T; Thompson-Westra, Johanna; Pearlstein, Teri B

2016-04-01

Our goal was to examine associations of infant sleep and feeding patterns with maternal sleep and mood among women at risk for postpartum depression. Participants were 30 women (age ± SD = 28.3 ± 5.1 years) with a history of MDD (but not in a mood episode at enrollment) who completed daily sleep diaries, wore wrist actigraphs to estimate sleep, and had their mood assessed with the Hamilton Depression Rating Scale (HAM-D-17) during four separate weeks of the perinatal period (33 weeks pregnancy and weeks 2, 6, and 16 postpartum). They logged their infants' sleep and feeding behaviors daily and reported postnatal stress on the Childcare Stress Inventory (CSI) at week 16. Mothers' actigraphically estimated sleep showed associations with infant sleep and feeding patterns only at postpartum week 2. Shorter duration of the longest infant-sleep bout was associated with shorter maternal sleep duration (p = .02) and lower sleep efficiency (p = .04), and maternal sleep efficiency was negatively associated with the number of infant-sleep bouts (p = .008) and duration of infant feeding (p = .008). Neither infant sleep nor feeding was associated with maternal sleep at 6 or 16 weeks, but more disturbed infant sleep and more frequent feeding at 6 weeks were associated with higher HAM-D scores at 6 and 16 weeks and higher CSI scores. Sleep in the mother-infant dyad is most tightly linked in the early postpartum weeks, but mothers continue to experience disturbed sleep and infant sleep and feeding behaviors continue to be associated with mothers' depressive symptoms and stress ratings as long as 16 weeks postpartum. These data imply that interventions designed to improve maternal sleep and postpartum mood should include both mothers and infants because improving infant sleep alone is not likely to improve maternal sleep, and poor infant sleep is linked to postpartum depression and stress.

Infant Sleep and Feeding Patterns are Associated with Maternal Sleep, Stress, and Depressed Mood in Women with a History of Major Depressive Disorder

PubMed Central

Sharkey, Katherine M.; Iko, Ijeoma N.; Machan, Jason T.; Thompson-Westra, Johanna; Pearlstein, Teri B.

2015-01-01

Purpose Our goal was to examine associations of infant sleep and feeding patterns with maternal sleep and mood among women at risk for postpartum depression. Methods Participants were 30 women (age±SD = 28.3±5.1 years) with a history of MDD (but not in a mood episode at enrollment) who completed daily sleep diaries, wore wrist actigraphs to estimate sleep, and had mood assessed with the Hamilton Depression Rating Scale (HAM-D-17) during 4 separate weeks of the perinatal period (33 weeks pregnancy and weeks 2, 6, and 16 postpartum). They logged their infants’ sleep and feeding behaviors daily and reported postnatal stress on the Childcare Stress Inventory (CSI) at week 16. Results Mothers’ actigraphically-estimated sleep showed associations with infant sleep and feeding patterns only at postpartum week 2. Shorter duration of the longest infant sleep bout was associated with shorter maternal sleep duration (p=.02) and lower sleep efficiency (p=.04), and maternal sleep efficiency was negatively associated with number of infant sleep bouts (p =.008) and duration of infant feeding (p =.008). Neither infant sleep nor feeding was associated with maternal sleep at 6 or 16 weeks, but more disturbed infant sleep and more frequent feeding at 6 weeks were associated with higher HAM-D scores at 6 and 16 weeks and higher CSI scores. Conclusions Sleep in the mother-infant dyad is most tightly linked in the early postpartum weeks, but mothers continue to experience disturbed sleep and infant sleep and feeding behaviors continue to be associated with mothers’ depressive symptoms and stress ratings as long as 16 weeks postpartum. These data imply that interventions designed to improve maternal sleep and postpartum mood should include both mothers and infants, because improving infant sleep alone is not likely to improve maternal sleep and poor infant sleep is linked to postpartum depression and stress. PMID:26228760

High efficiency cell-recycle continuous sodium gluconate production by Aspergillus niger using on-line physiological parameters association analysis to regulate feed rate rationally.

PubMed

Lu, Fei; Li, Chao; Wang, Zejian; Zhao, Wei; Chu, Ju; Zhuang, Yingping; Zhang, Siliang

2016-11-01

In this paper, a system of cell-recycle continuous fermentation for sodium gluconate (SG) production by Aspergillus niger (A. niger) was established. Based on initial continuous fermentation result (100.0h) with constant feed rate, an automatic feedback strategy to regulate feed rate using on-line physiological parameters (OUR and DO) was proposed and applied successfully for the first time in the improved continuous fermentation (240.5h). Due to less auxiliary time, highest SG production rate (31.05±0.29gL(-1)h(-1)) and highest yield (0.984±0.067molmol(-1)), overall SG production capacity (975.8±5.8gh(-1)) in 50-L fermentor of improved continuous fermentation increased more than 300.0% compared to that of batch fermentation. Improvement of mass transfer and dispersed mycelia morphology were the two major reasons responsible for the high SG production rate. This system had been successfully applied to industrial fermentation and SG production was greatly improved. Copyright © 2016 Elsevier Ltd. All rights reserved.

Harnessing the genetics of the modern dairy cow to continue improvements in feed efficiency.

PubMed

VandeHaar, M J; Armentano, L E; Weigel, K; Spurlock, D M; Tempelman, R J; Veerkamp, R

2016-06-01

Feed efficiency, as defined by the fraction of feed energy or dry matter captured in products, has more than doubled for the US dairy industry in the past 100 yr. This increased feed efficiency was the result of increased milk production per cow achieved through genetic selection, nutrition, and management with the desired goal being greater profitability. With increased milk production per cow, more feed is consumed per cow, but a greater portion of the feed is partitioned toward milk instead of maintenance and body growth. This dilution of maintenance has been the overwhelming driver of enhanced feed efficiency in the past, but its effect diminishes with each successive increment in production relative to body size and therefore will be less important in the future. Instead, we must also focus on new ways to enhance digestive and metabolic efficiency. One way to examine variation in efficiency among animals is residual feed intake (RFI), a measure of efficiency that is independent of the dilution of maintenance. Cows that convert feed gross energy to net energy more efficiently or have lower maintenance requirements than expected based on body weight use less feed than expected and thus have negative RFI. Cows with low RFI likely digest and metabolize nutrients more efficiently and should have overall greater efficiency and profitability if they are also healthy, fertile, and produce at a high multiple of maintenance. Genomic technologies will help to identify these animals for selection programs. Nutrition and management also will continue to play a major role in farm-level feed efficiency. Management practices such as grouping and total mixed ration feeding have improved rumen function and therefore efficiency, but they have also decreased our attention on individual cow needs. Nutritional grouping is key to helping each cow reach its genetic potential. Perhaps new computer-driven technologies, combined with genomics, will enable us to optimize management for each individual cow within a herd, or to optimize animal selection to match management environments. In the future, availability of feed resources may shift as competition for land increases. New approaches combining genetic, nutrition, and other management practices will help optimize feed efficiency, profitability, and environmental sustainability. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Recovery of Butanol by Counter-Current Carbon Dioxide Fractionation with its Potential Application to Butanol Fermentation

PubMed Central

Solana, Miriam; Qureshi, Nasib; Bertucco, Alberto; Eller, Fred

2016-01-01

A counter-current CO2 fractionation method was applied as a mean to recover n-butanol and other compounds that are typically obtained from biobutanol fermentation broth from aqueous solutions. The influence of operating variables, such as solvent-to-feed ratio, temperature, pressure and feed solution composition was experimentally studied in terms of separation efficiency, butanol removal rate, total removal and butanol concentration in the extract at the end of the continuous cycle. With respect to the temperature and pressure conditions investigated, results show that the highest separation efficiency was obtained at 35 °C and 10.34 MPa. At these operating conditions, 92.3% of the butanol present in the feed solution was extracted, and a concentration of 787.5 g·L−1 of butanol in the extract was obtained, starting from a feed solution of 20 g·L−1. Selectivity was calculated from experimental data, concluding that our column performs much better than a single equilibrium stage. When adding ethanol and acetone to the feed solution, ethanol was detected in the water-rich fraction (raffinate), whereas the highest concentration of acetone was found in the butanol rich fraction (extract). PMID:28773654

Optimization of operating parameters of hybrid vertical down-flow constructed wetland systems for domestic sewerage treatment.

PubMed

Huang, Zhujian; Zhang, Xianning; Cui, Lihua; Yu, Guangwei

2016-09-15

In this work, three hybrid vertical down-flow constructed wetland (HVDF-CW) systems with different compound substrates were fed with domestic sewage and their pollutants removal performance under different hydraulic loading and step-feeding ratio was investigated. The results showed that the hydraulic loading and step-feeding ratio were two crucial factors determining the removal efficiency of most pollutants, while substrate types only significantly affected the removal of COD and NH4(+)-N. Generally, the lower the hydraulic loading, the better removal efficiency of all contaminants, except for TN. By contrast, the increase of step-feeding ratio would slightly reduce the removal rate of ammonium and TP but obviously promoted the TN removal. Therefore, the optimal operation of this CWs could be achieved with low hydraulic loading combined with 50% of step-feeding ratio when TN removal is the priority, whereas medium or low hydraulic loading without step-feeding would be suitable when TN removal is not taken into consideration. The obtained results in this study can provide us with a guideline for design and optimization of hybrid vertical flow constructed wetland systems to improve the pollutants removal from domestic sewage. Copyright © 2016 Elsevier Ltd. All rights reserved.

Development of a Compact Eleven Feed Cryostat for the Patriot 12-m Antenna System

NASA Technical Reports Server (NTRS)

Beaudoin, Christopher; Kildal, Per-Simon; Yang, Jian; Pantaleev, Miroslav

2010-01-01

The Eleven antenna has constant beam width, constant phase center location, and low spillover over a decade bandwidth. Therefore, it can feed a reflector for high aperture efficiency (also called feed efficiency). It is equally important that the feed efficiency and its subefficiencies not be degraded significantly by installing the feed in a cryostat. The MIT Haystack Observatory, with guidance from Onsala Space Observatory and Chalmers University, has been working to integrate the Eleven antenna into a compact cryostat suitable for the Patriot 12-m antenna. Since the analysis of the feed efficiencies in this presentation is purely computational, we first demonstrate the validity of the computed results by comparing them to measurements. Subsequently, we analyze the dependence of the cryostat size on the feed efficiencies, and, lastly, the Patriot 12-m subreflector is incorporated into the computational model to assess the overall broadband efficiency of the antenna system.

Single nucleotide polymorphisms and haplotypes associated with feed efficiency in beef cattle

PubMed Central

2013-01-01

Background General, breed- and diet-dependent associations between feed efficiency in beef cattle and single nucleotide polymorphisms (SNPs) or haplotypes were identified on a population of 1321 steers using a 50 K SNP panel. Genomic associations with traditional two-step indicators of feed efficiency – residual feed intake (RFI), residual average daily gain (RADG), and residual intake gain (RIG) – were compared to associations with two complementary one-step indicators of feed efficiency: efficiency of intake (EI) and efficiency of gain (EG). Associations uncovered in a training data set were evaluated on independent validation data set. A multi-SNP model was developed to predict feed efficiency. Functional analysis of genes harboring SNPs significantly associated with feed efficiency and network visualization aided in the interpretation of the results. Results For the five feed efficiency indicators, the numbers of general, breed-dependent, and diet-dependent associations with SNPs (P-value < 0.0001) were 31, 40, and 25, and with haplotypes were six, ten, and nine, respectively. Of these, 20 SNP and six haplotype associations overlapped between RFI and EI, and five SNP and one haplotype associations overlapped between RADG and EG. This result confirms the complementary value of the one and two-step indicators. The multi-SNP models included 89 SNPs and offered a precise prediction of the five feed efficiency indicators. The associations of 17 SNPs and 7 haplotypes with feed efficiency were confirmed on the validation data set. Nine clusters of Gene Ontology and KEGG pathway categories (mean P-value < 0.001) including, 9nucleotide binding; ion transport, phosphorous metabolic process, and the MAPK signaling pathway were overrepresented among the genes harboring the SNPs associated with feed efficiency. Conclusions The general SNP associations suggest that a single panel of genomic variants can be used regardless of breed and diet. The breed- and diet-dependent associations between SNPs and feed efficiency suggest that further refinement of variant panels require the consideration of the breed and management practices. The unique genomic variants associated with the one- and two-step indicators suggest that both types of indicators offer complementary description of feed efficiency that can be exploited for genome-enabled selection purposes. PMID:24066663

Feed efficiency of diets with different energy and protein concentrations supplemented with methionine in laying quails

NASA Astrophysics Data System (ADS)

Ratriyanto, A.; Indreswari, R.; Nuhriawangsa, A. M. P.; Purwanti, E.

2018-03-01

The study was conducted to evaluate the feed efficiency of quail diets containing different concentrations of metabolizable energy (ME) and crude protein (CP) with constant ratio and supplemented with methionine. Four hundred laying quails (Coturnix coturnix japonica) were randomly assigned to four experimental diets in a 2×2 factorial arrangement. Each dietary treatment used 5 replicates of 20 quails. Two basal diets were formulated to contain 2,800 kcal kg-1 ME and 18.7% CP (High ME-CP) and 2,600 kcal kg-1 ME and 17.3% CP (Low ME-CP). Each basal diet was supplemented with 0 and 0.12% methionine. The High ME-CP diets generated lower feed consumption but higher egg mass and feed efficiency (P<0.01) compared with the Low ME-CP. Furthermore, supplementation of methionine increased egg mass, feed efficiency, energy efficiency ratio and protein efficiency ratio (P<0.01). The High ME-CP supplemented with methionine resulted the highest feed efficiency followed by the Low ME-CP supplemented with methionine, while both High ME-CP and Low ME-CP without methionine supplementation resulted the lowest feed efficiency (P<0.05). In addition, ME and CP consumption of the birds were not influenced by the treatments. Thus, feeding High ME-CP supplemented with 0.12% methionine provided benefit to improve the feed efficiency in laying quails.

Food, feeding and absorption efficiencies of the sand dollar, Mellita quinquiesperforata (Leske)

NASA Astrophysics Data System (ADS)

Lane, Jacqueline M.; Lawrence, John M.

1982-04-01

The sand dollar, Melitta quinquiesperforata, is a ciliary-mucoid feeder, selective for <62 μm (silt-clay) size fraction of surface sediments. Lipid is the primary component of the organic fraction of silt-clay; levels were highest in May and June (17%) and lowest in December and January (8%). Mellita absorbed primarily lipid from the silt-clay; absorption efficiency of all biochemical components was highest in May and June (67 and 61%) and lowest in December and January (negative values). M. quinquiesperforata fed almost continuously with rate of feeding being higher in small animals and at warmer, summer water temperatures. There was significantly more food in the gut at night than in the day.

Membrane reactor for water detritiation: a parametric study on operating parameters

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

Mascarade, J.; Liger, K.; Troulay, M.

2015-03-15

This paper presents the results of a parametric study done on a single stage finger-type packed-bed membrane reactor (PBMR) used for heavy water vapor de-deuteration. Parametric studies have been done on 3 operating parameters which are: the membrane temperature, the total feed flow rate and the feed composition through D{sub 2}O content variations. Thanks to mass spectrometer analysis of streams leaving the PBMR, speciation of deuterated species was achieved. Measurement of the amounts of each molecular component allowed the calculation of reaction quotient at the packed-bed outlet. While temperature variation mainly influences permeation efficiency, feed flow rate perturbation reveals dependencemore » of conversion and permeation properties to contact time between catalyst and reacting mixture. The study shows that isotopic exchange reactions occurring on the catalyst particles surface are not thermodynamically balanced. Moreover, the variation of the heavy water content in the feed exhibits competition between permeation and conversion kinetics.« less

CONTROL OF REPRODUCTION

USDA-ARS?s Scientific Manuscript database

Control of reproduction is important for seed stock production, selective breeding, growth rate, feed efficiency, meat quality, and biosecurity. These needs to control reproduction differ among cultivars and even segments of the same industry. No matter the impetus for aquaculturists to want to alte...

The transgenic cloned pig population with integrated and controllable GH expression that has higher feed efficiency and meat production

PubMed Central

Ju, Huiming; Zhang, Jiaqing; Bai, Lijing; Mu, Yulian; Du, Yutao; Yang, Wenxian; Li, Yong; Sheng, Anzhi; Li, Kui

2015-01-01

Sustained expression of the GH gene has been shown to have detrimental effects on the health of animals. In the current study, transgenic founder pigs, with controllable pig growth hormone (pGH) expression, were cloned via the handmade cloning method (HMC), and pGH expression levels were examined at the cellular and organismal levels. The serum pGH levels in 3 founder male pigs were found to be significantly higher after induction with intramuscular injection of doxycycline (DOX) compared to baseline. A daily dose of DOX was administered via feed to these animals for a period of 65 to 155 days. The growth rate, feed efficiency and pGH serum concentration increased in the DOX-induced transgenic group compared with the other groups. 8 numbers of animals were euthanized and the dressing percentage, loin muscle and lean meat percentage were significantly higher in the DOX-induced F1 transgenic group compared with the other groups. In this study a large population of transgenic pigs, with integrated controllable expression of a transgene, was obtained. The transgenic pigs were healthy and normal in terms of reproductive capability. At the same time, feed efficiency was improved, production processes were accelerated and meat yield was increased. PMID:25959098

The transgenic cloned pig population with integrated and controllable GH expression that has higher feed efficiency and meat production.

PubMed

Ju, Huiming; Zhang, Jiaqing; Bai, Lijing; Mu, Yulian; Du, Yutao; Yang, Wenxian; Li, Yong; Sheng, Anzhi; Li, Kui

2015-05-11

Sustained expression of the GH gene has been shown to have detrimental effects on the health of animals. In the current study, transgenic founder pigs, with controllable pig growth hormone (pGH) expression, were cloned via the handmade cloning method (HMC), and pGH expression levels were examined at the cellular and organismal levels. The serum pGH levels in 3 founder male pigs were found to be significantly higher after induction with intramuscular injection of doxycycline (DOX) compared to baseline. A daily dose of DOX was administered via feed to these animals for a period of 65 to 155 days. The growth rate, feed efficiency and pGH serum concentration increased in the DOX-induced transgenic group compared with the other groups. 8 numbers of animals were euthanized and the dressing percentage, loin muscle and lean meat percentage were significantly higher in the DOX-induced F1 transgenic group compared with the other groups. In this study a large population of transgenic pigs, with integrated controllable expression of a transgene, was obtained. The transgenic pigs were healthy and normal in terms of reproductive capability. At the same time, feed efficiency was improved, production processes were accelerated and meat yield was increased.

Compensatory growth in hybrid tilapia ( Oreochromis mossambicus ×O. niloticus) reared in seawater, following restricted feeding

NASA Astrophysics Data System (ADS)

Wang, Yan; Cui, Yibo; Yang, Yunxia; Cai, Fasheng

2004-12-01

Hybrid tilapia weighing 7.71 g were reared in seawater at 24.0 29.0°C for 8 weeks. The controls were fed to satiation twice a day throughout the experiment, whereas treatment groups were fed at 0.5%, 1.5% or 3.0% body weight per day for 4 weeks, and then to satiation for the remainder of the experiment. During the first 4-week period, there was a curvilinear relationship between growth rate and ration size. Fish fed 0.5% and 1.5% rations displayed compensatory growth response of 2 weeks duration during realimentation. The weight-adjusted growth rate of fish fed at 3% ration was not significantly different from that of the controls by the end of the experiment, when none of the treatment groups had caught up in body weight with the controls. Hyperphagia was observed for the first 2 weeks of realimenatation in fish previously fed at 3% ration, but persisted for the whole realimentation period in groups previously fed at 0.5% and 1.5% rations. None of the feed restricted groups showed improved digestibility, feed efficiency, or protein and energy retention efficiency.

Identification of genomic regions associated with feed efficiency in Nelore cattle

USDA-ARS?s Scientific Manuscript database

Feed efficiency is jointly determined by productivity and feed requirements, both of which are economically relevant traits in beef cattle production systems. The objective of this study was to identify genes/QTLs associated with components of feed efficiency in Nelore cattle using Illumina BovineHD...

Replication and validation of genome-wide associations with feed efficiency of dairy cattle

USDA-ARS?s Scientific Manuscript database

Improving feed efficiency in dairy production is an important endeavor as it can reduce feed costs and mitigate negative impacts of production on the environment. Feed efficiency is a multivariate phenotype characterized by a variety of phenotypic variables such as dry matter intake, body weight gai...

Ontogenetic variability in the feeding behavior of a marine amphipod in response to ocean acidification.

PubMed

Benítez, Samanta; Duarte, Cristian; López, Jorge; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro A

2016-11-15

Global stressors like ocean acidification (OA) are expected to influence the quality or palatability of primary producers like algae. Such changes can trigger a response on algal consumers' feeding strategies, and this response may not necessarily be the same for the consumers during the ontogeny. We used a mesocosm's system to expose algae to current and projected OA conditions (390 and 1000ppm, respectively) and then compared the feeding behavior and absorption efficiency of juvenile and adult stages of the amphipod Orchestoidea tuberculata. Specifically, we measured consumption rates (with and without a choice) and absorption efficiency on algae exposed and not exposed to OA. Our results show that OA affect the amphipod's consumption and feeding preferences, and that these effects were related with the analyzed ontogenetic stage (juveniles versus adults). These results support the existence of an ontogenetic change in the response of this species and others similar marine invertebrates to OA, which highlight the need to incorporate different life stages in the study of OA or others global stressors. Copyright © 2016 Elsevier Ltd. All rights reserved.

Economic evaluation of alternative crossbreeding systems involving four breeds of swine. I. The simulation model.

PubMed

McLaren, D G; Buchanan, D S; Williams, J E

1987-10-01

A static, deterministic computer model, programmed in Microsoft Basic for IBM PC and Apple Macintosh computers, was developed to calculate production efficiency (cost per kg of product) for nine alternative types of crossbreeding system involving four breeds of swine. The model simulates efficiencies for four purebred and 60 alternative two-, three- and four-breed rotation, rotaterminal, backcross and static cross systems. Crossbreeding systems were defined as including all purebred, crossbred and commercial matings necessary to maintain a total of 10,000 farrowings. Driving variables for the model are mean conception rate at first service and for an 8-wk breeding season, litter size born, preweaning survival rate, postweaning average daily gain, feed-to-gain ratio and carcass backfat. Predictions are computed using breed direct genetic and maternal effects for the four breeds, plus individual, maternal and paternal specific heterosis values, input by the user. Inputs required to calculate the number of females farrowing in each sub-system include the proportion of males and females replaced each breeding cycle in purebred and crossbred populations, the proportion of male and female offspring in seedstock herds that become breeding animals, and the number of females per boar. Inputs required to calculate the efficiency of terminal production (cost-to-product ratio) for each sub-system include breeding herd feed intake, gilt development costs, feed costs and labor and overhead costs. Crossbreeding system efficiency is calculated as the weighted average of sub-system cost-to-product ratio values, weighting by the number of females farrowing in each sub-system.

Growth, efficiency, and yield of commercial broilers from 1957, 1978, and 20051

PubMed Central

Zuidhof, M. J.; Schneider, B. L.; Carney, V. L.; Korver, D. R.; Robinson, F. E.

2014-01-01

The effect of commercial selection on the growth, efficiency, and yield of broilers was studied using 2 University of Alberta Meat Control strains unselected since 1957 and 1978, and a commercial Ross 308 strain (2005). Mixed-sex chicks (n = 180 per strain) were placed into 4 replicate pens per strain, and grown on a current nutritional program to 56 d of age. Weekly front and side profile photographs of 8 birds per strain were collected. Growth rate, feed intake, and measures of feed efficiency including feed conversion ratio, residual feed intake, and residual maintenance energy requirements were characterized. A nonlinear mixed Gompertz growth model was used to predict BW and BW variation, useful for subsequent stochastic growth simulation. Dissections were conducted on 8 birds per strain semiweekly from 21 to 56 d of age to characterize allometric growth of pectoralis muscles, leg meat, abdominal fat pad, liver, gut, and heart. A novel nonlinear analysis of covariance was used to test the hypothesis that allometric growth patterns have changed as a result of commercial selection pressure. From 1957 to 2005, broiler growth increased by over 400%, with a concurrent 50% reduction in feed conversion ratio, corresponding to a compound annual rate of increase in 42 d live BW of 3.30%. Forty-two-day FCR decreased by 2.55% each year over the same 48-yr period. Pectoralis major growth potential increased, whereas abdominal fat decreased due to genetic selection pressure over the same time period. From 1957 to 2005, pectoralis minor yield at 42 d of age was 30% higher in males and 37% higher in females; pectoralis major yield increased by 79% in males and 85% in females. Over almost 50 yr of commercial quantitative genetic selection pressure, intended beneficial changes have been achieved. Unintended changes such as enhanced sexual dimorphism are likely inconsequential, though musculoskeletal, immune function, and parent stock management challenges may require additional attention in future selection programs. PMID:25260522

Ocean acidification induces changes in algal palatability and herbivore feeding behavior and performance.

PubMed

Duarte, Cristian; López, Jorge; Benítez, Samanta; Manríquez, Patricio H; Navarro, Jorge M; Bonta, Cesar C; Torres, Rodrigo; Quijón, Pedro

2016-02-01

The effects of global stressors on a species may be mediated by the stressors' impact on coexisting taxa. For instance, herbivore-algae interactions may change due to alterations in algal nutritional quality resulting from high CO2 levels associated with ocean acidification (OA). We approached this issue by assessing the indirect effects of OA on the trophic interactions between the amphipod Orchestoidea tuberculata and the brown alga Durvillaea antarctica, two prominent species of the South-east Pacific coast. We predicted that amphipod feeding behavior and performance (growth rate) will be affected by changes in the palatability of the algae exposed to high levels (1000 ppm) of CO2. We exposed algae to current and predicted (OA) atmospheric CO2 levels and then measured their nutritive quality and amphipod preference in choice trials. We also assessed consumption rates separately in no-choice trials, and measured amphipod absorption efficiency and growth rates. Protein and organic contents of the algae decreased in acidified conditions and amphipods showed low preference for these algae. However, in the no-choice trials we recorded higher grazing rates on algae exposed to OA. Although amphipod absorption efficiency was lower on these algae, growth rates did not differ between treatments, which suggests the occurrence of compensatory feeding. Our results suggest that changes in algal nutritional value in response to OA induce changes in algal palatability and these in turn affect consumers' food preference and performance. Indirect effects of global stressors like OA can be equally or more important than the direct effects predicted in the literature.

Unraveling the Fecal Microbiota and Metagenomic Functional Capacity Associated with Feed Efficiency in Pigs

PubMed Central

Yang, Hui; Huang, Xiaochang; Fang, Shaoming; He, Maozhang; Zhao, Yuanzhang; Wu, Zhenfang; Yang, Ming; Zhang, Zhiyan; Chen, Congying; Huang, Lusheng

2017-01-01

Gut microbiota plays fundamental roles in energy harvest, nutrient digestion, and intestinal health, especially in processing indigestible components of polysaccharides in diet. Unraveling the microbial taxa and functional capacity of gut microbiome associated with feed efficiency can provide important knowledge to improve pig feed efficiency in swine industry. In the current research, we studied the association of fecal microbiota with feed efficiency in 280 commercial Duroc pigs. All experimental pigs could be clustered into two enterotype-like groups. Different enterotypes showed the tendency of association with the feed efficiency (P = 0.07). We further identified 31 operational taxonomic units (OTUs) showing the potential associations with porcine feed efficiency. These OTUs were mainly annotated to the bacteria related to the metabolisms of dietary polysaccharides. Although we did not identify the RFI-associated bacterial species at FDR < 0.05 level, metagenomic sequencing analysis did find the distinct function capacities of gut microbiome between the high and low RFI pigs (FDR < 0.05). The KEGG orthologies related to nitrogen metabolism, amino acid metabolism, and transport system, and eight KEGG pathways including glycine, serine, and threonine metabolism were positively associated with porcine feed efficiency. We inferred that gut microbiota might improve porcine feed efficiency through promoting intestinal health by the SCFAs produced by fermenting dietary polysaccharides and improving the utilization of dietary protein. The present results provided important basic knowledge for improving porcine feed efficiency through modulating gut microbiome. PMID:28861066

Extruded leftover food as animal feed: I. Effect of extruded feed on growth and feed utilization of tilapia (Oreochromis niloticus) in Saudi Arabia.

PubMed

Al-Ruqaie, Ibrahim M

2007-10-01

A Laboratory experiment was used to evaluate the effect of extruded leftover food as an alternate source of fish diet to Nile tilapia (Oreochromis niloticus, 76.75 +/- 1.27 g). Three experimental diets were used. Two extruded leftover food types [with minerals and vitamins (type-1) and without (type-2) were used to prepare two experimental treatments in duplicate as compared to a commercial tilapia diet (ARASCO) as a control. The final body weight and Specific Growth Rate (SGR) were not affected by different types of leftover feed. Whereas, the Feed Conversion Ratio (FCR) and the Protein Efficiency Ratio (PER) were significantly affected by the different feeds. The highest significant values of FCR was shown for fish fed with extruded leftover feed without premix, while Nile tilapia fed with control diet recorded the highest values of PER. The present study showed that the extruded leftover food could be used to prepare least cost diet for Nile tilapia.

Enteric coating of soft gelatin capsules by spouted bed: effect of operating conditions on coating efficiency and on product quality.

PubMed

Pissinati, Rafael; Oliveira, Wanderley Pereira

2003-05-01

The present study was conducted in order to analyze the viability of the spouted bed process for application of a gastric-resistant coating to soft gelatin capsules. The variables investigated were: included angle of conical base, (gamma), the relation between the feed mass flow rate of the coating suspension and the feed mass flow rate of spouting gas (W(s)/W(g)); the ratio between the flow rate of the spouting gas and the flow rate at minimum spouting condition (Q/Q(ms)); the mass of capsules in the bed (M(0)), and the capsule's size. The product quality was measured by disintegration tests, traction x deformation tests, image analysis and by the evaluation of the coating mass distribution and shape factor variation during the coating operation. The experiments were performed in a spouted bed with a column diameter of 200 mm and included a conical base angle of 40 degrees. The best coating efficiency values were obtained for M(0)=300 g. Coating efficiency tended to increase with increasing W(s)/W(g) ratio. Disintegration tests showed that the gastric-resistant effect was obtained with a coating mass of 3.86 mg/cm(2). The shape factor increase during the coating operation. The capsule's coating mass distribution tended to maintain the original distribution.

Small intestine histomorphometry of beef cattle with divergent feed efficiency

PubMed Central

2013-01-01

Background The provision of feed is a major cost in beef production. Therefore, the improvement of feed efficiency is warranted. The direct assessment of feed efficiency has limitations and alternatives are needed. Small intestine micro-architecture is associated with function and may be related to feed efficiency. The objective was to verify the potential histomorphological differences in the small intestine of animals with divergent feed efficiency. Methods From a population of 45 feedlot steers, 12 were selected with low-RFI (superior feed efficiency) and 12 with high-RFI (inferior feed efficiency) at the end of the finishing period. The animals were processed at 13.79 ± 1.21 months of age. Within 1.5 h of slaughter the gastrointestinal tract was collected and segments from duodenum and ileum were harvested. Tissue fragments were processed, sectioned and stained with hematoxylin and eosin. Photomicroscopy images were taken under 1000x magnification. For each animal 100 intestinal crypts were imaged, in a cross section view, from each of the two intestinal segments. Images were analyzed using the software ImageJ®. The measurements taken were: crypt area, crypt perimeter, crypt lumen area, nuclei number and the cell size was indirectly calculated. Data were analyzed using general linear model and correlation procedures of SAS®. Results Efficient beef steers (low-RFI) have a greater cellularity (indicated by nuclei number) in the small intestinal crypts, both in duodenum and ileum, than less efficient beef steers (high-RFI) (P < 0.05). The mean values for the nuclei number of the low-RFI and high-RFI groups were 33.16 and 30.30 in the duodenum and 37.21 and 33.65 in the ileum, respectively. The average size of the cells did not differ between feed efficiency groups in both segments (P ≥ 0.10). A trend was observed (P ≤ 0.10) for greater crypt area and crypt perimeter in the ileum for cattle with improved feed efficiency. Conclusion Improved feed efficiency is associated with greater cellularity and no differences on average cell size in the crypts of the small intestine in the bovine. These observations are likely to lead to an increase in the energy demand by the small intestine regardless of the more desirable feed efficiency. PMID:23379622

Cultivation of Aquincola tertiaricarbonis L108 on the fuel oxygenate intermediate tert-butyl alcohol induces aerobic anoxygenic photosynthesis at extremely low feeding rates.

PubMed

Rohwerder, Thore; Müller, Roland H; Weichler, M Teresa; Schuster, Judith; Hübschmann, Thomas; Müller, Susann; Harms, Hauke

2013-10-01

Aerobic anoxygenic photosynthesis (AAP) is found in an increasing number of proteobacterial strains thriving in ecosystems ranging from extremely oligotrophic to eutrophic. Here, we have investigated whether the fuel oxygenate-degrading betaproteobacterium Aquincola tertiaricarbonis L108 can use AAP to compensate kinetic limitations at low heterotrophic substrate fluxes. In a fermenter experiment with complete biomass retention and also during chemostat cultivation, strain L108 was challenged with extremely low substrate feeding rates of tert-butyl alcohol (TBA), an intermediate of methyl tert-butyl ether (MTBE). Interestingly, formation of photosynthetic pigments, identified as bacteriochlorophyll a and spirilloxanthin, was only induced in growing cells at TBA feeding rates less than or equal to maintenance requirements observed under energy excess conditions. Growth continued at rates between 0.001 and 0.002 h(-1) even when the TBA feed was decreased to values close to 30 % of this maintenance rate. Partial sequencing of genomic DNA of strain L108 revealed a bacteriochlorophyll synthesis gene cluster (bchFNBHL) and photosynthesis regulator genes (ppsR and ppaA) typically found in AAP and other photosynthetic proteobacteria. The usage of light as auxiliary energy source enabling evolution of efficient degradation pathways for kinetically limited heterotrophic substrates and for lowering the threshold substrate concentration Smin at which growth becomes zero is discussed.

Invited review: improving feed efficiency in dairy production: challenges and possibilities.

PubMed

Connor, E E

2015-03-01

Despite substantial advances in milk production efficiency of dairy cattle over the last 50 years, rising feed costs remain a significant threat to producer profitability. There also is a greater emphasis being placed on reducing the negative impacts of dairy production on the environment; thus means to lower greenhouse gas (GHG) emissions and nutrient losses to the environment associated with cattle production are being sought. Improving feed efficiency among dairy cattle herds offers an opportunity to address both of these issues for the dairy industry. However, the best means to assess feed efficiency and make genetic progress in efficiency-related traits among lactating cows without negatively impacting other economically important traits is not entirely obvious. In this review, multiple measurements of feed efficiency for lactating cows are described, as well as the heritability of the traits and their genetic and phenotypic correlations with other production traits. The measure of feed efficiency, residual feed intake is discussed in detail in terms of the benefits for its selection, how it could be assessed in large commercial populations, as well as biological mechanisms contributing to its variation among cows, as it has become a commonly used method to estimate efficiency in the recent scientific literature.

Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products.

PubMed

Oonincx, Dennis G A B; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J A

2015-01-01

A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food.

Feed Conversion, Survival and Development, and Composition of Four Insect Species on Diets Composed of Food By-Products

PubMed Central

Oonincx, Dennis G. A. B.; van Broekhoven, Sarah; van Huis, Arnold; van Loon, Joop J. A.

2015-01-01

A large part of the environmental impact of animal production systems is due to the production of feed. Insects are suggested to efficiently convert feed to body mass and might therefore form a more sustainable food and/or feed source. Four diets were composed from by-products of food manufacturing and formulated such as to vary in protein and fat content. These were offered to newly hatched Argentinean cockroaches, black soldier flies, yellow mealworms, and house crickets. The first two species are potentially interesting as a feed ingredient, while the latter two are considered edible for humans. Feed conversion efficiency, survival, development time, as well as chemical composition (nitrogen, phosphorus, and fatty acids), were determined. The Argentinean cockroaches and the black soldier flies converted feed more efficiently than yellow mealworms, and house crickets. The first two were also more efficient than conventional production animals. On three of the four diets yellow mealworms and house crickets had a feed conversion efficiency similar to pigs. Furthermore, on the most suitable diet, they converted their feed as efficiently as poultry, when corrected for edible portion. All four species had a higher nitrogen-efficiency than conventional production animals, when corrected for edible portion. Offering carrots to yellow mealworms increased dry matter- and nitrogen-efficiency and decreased development time. Diet affected survival in all species but black soldier flies, and development time was strongly influenced in all four species. The chemical composition of Argentinean cockroaches was highly variable between diets, for black soldier flies it remained similar. The investigated species can be considered efficient production animals when suitable diets are provided. Hence, they could form a sustainable alternative to conventional production animals as a source of feed or food. PMID:26699129

Genetics of residual feed intake in growing pigs: Relationships with production traits, and nitrogen and phosphorus excretion traits.

PubMed

Saintilan, R; Mérour, I; Brossard, L; Tribout, T; Dourmad, J Y; Sellier, P; Bidanel, J; van Milgen, J; Gilbert, H

2013-06-01

Residual feed intake (RFI) is defined as the difference between the observed ADFI and the ADFI predicted from production and maintenance requirements. The objectives of this study were to evaluate RFI as a selection criterion to improve feed efficiency and its potential to reduce N and P excretion in 4 pig breeds. Data were collected between 2000 and 2009 in French central test stations for 2 dam breeds [French Landrace (LR) and Large White (LWD)], and 2 sire breeds [Large White (LWS) and Piétrain (PP)]. Numbers of recorded pigs were 6407, 10,694, 2342, and 2448 for the LR, LWD, LWS, and PP breeds, respectively. All PP animals were genotyped for the halothane mutation. This data set was used to calculate RFI equations for each of the 4 breeds, and to estimate genetic parameters for RFI together with growth, carcass, and meat quality traits, and N and P excretion during the test period (35 to 110 kg BW). The RFI explained 20.1% in PP, 26.5% in LWS, 27.6% in LWD, and 29.5% in LR of the phenotypic variability of ADFI. The PP breed differed from the others in this respect, probably due to a lower impact of the variation of body composition on ADFI. Heritability estimates of RFI ranged from 0.21 ± 0.03 (LWD) to 0.33 ± 0.06 (PP) depending on the breed. Heritabilities of N and P excretion traits ranged from 0.29 ± 0.06 to 0.40 ± 0.06. The RFI showed positive genetic correlations with feed conversion ratio (FCR) and excretion traits, these correlations being greater in the sire breeds (from 0.57 to 0.86) than in the dam breeds (from 0.38 to 0.53). Compared with FCR, RFI had weaker genetic correlations with carcass composition, growth rate, and excretion traits. Estimates of genetic correlations between FCR and excretion traits were very close to 1 for all breeds. Finally, excretion traits were, at the genetic level, correlated positively with ADFI, negatively with growth rate and carcass leanness, whereas the halothane n mutation in PP was shown to reduce N and P excretion levels. To conclude, new selection indexes including RFI can be envisaged to efficiently disentangle the responses to selection on growth rate and body composition from those on feed efficiency, with favorable impacts on N and P excretions, particularly in sire pig breeds. However, the switch from FCR to RFI in selection indexes should not resolve the genetic antagonism between feed efficiency and meat quality.

Non-linear feeding functional responses in the Greater Flamingo (Phoenicopterus roseus) predict immediate negative impact of wetland degradation on this flagship species

PubMed Central

Deville, Anne-Sophie; Grémillet, David; Gauthier-Clerc, Michel; Guillemain, Matthieu; Von Houwald, Friederike; Gardelli, Bruno; Béchet, Arnaud

2013-01-01

Accurate knowledge of the functional response of predators to prey density is essential for understanding food web dynamics, to parameterize mechanistic models of animal responses to environmental change, and for designing appropriate conservation measures. Greater flamingos (Phoenicopterus roseus), a flagship species of Mediterranean wetlands, primarily feed on Artemias (Artemia spp.) in commercial salt pans, an industry which may collapse for economic reasons. Flamingos also feed on alternative prey such as Chironomid larvae (e.g., Chironomid spp.) and rice seeds (Oryza sativa). However, the profitability of these food items for flamingos remains unknown. We determined the functional responses of flamingos feeding on Artemias, Chironomids, or rice. Experiments were conducted on 11 captive flamingos. For each food item, we offered different ranges of food densities, up to 13 times natural abundance. Video footage allowed estimating intake rates. Contrary to theoretical predictions for filter feeders, intake rates did not increase linearly with increasing food density (type I). Intake rates rather increased asymptotically with increasing food density (type II) or followed a sigmoid shape (type III). Hence, flamingos were not able to ingest food in direct proportion to their abundance, possibly because of unique bill structure resulting in limited filtering capabilities. Overall, flamingos foraged more efficiently on Artemias. When feeding on Chironomids, birds had lower instantaneous rates of food discovery and required more time to extract food from the sediment and ingest it, than when filtering Artemias from the water column. However, feeding on rice was energetically more profitable for flamingos than feeding on Artemias or Chironomids, explaining their attraction for rice fields. Crucially, we found that food densities required for flamingos to reach asymptotic intake rates are rarely met under natural conditions. This allows us to predict an immediate negative effect of any decrease in prey density upon flamingo foraging performance. PMID:23762525

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2011 CFR

2011-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2010 CFR

2010-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 046573 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

21 CFR 558.76 - Bacitracin methylene disalicylate.

Code of Federal Regulations, 2014 CFR

2014-04-01

... gramsper ton Indications for use Limitations Sponsor (i) 4 to 50 Chickens, turkeys, and pheasants... age; increased rate of weight gain and improved feed efficiency 1 054771 (iii) 10 to 25 Chickens; for... Salmonella choleraesuis and bacterial pneumonia caused by Pasteurella multocida susceptible to...

Metatranscriptomic Profiling Reveals Linkages between the Active Rumen Microbiome and Feed Efficiency in Beef Cattle

PubMed Central

Li, Fuyong

2017-01-01

ABSTRACT Exploring compositional and functional characteristics of the rumen microbiome can improve the understanding of its role in rumen function and cattle feed efficiency. In this study, we applied metatranscriptomics to characterize the active rumen microbiomes of beef cattle with different feed efficiencies (efficient, n = 10; inefficient, n = 10) using total RNA sequencing. Active bacterial and archaeal compositions were estimated based on 16S rRNAs, and active microbial metabolic functions including carbohydrate-active enzymes (CAZymes) were assessed based on mRNAs from the same metatranscriptomic data sets. In total, six bacterial phyla (Proteobacteria, Firmicutes, Bacteroidetes, Spirochaetes, Cyanobacteria, and Synergistetes), eight bacterial families (Succinivibrionaceae, Prevotellaceae, Ruminococcaceae, Lachnospiraceae, Veillonellaceae, Spirochaetaceae, Dethiosulfovibrionaceae, and Mogibacteriaceae), four archaeal clades (Methanomassiliicoccales, Methanobrevibacter ruminantium, Methanobrevibacter gottschalkii, and Methanosphaera), 112 metabolic pathways, and 126 CAZymes were identified as core components of the active rumen microbiome. As determined by comparative analysis, three bacterial families (Lachnospiraceae, Lactobacillaceae, and Veillonellaceae) tended to be more abundant in low-feed-efficiency (inefficient) animals (P < 0.10), and one archaeal taxon (Methanomassiliicoccales) tended to be more abundant in high-feed-efficiency (efficient) cattle (P < 0.10). Meanwhile, 32 microbial metabolic pathways and 12 CAZymes were differentially abundant (linear discriminant analysis score of >2 with a P value of <0.05) between two groups. Among them, 30 metabolic pathways and 11 CAZymes were more abundant in the rumen of inefficient cattle, while 2 metabolic pathways and 1 CAZyme were more abundant in efficient animals. These findings suggest that the rumen microbiomes of inefficient cattle have more diverse activities than those of efficient cattle, which may be related to the host feed efficiency variation. IMPORTANCE This study applied total RNA-based metatranscriptomics and showed the linkage between the active rumen microbiome and feed efficiency (residual feed intake) in beef cattle. The data generated from the current study provide fundamental information on active rumen microbiome at both compositional and functional levels, which serve as a foundation to study rumen function and its role in cattle feed efficiency. The findings that the active rumen microbiome may contribute to variations in feed efficiency of beef cattle highlight the possibility of enhancing nutrient utilization and improve cattle feed efficiency through modification of rumen microbial functions. PMID:28235871

Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus).

PubMed

Sarker, Pallab K; Kapuscinski, Anne R; Lanois, Alison J; Livesey, Erin D; Bernhard, Katie P; Coley, Mariah L

2016-01-01

We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds.

Systems Biology Analysis Merging Phenotype, Metabolomic and Genomic Data Identifies Non-SMC Condensin I Complex, Subunit G (NCAPG) and Cellular Maintenance Processes as Major Contributors to Genetic Variability in Bovine Feed Efficiency

PubMed Central

Widmann, Philipp; Reverter, Antonio; Weikard, Rosemarie; Suhre, Karsten; Hammon, Harald M.; Albrecht, Elke; Kuehn, Christa

2015-01-01

Feed efficiency is a paramount factor for livestock economy. Previous studies had indicated a substantial heritability of several feed efficiency traits. In our study, we investigated the genetic background of residual feed intake, a commonly used parameter of feed efficiency, in a cattle resource population generated from crossing dairy and beef cattle. Starting from a whole genome association analysis, we subsequently performed combined phenotype-metabolome-genome analysis taking a systems biology approach by inferring gene networks based on partial correlation and information theory approaches. Our data about biological processes enriched with genes from the feed efficiency network suggest that genetic variation in feed efficiency is driven by genetic modulation of basic processes relevant to general cellular functions. When looking at the predicted upstream regulators from the feed efficiency network, the Tumor Protein P53 (TP53) and Transforming Growth Factor beta 1 (TGFB1) genes stood out regarding significance of overlap and number of target molecules in the data set. These results further support the hypothesis that TP53 is a major upstream regulator for genetic variation of feed efficiency. Furthermore, our data revealed a significant effect of both, the Non-SMC Condensin I Complex, Subunit G (NCAPG) I442M (rs109570900) and the Growth /differentiation factor 8 (GDF8) Q204X (rs110344317) loci, on residual feed intake and feed conversion. For both loci, the growth promoting allele at the onset of puberty was associated with a negative, but favorable effect on residual feed intake. The elevated energy demand for increased growth triggered by the NCAPG 442M allele is obviously not fully compensated for by an increased efficiency in converting feed into body tissue. As a consequence, the individuals carrying the NCAPG 442M allele had an additional demand for energy uptake that is reflected by the association of the allele with increased daily energy intake as observed in our study. PMID:25875852

Effect of feeding mode and dilution on the performance and microbial community population in anaerobic digestion of food waste.

PubMed

Park, Jong-Hun; Kumar, Gopalakrishnan; Yun, Yeo-Myeong; Kwon, Joong-Chun; Kim, Sang-Hyoun

2018-01-01

The effect of feeding mode and dilution was studied in anaerobic digestion of food waste. An upflow anaerobic digester with a settler was fed at six different organic loading rates (OLRs) from 4.6 to 8.6kgCOD/m 3 /d for 200days. The highest methane productivity of 2.78LCH 4 /L/d was achieved at 8.6kgCOD/m 3 /d during continuous feeding of diluted FW. Continuous feeding of diluted food waste showed more stable and efficient performance than stepwise feeding of undiluted food waste. Sharp increase in propionate concentration attributed towards deterioration of the digester performances in stepwise feeding of undiluted food waste. Microbial communities at various OLRs divulged that the microbial distribution in the continuous feeding of diluted food waste was not significantly perturbed despite the increase of OLR up to 8.6kgCOD/m 3 /d, which was contrast to the unstable distribution in stepwise feeding of undiluted food waste at 6.1kgCOD/m 3 /d. Copyright © 2017 Elsevier Ltd. All rights reserved.

Effect of temperature during embryonic development and first feeding of Trichogaster leeri larvae.

PubMed

Pereira, Samuel Louzada; de Andrade, Dalcio Ricardo; Radael, Marcella Costa; Fosse Filho, João Carlos; de Azevedo, Rafael Vieira; Mattos, Douglas da Cruz; Vidal Junior, Manuel Vazquez

2016-10-01

Temperature is an environmental factor that influences the development of fish, and when changed abruptly can lead to high mortality. Some species of fish are influenced by this factor, exhibiting a longer time for embryonic development and time to first feeding. This study aims to evaluate the effect of water temperature on embryonic and larval development up to first feeding, to describe the time in hours post fertilization (hpf) of the emergence of different structures and to determine the best hatching rate and survival of animals under different treatments. Five different egg incubation temperatures were used (24, 26, 28, 30 or 32°C, respectively). The eggs were observed at regular intervals of 30 min up to 24 h, every 2 h until 48 h and every 4 h until the display of first feeding in all treatments. Embryonic development was longer for eggs incubated at 24°C and the best results for hatching rate and survival of spawning efficiency were at 28°C. We recommend that incubation of Trichogaster leeri eggs is carried out at 28°C up to the first feeding of larvae.

Increasing efficiency of human mesenchymal stromal cell culture by optimization of microcarrier concentration and design of medium feed.

PubMed

Chen, Allen Kuan-Liang; Chew, Yi Kong; Tan, Hong Yu; Reuveny, Shaul; Weng Oh, Steve Kah

2015-02-01

Large amounts of human mesenchymal stromal cells (MSCs) are needed for clinical cellular therapy. In a previous publication, we described a microcarrier-based process for expansion of MSCs. The present study optimized this process by selecting suitable basal media, microcarrier concentration and feeding regime to achieve higher cell yields and more efficient medium utilization. MSCs were expanded in stirred cultures on Cytodex 3 microcarriers with media containing 10% fetal bovine serum. Process optimization was carried out in spinner flasks. A 2-L bioreactor with an automated feeding system was used to validate the optimized parameters explored in spinner flask cultures. Minimum essential medium-α-based medium supported faster MSC growth on microcarriers than did Dulbecco's modified Eagle's medium (doubling time, 31.6 ± 1.4 vs 42 ± 1.7 h) and shortened the process time. At microcarrier concentration of 8 mg/mL, a high cell concentration of 1.08 × 10(6) cells/mL with confluent cell concentration of 4.7 × 10(4)cells/cm(2) was achieved. Instead of 50% medium exchange every 2 days, we have designed a full medium feed that is based on glucose consumption rate. The optimal medium feed that consisted of 1.5 g/L glucose supported MSC growth to full confluency while achieving the low medium usage efficiency of 3.29 mL/10(6)cells. Finally, a controlled bioreactor with the optimized parameters achieved maximal confluent cell concentration with 16-fold expansion and a further improved medium usage efficiency of 1.68 mL/10(6)cells. We have optimized the microcarrier-based platform for expansion of MSCs that generated high cell yields in a more efficient and cost-effective manner. This study highlighted the critical parameters in the optimization of MSC production process. Copyright © 2015 International Society for Cellular Therapy. Published by Elsevier Inc. All rights reserved.

Validating selective breeding approaches for disease resistance

USDA-ARS?s Scientific Manuscript database

Selective breeding of rainbow trout at the USDA/ARS National Center for Cool and Cold Water Aquaculture (NCCCWA) in Leetown, West Virginia is designed to accomplish four goals: 1) define commercially important traits such as disease resistance, growth rate, stress response, and feed efficiency; 2) d...

The FEM Simulation on End Mill of Plastic Doors and Windows Corner Cleaning Based on Deform-3D

NASA Astrophysics Data System (ADS)

Li, Guoping; Huang, Zhenyong; Wang, Xiaohui

2017-12-01

In the plastic doors and windows corner cleaning process, the rotating speed, the feed rate and the milling cutter diameter are the main factors that affect the efficiency and quality of the of corner cleaning. In this paper, SolidWorks will be used to establish the 3D model of end mills, and use Deform-3D to research the end mill milling process. And using orthogonal experiment design method to analyze the effect of rotating speed, the feed rate and the milling cutter diameter on the axial force variation, and to get the overall trend of axial force and the selection of various parameters according to the influence of axial force change. Finally, simulate milling experiment used to get the actual axial force data to verify the reliability of the FEM simulation model. And the conclusion obtained in this paper has important theoretical value in improving the plastic doors and windows corner cleaning efficiency and quality.

High-efficiency K-band tracking antenna feed

NASA Technical Reports Server (NTRS)

Beavin, R. L.; Simanyi, A. I.

1975-01-01

Antenna feed features high aperture efficiency of multimode near-field horn and develops tracking signals without conventional monopulse bridge. Feed assembly is relatively simple and very compact. However, feed is sensitive to cross-polarized energy which couples into orthogonal error channel.

Intermittent fasting induces hypothalamic modifications resulting in low feeding efficiency, low body mass and overeating.

PubMed

Chausse, Bruno; Solon, Carina; Caldeira da Silva, Camille C; Masselli Dos Reis, Ivan G; Manchado-Gobatto, Fúlvia B; Gobatto, Claudio A; Velloso, Licio A; Kowaltowski, Alicia J

2014-07-01

Intermittent fasting (IF) is an often-used intervention to decrease body mass. In male Sprague-Dawley rats, 24 hour cycles of IF result in light caloric restriction, reduced body mass gain, and significant decreases in the efficiency of energy conversion. Here, we study the metabolic effects of IF in order to uncover mechanisms involved in this lower energy conversion efficiency. After 3 weeks, IF animals displayed overeating during fed periods and lower body mass, accompanied by alterations in energy-related tissue mass. The lower efficiency of energy use was not due to uncoupling of muscle mitochondria. Enhanced lipid oxidation was observed during fasting days, whereas fed days were accompanied by higher metabolic rates. Furthermore, an increased expression of orexigenic neurotransmitters AGRP and NPY in the hypothalamus of IF animals was found, even on feeding days, which could explain the overeating pattern. Together, these effects provide a mechanistic explanation for the lower efficiency of energy conversion observed. Overall, we find that IF promotes changes in hypothalamic function that explain differences in body mass and caloric intake.

Effects of chronic metal exposure and sediment organic matter on digestive absorption efficiency of cadmium by the deposit-feeding polychaete Capitella species I

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

Selck, H.; Forbes, V.E.; Decho, A.W.

1999-06-01

Organic matter such as humic acid and bacterial slime exopolymer are common in estuarine and coastal sediments, where they are ingested by animals that process particulate detritus. Both humic acid (HA; refractory) and exopolymer (EPS; easily digestible) bind metals and therefore might represent a source of particulate-bound metals to deposit-feeding organisms. This study examined how cadmium preexposure, gut passage time (GPT), and quality and quantity of the organic coating on sediment particles interact to determine cadmium absorption efficiency (Cd-AE) in Capitella sp. I. Pulse-chase experiments using [sup 109]Cd and [sup 51]Cr were used to determine Cd-AE in individual worms. Wormsmore » were given a pulse of carbon-cleaned, HA-coated or EPS-coated sediment particles. The third treatment was divided into three EPS concentrations (high, medium, and low). A 5-d preexposure to cadmium did not affect the egestion rates during either the preexposure period or the chase phase. Worms given a pulse of carbon-cleaned particles exhibited higher egestion rates during the chase phase than worms given a pulse of organic-coated particles, and no differences were seen in egestion rate between worms exposed to HA- and high-EPS-coated particles. Egestion rates decreased with increasing EPS concentration. The presence of refractory organic material decreased the absorption efficiency of cadmium from sediment relative to Cd-AE from carbon-cleaned sediment but not relative to Cd-AE from sediment coated with a high concentration of EPS. The Cd-AE increased linearly with increasing exopolymer coating on sediment particles. Overall, Cd-AE increased with increasing gut passage time in worms that were not preexposed, although Cd-AE from HA-coated particles was independent of gut passage time. Preexposure to cadmium reversed the relationship between gut passage time and cadmium absorption efficiency. Thus, the implications are that sedimentary organic matter and worm physiology might be especially important in controlling metal bioavailability in deposit-feeding organisms and should be considered in sediment quality approaches.« less

The effect of brain size evolution on feeding propensity, digestive efficiency, and juvenile growth

PubMed Central

Kotrschal, Alexander; Corral‐Lopez, Alberto; Szidat, Sönke; Kolm, Niclas

2015-01-01

One key hypothesis in the study of brain size evolution is the expensive tissue hypothesis; the idea that increased investment into the brain should be compensated by decreased investment into other costly organs, for instance the gut. Although the hypothesis is supported by both comparative and experimental evidence, little is known about the potential changes in energetic requirements or digestive traits following such evolutionary shifts in brain and gut size. Organisms may meet the greater metabolic requirements of larger brains despite smaller guts via increased food intake or better digestion. But increased investment in the brain may also hamper somatic growth. To test these hypotheses we here used guppy (Poecilia reticulata) brain size selection lines with a pronounced negative association between brain and gut size and investigated feeding propensity, digestive efficiency (DE), and juvenile growth rate. We did not find any difference in feeding propensity or DE between large‐ and small‐brained individuals. Instead, we found that large‐brained females had slower growth during the first 10 weeks after birth. Our study provides experimental support that investment into larger brains at the expense of gut tissue carries costs that are not necessarily compensated by a more efficient digestive system. PMID:26420573

Gene expression profiling reveals candidate genes related to residual feed intake in duodenum of laying ducks.

PubMed

Zeng, T; Huang, L; Ren, J; Chen, L; Tian, Y; Huang, Y; Zhang, H; Du, J; Lu, L

2017-12-01

Feed represents two-thirds of the total costs of poultry production, especially in developing countries. Improvement in feed efficiency would reduce the amount of feed required for production (growth or laying), the production cost, and the amount of nitrogenous waste. The most commonly used measures for feed efficiency are feed conversion ratio (FCR) and residual feed intake (RFI). As a more suitable indicator assessing feed efficiency, RFI is defined as the difference between observed and expected feed intake based on maintenance and growth or laying. However, the genetic and biological mechanisms regulating RFI are largely unknown. Identifying molecular mechanisms explaining divergence in RFI in laying ducks would lead to the development of early detection methods for the selection of more efficient breeding poultry. The objective of this study was to identify duodenum genes and pathways through transcriptional profiling in 2 extreme RFI phenotypes (HRFI and LRFI) of the duck population. Phenotypic aspects of feed efficiency showed that RFI was strongly positive with FCR and feed intake (FI). Transcriptomic analysis identified 35 differentially expressed genes between LRFI and HRFI ducks. These genes play an important role in metabolism, digestibility, secretion, and innate immunity including (), (), (), β (), and (). These results improve our knowledge of the biological basis underlying RFI, which would be useful for further investigations of key candidate genes for RFI and for the development of biomarkers.

Investigation of operating parameters on CO2 splitting by dielectric barrier discharge plasma

NASA Astrophysics Data System (ADS)

Pan, CHEN; Jun, SHEN; Tangchun, RAN; Tao, YANG; Yongxiang, YIN

2017-12-01

Experiments of CO2 splitting by dielectric barrier discharge (DBD) plasma were carried out, and the influence of CO2 flow rate, plasma power, discharge voltage, discharge frequency on CO2 conversion and process energy efficiency were investigated. It was shown that the absolute quantity of CO2 decomposed was only proportional to the amount of conductive electrons across the discharge gap, and the electron amount was proportional to the discharge power; the energy efficiency of CO2 conversion was almost a constant at a lower level, which was limited by CO2 inherent discharge character that determined a constant gap electric field strength. This was the main reason why CO2 conversion rate decreased as the CO2 flow rate increase and process energy efficiency was decreased a little as applied frequency increased. Therefore, one can improve the CO2 conversion by less feed flow rate or larger discharge power in DBD plasma, but the energy efficiency is difficult to improve.

Strategies for implementing genomic selection for feed efficiency in dairy cattle breeding schemes.

PubMed

Wallén, S E; Lillehammer, M; Meuwissen, T H E

2017-08-01

Alternative genomic selection and traditional BLUP breeding schemes were compared for the genetic improvement of feed efficiency in simulated Norwegian Red dairy cattle populations. The change in genetic gain over time and achievable selection accuracy were studied for milk yield and residual feed intake, as a measure of feed efficiency. When including feed efficiency in genomic BLUP schemes, it was possible to achieve high selection accuracies for genomic selection, and all genomic BLUP schemes gave better genetic gain for feed efficiency than BLUP using a pedigree relationship matrix. However, introducing a second trait in the breeding goal caused a reduction in the genetic gain for milk yield. When using contracted test herds with genotyped and feed efficiency recorded cows as a reference population, adding an additional 4,000 new heifers per year to the reference population gave accuracies that were comparable to a male reference population that used progeny testing with 250 daughters per sire. When the test herd consisted of 500 or 1,000 cows, lower genetic gain was found than using progeny test records to update the reference population. It was concluded that to improve difficult to record traits, the use of contracted test herds that had additional recording (e.g., measurements required to calculate feed efficiency) is a viable option, possibly through international collaborations. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Feed efficiency and the microbiota of the alimentary tract

USDA-ARS?s Scientific Manuscript database

There is considerable variation in the efficiency that cattle convert feed for maintenance and product (body weight gain, milk, and conceptus). Both intake and gain are polygenic traits and to better understand factors that contribute to variation in feed efficiency more defined phenotypes are need...

Enteric methane production from beef cattle that vary in feed efficiency

USDA-ARS?s Scientific Manuscript database

We hypothesized that CH4 production will decrease with increased feed efficiency. Two experiments were conducted to determine CH4 production of cattle that differed in feed efficiency. Cattle in both studies were selected from larger contemporary groups. Animals furthest from the confidence ellip...

Fluidized-bed combustion reduces atmospheric pollutants

NASA Technical Reports Server (NTRS)

Jonke, A. A.

1972-01-01

Method of reducing sulfur and nitrogen oxides released during combustion of fossil fuels is described. Fuel is burned in fluidized bed of solids with simultaneous feeding of crushed or pulverized limestone to control emission. Process also offers high heat transfer rates and efficient contacting for gas-solid reactions.

Assimilation of trace elements ingested by the mussel Mytilus edulis: effects of algal food abundance

USGS Publications Warehouse

Wang, W.-X.; Fisher, N.S.; Luoma, S.N.

1995-01-01

Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements (110mAg, 241Am, 109Cd, 57Co, 75Se and 65Zn) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h-1). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with ingestion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis. In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels.

The implications of condensed tannins on the nutritive value of temperate forages fed to ruminants.

PubMed

Barry, T N; McNabb, W C

1999-04-01

New methodology for measuring forage condensed tannin (CT) content is described and the effects of CT upon forage feeding and nutritive value for ruminant animals are reviewed. CT react with forage proteins in a pH-reversible manner, with reactivity determined by the concentration, structure and molecular mass of the CT. Increasing concentrations of CT in Lotus corniculatus and Lotus pedunculatus reduce the rates of solubilization and degradation of fraction 1 leaf protein in the rumen and increase duodenal non-NH3 N flow. Action of medium concentrations of total CT in Lotus corniculatus (30-40 g/kg DM) increased the absorption of essential amino acids from the small intestine and increased wool growth, milk secretion and reproductive rate in grazing sheep without affecting voluntary feed intake, thus improving the efficiency of food conversion. High concentrations of CT in Lotus pedunculatus (75-100 g/kg DM) depressed voluntary feed intake and rumen carbohydrate digestion and depressed rates of body and wool growth in grazing sheep. The minimum concentration of CT to prevent rumen frothy bloat in cattle is defined as 5 g/kg DM and sheep grazing CT-containing legumes were shown to better tolerate internal parasite infections than sheep grazing non CT-containing forages. It was concluded that defined concentrations of forage CT can be used to increase the efficiencies of protein digestion and animal productivity in forage-fed ruminants and to develop more ecologically sustainable systems of controlling some diseases under grazing.

Effect of milk thistle, Silybium marianum, extract on toxicity, development, nutrition, and enzyme activities of the small white butterfly, Pieris rapae.

PubMed

Hasheminia, Seyedeh M; Sendi, Jalal J; Jahromi, Khalil T; Moharramipour, Saeid

2013-01-01

The methanolic extract of milk thistle, Silybium marianum L. (Asterales: Asteraceae), was investigated for its effects on the mortality, growth, feeding indices, enzymatic activity, and levels of non-enzymatic molecules of the small white butterfly, Pieris rapae L. (Lepidoptera: Pieridae), a pest of cruciferous plants. Feeding indices including approximate digestibility (AD), efficiency of conversion of digested food (ECD), efficiency of conversion of ingested food (ECI), relative growth rate (RGR), and relative consumption rate (RCR) were measured. These indices were variously affected: the RGR, RCR, and AD decreased, but the ECD and ECI increased. The LC50 and LC25 values were estimated as 2.94% and 1.20%, respectively. At the lowest concentration of S. marianum extract (0.625%), the feeding deterrence index was 40.48%. The duration of the pupal stage and the rate of larval growth decreased. These changes may be due to alterations in metabolic activity, such as the increase in alkaline phosphatase activity, which is likely involved in detoxification. Additionally, the activities of alanine aminotransferase and aspartate aminotransferase, which are key components of amino acid catabolism, decreased. The amount of glucose (an energy source) and uric acid (the excreted end product) increased, while total protein (another energy source) and cholesterol decreased. These results indicate that this plant possesses potential secondary metabolites that may be useful for the future study of the control of insect pests.

Liver morphometrics and metabolic blood profile across divergent phenotypes for feed efficiency in the bovine.

PubMed

Montanholi, Yuri Regis; Haas, Livia Sadocco; Swanson, Kendall Carl; Coomber, Brenda Lynn; Yamashiro, Shigeto; Miller, Stephen Paul

2017-04-26

Feed costs are a major expense in the production of beef cattle. Individual variation in the efficiency of feed utilization may be evident through feed efficiency-related phenotypes such as those related to major energetic sinks. Our objectives were to assess the relationships between feed efficiency with liver morphometry and metabolic blood profile in feedlot beef cattle. Two populations (A = 112 and B = 45) of steers were tested for feed efficiency. Blood from the 12 most (efficient) and 12 least feed inefficient (inefficient) steers from population A was sampled hourly over the circadian period. Blood plasma samples were submitted for analysis on albumin, aspartate aminotransferase, γ-glutamyl transpeptidase urea, cholesterol, creatinine, alkaline phosphatase, creatine kinase, lipase, carbon dioxide, β-hydroxybutyrate, acetate and bile acids. Liver tissue was also harvested from 24 steers that were blood sampled from population A and the 10 steers with divergent feed efficiency in each tail of population B was sampled for microscopy at slaughter. Photomicroscopy images were taken using the portal triad and central vein as landmarks. Histological quantifications included cross-sectional hepatocyte perimeter and area, hepatocyte nuclear area and nuclei area as proportion of the hepatocyte area. The least square means comparison between efficient and inefficient steers for productive performance and liver morphometry and for blood analytes data were analyzed using general linear model and mixed model procedures of SAS, respectively. No differences were observed for liver weight; however, efficient steers had larger hepatocyte (i.e. hepatocyte area at the porta triad 323.31 vs. 286.37 µm 2 ) and nuclei dimensions at portal triad and central vein regions, compared with inefficient steers. The metabolic profile indicated efficient steers had lower albumin (36.18 vs. 37.65 g/l) and cholesterol (2.62 vs. 3.05 mmol/l) and higher creatinine (118.59 vs. 110.50 mmol/l) and carbon dioxide (24.36 vs. 23.65 mmol/l) than inefficient steers. Improved feed efficiency is associated with increased metabolism by the liver (enlarged hepatocytes and no difference on organ size), muscle (higher creatinine) and whole body (higher carbon dioxide); additionally, efficient steers had reduced bloodstream pools of albumin and cholesterol. These metabolic discrepancies between feed efficient and inefficient cattle may be determinants of productive performance.

Effects of guar meal by-product with and without beta-mannanase Hemicell on broiler performance.

PubMed

Lee, J T; Connor-Appleton, S; Bailey, C A; Cartwright, A L

2005-08-01

Guar gum production yields a high protein guar meal that can be subdivided into germ and hull fractions. Feeding high concentrations of guar meal reduces body weight and feed efficiency in chickens due to the presence of a residual guar gum. Two experiments determined the upper feeding levels of guar meal and the hull and germ fractions in broiler chickens. An industrial source beta-mannanase (Hemicell) also was fed in combination with guar meals. Experiment 1 utilized a 3 x 4 factorial design to feed broiler chickens diets containing guar germ, guar hull, or guar meal at 4 levels (2.5, 5.0, 7.5, and 10.0%) compared with a negative control diet. Results indicated that any of the 3 guar meals could be fed at a 2.5% dietary inclusion rate without adversely affecting broiler chicken growth to 6 wk of age. In experiment 2, a 4 x 2 factorial design consisting of the 3 by-products meals at 5% inclusion and soybean meal control with and without enzyme tested whether Hemicell could increase inclusion rates without decreasing broiler growth or feed consumption to 6 wk of age. Addition of Hemicell to feed had no effect on measures of growth in chickens fed the control diet. Hemicell significantly improved feed:gain ratio of diets containing 5% of each fraction of guar meal versus the untreated diets. Feed:gain ratio for the Hemicell-treated 5% germ fraction diet was improved to control diet levels. Results indicated that the upper feeding level of guar meal and germ and hull fraction of guar meal is 2.5%, and addition of beta-mannanase (Hemicell) increases the upper feeding level for the germ fraction to 5%.

Feed intake and efficiency of F1 lambs

USDA-ARS?s Scientific Manuscript database

Objective estimates of feed efficiency for progeny of terminal-sire breeds of sheep are needed to improve the value of market lambs. Because recent terminal-sire breed-comparison data are lacking, we determined effects of terminal-sire breed on feed efficiency of F1 lambs. Each year for 3 yr, Columb...

Relationship among performance, carcass, and feed efficiency characteristics, and their ability to predict economic value in the feedlot.

PubMed

Retallick, K M; Faulkner, D B; Rodriguez-Zas, S L; Nkrumah, J D; Shike, D W

2013-12-01

A 4-yr study was conducted using 736 steers of known Angus, Simmental, or Simmental × Angus genetics to determine performance, carcass, and feed efficiency factors that explained variation in economic performance. Steers were pen fed and individual DMI was recorded using a GrowSafe automated feeding system (GrowSafe Systems Ltd., Airdrie, Alberta, Canada). Steers consumed a similar diet and received similar management each year. The objectives of this study were to: 1) determine current economic value of feed efficiency and 2) identify performance, carcass, and feed efficiency characteristics that predict: carcass value, profit, cost of gain, and feed costs. Economic data used were from 2011 values. Feed efficiency values investigated were: feed conversion ratio (FCR; feed to gain), residual feed intake (RFI), residual BW gain (RG), and residual intake and BW gain (RIG). Dependent variables were carcass value ($/steer), profit ($/steer), feed costs ($/steer • d(-1)), and cost of gain ($/kg). Independent variables were year, DMI, ADG, HCW, LM area, marbling, yield grade, dam breed, and sire breed. A 10% improvement in RG (P < 0.05) yielded the lowest cost of gain at $0.09/kg and highest carcass value at $17.92/steer. Carcass value increased (P < 0.05) as feed efficiency improved for FCR, RG, and RIG. Profit increased with a 10% improvement in feed efficiency (P < 0.05) with FCR at $34.65/steer, RG at $31.21/steer, RIG at $21.66/steer, and RFI at $11.47/steer. The carcass value prediction model explained 96% of the variation among carcasses and included HCW, marbling score, and yield grade. Average daily gain, marbling score, yield grade, DMI, HCW, and year born constituted 81% of the variation for prediction of profit. Eighty-five percent of the variation in cost of gain was explained by ADG, DMI, HCW, and year. Prediction equations were developed that excluded ADG and DMI, and included feed efficiency values. Using these equations, cost of gain was explained primarily by FCR (R(2) = 0.71). Seventy-three percent of profitability was explained, with 55% being accounted for by RG and marbling. These prediction equations represent the relative importance of factors contributing to economic success in feedlot cattle based on current prices.

Short communication: Effect of canola meal use as a protein source in a starter mixture on feeding behavior and performance of calves during the weaning transition.

PubMed

Hadam, D; Kański, J; Burakowska, K; Penner, G B; Kowalski, Z M; Górka, P

2016-02-01

The aim of this study was to determine the effect of canola meal use as a protein source in a starter mixture (SM) on feeding behavior and performance of calves during weaning transition. A total of 36 female Holstein calves of a mean age 14.9±1.6 d and body weight 40.1±4.2 kg (mean ± SD) were allocated to 1 of 3 treatments differing in the main source of protein for the SM (12 calves per treatment): (1) soybean meal (TSBM); (2) soybean meal and canola meal (TSBM/TCM); and (3) canola meal (TCM). The SM was offered for ad libitum consumption beginning on the first day of the study, whereas milk replacer (MR) was fed in amounts equal to 900 g (as fed) per day from d 1 to 35 and 450 g/d from d 36 to 42 of the study. Calves were completely weaned on d 43 of the study (57.9±1.6 d of age; mean ± SD), and their performance was monitored for an additional 2 wk. Calf body weight was recorded weekly, and MR and SM intake and fecal fluidity were recorded daily. Feeding behavior of calves during weaning transition, including frequency (no./d), time (min/d), and rate (g/min) of eating the SM as well as frequency and time of drinking water, was monitored on 6 calves per treatment for 2 consecutive days before MR step-down (d 34-35), at MR step-down (d 41-42), and after weaning (d 48-49 of study). Starter mixture intake tended to be higher for TSBM calves as compared with TSBM/TCM calves from d 1 to 35 of the study but was not different between TSBM and TCM calves and was not different between treatments in the whole study period. Calves from TCM treatment had reduced average daily gain (ADG) and feed efficiency (g of ADG/kg of dry matter intake) and a higher fecal score in the period from d 1 to 35 of the study and had lower feed efficiency and tended to have lower ADG in the whole study period as compared with TSBM calves. Average daily gain and feed efficiency did not differ between TSBM and TSBM/TCM calves. Frequency of eating the SM and drinking water as well as time and rate of eating the SM and time of drinking water did not differ between treatments. It is concluded that presence of canola meal in a SM does not affect feeding behavior and performance of calves during weaning transition but has a negative effect on ADG, feed efficiency, and number of days with diarrhea during the preweaning phase of rearing. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Towards Sustainable Aquafeeds: Complete Substitution of Fish Oil with Marine Microalga Schizochytrium sp. Improves Growth and Fatty Acid Deposition in Juvenile Nile Tilapia (Oreochromis niloticus)

PubMed Central

Sarker, Pallab K.; Kapuscinski, Anne R.; Lanois, Alison J.; Livesey, Erin D.; Bernhard, Katie P.; Coley, Mariah L.

2016-01-01

We conducted a 84-day nutritional feeding experiment with dried whole cells of DHA-rich marine microalga Schizochytrium sp. (Sc) to determine the optimum level of fish-oil substitution (partial or complete) for maximum growth of Nile tilapia. When we fully replaced fish oil with Schizochytrium (Sc100 diet), we found significantly higher weight gain and protein efficiency ratio (PER), and lower (improved) feed conversion ratio (FCR) and feed intake compared to a control diet containing fish oil (Sc0); and no significant change in SGR and survival rate among all diets. The Sc100 diet had the highest contents of 22:6n3 DHA, led to the highest DHA content in fillets, and consequently led to the highest DHA:EPA ratios in tilapia fillets. Schizochytrium sp. is a high quality candidate for complete substitution of fish oil in juvenile Nile tilapia feeds, providing an innovative means to formulate and optimize the composition of tilapia juvenile feed while simultaneously raising feed efficiency of tilapia aquaculture and to further develop environmentally and socially sustainable aquafeeds. Results show that replacing fish oil with DHA-rich marine Sc improves the deposition of n3 LC PUFA levels in tilapia fillet. These results support further studies to lower Schizochytrium production costs and to combine different marine microalgae to replace fish oil and fishmeal into aquafeeds. PMID:27258552

Impact of selection for residual feed intake on production traits and behavior of mule ducks.

PubMed

Drouilhet, L; Monteville, R; Molette, C; Lague, M; Cornuez, A; Canario, L; Ricard, E; Gilbert, H

2016-09-01

A divergent selection experiment of Muscovy sires based on the residual feed intake (RFI) of their male mule progeny was initiated in 2009. Using electronic feeders, the aim of this study was to establish whether 3 generations of selection for RFI had an impact on feeding behavior traits and general behavior, and to examine its effect on liver and meat quality. Eighty mule ducks, issued from 8 Muscovy drakes per line with extreme RFI, were tested in a pen equipped with 4 electronic feeders. Feeding behaviors were recorded from 3 to 7 wk after hatching under ad libitum feeding conditions. Then animals were prepared for overfeeding with a 3-week period of restricted feeding, and overfed during 12 d before slaughter. The RFI was significantly lower in the low RFI line than in the high RFI line (-5.4 g/d, P = 0.0005) and daily feed intake was reduced both over the entire test period (-5 g/d, P = 0.049) and on a weekly basis (P = 0.006). Weekly and total feed conversion ratios were also significantly lower (-0.08, P = 0.03 and -0.06, P = 0.01, respectively). Low RFI ducks had more frequent meals, spent as much time eating as high RFI ducks, and their feeding rate was lower when analyzed at the wk level only. Additionally no significant correlation between feed efficiency and feeding behavior traits was evidenced, indicating only limited relationships between RFI and feeding patterns. Some differences in behavioral responses to stressors (open field test combined with a test measuring the response to human presence) suggested that a lower RFI is associated with less fearfulness. Selection for RFI had no effect on liver weight and quality and a slightly deleterious impact on meat quality (decreased drip loss and L*). Finally, low RFI animals had higher body weights after restricted feeding from wk 10 to wk 12 and after overfeeding than high RFI ducks. This suggests that selection for reduced RFI until 7 wk of age increases the feed efficiency up to slaughter. © The Author 2016. Published by Oxford University Press on behalf of Poultry Science Association.

Impact of selection for residual feed intake on production traits and behavior of mule ducks

PubMed Central

Drouilhet, L.; Monteville, R.; Molette, C.; Lague, M.; Cornuez, A.; Canario, L.; Ricard, E.; Gilbert, H.

2016-01-01

A divergent selection experiment of Muscovy sires based on the residual feed intake (RFI) of their male mule progeny was initiated in 2009. Using electronic feeders, the aim of this study was to establish whether 3 generations of selection for RFI had an impact on feeding behavior traits and general behavior, and to examine its effect on liver and meat quality. Eighty mule ducks, issued from 8 Muscovy drakes per line with extreme RFI, were tested in a pen equipped with 4 electronic feeders. Feeding behaviors were recorded from 3 to 7 wk after hatching under ad libitum feeding conditions. Then animals were prepared for overfeeding with a 3-week period of restricted feeding, and overfed during 12 d before slaughter. The RFI was significantly lower in the low RFI line than in the high RFI line (−5.4 g/d, P = 0.0005) and daily feed intake was reduced both over the entire test period (−5 g/d, P = 0.049) and on a weekly basis (P = 0.006). Weekly and total feed conversion ratios were also significantly lower (−0.08, P = 0.03 and −0.06, P = 0.01, respectively). Low RFI ducks had more frequent meals, spent as much time eating as high RFI ducks, and their feeding rate was lower when analyzed at the wk level only. Additionally no significant correlation between feed efficiency and feeding behavior traits was evidenced, indicating only limited relationships between RFI and feeding patterns. Some differences in behavioral responses to stressors (open field test combined with a test measuring the response to human presence) suggested that a lower RFI is associated with less fearfulness. Selection for RFI had no effect on liver weight and quality and a slightly deleterious impact on meat quality (decreased drip loss and L*). Finally, low RFI animals had higher body weights after restricted feeding from wk 10 to wk 12 and after overfeeding than high RFI ducks. This suggests that selection for reduced RFI until 7 wk of age increases the feed efficiency up to slaughter. PMID:27333975

Maltase-glucoamylase: Mucosal regulator of prandial starch glucogenesis and complimentary hepatic gluconeogenesis of mice

USDA-ARS?s Scientific Manuscript database

In previous studies we have shown that maltase-glucoamylase (Mgam) is required for efficient starch digestion and insulin response to starch feeding. It was hypothesized that the slower rate of starch digestion by residual sucrase-isomaltase (Si) maltase failed to regulate gluconeogenesis. Here, rat...

Conversion of organic material by black soldier fly larvae: establishing optimal feeding rates.

PubMed

Diener, Stefan; Zurbrügg, Christian; Tockner, Klement

2009-09-01

Larvae of the black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), are voracious feeders of organic material and may thus be used in simple engineered systems to reduce organic waste in low- and middle-income countries. Controlled feeding experiments with standard fodder were conducted to assess the optimum amount of organic waste to be added to a CORS system (Conversion of Organic Refuse by Saprophages). A daily feeding rate of 100 mg chicken feed (60% moisture content) per larva resulted in an optimum trade-off between material reduction efficiency (41.8%, SE 0.61) and biomass production (prepupal dry weight: 48.0 mg, SE 2.0). Applied to market waste and human faeces, this corresponds to a potential daily feeding capacity of 3-5 kg/m(2) and 6.5 kg/m(2), respectively. In addition, H. illucens prepupae quality was assessed to determine their suitability to substitute fishmeal in animal feed production. The chitin-corrected crude protein content ranged from 28.2 to 42.5%, depending on the amount of food provided to the larvae. Based on our study, a waste processing unit could yield a daily prepupal biomass of 145 g (dry mass) per m(2). We conclude that larvae of the black soldier fly are potentially capable of converting large amounts of organic waste into protein-rich biomass to substitute fishmeal, thereby contributing to sustainable aquaculture.

Genome-wide association study for feed efficiency traits using SNP and haplotype models

USDA-ARS?s Scientific Manuscript database

Feed costs comprise the majority of variable expenses in beef cattle systems making feed efficiency an important economic consideration within the beef industry. Due to the expense of recording individual feed intake phenotypes, a genomic-enabled approach could be advantageous towards improving this...

Development of an immunochromatographic assay for the detection of the feed additive zilpaterol

USDA-ARS?s Scientific Manuscript database

Zilpaterol is a beta-adrenergic agonist feed additive approved in the United States to increase weight gain and improve feed efficiency of cattle. Countries which ban beta-adrenergic agonist feed additives can reject imported beef products that contain zilpaterol. Therefore, efficient, portable, a...

A parametric study of the microwave plasma-assisted combustion of premixed ethylene/air mixtures

NASA Astrophysics Data System (ADS)

Fuh, Che A.; Wu, Wei; Wang, Chuji

2017-11-01

A parametric study of microwave argon plasma assisted combustion (PAC) of premixed ethylene/air mixtures was carried out using visual imaging, optical emission spectroscopy and cavity ringdown spectroscopy as diagnostic tools. The parameters investigated included the plasma feed gas flow rate, the plasma power, the fuel equivalence ratio and the total flow rate of the fuel/air mixture. The combustion enhancement effects were characterized by the minimum ignition power, the flame length and the fuel efficiency of the combustor. It was found that: (1) increasing the plasma feed gas flow rate resulted in a decrease in the flame length, an increase in the minimum ignition power for near stoichiometric fuel equivalence ratios and a corresponding decrease in the minimum ignition power for ultra-lean and rich fuel equivalence ratios; (2) at a constant plasma power, increasing the total flow rate of the ethylene/air mixture from 1.0 slm to 1.5 slm resulted in an increase in the flame length and a reduction in the fuel efficiency; (3) increasing the plasma power resulted in a slight increase in flame length as well as improved fuel efficiency with fewer C2(d) and CH(A) radicals present downstream of the flame; (4) increasing the fuel equivalence ratio caused an increase in flame length but at a reduced fuel efficiency when plasma power was kept constant; and (5) the ground state OH(X) number density was on the order of 1015 molecules/cm3 and was observed to drop downstream along the propagation axis of the flame at all parameters investigated. Results suggest that each of the parameters independently influences the PAC processes.

Feed conversion efficiency in aquaculture: do we measure it correctly?

NASA Astrophysics Data System (ADS)

Fry, Jillian P.; Mailloux, Nicholas A.; Love, David C.; Milli, Michael C.; Cao, Ling

2018-02-01

Globally, demand for food animal products is rising. At the same time, we face mounting, related pressures including limited natural resources, negative environmental externalities, climate disruption, and population growth. Governments and other stakeholders are seeking strategies to boost food production efficiency and food system resiliency, and aquaculture (farmed seafood) is commonly viewed as having a major role in improving global food security based on longstanding measures of animal production efficiency. The most widely used measurement is called the ‘feed conversion ratio’ (FCR), which is the weight of feed administered over the lifetime of an animal divided by weight gained. By this measure, fed aquaculture and chickens are similarly efficient at converting feed into animal biomass, and both are more efficient compared to pigs and cattle. FCR does not account for differences in feed content, edible portion of an animal, or nutritional quality of the final product. Given these limitations, we searched the literature for alternative efficiency measures and identified ‘nutrient retention’, which can be used to compare protein and calories in feed (inputs) and edible portions of animals (outputs). Protein and calorie retention have not been calculated for most aquaculture species. Focusing on commercial production, we collected data on feed composition, feed conversion ratios, edible portions (i.e. yield), and nutritional content of edible flesh for nine aquatic and three terrestrial farmed animal species. We estimate that 19% of protein and 10% of calories in feed for aquatic species are ultimately made available in the human food supply, with significant variation between species. Comparing all terrestrial and aquatic animals in the study, chickens are most efficient using these measures, followed by Atlantic salmon. Despite lower FCRs in aquaculture, protein and calorie retention for aquaculture production is comparable to livestock production. This is, in part, due to farmed fish and shrimp requiring higher levels of protein and calories in feed compared to chickens, pigs, and cattle. Strategies to address global food security should consider these alternative efficiency measures.

Metabolic and physiological mechanisms responsible for variation in feed efficiency

USDA-ARS?s Scientific Manuscript database

There has been an increase in the number of experiments in the past few years that explore the underlying mechanisms involved in feed efficiency of beef cattle. This is a byproduct of the need to improve feed efficiency to increase the sustainability of beef production and improve the economic situa...

Evaluation of a chinook salmon (Oncorhynchus tshawytscha) bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; O'Connor, Daniel V.; Chernyak, Sergei M.; Rediske, Richard R.; O'Keefe, James P.

2004-01-01

We evaluated the Wisconsin bioenergetics model for chinook salmon (Oncorhynchus tshawytscha) in both the laboratory and the field. Chinook salmon in laboratory tanks were fed alewife (Alosa pseudoharengus), the predominant food of chinook salmon in Lake Michigan. Food consumption and growth by chinook salmon during the experiment were measured. To estimate the efficiency with which chinook salmon retain polychlorinated biphenyls (PCBs) from their food in the laboratory, PCB concentrations of the alewife and of the chinook salmon at both the beginning and end of the experiment were determined. Based on our laboratory evaluation, the bioenergetics model was furnishing unbiased estimates of food consumption by chinook salmon. Additionally, from the laboratory experiment, we calculated that chinook salmon retained 75% of the PCBs contained within their food. In an earlier study, assimilation rate of PCBs to chinook salmon from their food in Lake Michigan was estimated at 53%, thereby suggesting that the model was substantially overestimating food consumption by chinook salmon in Lake Michigan. However, we concluded that field performance of the model could not be accurately assessed because PCB assimilation efficiency is dependent on feeding rate, and feeding rate of chinook salmon was likely much lower in our laboratory tanks than in Lake Michigan.

More feed efficient sheep produce less methane and carbon dioxide when eating high-quality pellets.

PubMed

Paganoni, B; Rose, G; Macleay, C; Jones, C; Brown, D J; Kearney, G; Ferguson, M; Thompson, A N

2017-09-01

The Australian sheep industry aims to increase the efficiency of sheep production by decreasing the amount of feed eaten by sheep. Also, feed intake is related to methane production, and more efficient (low residual feed intake) animals eat less than expected. So we tested the hypothesis that more efficient sheep produce less methane by investigating the genetic correlations between feed intake, residual feed intake, methane, carbon dioxide, and oxygen. Feed intake, methane, oxygen, and carbon dioxide were measured on Merino ewes at postweaning (1,866 at 223 d old), hogget (1,010 sheep at 607 d old), and adult ages (444 sheep at 1,080 d old). Sheep were fed a high-energy grower pellet ad libitum for 35 d. Individual feed intake was measured using automated feeders. Methane was measured using portable accumulation chambers up to 3 times during this feed intake period. Heritabilities and phenotypic and genotypic correlations between traits were estimated using ASReml. Oxygen (range 0.10 to 0.20) and carbon dioxide (range 0.08 to 0.28) were generally more heritable than methane (range 0.11 to 0.14). Selecting to decrease feed intake or residual feed intake will decrease methane (genetic correlation [] range 0.76 to 0.90) and carbon dioxide ( range 0.65 to 0.96). Selecting to decrease intake ( range 0.64 to 0.78) and methane ( range 0.81 to 0.86) in sheep at postweaning age would also decrease intake and methane in hoggets and adults. Furthermore, selecting for lower residual feed intake ( = 0.75) and carbon dioxide ( = 0.90) in hoggets would also decrease these traits in adults. Similarly, selecting for higher oxygen ( = 0.69) in hoggets would also increase this trait in adults. Given these results, the hypothesis that making sheep more feed efficient will decrease their methane production can be accepted. In addition, carbon dioxide is a good indicator trait for feed intake because it has the highest heritability of the gas traits measured; is cheaper, faster, and easier to measure than feed intake and has strong phenotypic and genetic correlations with feed intake. Furthermore, selection for feed intake, feed efficiency, methane, and carbon dioxide can be done early in sheep at postweaning age or hoggets. This early selection reduces the generation interval for breeding, thereby increasing response to selection.

Determining Suction Feeding Efficiency in the Bowfin fish (Amia) using Particle Image Velocimery and Computaional Fluid Dynamics

NASA Astrophysics Data System (ADS)

Rua, Yenny; Kharbouch, Karim; Sanford, Christopher; Reckinger, Shanon

2014-11-01

Suction feeding is the most common form of prey capture in aquatic vertebrates. During the early evolution of fishes there was a major change in shape of the mouth, from a wedge shaped mouth opening in more primitive fishes to a more circular and planar mouth. This change in shape resulted from increased mobility of a key upper jaw bone, the maxilla. It has been suggested that this change in shape dramatically increased suction feeding efficiency. This study examines the hydrodynamic effects of these two mouth shapes in the same animal, the bowfin fish (Amia calva). 2D Particle Image Velocimetry (PIV) is used to analyze suction feeding events. Post-processing algorithms have been developed to determine the flow rate of water into the mouth of the fish; the area of fluid, the velocity of fluid and the volume of fluid affected by the fish; the velocity of the fluid at the mouth, as well as the velocity of the fluid as a function of the distance from the mouth, finally the force exerted on the fluid by the fish is also determined. Lastly, a numerical model has been developed for comparison using a non-uniform mesh, which adapts dynamically in space and time to the fish feeding event. The realistic geometry of the fish's head is modeled in CAD.

Development of a fast, lean and agile direct pelletization process using experimental design techniques.

PubMed

Politis, Stavros N; Rekkas, Dimitrios M

2017-04-01

A novel hot melt direct pelletization method was developed, characterized and optimized, using statistical thinking and experimental design tools. Mixtures of carnauba wax (CW) and HPMC K100M were spheronized using melted gelucire 50-13 as a binding material (BM). Experimentation was performed sequentially; a fractional factorial design was set up initially to screen the factors affecting the process, namely spray rate, quantity of BM, rotor speed, type of rotor disk, lubricant-glidant presence, additional spheronization time, powder feeding rate and quantity. From the eight factors assessed, three were further studied during process optimization (spray rate, quantity of BM and powder feeding rate), at different ratios of the solid mixture of CW and HPMC K100M. The study demonstrated that the novel hot melt process is fast, efficient, reproducible and predictable. Therefore, it can be adopted in a lean and agile manufacturing setting for the production of flexible pellet dosage forms with various release rates easily customized between immediate and modified delivery.

Feeding and metabolism of mesozooplankton in the equatorial Pacific high-nutrient, low-chlorophyll zone along 180°

NASA Astrophysics Data System (ADS)

Gaudy, Raymond; Champalbert, GisèLe; Le Borgne, Robert

2003-12-01

Feeding, respiration, and excretion rates (ammonium and phosphate) of mesozooplankton from the equatorial Pacific upper water column (0-100 m) were measured along the 180th meridian at different stations between 8°S and 8°N, and more repeatedly, at two time series stations, located at 3°S (TSS1) and the equator (TSS2). Only particles of size >8 μm were grazed by the organisms used for the experiments. Grazing rates were higher at TSS1. Ammonium excretion was also maximum at TSS2, resulting in lower O/N values. This suggests that food particles were richer in terms of protein content at the equator, as is also indicated by the lower C/N ratio of particles and the higher proportion of heterotrophic protozoans. Some variations in mesozooplankton specific composition (more carnivorous copepods being present in the equatorial samples) could also explain these O/N differences. Diel variations were observed. Significantly higher grazing, respiration (only at TSS1), and excretion rates were recorded during the day, suggesting that feeding activity was related to the daytime increase of primary production. Using the grazing rates determined under experimental conditions, the grazing pressure on the stock of food particles >8 μm was very low (<1%) and the daily food intake (2.7-3.1% of the zooplankton body carbon), was far from compensating for respiration losses (22% of the body carbon). We conclude that the experimentally measured feeding activity was underestimated because of methodological problems. More realistic values were obtained from energy balance considerations, using measured respiration rates as an indication of minimal carbon requirement and extrapolating to ingestion using literature coefficients for assimilation efficiency (0.7) and net growth efficiency (0.4). According to these calculations the daily food carbon intake necessary to sustain both secondary production and respiration needs would be equivalent to 63% of the mesozooplankton body carbon, and the grazing pressure on >8-μm food particles would reach 14% of the standing stock d-1.

RNA-Seq detection of differential gene expression in the rumen of beef steers associated with feed efficiency phenotypes

USDA-ARS?s Scientific Manuscript database

The efficient utilization of feedstuffs is an economically important trait in beef production. The rumen is important to the digestive process of steers interacting with feed, microbial populations, and volatile fatty acids indicating it may play a critical role in feed efficiency. To gain an unders...

Impact of selection for residual feed intake on breeding soundness and reproductive performance of bulls on pasture-based multisire mating.

PubMed

Wang, Z; Colazo, M G; Basarab, J A; Goonewardene, L A; Ambrose, D J; Marques, E; Plastow, G; Miller, S P; Moore, S S

2012-09-01

There is concern in the beef industry that selecting bulls for feed efficiency based on residual feed intake (RFI) may have a negative impact on bull reproductive performance and fertility. Here we investigated the impact of selection of bulls for low RFI on breeding soundness evaluation (BSE), reproductive performance, and fertility of bulls under natural service in multisire mating groups on pasture. Of the 412 RFI-tested bulls available, 98 (23.8%) were culled for performance, type, temperament, or other reasons, and 88 (21.4%) were culled for failing BSE, for an overall cull rate of 45.1%. From among the 314 bulls subjected to BSE, 32 (10.2%), 20 (6.4%), and 36 (11.4%) were culled for poor feet and legs, scrotal circumference, and semen quality, respectively. The BSE traits were not different (P > 0.10) between bulls categorized as either inefficient (+RFI) or efficient (-RFI), but the proportion of bulls that failed to meet the 60% minimum sperm motility requirement tended (P = 0.07) to be greater in the -RFI group than in the +RFI group (10.2% vs. 4.4%, respectively). In a subpopulation of 115 bulls, individual progressive sperm motility was greater (P < 0.05) in +RFI (85%) than -RFI (80%) bulls. A multisire natural mating experiment was conducted during 2 consecutive breeding seasons (2006 to 2007 and 2007 to 2008) using 18 +RFI and 18 -RFI bulls. The overall calving rate (calves born/cows exposed) was 72.9%. Mean number of progeny per sire was significantly greater (P < 0.01) in -RFI bulls (18.3) than in +RFI bulls (11.8). Selection for feed efficiency based on RFI appears to have no detrimental impact on reproductive performance and fertility in beef bulls bred in multisire groups on pasture. However, the decreased sperm motility and the greater number of progeny per sire associated with -RFI status need further investigation.

Novel transgenic pigs with enhanced growth and reduced environmental impact

PubMed Central

Yang, Huaqiang; Liu, Dewu; Cai, Gengyuan; Li, Guoling; Mo, Jianxin; Wang, Dehua; Zhong, Cuili; Wang, Haoqiang; Sun, Yue; Shi, Junsong; Zheng, Enqin; Meng, Fanming; Zhang, Mao; He, Xiaoyan; Zhou, Rong; Zhang, Jian; Huang, Miaorong; Zhang, Ran; Li, Ning; Fan, Mingzhe; Yang, Jinzeng

2018-01-01

In pig production, inefficient feed digestion causes excessive nutrients such as phosphorus and nitrogen to be released to the environment. To address the issue of environmental emissions, we established transgenic pigs harboring a single-copy quad-cistronic transgene and simultaneously expressing three microbial enzymes, β-glucanase, xylanase, and phytase in the salivary glands. All the transgenic enzymes were successfully expressed, and the digestion of non-starch polysaccharides (NSPs) and phytate in the feedstuff was enhanced. Fecal nitrogen and phosphorus outputs in the transgenic pigs were reduced by 23.2–45.8%, and growth rate improved by 23.0% (gilts) and 24.4% (boars) compared with that of age-matched wild-type littermates under the same dietary treatment. The transgenic pigs showed an 11.5–14.5% improvement in feed conversion rate compared with the wild-type pigs. These findings indicate that the transgenic pigs are promising resources for improving feed efficiency and reducing environmental impact. PMID:29784082

An analysis of partial efficiencies of energy utilisation of different macronutrients by barramundi (Lates calcarifer) shows that starch restricts protein utilisation in carnivorous fish.

PubMed

Glencross, Brett D; Blyth, David; Bourne, Nicholas; Cheers, Susan; Irvin, Simon; Wade, Nicholas M

2017-02-01

This study examined the effect of including different dietary proportions of starch, protein and lipid, in diets balanced for digestible energy, on the utilisation efficiencies of dietary energy by barramundi (Lates calcarifer). Each diet was fed at one of three ration levels (satiety, 80 % of initial satiety and 60 % of initial satiety) for a 42-d period. Fish performance measures (weight gain, feed intake and feed conversion ratio) were all affected by dietary energy source. The efficiency of energy utilisation was significantly reduced in fish fed the starch diet relative to the other diets, but there were no significant effects between the other macronutrients. This reduction in efficiency of utilisation was derived from a multifactorial change in both protein and lipid utilisation. The rate of protein utilisation deteriorated as the amount of starch included in the diet increased. Lipid utilisation was most dramatically affected by inclusion levels of lipid in the diet, with diets low in lipid producing component lipid utilisation rates well above 1·3, which indicates substantial lipid synthesis from other energy sources. However, the energetic cost of lipid gain was as low as 0·65 kJ per kJ of lipid deposited, indicating that barramundi very efficiently store energy in the form of lipid, particularly from dietary starch energy. This study defines how the utilisation efficiency of dietary digestible energy by barramundi is influenced by the macronutrient source providing that energy, and that the inclusion of starch causes problems with protein utilisation in this species.

Acquired Phototrophy through Retention of Functional Chloroplasts Increases Growth Efficiency of the Sea Slug Elysia viridis

PubMed Central

Baumgartner, Finn A.; Pavia, Henrik; Toth, Gunilla B.

2015-01-01

Photosynthesis is a fundamental process sustaining heterotrophic organisms at all trophic levels. Some mixotrophs can retain functional chloroplasts from food (kleptoplasty), and it is hypothesized that carbon acquired through kleptoplasty may enhance trophic energy transfer through increased host growth efficiency. Sacoglossan sea slugs are the only known metazoans capable of kleptoplasty, but the relative fitness contributions of heterotrophy through grazing, and phototrophy via kleptoplasts, are not well understood. Fitness benefits (i.e. increased survival or growth) of kleptoplasty in sacoglossans are commonly studied in ecologically unrealistic conditions under extended periods of complete darkness and/or starvation. We compared the growth efficiency of the sacoglossan Elysia viridis with access to algal diets providing kleptoplasts of differing functionality under ecologically relevant light conditions. Individuals fed Codium fragile, which provide highly functional kleptoplasts, nearly doubled their growth efficiency under high compared to low light. In contrast, individuals fed Cladophora rupestris, which provided kleptoplasts of limited functionality, showed no difference in growth efficiency between light treatments. Slugs feeding on Codium, but not on Cladophora, showed higher relative electron transport rates (rETR) in high compared to low light. Furthermore, there were no differences in the consumption rates of the slugs between different light treatments, and only small differences in nutritional traits of algal diets, indicating that the increased growth efficiency of E. viridis feeding on Codium was due to retention of functional kleptoplasts. Our results show that functional kleptoplasts from Codium can provide sacoglossan sea slugs with fitness advantages through photosynthesis. PMID:25830355

Methods for the investigation of the statistics of the commercial fisheries of the Great Lakes

USGS Publications Warehouse

Hile, Ralph; Duden, William R.

1933-01-01

During the summer and fall of 1939 four experiments were conducted at the Patuxent Research Refuge, Bowie, Maryland, to determine the protein requirements of bobwhite chicks. A total of 816 chicks were used to compare six levels of protein, namely, 22,24,26, 28, 30, and 32 per cent.....From the three standpoints of survival, rate of growth, and efficiency of feed utilization for the first ten weeks of life, the 28 per cent level of protein gave the best results. During the ninth and tenth weeks, the highest efficiency of feed utilization was obtained on the 22 per cent level. The results indicate that after the birds have reached about twothirds of their mature weight, the difference in efficiency between a diet containing 28 per cent of protein and one containing 22 per cent may be small enough to justify, in the interest of economy, the use of a diet containing the lower percentage of protein.

Using radiotelemetry to monitor cardiac response of free-living tule greater white-fronted geese (Anser albifrons elgasi) to human disturbance

USGS Publications Warehouse

Ackerman, Joshua T.; Takekawa, John Y.; Kruse, K.L.; Orthmeyer, D.L.; Yee, J.L.; Ely, Craig R.; Ward, D.H.; Bollinger, K.S.; Mulcahy, D.M.

2004-01-01

During the summer and fall of 1939 four experiments were conducted at the Patuxent Research Refuge, Bowie, Maryland, to determine the protein requirements of bobwhite chicks. A total of 816 chicks were used to compare six levels of protein, namely, 22,24,26, 28, 30, and 32 per cent.....From the three standpoints of survival, rate of growth, and efficiency of feed utilization for the first ten weeks of life, the 28 per cent level of protein gave the best results. During the ninth and tenth weeks, the highest efficiency of feed utilization was obtained on the 22 per cent level. The results indicate that after the birds have reached about twothirds of their mature weight, the difference in efficiency between a diet containing 28 per cent of protein and one containing 22 per cent may be small enough to justify, in the interest of economy, the use of a diet containing the lower percentage of protein.

Interactive Effects of Dietary Lipid and Phenotypic Feed Efficiency on the Expression of Nuclear and Mitochondrial Genes Involved in the Mitochondrial Electron Transport Chain in Rainbow Trout

PubMed Central

Eya, Jonathan C.; Ukwuaba, Vitalis O.; Yossa, Rodrigue; Gannam, Ann L.

2015-01-01

A 2 × 3 factorial study was conducted to evaluate the effects of dietary lipid level on the expression of mitochondrial and nuclear genes involved in electron transport chain in all-female rainbow trout Oncorhynchus mykiss. Three practical diets with a fixed crude protein content of 40%, formulated to contain 10% (40/10), 20% (40/20) and 30% (40/30) dietary lipid, were fed to apparent satiety to triplicate groups of either low-feed efficient (F120; 217.66 ± 2.24 g initial average mass) or high-feed efficient (F136; 205.47 ± 1.27 g) full-sib families of fish, twice per day, for 90 days. At the end of the experiment, the results showed that there is an interactive effect of the dietary lipid levels and the phenotypic feed efficiency (growth rate and feed efficiency) on the expression of the mitochondrial genes nd1 (NADH dehydrogenase subunit 1), cytb (Cytochrome b), cox1 (Cytochrome c oxidase subunits 1), cox2 (Cytochrome c oxidase subunits 2) and atp6 (ATP synthase subunit 6) and nuclear genes ucp2α (uncoupling proteins 2 alpha), ucp2β (uncoupling proteins 2 beta), pparα (peroxisome proliferator-activated receptor alpha), pparβ (peroxisome proliferatoractivated receptor beta) and ppargc1α (proliferator-activated receptor gamma coactivator 1 alpha) in fish liver, intestine and muscle, except on ppargc1α in the muscle which was affected by the diet and the family separately. Also, the results revealed that the expression of mitochondrial genes is associated with that of nuclear genes involved in electron transport chain in fish liver, intestine and muscle. Furthermore, this work showed that the expression of mitochondrial genes parallels with the expression of genes encoding uncoupling proteins (UCP) in the liver and the intestine of rainbow trout. This study for the first time presents the molecular basis of the effects of dietary lipid level on mitochondrial and nuclear genes involved in mitochondrial electron transport chain in fish. PMID:25853266

Effect of dietary taurine supplementation on growth, feed efficiency, and nutrient composition of juvenile sablefish (Anoplopoma fimbria)

USDA-ARS?s Scientific Manuscript database

Juvenile sablefish were fed a low taurine, basal feed with seven graded levels of supplemental taurine to determine taurine requirements for growth and feed efficiency. The basal feed was plant based, formulated primarily with soy and corn proteins with a minimal (9%) amount of fishmeal. The unsuppl...

Genetic variance and covariance and breed differences for feed intake and average daily gain to improve feed efficiency in growing cattle

USDA-ARS?s Scientific Manuscript database

Feed costs are a major economic expense in finishing and developing cattle; however, collection of feed intake data is costly. Examining relationships among measures of growth and intake, including breed differences, could facilitate selection for efficient cattle. Objectives of this study were to e...

Performance of Clarias gariepinus Fed Dried Brewer's Yeast (Saccharomyces cerevisiae) Slurry in Replacement for Soybean Meal.

PubMed

Solomon, Shola Gabriel; Ataguba, Gabriel Arome; Itodo, Gabriel Enemona

2017-01-01

Following disparity of earlier results, this study tested the performance of African catfish Clarias gariepinus fed dried brewer's yeast slurry meal (DBYM) based diets. Fingerlings of C. gariepinus with pooled mean initial weight of 1.58 ± 0.01 g were stocked in hapas (1 m × 1 m × 1 m) immersed in an earthen pond at a density of 15 fish per cage. Five diets with increasing substitution of soybean meal with 25%, 50%, 75%, and 100% of dried brewer's yeast and a control without dried brewer's yeast (0% substitution) were evaluated for 8 weeks. Palatability of diets reduced with increasing levels of DBYM. Growth and utilization parameters such as weight gain, feed conversion ratio, protein efficiency ratio, and specific growth rate differed significantly ( p < 0.05) among treated groups. Specific growth rate decreased with increasing substitution while the best feed conversion ratio was obtained in the diet devoid of DBYM. Protein efficiency and utilization decreased with increasing levels of DBYM. Body composition was also affected by inclusion of DBYM with significant differences ( p < 0.05) being observed across the diets. The trend in body composition follows the utilization of the diets. We conclude that the optimal range of inclusion and substitution of soybean meal with DBYM in C. gariepinus feed is between 1% and 14% of dry matter.

Performance of Clarias gariepinus Fed Dried Brewer's Yeast (Saccharomyces cerevisiae) Slurry in Replacement for Soybean Meal

PubMed Central

Solomon, Shola Gabriel; Itodo, Gabriel Enemona

2017-01-01

Following disparity of earlier results, this study tested the performance of African catfish Clarias gariepinus fed dried brewer's yeast slurry meal (DBYM) based diets. Fingerlings of C. gariepinus with pooled mean initial weight of 1.58 ± 0.01 g were stocked in hapas (1 m × 1 m × 1 m) immersed in an earthen pond at a density of 15 fish per cage. Five diets with increasing substitution of soybean meal with 25%, 50%, 75%, and 100% of dried brewer's yeast and a control without dried brewer's yeast (0% substitution) were evaluated for 8 weeks. Palatability of diets reduced with increasing levels of DBYM. Growth and utilization parameters such as weight gain, feed conversion ratio, protein efficiency ratio, and specific growth rate differed significantly (p < 0.05) among treated groups. Specific growth rate decreased with increasing substitution while the best feed conversion ratio was obtained in the diet devoid of DBYM. Protein efficiency and utilization decreased with increasing levels of DBYM. Body composition was also affected by inclusion of DBYM with significant differences (p < 0.05) being observed across the diets. The trend in body composition follows the utilization of the diets. We conclude that the optimal range of inclusion and substitution of soybean meal with DBYM in C. gariepinus feed is between 1% and 14% of dry matter. PMID:28239492

Acetic acid effects on enhancement of growth rate and reduction of amorphous carbon deposition on CNT arrays along a growth window in a floating catalyst reactor

NASA Astrophysics Data System (ADS)

Maghrebi, Morteza; Khodadadi, Abbas Ali; Mortazavi, Yadollah; Sane, Ali; Rahimi, Mohsen; Shirazi, Yaser; Tsakadze, Zviad; Mhaisalkar, Subodh

2009-11-01

The mm-long carbon nanotube (CNT) arrays were grown in a floating catalyst reactor, using xylene-ferrocene and a small amount of acetic acid as the feed. The CNT arrays deposited on a quartz substrate at several positions along the reactor were extensively characterized using Raman spectroscopy, scanning electron microscopy, X-ray diffraction, high-resolution transmission electron microscopy, and optical microscopy. Various characterization methods consistently reveal that the acetic acid additive to the feed alleviates deposition of amorphous carbon layer, which gradually thickens CNTs along the reactor. The acetic acid also resulted in a higher growth rate along the so-called growth window, where CNT arrays are deposited on the quartz substrate. High-performance liquid chromatography of extracted byproducts (PAHs) confirmed the presence of some polycyclic aromatic hydrocarbons. The solid weight of PAHs decreased upon addition of ferrocene as the catalyst precursor, as well as of acetic acid to xylene feed. The results suggest that primary light products of xylene pyrolysis can be competitive reactants for both catalytic and subsequent pyrolytic reactions. They may also be more efficient feeds for CNT growth than xylene itself.

Phenotypic and genetic correlations among milk energy output, body weight, and feed intake, and their effects on feed efficiency in lactating dairy cattle

USDA-ARS?s Scientific Manuscript database

Continued improvements in feed efficiency are essential for a thriving and sustainable dairy industry. Gross efficiency (GrEff) is defined as the energy captured in milk and body tissues as a percentage of gross energy intake. Our objective was to characterize the relationships among component tra...

Trial finds biomass harvest of cobia unaffected by stocking density in RAS

USDA-ARS?s Scientific Manuscript database

Cobia, Rachycentron canadum, were reared for 119 days from 322 g to market size in production-scale recirculating aquaculture systems at in-tank densities of 10, 20, or 30 kg/m3. No significant differences were detected in growth rate, survival, feed efficiency or body composition. This study is t...

21 CFR 520.2123b - Spectinomycin powder.

Code of Federal Regulations, 2010 CFR

2010-04-01

... tolerances. See § 556.600 of this chapter. (d) Conditions of use in chickens. It is administered in the drinking water of growing chickens as follows: (1) Indications for use and amounts—(i) For increased rate of weight gain and improved feed efficiency in broiler chickens, administer 0.5 g per gallon of water...

40 CFR 60.642 - Standards for sulfur dioxide.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 40 Protection of Environment 6 2011-07-01 2011-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the sulfur...

40 CFR 60.642 - Standards for sulfur dioxide.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 40 Protection of Environment 7 2012-07-01 2012-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the sulfur...

40 CFR 60.642 - Standards for sulfur dioxide.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 40 Protection of Environment 6 2010-07-01 2010-07-01 false Standards for sulfur dioxide. 60.642... Gas Processing: SO2 Emissions § 60.642 Standards for sulfur dioxide. (a) During the initial... reduction efficiency (Zi) to be determined from table 1 based on the sulfur feed rate (X) and the sulfur...

Effects of dietary carbohydrate-to-lipid ratio on the growth performance and feed utilization of juvenile turbot ( Scophthalmus maximus)

NASA Astrophysics Data System (ADS)

Miao, Shuyan; Nie, Qin; Miao, Huijun; Zhang, Wenbing; Mai, Kangsen

2016-08-01

A 9-week feeding trial was conducted to investigate the effects of dietary carbohydrate to lipid ratio (CHO:LIP) on the growth performance and feed utilization of juvenile turbot Scophthalmus maximus (initial body weight 8.75 g ± 0.04 g). Four isonitrogenous and isoenergetic low protein level (39%) diets were formulated with increasing ratios of dietary carbohydrate to lipid (2:18, 6:18, 18:12 and 28:6). A high protein level (50%) diet with the 2:12 ratio of carbohydrate to lipid was used as the control. Results showed that the survival rate, contents of moisture, crude protein and ash in muscle were not significantly affected by dietary treatments. With the dietary CHO:LIP ratio increased from 2:18 to 18:12, weight gain rate significantly increased ( P < 0.05). Higher dietary CHO:LIP ratio (28:6) resulted in the significantly decreased weight gain rate ( P < 0.05). Meanwhile, this treatment also resulted in the highest daily feed intake and liver glycogen content, as well as the lowest feed efficiency ( P < 0.05). Muscle glycogen content in fish fed the diet with 2:12 or 2:18 CHO:LIP ratio was significantly lower than those fed with the other three diets ( P < 0.05). The present results confirmed that the juvenile turbot can utilize carbohydrate. Furthermore, the appropriate ratio of dietary carbohydrate to lipid was important to the growth and feed utilization of turbot. The proper CHO:LIP ratio based on the growth performance in the present study was determined to be 18:12 when the dietary protein level was 39%.

Dietary supplement of banana (Musa acuminata) peels hot-water extract to enhance the growth, anti-hypothermal stress, immunity and disease resistance of the giant freshwater prawn, Macrobrachium rosenbergii.

PubMed

Rattanavichai, Wutti; Cheng, Winton

2015-04-01

In the present study, Macrobrachium rosenbergii were fed with diets containing extracts of banana, Musa acuminate, fruit's peel (banana peels extract, BPE) at 0, 1.0, 3.0 and 6.0 g kg(-1). The non-specific immune parameters, disease resistance and anti-hypothermal stress were evaluated at 2, 4, 8, 16 and 32 days of post feeding. Also, we demonstrated the percent weight gain (PWG), percent length gain (PLG), feeding efficiency (FE), and survival rate of giant freshwater prawn at 30, 60, 90, and 120 days of post feeding. The PWG, PLG, FE and survival rate of prawns fed at 0, 1.0, 3.0 and 6.0 g kg(-1) BPE-containing diets after 120 days were 69.5%, 75.4%, 77.8% and 83.3%; 21.8%, 23.6%, 27.8% and 33.9%; 0.60, 0.72, 0.75 and 0.90; and 55.4%, 62.2%, 62.3% and 75.3%, respectively. After 32 days of post feeding, a significant increase in total haemocyte count (THC), different haemocyte count (DHC), respiratory bursts (RBs), superoxide dismutase (SOD) activity, glutathione peroxidase (GPx) activity, phenoloxidase (PO) activity and transglutaminase (TG) activity, and meanwhile, a decreased haemolymph coagulation time was observed. Furthermore, phagocytic activity and clearance efficiency of prawns against Lactococcus garvieae infection were significantly increased. Prawns challenged with L. garvieae after 32 days of feeding at 1.0, 3.0 and 6.0 g kg(-1) had a significantly higher survival rate (33.3%, 40.0% and 56.7%) than those fed with the control diet. Subsequently, hypothermal (14 °C) stress was 43.4%, 50.0% and 50.0%, respectively. Altogether, we therefore recommend the dietary BPE administration at 6.0 g kg(-1) promotes growth, anti-hypothermal stress, and enhance immunity and resistance against L. garvieae in M. rosenbergii. Copyright © 2015 Elsevier Ltd. All rights reserved.

Assimilation of trace elements ingested by the mussel Mytilus edulis: effects of algal food abundance

USGS Publications Warehouse

Wang, W.-X.; Fisher, N.S.; Luoma, S. N.

1995-01-01

Pulse-chase feeding and multi-labeled radiotracer techniques were employed to measure the assimilation of 6 trace elements (110mAg, 241Am, 109Cd, 57Co, 75Se and 65Zn) from ingested diatoms in the mussel Mytilus edulis feeding at different rates (0.1, 0.49 and 1.5 mg dry wt h-1). Uniformly radiolabeled diatoms Thalassiosira pseudonana were fed to mussels for 0.5 h, and the behavior of the radiotracers in individual mussels was followed for 96 h in a depuration seawater system. Assimilation efficiency (AE) of each element declined with increasing ingestion rate and increased with gut passage time. The importance of extracellular digestion relative to intracellular digestion increased with ingestion activity, which, when coupled with a decline in AE, suggested that extracellular digestion is less efficient in metal absorption. Zn assimilation was most affected by ingestion rate, suggesting that AE may play a role in the physiological regulation of this metal in M. edulis. In an experiment to simulate the effects of an acidic gut, lowered pH (5.5) enhanced the release of elements from intact diatom cells, especially at low particle concentration. These results indicate that both feeding components of the mussel (i.e. gut passage time, digestive partitioning) and metal chemistry (i.e. metal release at lowered pH within the bivalve gut) are responsible for the difference in the assimilation of trace metals at different food quantities observed in mussels.

Body composition and compensatory growth in Nile tilapia Oreochromis niloticus under different feeding intervals

NASA Astrophysics Data System (ADS)

Gao, Yang; Wang, Ziwei; Hur, Jun-wook; Lee, Jeong-Yeol

2015-07-01

We investigated the growth and body composition of Nile tilapia under five different feeding regimes. A control group was fed to satiation twice daily for 185 days; four treatment groups were fed at intervals of 2, 3, 4 or 7 days (dietary `restricted' period, days 0-80) and then fed to satiation (`refeeding' period, days 80-185). Compensatory growth in weight and length of the feed-restricted groups was observed during the refeeding period. However, the growth of none of the restricted groups caught up with that of the control group over the experimental period. Feed intake upon refeeding increased with the duration of deprivation. There were no significant differences in feed efficiency between the restricted and control groups during the refeeding stage, suggesting that hyperphagia was the mechanism responsible for the increased growth rates during this period. Tilapia preferentially used n-3 polyunsaturated fatty acids and nonessential amino acids during the restricted-feeding period. Higher production was achieved by higher feed consumption. We suggest that if attainment of market size in minimum time is required, fish should be consistently fed to satiation, while taking care to avoid the possible negative consequences of overfeeding.

pH, dissolved oxygen, and adsorption effects on metal removal in anaerobic bioreactors.

PubMed

Willow, Mark A; Cohen, Ronald R H

2003-01-01

Anaerobic bioreactors were used to test the effect of the pH of influent on the removal efficiency of heavy metals from acid-rock drainage. Two studies used a near-neutral-pH, metal-laden influent to examine the heavy metal removal efficiency and hydraulic residence time requirements of the reactors. Another study used the more typical low-pH mine drainage influent. Experiments also were done to (i) test the effects of oxygen content of feed water on metal removal and (ii) the adsorptive capacity of the reactor organic substrate. Analysis of the results indicates that bacterial sulfate reduction may be a zero-order kinetic reaction relative to sulfate concentrations used in the experiments, and may be the factor that controls the metal mass removal efficiency in the anaerobic treatment systems. The sorptive capacities of the organic substrate used in the experiments had not been exhausted during the experiments as indicated by the loading rates of removal of metals exceeding the mass production rates of sulfide. Microbial sulfate reduction was less in the reactors receiving low-pH influent during experiments with short residence times. Sulfate-reducing bacteria may have been inhibited by high flows of low-pH water. Dissolved oxygen content of the feed waters had little effect on sulfate reduction and metal removal capacity.

Efficiency of inductively torch plasma operating at atmospheric pressure on destruction of chlorinated liquid wastes- A path to the treatment of radioactive organic halogen liquid wastes

NASA Astrophysics Data System (ADS)

Kamgang-Youbi, G.; Poizot, K.; Lemont, F.

2012-12-01

The performance of a plasma reactor for the degradation of chlorinated hydrocarbon waste is reported. Chloroform was used as a target for a recently patented destruction process based using an inductive plasma torch. Liquid waste was directly injected axially into the argon plasma with a supplied power of ~4 kW in the presence of oxygen as oxidant and carrier gas. Decomposition was performed at CHCl3 feed rates up to 400 g·h-1 with different oxygen/waste molar ratios, chloroform destruction was obtained with at least 99% efficiency and the energy efficiency reached 100 g·kWh-1. The conversion end products were identified and assayed by online FTIR spectroscopy (CO2, HCl and H2O) and redox titration (Cl2). Considering phosgene as representative of toxic compounds, only very small quantities of toxics were released (< 1 g·h-1) even with high waste feed rates. The experimental results were very close to the equilibrium composition predicted by thermodynamic calculations. At the bottom of the reactor, the chlorinated acids were successfully trapped in a scrubber and transformed into mineral salts, hence, only CO2 and H2O have been found in the final off-gases composition.

Novel concept of recycling sludge and dust to BOF converter through dispersed in-situ phase induced by composite ball explosive reaction

NASA Astrophysics Data System (ADS)

Tang, Fu-ping; Yu, Shu-juan; Fei, Peng; Hou, Hou-yu; Qian, Feng; Wang, Xiao-feng

2017-08-01

Recycling of iron and steelmaking dusts is a key issue in environmental protection efforts and to ensure efficient utilization. In this investigation, we developed a novel recovery process that uses a dispersed in-situ phase induced by an explosive reaction of composite balls of iron and steelmaking dusts. We designed and prepared composite balls for this function using a laboratory model batch-type balling disc (at 12 r/min) and optimized the feeding modes in 180-t and 260-t basic oxygen furnace (BOF) converters. The results indicate that feeding composite balls into BOF converters is an effective novel technology for recovering iron and steelmaking dusts. The period after hot metal charging and prior to the oxygen-blowing process is the most reasonable time to feed composite balls. Composite ball treatment is not appropriate for steel production with sulfur requirements lower than 80 ppm. The maximum composite ball feeding amount is 40 kg/t and the iron yield rate is better than 95%. Compared with the conventional recycling process of sludge and dust, this novel technology is more convenient and efficient, saving up to 309 RMB per ton of steel. Further investigation of this novel recycling technology is merited.

Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: II. Carcass and meat quality.

PubMed

Molette, C; Gilbert, H; Larzul, C; Balmisse, E; Ruesche, J; Manse, H; Tircazes, A; Theau-Clément, M; Joly, T; Gidenne, T; Garreau, H; Drouilhet, L

2016-01-01

To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding. The aim of the present study was to evaluate the impact on carcass and meat quality of the genetic selections. This comparison was performed using 2 different feeding strategies corresponding to the selection design. Carcass and meat quality traits were recorded for the 3 lines (ConsoResidual, ADGrestrict, and an unselected control [generation 0 {G0}]) in the 2 feeding systems (ad libitum and restricted) for 163 animals. Concerning the line effect, the BW at 63 d old was higher for the ADGrestrict line compared with the G0 and ConsoResidual lines ( < 0.0001). There was no line effect on the gastrointestinal tract. The rabbits did not exhibit a different carcass yield but showed different carcass traits. Indeed, the ConsoResidual rabbits had a higher hind leg yield ( < 0.0001) but no difference in the meat-to-bone ratio of the hind leg. On the contrary, the ADGrestrict line had a higher proportion of forelegs plus thoracic cage ( = 0.03). We also found lower perirenal ( < 0.0001) and scapular fat yields ( < 0.0001) in ConsoResidual rabbits. The ADGrestrict line had an intermediate perirenal fat yield compared with the other 2 lines. The G0 line always exhibited higher fat yields. Concerning meat quality, the ConsoResidual rabbits showed a lower ultimate pH ( < 0.0001) and higher water loss (drip and cooking loss; < 0.002) compared with the G0 and ADGrestrict rabbits. The feeding level had a strong effect on the gastrointestinal tract ( = 0.0004) and the carcass yield ( = 0.001). The latter was decreased in restricted rabbits. The effects of feeding strategy on meat quality were detrimental in the case of restricted feeding. Even if the ultimate pH was slightly higher in restricted rabbits ( = 0.0002), the carcass chilling loss ( = 0.0005) and the drip loss during 6 d ( < 0.0001) were higher. The selection on ADG with restricted access to feed seems to be less adversely correlated with carcass traits and meat quality traits but it leads to an increase in the live weight of the rabbits. Adversely, the selection on RFI, without affecting growth rate, would not modify age at slaughter because growth rate is not affected, but it might induce detrimental effects on meat quality.

Phenotypic and genetic relationships of residual feed intake measures and their component traits with fatty acid composition in subcutaneous adipose of beef cattle.

PubMed

Zhang, F; Ekine-Dzivenu, C; Vinsky, M; Basarab, J A; Aalhus, J L; Dugan, M E R; Li, C

2017-07-01

Feed efficiency is of particular interest to the beef industry because feed is the largest variable cost in production and fatty acid composition is emerging as an important trait, both economically and socially, due to the potential implications of dietary fatty acids on human health. Quantifying correlations between feed efficiency and fatty acid composition will contribute to construction of optimal multiple-trait selection indexes to maximize beef production profitability. In the present study, we estimated phenotypic and genetic correlations of feed efficiency measures including residual feed intake (RFI), RFI adjusted for final ultrasound backfat thickness (RFIf); their component traits ADG, DMI, and metabolic BW; and final ultrasound backfat thickness measured at the end of feedlot test with 25 major fatty acids in the subcutaneous adipose tissues of 1,366 finishing steers and heifers using bivariate animal models. The phenotypic correlations of RFI and RFIf with the 25 individual and grouped fatty acid traits were generally low (<0.25 in magnitude). However, relatively stronger genetic correlation coefficients of RFI and RFIf with PUFA traits including the -6:-3 ratio (0.52 ± 0.29 and 0.45 ± 0.31, respectively), 18:2-6 (0.45 ± 0.18 and 0.40 ± 0.19, respectively), -6 (0.43 ± 0.18 and 0.38 ± 0.19, respectively), PUFA (0.42 ± 0.18 and 0.36 ± 0.20, respectively), and 9-16:1 (-0.43 ± 0.20 and -0.33 ± 0.22, respectively) were observed. Hence, selection for low-RFI or more efficient beef cattle will improve fatty acid profiles by lowering the content of -6 PUFA, thus reducing the ratio of -6 to -3 along with increasing the amount of 9-16:1. Moderate to moderately high genetic correlations were also observed for DMI with 9-14:1 (-0.32 ± 0.17) and the sum of CLA analyzed (SumCLA; -0.45 ± 0.21), suggesting that selection of beef cattle with lower DMI will lead to an increase amount of 9-14:1 and SumCLA in the subcutaneous adipose tissue. However, unfavorable genetic correlations were detected for ADG with 11-18:1 (-0.38 ± 0.23) and SumCLA (-0.73 ± 0.26), implying that selection of beef cattle with a better growth rate will decrease the contents of healthy fatty acids 11-18:1 and SumCLA. Therefore, it is recommended that a multiple-trait selection index be used when genetic improvements of fatty acid composition, feed efficiency, feed intake, and growth are important in the breeding objective.

Mitigation of harmful indoor organic vapors using plug-flow unit coated with 2D g-C3N4 and metallic Cu dual-incorporated 1D titania heterostructure.

PubMed

Kim, Dong Jin; Jo, Wan-Kuen

2018-07-01

Herein, a plug-flow reactor coated with one-dimensional (1D) TiO 2 nanotube (TNT) heterostructures incorporated with g-C 3 N 4 (CN) and metallic Cu (CN/Cu/TNT) nanocomposite and irradiated by a daylight lamp was newly applied for the mitigation of harmful indoor organic vapors. The CN/Cu/TNT catalyst showed high mitigation efficiency for all target pollutants, followed by Cu-incorporated TNT (Cu/TNT), CN-incorporated TNT (CN/TNT), TNT, and TiO 2 , in that order. The order of their photocatalytic activities agrees with that of the electron‒hole separation rates determined from their photoluminescence emission spectra. The mitigation efficiency of the CN/Cu/TNT catalyst increased as the CN-to-Cu/TNT percentage was increased from 1% to 10%, but subsequently decreased as the CN-to-Cu/TNT percentage increased to 20%. The mitigation efficiencies of the CN/Cu/TNT catalyst decreased with increasing relative humidity, feed pollutant concentrations, and airstream flow rates. However, in most cases, the reaction rates of the target compounds increased when the feed concentration was increased from 1 to 5 ppm. The mineralization rates of all target pollutants were lower than the corresponding photocatalytic mitigation rates, which could be ascribed to the production of CO and organic intermediates observed during the photocatalysis of the target pollutants. Nevertheless, the intermediates formed during the photocatalytic mitigation process would not cause significant adverse health effects to building occupants, because their concentrations were far below their exposure or threshold limit values. A probable mechanism for the photocatalytic mitigation of the organic vapors by the CN/Cu/TNT catalyst under daylight illumination was also proposed. Copyright © 2018 Elsevier Ltd. All rights reserved.

Creep feeding nursing beef calves.

PubMed

Lardy, Gregory P; Maddock, Travis D

2007-03-01

Creep feeding can be used to increase calf weaning weights. However, the gain efficiency of free-choice, energy-based creep feeds is relatively poor. Generally, limit-feeding, high-protein creep feeds are more efficient, and gains may be similar to those produced by creep feeds offered free choice. Creep feeding can increase total organic matter intake and improve the overall energy status of the animal. Creep-fed calves tend to acclimate to the feedlot more smoothly than unsupplemented calves. Furthermore, provision of a high-starch creep feed may have a positive influence on subsequent carcass quality traits. Creep feeding can be applied to numerous environmental situations to maximize calf performance; however, beef cattle producers should consider their individual situations carefully before making the decision to creep feed.

21 CFR 558.62 - Arsanilic acid.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Indications for use Limitations Sponsor (i) 45 to 90 1. Growing chickens: For growth promotion and feed...) .......do 015565 (iii) Erythromycin 4.6 Chickens; growth promotion and feed efficiency; improving.... 012487 (iv) Erythromycin 4.6 to 18.5 Chickens; growth promotion and feed efficiency; improving...

Design of a novel automated methanol feed system for pilot-scale fermentation of Pichia pastoris.

PubMed

Hamaker, Kent H; Johnson, Daniel C; Bellucci, Joseph J; Apgar, Kristie R; Soslow, Sherry; Gercke, John C; Menzo, Darrin J; Ton, Christopher

2011-01-01

Large-scale fermentation of Pichia pastoris requires a large volume of methanol feed during the induction phase. However, a large volume of methanol feed is difficult to use in the processing suite because of the inconvenience of constant monitoring, manual manipulation steps, and fire and explosion hazards. To optimize and improve safety of the methanol feed process, a novel automated methanol feed system has been designed and implemented for industrial fermentation of P. pastoris. Details of the design of the methanol feed system are described. The main goals of the design were to automate the methanol feed process and to minimize the hazardous risks associated with storing and handling large quantities of methanol in the processing area. The methanol feed system is composed of two main components: a bulk feed (BF) system and up to three portable process feed (PF) systems. The BF system automatically delivers methanol from a central location to the portable PF system. The PF system provides precise flow control of linear, step, or exponential feed of methanol to the fermenter. Pilot-scale fermentations with linear and exponential methanol feeds were conducted using two Mut(+) (methanol utilization plus) strains, one expressing a recombinant therapeutic protein and the other a monoclonal antibody. Results show that the methanol feed system is accurate, safe, and efficient. The feed rates for both linear and exponential feed methods were within ± 5% of the set points, and the total amount of methanol fed was within 1% of the targeted volume. Copyright © 2011 American Institute of Chemical Engineers (AIChE).

Oxygen minimum zone: An important oceanographic habitat for deep-diving northern elephant seals, Mirounga angustirostris.

PubMed

Naito, Yasuhiko; Costa, Daniel P; Adachi, Taiki; Robinson, Patrick W; Peterson, Sarah H; Mitani, Yoko; Takahashi, Akinori

2017-08-01

Little is known about the foraging behavior of top predators in the deep mesopelagic ocean. Elephant seals dive to the deep biota-poor oxygen minimum zone (OMZ) (>800 m depth) despite high diving costs in terms of energy and time, but how they successfully forage in the OMZ remains largely unknown. Assessment of their feeding rate is the key to understanding their foraging behavior, but this has been challenging. Here, we assessed the feeding rate of 14 female northern elephant seals determined by jaw motion events (JME) and dive cycle time to examine how feeding rates varied with dive depth, particularly in the OMZ. We also obtained video footage from seal-mounted videos to understand their feeding in the OMZ. While the diel vertical migration pattern was apparent for most depths of the JME, some very deep dives, beyond the normal diel depth ranges, occurred episodically during daylight hours. The midmesopelagic zone was the main foraging zone for all seals. Larger seals tended to show smaller numbers of JME and lower feeding rates than smaller seals during migration, suggesting that larger seals tended to feed on larger prey to satisfy their metabolic needs. Larger seals also dived frequently to the deep OMZ, possibly because of a greater diving ability than smaller seals, suggesting their dependency on food in the deeper depth zones. Video observations showed that seals encountered the rarely reported ragfish ( Icosteus aenigmaticus ) in the depths of the OMZ, which failed to show an escape response from the seals, suggesting that low oxygen concentrations might reduce prey mobility. Less mobile prey in OMZ would enhance the efficiency of foraging in this zone, especially for large seals that can dive deeper and longer. We suggest that the OMZ plays an important role in structuring the mesopelagic ecosystem and for the survival and evolution of elephant seals.

Filter-feeding, near-field flows, and the morphologies of colonial choanoflagellates

NASA Astrophysics Data System (ADS)

Kirkegaard, Julius B.; Goldstein, Raymond E.

2016-11-01

Efficient uptake of prey and nutrients from the environment is an important component in the fitness of all microorganisms, and its dependence on size may reveal clues to the origins of evolutionary transitions to multicellularity. Because potential benefits in uptake rates must be viewed in the context of other costs and benefits of size, such as varying predation rates and the increased metabolic costs associated with larger and more complex body plans, the uptake rate itself is not necessarily that which is optimized by evolution. Uptake rates can be strongly dependent on local organism geometry and its swimming speed, providing selective pressure for particular arrangements. Here we examine these issues for choanoflagellates, filter-feeding microorganisms that are the closest relatives of the animals. We explore the different morphological variations of the choanoflagellate Salpingoeca rosetta, which can exist as a swimming cell, as a sessile thecate cell, and as colonies of cells in various shapes. In the absence of other requirements and in a homogeneously nutritious environment, we find that the optimal strategy to maximize filter-feeding by the collar of microvilli is to swim fast, which favors swimming unicells. In large external flows, the sessile thecate cell becomes advantageous. Effects of prey diffusion are discussed and also found to be to the advantage of the swimming unicell.

Feeding of swimming Paramecium with fore-aft asymmetry in viscous fluid

NASA Astrophysics Data System (ADS)

Zhang, Peng; Jana, Saikat; Giarra, Matthew; Vlachos, Pavlos; Jung, Sunghwan

2013-11-01

Swimming behaviours and feeding efficiencies of Paramecium Multimicronucleatum with fore-aft asymmetric body shapes are studied experimentally and numerically. Among various possible swimming ways, ciliates typically exhibit only one preferred swimming directions in favorable conditions. Ciliates, like Paramecia, with fore-aft asymmetric shapes preferably swim towards the slender anterior while feeding fluid to the oral groove located at the center of the body. Since both feeding and swimming efficiencies are influenced by fluid motions around the body, it is important to reveal the fluid mechanics around a moving object. Experimentally, μ-PIV methods are employed to characterize the source-dipole streamline patterns and fluid motions around Paramecium. Numerical simulations by boundary element methods are also used to evaluate surface stresses and velocities, which give insights into the efficiencies of swimming and feeding depending on body asymmetry. It is concluded that a slender anterior and fat posterior increases the combined efficiency of swimming and feeding, which matches well with actual shapes of Paramecium. Discrepancies between experiments and simulations are also discussed.

Application of the multiphase optimization strategy to a pilot study: an empirical example targeting obesity among children of low-income mothers.

PubMed

Kugler, Kari C; Balantekin, Katherine N; Birch, Leann L; Savage, Jennifer S

2016-11-22

Emerging approaches to building more efficient and effective behavioral interventions are becoming more widely available. The current paper provides an empirical example of the use of the engineering-inspired multiphase optimization strategy (MOST) to build a remotely delivered responsive parenting intervention to prevent obesity among children of low-income mothers with and without depressive symptoms. Participants were 107 mothers with (n = 45) and without (n = 62) depressive symptoms who had a child aged 12 to 42 months participating in the Women, Infants and Children program. Participants were randomized to one of sixteen experimental conditions using a factorial design that included a combination of the following eight remotely delivered intervention components: responsive feeding curriculum (given to all participants), parenting curriculum, portion size guidance, obesogenic risk assessment, personalized feedback on mealtime routines, feeding curriculum counseling, goal setting, mobile messaging, and social support. This design enabled efficient identification of components with low feasibility and acceptability. Completion rates were high (85%) and did not statistically differ by depressive symptoms. However, mothers with depressive symptoms who received obesogenic risk assessment and personalized feedback on mealtime routines components had lower completion rates than mothers without depressive symptoms. All intervention components were feasible to implement except the social support component. Regardless of experimental condition, most participants reported that the program increased their awareness of what, when, and how to feed their children. MOST provided an efficient way to assess the feasibility of components prior to testing them with a fully powered experiment. This framework helped identify potentially challenging combinations of remotely delivered intervention components. Consideration of how these results can inform future studies focused on the optimization phase of MOST is discussed.

Improving the efficiency of feed utilization in poultry by selection. 2. Genetic parameters of excretion traits and correlations with anatomy of the gastro-intestinal tract and digestive efficiency.

PubMed

de Verdal, Hugues; Narcy, Agnès; Bastianelli, Denis; Chapuis, Hervé; Même, Nathalie; Urvoix, Séverine; Le Bihan-Duval, Elisabeth; Mignon-Grasteau, Sandrine

2011-08-17

Poultry production has been widely criticized for its negative environmental impact related to the quantity of manure produced and to its nitrogen and phosphorus content. In this study, we investigated which traits related to excretion could be used to select chickens for lower environmental pollution.The genetic parameters of several excretion traits were estimated on 630 chickens originating from 2 chicken lines divergently selected on apparent metabolisable energy corrected for zero nitrogen (AMEn) at constant body weight. The quantity of excreta relative to feed consumption (CDUDM), the nitrogen and phosphorus excreted, the nitrogen to phosphorus ratio and the water content of excreta were measured, and the consequences of such selection on performance and gastro-intestinal tract (GIT) characteristics estimated. The genetic correlations between excretion, GIT and performance traits were established. Heritability estimates were high for CDUDM and the nitrogen excretion rate (0.30 and 0.29, respectively). The other excretion measurements showed low to moderate heritability estimates, ranging from 0.10 for excreta water content to 0.22 for the phosphorus excretion rate. Except for the excreta water content, the CDUDM was highly correlated with the excretion traits, ranging from -0.64 to -1.00. The genetic correlations between AMEn or CDUDM and the GIT characteristics were very similar and showed that a decrease in chicken excretion involves an increase in weight of the upper part of the GIT, and a decrease in the weight of the small intestine. In order to limit the environmental impact of chicken production, AMEn and CDUDM seem to be more suitable criteria to include in selection schemes than feed efficiency traits.

Specific microbiome-dependent mechanisms underlie the energy harvest efficiency of ruminants

PubMed Central

Shabat, Sheerli Kruger Ben; Sasson, Goor; Doron-Faigenboim, Adi; Durman, Thomer; Yaacoby, Shamay; Berg Miller, Margret E; White, Bryan A; Shterzer, Naama; Mizrahi, Itzhak

2016-01-01

Ruminants have the remarkable ability to convert human-indigestible plant biomass into human-digestible food products, due to a complex microbiome residing in the rumen compartment of their upper digestive tract. Here we report the discovery that rumen microbiome components are tightly linked to cows' ability to extract energy from their feed, termed feed efficiency. Feed efficiency was measured in 146 milking cows and analyses of the taxonomic composition, gene content, microbial activity and metabolomic composition was performed on the rumen microbiomes from the 78 most extreme animals. Lower richness of microbiome gene content and taxa was tightly linked to higher feed efficiency. Microbiome genes and species accurately predicted the animals' feed efficiency phenotype. Specific enrichment of microbes and metabolic pathways in each of these microbiome groups resulted in better energy and carbon channeling to the animal, while lowering methane emissions to the atmosphere. This ecological and mechanistic understanding of the rumen microbiome could lead to an increase in available food resources and environmentally friendly livestock agriculture. PMID:27152936

Specific microbiome-dependent mechanisms underlie the energy harvest efficiency of ruminants.

PubMed

Shabat, Sheerli Kruger Ben; Sasson, Goor; Doron-Faigenboim, Adi; Durman, Thomer; Yaacoby, Shamay; Berg Miller, Margret E; White, Bryan A; Shterzer, Naama; Mizrahi, Itzhak

2016-12-01

Ruminants have the remarkable ability to convert human-indigestible plant biomass into human-digestible food products, due to a complex microbiome residing in the rumen compartment of their upper digestive tract. Here we report the discovery that rumen microbiome components are tightly linked to cows' ability to extract energy from their feed, termed feed efficiency. Feed efficiency was measured in 146 milking cows and analyses of the taxonomic composition, gene content, microbial activity and metabolomic composition was performed on the rumen microbiomes from the 78 most extreme animals. Lower richness of microbiome gene content and taxa was tightly linked to higher feed efficiency. Microbiome genes and species accurately predicted the animals' feed efficiency phenotype. Specific enrichment of microbes and metabolic pathways in each of these microbiome groups resulted in better energy and carbon channeling to the animal, while lowering methane emissions to the atmosphere. This ecological and mechanistic understanding of the rumen microbiome could lead to an increase in available food resources and environmentally friendly livestock agriculture.

Improving production efficiency in the presence of genotype by environment interactions in pig genomic selection breeding programmes.

PubMed

Nirea, K G; Meuwissen, T H E

2017-04-01

We simulated a genomic selection pig breeding schemes containing nucleus and production herds to improve feed efficiency of production pigs that were cross-breed. Elite nucleus herds had access to high-quality feed, and production herds were fed low-quality feed. Feed efficiency in the nucleus herds had a heritability of 0.3 and 0.25 in the production herds. It was assumed the genetic relationships between feed efficiency in the nucleus and production were low (r g  = 0.2), medium (r g  = 0.5) and high (r g  = 0.8). In our alternative breeding schemes, different proportion of production animals were recorded for feed efficiency and genotyped with high-density panel of genetic markers. Genomic breeding value of the selection candidates for feed efficiency was estimated based on three different approaches. In one approach, genomic breeding value was estimated including nucleus animals in the reference population. In the second approach, the reference population was containing a mixture of nucleus and production animals. In the third approach, the reference population was only consisting of production herds. Using a mixture reference population, we generated 40-115% more genetic gain in the production environment as compared to only using nucleus reference population that were fed high-quality feed sources when the production animals were offspring of the nucleus animals. When the production animals were grand offspring of the nucleus animals, 43-104% more genetic gain was generated. Similarly, a higher genetic gain generated in the production environment when mixed reference population was used as compared to only using production animals. This was up to 19 and 14% when the production animals were offspring and grand offspring of nucleus animals, respectively. Therefore, in genomic selection pig breeding programmes, feed efficiency traits could be improved by properly designing the reference population. © 2016 Blackwell Verlag GmbH.

Flexibility of Physiological Traits Underlying Inter-Individual Growth Differences in Intertidal and Subtidal Mussels Mytilusgalloprovincialis

PubMed Central

Fernández-Reiriz, María José; Irisarri, Jade; Labarta, Uxio

2016-01-01

Mussel seed (Mytilusgalloprovincialis) gathered from the intertidal and subtidal environments of a Galician embayment (NW, Spain) were maintained in the laboratory during five months to select fast (F) and slow (S) growing mussels. The physiological basis underlying inter-individual growth variations were compared for F and S mussels from both origins. Fast growing seemed to be a consequence of greater energy intake (20% higher clearance and ingestion rate) and higher food absorption rate coupled with low metabolic costs. The enhanced energy absorption (around 65% higher) resulted in 3 times higher Scope for Growth in F mussels (20.5±4.9 J h−1) than S individuals (7.3±1.1 J h−1). The higher clearance rate of F mussels appears to be linked with larger gill filtration surface compared to S mussels. Intertidal mussels showed higher food acquisition and absorption per mg of organic weight (i.e. mass-specific standardization) than subtidal mussels under the optimal feeding conditions of the laboratory. However, the enhanced feeding and digestive rates were not enough to compensate for the initial differences in tissue weight between mussels of similar shell length collected from the intertidal and subtidal environments. At the end of the experiment, subtidal individuals had higher gill efficiency, which probably lead to higher total feeding and absorption rates relative to intertidal individuals. PMID:26849372

Revisiting Trypanosoma rangeli Transmission Involving Susceptible and Non-Susceptible Hosts

PubMed Central

Ferreira, Luciana de Lima; Pereira, Marcos Horácio; Guarneri, Alessandra Aparecida

2015-01-01

Trypanosoma rangeli infects several triatomine and mammal species in South America. Its transmission is known to occur when a healthy insect feeds on an infected mammal or when an infected insect bites a healthy mammal. In the present study we evaluated the classic way of T. rangeli transmission started by the bite of a single infected triatomine, as well as alternative ways of circulation of this parasite among invertebrate hosts. The number of metacyclic trypomastigotes eliminated from salivary glands during a blood meal was quantified for unfed and recently fed nymphs. The quantification showed that ~50,000 parasites can be liberated during a single blood meal. The transmission of T. rangeli from mice to R. prolixus was evaluated using infections started through the bite of a single infected nymph. The mice that served as the blood source for single infected nymphs showed a high percentage of infection and efficiently transmitted the infection to new insects. Parasites were recovered by xenodiagnosis in insects fed on mice with infections that lasted approximately four months. Hemolymphagy and co-feeding were tested to evaluate insect-insect T. rangeli transmission. T. rangeli was not transmitted during hemolymphagy. However, insects that had co-fed on mice with infected conspecifics exhibited infection rates of approximately 80%. Surprisingly, 16% of the recipient nymphs became infected when pigeons were used as hosts. Our results show that T. rangeli is efficiently transmitted between the evaluated hosts. Not only are the insect-mouse-insect transmission rates high, but parasites can also be transmitted between insects while co-feeding on a living host. We show for the first time that birds can be part of the T. rangeli transmission cycle as we proved that insect-insect transmission is feasible during a co-feeding on these hosts. PMID:26469403

Performance assessment of two-stage anaerobic digestion of kitchen wastes.

PubMed

Bo, Zhang; Pin-Jing, He

2014-01-01

This study is aimed at investigating the performance of the two-phase anaerobic digestion of kitchen wastes in a lab-scale setup. The semi-continuous experiment showed that the two-phase anaerobic digestion of kitchen wastes had a bioconversion rate of 83%, biogas yield of 338 mL x (g chemical oxygen demand (COD))(-1) and total solid conversion of 63% when the entire two-phase anaerobic digestion process was subjected to an organic loading rate (OLR) of 10.7 g x (L d)(-1). In the hydrolysis-acidogenesis process, the efficiency of solubilization decreased from 72.6% to 41.1%, and the acidogenesis efficiency decreased from 31.8% to 17.8% with an increase in the COD loading rate. On the other hand, the performance of the subsequent methanogenic process was not susceptible to the increase in the feeding COD loading rate in the hydrolysis-acidogenesis stage. Lactic acid was one of the main fermentation products, accounting for over 40% of the total soluble COD in the fermentation liquid. The batch experiments indicated that the lactic acid was the earliest predominant fermentation product, and distributions of fermentation products were pH dependent. Results showed that increasing the feeding OLR of kitchen wastes made the two-stage anaerobic digestion process more effective. Moreover, there was a potential improvement in the performance of anaerobic digestion of kitchen wastes with a corresponding improvement in the hydrolysis process.

The effects of aquaculture production noise on the growth, condition factor, feed conversion, and survival of rainbow trout, Oncorhynchus mykiss

USGS Publications Warehouse

Davidson, J.; Bebak, J.; Mazik, P.

2009-01-01

Intensive aquaculture systems, particularly recirculating systems, utilize equipment such as aerators, air and water pumps, blowers, and filtration systems that inadvertently increase noise levels in fish culture tanks. Sound levels and frequencies measured within intensive aquaculture systems are within the range of fish hearing, but species-specific effects of aquaculture production noise are not well defined. Field and laboratory studies have shown that fish behavior and physiology can be negatively impacted by intense sound. Therefore, chronic exposure to aquaculture production noise could cause increased stress, reduced growth rates and feed conversion efficiency, and decreased survival. The objective of this study was to provide an in-depth evaluation of the long term effects of aquaculture production noise on the growth, condition factor, feed conversion efficiency, and survival of cultured rainbow trout, Oncorhynchus mykiss. Rainbow trout were cultured in replicated tanks using two sound treatments: 117??dB re 1????Pa RMS which represented sound levels lower than those recorded in an intensive recycle system and 149??dB re 1????Pa RMS, representing sound levels near the upper limits known to occur in recycle systems. To begin the study mean fish weights in the 117 and 149??dB tanks were 40 and 39??g, respectively. After five months of exposure no significant differences were identified between treatments for mean weight, length, specific growth rates, condition factor, feed conversion, or survival (n = 4). Mean final weights for the 117 and 149??dB treatments were 641 ?? 3 and 631 ?? 10??g, respectively. Overall specific growth rates were equal, i.e. 1.84 ?? 0.00 and 1.84 ?? 0.01%/day. Analysis of growth rates of individually tagged rainbow trout indicated that fish from the 149??dB tanks grew slower during the first month of noise exposure (p < 0.05); however, fish acclimated to the noise thereafter. This study further suggests that rainbow trout growth and survival are unlikely to be affected over the long term by noise levels common to intensive aquaculture systems. ?? 2008 Elsevier B.V.

Ingestive Behavior of Heifers Supplemented with Glycerin in Substitution of Corn on Brachiaria brizantha Pasture

PubMed Central

Facuri, L. M. A. M.; Silva, R. R.; da Silva, F. F.; de Carvalho, G. G. P.; Sampaio, C. B.; Mendes, F. B. L.; Lisboa, M. M.; Barroso, D. S.; Carvalho, V. M.; Pereira, M. M. S.

2014-01-01

The objective was to evaluate the ingestive behavior of crossbred heifers finished on a Brachiaria brizantha cv. Marandu pasture receiving four levels of glycerin in their supplementation. Thirty-six crossbred heifers with average initial weight of 264.83±3.83 kg and 20 months of age were distributed into a completely randomized design with four treatments and nine replications: control (0%), 4.82%, 10.12%, and 15.56% glycerin in the dry matter. The grazing time reduced linearly (p<0.05), whereas the time spent on activities like rumination, idleness, trough and total chewing time were quadratically affected (p<0.05). Bite rate and number of bites/day were quadratically influenced (p<0.05). The number of bites/swallowed cud and the number of bites/minute, however, increased linearly (p<0.05). Although the time spent on each cud and number of chews per cud were not affected (p>0.05). The number of rumination periods reduced linearly (p<0.05), whereas the number of grazing, idle and trough periods, and the times per grazing, idle, rumination and trough periods were quadratically affected (p<0.05). The feed and rumination efficiencies of the dry matter, non-fibrous carbohydrates, pasture dry matter and concentrate were quadratically affected (p>0.05) whereas the feed efficiency of neutral detergent fiber reduced linearly (p<0.05). Addition of glycerin in substitution of corn in supplements for animals managed on pastures does not influenced feed intake, but reduces the grazing time and increases the idle time. The supplementation also improves feed and rumination efficiencies. PMID:25358318

Process optimization for ultrasonic vibration assisted polishing of micro-structured surfaces on super hard material

NASA Astrophysics Data System (ADS)

Sun, Zhiyuan; Guo, Bing; Rao, Zhimin; Zhao, Qingliang

2014-08-01

In consideration of the excellent property of SiC, the ground micro-structured surface quality is hard to meet the requirement - consequently the ultrasonic vibration assisted polishing (UVAP) of micro-structures of molds is proposed in this paper. Through the orthogonal experiment, the parameters of UVAP of micro-structures were optimized. The experimental results show that, abrasive polishing process, the effect of the workpiece feed rate on the surface roughness (Ra), groove tip radius (R) and material removal rate (MRR) of micro-structures is significant. While, the UVAP, the most significant effect factor for Ra, R and MRR is the ultrasonic amplitude of the ultrasonic vibration. In addition, within the scope of the polishing process parameters selected by preliminary experiments, ultrasonic amplitude of 2.5μm, polishing force of 0.5N, workpiece feed rate of 5 mm·min-1, polishing wheel rotational speed of 50rpm, polishing time of 35min, abrasive size of 100nm and the polishing liquid concentration of 15% is the best technology of UVAP of micro-structures. Under the optimal parameters, the ground traces on the micro-structured surface were removed efficiently and the integrity of the edges of the micro-structure after grinding was maintained efficiently.

Western Spruce Budworm Consumption-Effects of Host Species and Foliage Chemistry

Treesearch

Michael R. Wagner; Elizabeth A.  Blake

1983-01-01

Feeding efficiencies and growth rates of western spruce budworm larvae varied among hosts tested. Pupae attained normal size regardless of host species. Candidate defensive compounds (tannins and phenols) varied only slightly with the vigor of the host. The relationship between these defensive compounds and measures of larvae growth were not entirely consistent with...

High speed machining of space shuttle external tank liquid hydrogen barrel panel

NASA Technical Reports Server (NTRS)

Hankins, J. D.

1983-01-01

Actual and projected optimum High Speed Machining data for producing shuttle external tank liquid hydrogen barrel panels of aluminum alloy 2219-T87 are reported. The data included various machining parameters; e.g., spindle speeds, cutting speed, table feed, chip load, metal removal rate, horsepower, cutting efficiency, cutter wear (lack of) and chip removal methods.

High speed machining of space shuttle external tank liquid hydrogen barrel panel

NASA Astrophysics Data System (ADS)

Hankins, J. D.

1983-11-01

Actual and projected optimum High Speed Machining data for producing shuttle external tank liquid hydrogen barrel panels of aluminum alloy 2219-T87 are reported. The data included various machining parameters; e.g., spindle speeds, cutting speed, table feed, chip load, metal removal rate, horsepower, cutting efficiency, cutter wear (lack of) and chip removal methods.

Associations of rumen parameters with feed efficiency and sampling routine in beef cattle.

PubMed

Lam, S; Munro, J C; Zhou, M; Guan, L L; Schenkel, F S; Steele, M A; Miller, S P; Montanholi, Y R

2018-07-01

Characterizing ruminal parameters in the context of sampling routine and feed efficiency is fundamental to understand the efficiency of feed utilization in the bovine. Therefore, we evaluated microbial and volatile fatty acid (VFA) profiles, rumen papillae epithelial and stratum corneum thickness and rumen pH (RpH) and temperature (RT) in feedlot cattle. In all, 48 cattle (32 steers plus 16 bulls), fed a high moisture corn and haylage-based ration, underwent a productive performance test to determine residual feed intake (RFI) using feed intake, growth, BW and composition traits. Rumen fluid was collected, then RpH and RT logger were inserted 5.5±1 days before slaughter. At slaughter, the logger was recovered and rumen fluid and rumen tissue were sampled. The relative daily time spent in specific RpH and RT ranges were determined. Polynomial regression analysis was used to characterize RpH and RT circadian patterns. Animals were divided into efficient and inefficient groups based on RFI to compare productive performance and ruminal parameters. Efficient animals consumed 1.8 kg/day less dry matter than inefficient cattle (P⩽0.05) while achieving the same productive performance (P⩾0.10). Ruminal bacteria population was higher (P⩽0.05) (7.6×1011 v. 4.3×1011 copy number of 16S rRNA gene/ml rumen fluid) and methanogen population was lower (P⩽0.05) (2.3×109 v. 4.9×109 copy number of 16S rRNA gene/ml rumen fluid) in efficient compared with inefficient cattle at slaughter with no differences (P⩾0.10) between samples collected on-farm. No differences (P⩾0.10) in rumen fluid VFA were also observed between feed efficiency groups either on-farm or at slaughter. However, increased (P⩽0.05) acetate, and decreased (P⩽0.05) propionate, butyrate, valerate and caproate concentrations were observed at slaughter compared with on-farm. Efficient had increased (P⩽0.05) rumen epithelium thickness (136 v. 126 µm) compared with inefficient cattle. Efficient animals also spent 318% and 93.2% more time (P⩽0.05) in acidotic (4.14% v. 1.30%) (pH⩽5.6) and optimal (5.6

Method for improving dissolution efficiency in gas-absorption and liquid extraction processes. [Patent application

DOEpatents

Kanak, B.E.; Stephenson, M.J.

1980-01-11

A method is described for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

Method for improving dissolution efficiency in gas-absorption and liquid extraction processes

DOEpatents

Kanak, Brant E.; Stephenson, Michael J.

1981-01-01

This invention is a method for improving dissolution efficiency in processes in which a feed fluid is introduced to a zone where it is contacted with a liquid solvent for preferentially removing a component of the feed and where part of the solvent so contacted undergoes transfer into the feed fluid to saturate the same. It has been found that such transfer significantly impairs dissolution efficiency. In accordance with the invention, an amount of the above-mentioned solvent is added to the feed fluid being introduced to the contact zone, the solvent being added in an amount sufficient to effect reduction or elimination of the above-mentioned transfer. Preferably, the solvent is added to the feed fluid in an amount saturating or supersaturating the feed fluid under the conditions prevailing in the contact zone.

Enhanced mitochondrial complex gene function and reduced liver size may mediate improved feed efficiency of beef cattle during compensatory growth

USDA-ARS?s Scientific Manuscript database

Growing ruminants maintained under dietary restriction for extended periods will exhibit compensatory growth when reverted to ad libitum feeding. This period of compensatory growth is associated with increased feed efficiency, lower basal energy requirements, and changes in circulating concentration...

Microbial community profiles of the colon from steers differing in feed efficiency

USDA-ARS?s Scientific Manuscript database

Ruminal microbial fermentation plays an essential role in host nutrition, and as a result, the rumen microbiota have been a major focus of research examining bovine feed efficiency. Microbial communities within other sections of the gastrointestinal tract may also be important with regard to feed ef...

A prototype national cattle evaluation for feed intake and efficiency of Angus cattle

USDA-ARS?s Scientific Manuscript database

Recent development of technologies for measuring individual feed intake has made possible the collection of data suitable for breed-wide genetic evaluation. Goals of this research were to estimate genetic parameters for components of feed efficiency and develop a prototype system for conducting a ge...

Partial-genome evaluation of postweaning feed intake and efficiency of crossbred beef cattle

USDA-ARS?s Scientific Manuscript database

Effects of individual single nucleotide polymorphisms (SNP), and variation explained by sets of SNP associated with dry matter intake (DMI), metabolic mid-test weight (MBW), BW gain (GN) and feed efficiency expressed as phenotypic and genetic residual feed intake (RFIp; RFIg) were estimated from wei...

Cecum microbial communities from steers differing in feed efficiency

USDA-ARS?s Scientific Manuscript database

Aims: To characterize the microbial communities of the cecum among steers differing in feed efficiency. Methods and Results: Individual feed intake (FI) and body weight (BW) gain were determined from animals fed the same ration, within two contemporary groups of steers. BW gain was regressed on F...

Temperament and dominance relate to feeding behaviour and activity in beef cattle: implications for performance and methane emissions.

PubMed

Llonch, P; Somarriba, M; Duthie, C A; Troy, S; Roehe, R; Rooke, J; Haskell, M J; Turner, S P

2018-04-02

In beef cattle, feeding behaviour and activity are associated with feed efficiency and methane (CH4) emissions. This study aimed to understand the underlying traits responsible for the contribution of cattle behaviour to individual differences in feed efficiency, performance and CH4 emissions. A total of 84 steers (530±114 kg BW) of two different breeds (crossbreed Charolais and Luing) were used. The experiment was a 2×2×3 factorial design with breed, basal diets (concentrate v. mixed) and dietary treatments (no additive, calcium nitrate or rapeseed cake) as the main factors. The individual dry matter intake (DMI; kg) was recorded daily and the BW was measured weekly over a 56-day period. Ultrasound fat depth was measured on day 56. Based on the previous data, the indexes average daily gain, food conversion and residual feed intake (RFI) were calculated. The frequency of meals, the duration per visit and the time spent feeding per day were taken as feeding behaviour measures. Daily activity was measured using the number of steps, the number of standing bouts and the time standing per day. Agonistic interactions (including the number of contacts, aggressive interactions, and displacements per day) between steers at the feeders were assessed as indicators of dominance. Temperament was assessed using the crush score test (which measures restlessness when restrained) and the flight speed on release from restraint. Statistical analysis was performed using multivariate regression models. Steers that spent more time eating showed better feed efficiency (P=0.039), which can be due to greater secretion of saliva. Feeding time was longer with the mixed diet (P<0.001), Luings (P=0.009) and dominant steers (P=0.032). Higher activity (more steps) in the pen was associated with poorer RFI, possibly because of higher energy expenditure for muscle activity. Frequent meals contributed to a reduction in CH4 emissions per kg DMI. The meal frequency was higher with a mixed diet (P<0.001) and increased in more temperamental (P=0.003) and dominant (P=0.017) steers. In addition, feed intake was lower (P=0.032) in more temperamental steers. This study reveals that efficiency increases with a longer feeding time and CH4 emissions decrease with more frequent meals. As dominant steers eat more frequently and for longer, a reduction in competition at the feeder would improve both feed efficiency and CH4 emissions. Feed efficiency can also be improved through a reduction in activity. Selection for calmer cattle would reduce activity and increase feed intake, which may improve feed efficiency and promote growth, respectively.

The Hungry Fly: Hydrodynamics of feeding in the common house fly

NASA Astrophysics Data System (ADS)

Prakash, Manu; Steele, Miles

2010-11-01

A large number of insect species feed primarily on a fluid diet. To do so, they must overcome the numerous challenges that arise in the design of high-efficiency, miniature pumps. Although the morphology of insect feeding structures has been described for decades, their dynamics remain largely unknown even in the most well studied species (e.g. fruit fly). Here, we use invivo imaging and microsurgery to elucidate the design principles of feeding structures of the common house fly. Using high-resolution X-ray microscopy, we record invivo flow of sucrose solutions through the body over many hours during fly feeding. Borrowing from microsurgery techniques common in neurophysiology, we are able to perturb the pump to a stall position and thus evaluate function under load conditions. Furthermore, fluid viscosity-dependent feedback is observed for optimal pump performance. As the gut of the fly starts to fill up, feedback from the stretch receptors in the cuticle dictates the effective flow rate. Finally, via comparative analysis between the house fly, blow fly, fruit fly and bumble bees, we highlight the common design principles and the role of interfacial phenomena in feeding.

Deoxynivalenol, zearalenone and T-2 in grain based swine feed in Hungary.

PubMed

Tima, Helga; Rácz, Anita; Guld, Zsuzsanna; Mohácsi-Farkas, Csilla; Kiskó, Gabriella

2016-12-01

Fusarium genera can produce trichothecenes like deoxynivalenol (DON), zearalenone (ZEN) and T-2 toxin, which can occur in feed cereal grains. Enzyme-linked immunosorbent assays (ELISA) tests of different Hungarian swine feedstuff proved that these mycotoxins were present. In this survey, 45 feed samples from 3 significant Hungarian swine feedstuff manufacturers were tested. ELISA methodology validation showed mean recovery rates in ranges from 85.3% to 98.1%, with intermediate precision of 86.9-96.9% and variation coefficients of 3.4-5.7% and 5.9-7.1%, respectively. The results showed that among Fusarium toxins, generally DON was present in the highest concentration, followed by T-2 and finally ZEN in all tested swine feeds. Each of the mycotoxins was found above the limit of detection in all swine feedstuffs. Boars feed's DON (average ± standard deviation was 872 ± 139 µg kg -1 ) and ZEN (172 ± 18 µg kg -1 ) results of one of the manufacturers were above the guidance values. It indicates the necessity for efficient monitoring of DON, ZEN and T-2 mycotoxins in swine feeds.

Shelf-life extension of preservative-free hydrated feed using gamma pasteurization and its effect on growth performance of eel

NASA Astrophysics Data System (ADS)

Kim, Dongho; Song, Hyunpa; Lim, Sangyong; Jo, Minho; Song, Duseop; Jo, Cheorun

2012-08-01

Hydrated feed (HF) promotes the growth performance and shortens the feeding time of fish by increasing the efficiency of digestion. However, the shelf-life of HF is a concern due to its relatively higher water content. In this study, radiation pasteurization was applied to improve the shelf-life and microbiological quality of HF for fish farming. Preservative-free HF containing 25% moisture was gamma-irradiated and its microbiological and nutritional properties evaluated in addition to a practical feeding trial carried out using eel. The viable counts of bacteria and fungi in HF were 106 and 104 CFU/g, respectively. All coliform bacteria and yeast in HF were eliminated by irradiation at a dose of 5 kGy, and total aerobic bacteria were eliminated at 10 kGy. The shelf-life of the preservative-free and irradiated (10 kGy) HF was estimated as 6 months under ambient conditions. The nutritional composition of HF was stable up to 10 kGy of irradiation. Based on a feeding trial, it was proven that eel fed HF had about 20% higher growth rate than that fed dried feed.

The Positive Impact of the Early-Feeding of a Plant-Based Diet on Its Future Acceptance and Utilisation in Rainbow Trout

PubMed Central

Geurden, Inge; Borchert, Peter; Balasubramanian, Mukundh N.; Schrama, Johan W.; Dupont-Nivet, Mathilde; Quillet, Edwige; Kaushik, Sadasivam J.; Panserat, Stéphane; Médale, Françoise

2013-01-01

Sustainable aquaculture, which entails proportional replacement of fish-based feed sources by plant-based ingredients, is impeded by the poor growth response frequently seen in fish fed high levels of plant ingredients. This study explores the potential to improve, by means of early nutritional exposure, the growth of fish fed plant-based feed. Rainbow trout swim-up fry were fed for 3 weeks either a plant-based diet (diet V, V-fish) or a diet containing fishmeal and fish oil as protein and fat source (diet M, M-fish). After this 3-wk nutritional history period, all V- or M-fish received diet M for a 7-month intermediate growth phase. Both groups were then challenged by feeding diet V for 25 days during which voluntary feed intake, growth, and nutrient utilisation were monitored (V-challenge). Three isogenic rainbow trout lines were used for evaluating possible family effects. The results of the V-challenge showed a 42% higher growth rate (P = 0.002) and 30% higher feed intake (P = 0.005) in fish of nutritional history V compared to M (averaged over the three families). Besides the effects on feed intake, V-fish utilized diet V more efficiently than M-fish, as reflected by the on average 18% higher feed efficiency (P = 0.003). We noted a significant family effect for the above parameters (P<0.001), but the nutritional history effect was consistent for all three families (no interaction effect, P>0.05). In summary, our study shows that an early short-term exposure of rainbow trout fry to a plant-based diet improves acceptance and utilization of the same diet when given at later life stages. This positive response is encouraging as a potential strategy to improve the use of plant-based feed in fish, of interest in the field of fish farming and animal nutrition in general. Future work needs to determine the persistency of this positive early feeding effect and the underlying mechanisms. PMID:24386155

Fabrication and test of a space power boiler feed electromagnetic pump. Part 2: Test facility and performance test

NASA Technical Reports Server (NTRS)

Powell, A. H.; Amos, J. C.; Ehde, C. L.; Gahan, J. W.

1972-01-01

A three-phase helical induction electromagnetic pump, designed for the boiler-feed pump of a potassium Rankine-cycle space power system, was built and tested. The pump was tested over a range of potassium temperatures from 900 to 1400 F, flow rates from 0.75 to 4.85 lb/sec, developed pressures up to 340 psi, net positive suction heads (NPSH) from 1 to 22 psi, and NaK coolant temperatures from 800 to 950 F. The maximum efficiency at the pump design point of 3.25 lb/sec flow rate, 240 psi developed pressure, 1000 F potassium inlet temperature, and 800 F NaK coolant temperature was 16.3 percent. The tests also showed successful operation of the pump at an NPSH as low as 1.5 psi without cavitating.

Classification Studies in an Advanced Air Classifier

NASA Astrophysics Data System (ADS)

Routray, Sunita; Bhima Rao, R.

2016-10-01

In the present paper, experiments are carried out using VSK separator which is an advanced air classifier to recover heavy minerals from beach sand. In classification experiments the cage wheel speed and the feed rate are set and the material is fed to the air cyclone and split into fine and coarse particles which are collected in separate bags. The size distribution of each fraction was measured by sieve analysis. A model is developed to predict the performance of the air classifier. The objective of the present model is to predict the grade efficiency curve for a given set of operating parameters such as cage wheel speed and feed rate. The overall experimental data with all variables studied in this investigation is fitted to several models. It is found that the present model is fitting good to the logistic model.

Proposed Solar Probe telecommunications system concept

NASA Astrophysics Data System (ADS)

Kellogg, K.; Devereaux, A.; Vacchione, J.; Kapoor, V.; Crist, R.

1992-01-01

A proposed telecommunications system concept for NASA's Solar Probe mission is described. Key system requirements include 70 kbps data rate at perihelion and operation at X-band (uplink/downlink) and Ka-band (downlink). A design control table is presented to demonstrate design compliance with telecommunication needs. The Ka-band feed is to be a hexagonal array of 37 active elements, each containing 1/4W HEMT amplifiers. The array is located at the Cassegrain point of a 0.75-m reflector. When compared to the TWTA-based system, the Ka-band active array feed provides advantages of reduced mass, increased dc power efficiency, enhanced reliability, graceful degradation, and reduced volume requirements.

Experimental Evaluation and Optimization of Flank Wear During Turning of AISI 4340 Steel with Coated Carbide Inserts Using Different Cutting Fluids

NASA Astrophysics Data System (ADS)

Lawal, S. A.; Choudhury, I. A.; Nukman, Y.

2015-01-01

The understanding of cutting fluids performance in turning process is very important in order to improve the efficiency of the process. This efficiency can be determined based on certain process parameters such as flank wear, cutting forces developed, temperature developed at the tool chip interface, surface roughness on the work piece, etc. In this study, the objective is to determine the influence of cutting fluids on flank wear during turning of AISI 4340 with coated carbide inserts. The performances of three types of cutting fluids were compared using Taguchi experimental method. The results show that palm kernel oil based cutting fluids performed better than the other two cutting fluids in reducing flank wear. Mathematical models for cutting parameters such as cutting speed, feed rate, depth of cut and cutting fluids were obtained from regression analysis using MINITAB 14 software to predict flank wear. Experiments were conducted based on the optimized values to validate the regression equations for flank wear and 5.82 % error was obtained. The optimal cutting parameters for the flank wear using S/N ratio were 160 m/min of cutting speed (level 1), 0.18 mm/rev of feed (level 1), 1.75 mm of depth of cut (level 2) and 2.97 mm2/s palm kernel oil based cutting fluid (level 3). ANOVA shows cutting speed of 85.36 %; and feed rate 4.81 %) as significant factors.

The effect of brain size evolution on feeding propensity, digestive efficiency, and juvenile growth.

PubMed

Kotrschal, Alexander; Corral-Lopez, Alberto; Szidat, Sönke; Kolm, Niclas

2015-11-01

One key hypothesis in the study of brain size evolution is the expensive tissue hypothesis; the idea that increased investment into the brain should be compensated by decreased investment into other costly organs, for instance the gut. Although the hypothesis is supported by both comparative and experimental evidence, little is known about the potential changes in energetic requirements or digestive traits following such evolutionary shifts in brain and gut size. Organisms may meet the greater metabolic requirements of larger brains despite smaller guts via increased food intake or better digestion. But increased investment in the brain may also hamper somatic growth. To test these hypotheses we here used guppy (Poecilia reticulata) brain size selection lines with a pronounced negative association between brain and gut size and investigated feeding propensity, digestive efficiency (DE), and juvenile growth rate. We did not find any difference in feeding propensity or DE between large- and small-brained individuals. Instead, we found that large-brained females had slower growth during the first 10 weeks after birth. Our study provides experimental support that investment into larger brains at the expense of gut tissue carries costs that are not necessarily compensated by a more efficient digestive system. © 2015 The Author(s). Evolution published by Wiley Periodicals, Inc. on behalf of The Society for the Study of Evolution.

Effect of wild mint (Mentha longifolia) infusion on the over all performance of broiler chicks.

PubMed

Durrani, F R; Sultan, A; Marri, Muhammad Latif; Chand, N; Durrani, Z

2007-04-01

An attempt was made to evaluate the effect of aqueous extract of wild mint (Mentha Ingifolia) on the overall performance of broiler chicks at NWFP Agricultural University, Peshawar in July 2005. Three levels of fresh wild mint infusion at the rate of 50, 40 and 30 mL L(-1) of fresh drinking water were provided to chicks in groups A, B and C, respectively and group D was kept as control, each group was replicated four times with 10 chicks per replicate, reared for 35 days, in an open sided house in cages of the same size. No vaccination was practiced. Data were recorded daily for feed intake, water intake and for weight gain on weekly basis. Feed conversion efficiency, dressing percentage, percent mortality, weight of different body organs (breast, thigh and leg), giblets (liver, heart and gizzard), intestine and economics for each group was calculated at the end of experimental period. It was found that group B receiving 40 mL L(-1) of wild mint infusion in drinking water had a significant (p < 0.05) effect on mean body weight gain, feed intake, water intake, feed conversion efficiency, dressing percentage and weight of different body organs (breast, thigh and leg). Significant (p < 0.05) differences were also found in mortality, highest mortality was observed in group D (10%) as compared with groups A, B and C, however there was no significant effect on giblets (liver, heart, gizzard), intestine and weight of abdominal fat. Mean feed cost and gross return was significantly (p < 0.05) effected for group B. Feed cost was lower and gross return was significantly (p < 0.05) higher for group B than other treated groups and control.

Inter-domain Synergism Is Required for Efficient Feeding of Cellulose Chain into Active Site of Cellobiohydrolase Cel7A.

PubMed

Kont, Riin; Kari, Jeppe; Borch, Kim; Westh, Peter; Väljamäe, Priit

2016-12-09

Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme systems. TrCel7A consists of a catalytic domain (CD) and a smaller carbohydrate-binding module (CBM) connected through the glycosylated linker peptide. A tunnel-shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two of them, Trp-40 and Trp-38, in the substrate binding sites near the tunnel entrance. Although addressed in numerous studies the elucidation of the role of CBM and active site aromatics has been obscured by a complex multistep mechanism of processive GHs. Here we studied the role of the CBM-linker and Trp-38 of TrCel7A with respect to binding affinity, on- and off-rates, processivity, and synergism with endoglucanase. The CBM-linker increased the on-rate and substrate affinity of the enzyme. The Trp-38 to Ala substitution resulted in increased off-rates and decreased processivity. The effect of the Trp-38 to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient degradation of cellulose in the presence of endoglucanase. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Inter-domain Synergism Is Required for Efficient Feeding of Cellulose Chain into Active Site of Cellobiohydrolase Cel7A*

PubMed Central

Kont, Riin; Kari, Jeppe; Borch, Kim; Westh, Peter; Väljamäe, Priit

2016-01-01

Structural polysaccharides like cellulose and chitin are abundant and their enzymatic degradation to soluble sugars is an important route in green chemistry. Processive glycoside hydrolases (GHs), like cellobiohydrolase Cel7A of Trichoderma reesei (TrCel7A) are key components of efficient enzyme systems. TrCel7A consists of a catalytic domain (CD) and a smaller carbohydrate-binding module (CBM) connected through the glycosylated linker peptide. A tunnel-shaped active site rests in the CD and contains 10 glucose unit binding sites. The active site of TrCel7A is lined with four Trp residues with two of them, Trp-40 and Trp-38, in the substrate binding sites near the tunnel entrance. Although addressed in numerous studies the elucidation of the role of CBM and active site aromatics has been obscured by a complex multistep mechanism of processive GHs. Here we studied the role of the CBM-linker and Trp-38 of TrCel7A with respect to binding affinity, on- and off-rates, processivity, and synergism with endoglucanase. The CBM-linker increased the on-rate and substrate affinity of the enzyme. The Trp-38 to Ala substitution resulted in increased off-rates and decreased processivity. The effect of the Trp-38 to Ala substitution on on-rates was strongly dependent on the presence of the CBM-linker. This compensation between CBM-linker and Trp-38 indicates synergism between CBM-linker and CD in feeding the cellulose chain into the active site. The inter-domain synergism was pre-requisite for the efficient degradation of cellulose in the presence of endoglucanase. PMID:27780868

Effect of non-feeding period length on the intermittent operation of UASB reactors treating dairy effluents.

PubMed

Coelho, N M; Rodrigues, A A; Arroja, L M; Capela, I F

2007-02-01

Recent environmental concerns have prompted a re-evaluation of conventional management strategies and refueled the search of innovative waste management practices. In this sense, the anaerobic digestion of both fat and the remaining complex organic matter present in dairy wastewaters is attractive, although the continuous operation of high rate anaerobic processes treating this type of wastewaters causes the failure of the process. This work accesses the influence of non-feeding period length on the intermittent operation of mesophilic UASB reactors treating dairy wastewater, in order to allow the biological degradation to catch up with adsorption phenomenon. During the experiments, two UASB reactors were subject to three organic loading rates, ranging from 6 to 12 g(COD) x L(-1) x d(-1), with the same daily load applied to both reactors, each one with a different non-feeding period. Both reactors showed good COD removal efficiencies (87-92%). A material balance for COD in the reactors during the feeding and non-feeding periods showed the importance of the feedless period, which allowed the biomass to degrade substrate that was accumulated during the feeding period. The reactor with the longest non-feeding period had a better performance, which resulted in a higher methane production and adsorption capacity for the same organic load applied with a consequent less accumulation of substrate into the biomass. In addition, both reactors had a stable operation for the organic load of 12 g(COD) x L(-1) x d(-1), which is higher than the maximum applicable load reported in literature for continuous systems (3-6 g(COD) x L(-1) x d(-1)). (c) 2006 Wiley Periodicals, Inc.

Correlation between production performance and feeding behavior of steers on pasture during the rainy-dry transition period.

PubMed

Brandão, Rita K C; de Carvalho, Gleidson G P; Silva, Robério R; Dias, Daniel L S; Mendes, Fabrício B L; Lins, Túlio O J D'A; Pereira, Maria M S; Guimarães, Joanderson O; Tosto, Manuela S L; Rufino, Luana M de A; de Araujo, Maria L G M L

2018-01-01

The aim of this study was to evaluate the correlation between production performance and feeding behavior of steers reared on pasture during the rainy-dry transition period. Twenty-two ½ Holstein-Zebu crossbred steers at an average age of 10 months and with an average initial body weight of 234.5 ± 16.0 kg were distributed in a completely randomized design with two types of supplementation and eleven replications. Pearson's linear correlation analysis was performed between behavioral variables and weight gain and feed conversion. Correlation coefficients were tested by the t test. The time expended feeding at the trough was positively correlated (P < 0.05) with average daily gain (ADG) and with the number of periods of permanence at the trough. Bite rate and the number of bites per day were positively correlated (P < 0.05) with ADG and negatively (P < 0.05) with feed conversion, unlike the number of bites per swallow, which was negatively correlated (P < 0.05) with ADG. There was a positive correlation (P < 0.05) between feed efficiency in dry matter and neutral detergent fiber and ADG. Feeding behavior characteristics have little association with the production performance of cattle on pasture receiving mineral or energy-protein supplementation.

Cambridge journals blog: Improving feed efficiency in dairy production

USDA-ARS?s Scientific Manuscript database

Because the cost of feeding animals is one of the greatest expenses in dairy production (40-60% of production costs), research focused on ways to identify and select for animals that are the most efficient at converting feed into milk has greatly expanded during the last decade. The animal Article o...

Genetic architecture of feed efficiency in mid-lactation Holstein dairy cows

USDA-ARS?s Scientific Manuscript database

The objective of this study was to explore the genetic architecture and biological basis of feed efficiency in lactating Holstein cows. In total, 4,918 cows with actual or imputed genotypes for 60,671 SNP had individual feed intake, milk yield, milk composition, and body weight records. Cows were ...

The genetic and biological basis of feed efficiency in mid-lactation Holstein dairy cows

USDA-ARS?s Scientific Manuscript database

The objective of this study was to characterize the genetic architecture and biological basis of feed efficiency in lactating Holstein cows. In total, 4,916 cows with actual or imputed genotypes for 60,671 SNP had individual feed intake, milk yield, milk composition, and body weight records. Cows we...

Effect of different levels of feed added black seed (Nigella sativa L.) on the performance of broiler chicks.

PubMed

Durrani, F R; Chand, N; Zaka, K; Sultan, A; Khattak, F M; Durrani, Z

2007-11-15

The study was conducted to investigate the effect of different levels of feed added black seed (Nigella sativa L.) on the overall performance and immunity of broiler chicks at NWFP Agricultural University, Peshawar in May 2005. Four experimental rations designated as A, B, C and D having black seed at the rate of 0, 20, 30 and 40 g kg(-1) feed were fed to 160 broiler chicks, randomly distributed into 16 replicates, so as to have 4 replicates per group and 10 chicks per replicate. The experiment was lasted for 35 days. Average weight gain, feed consumption, feed efficiency, dressing percentage, weight of different body organs (breast, thigh, intestine), giblets (liver, gizzard), abdominal fat weight, antibody titer against ND, IB and IBD were used as criteria of response. Economics for each group was calculated at the end of experimental period. It was found that group D receiving 40 g kg(-1) of black seed in the feed had a significant (p < 0.05) effect on mean body weight gain, feed intake, feed conversion ratio, dressing percentage and weight of different body organs (breast and thigh). Non significant (p > 0.05) effect was observed in gizzard, intestine, weight of abdominal fat and feed cost. Antibody titer against ND and IBD were higher in group D, however high antibody titer against IB was recorded in group C. Return per unit of feed cost and gross return were significantly (p < 0.05) effected by group D.

Consequences of divergent selection for residual feed intake in pigs on muscle energy metabolism and meat quality.

PubMed

Faure, J; Lefaucheur, L; Bonhomme, N; Ecolan, P; Meteau, K; Coustard, S Metayer; Kouba, M; Gilbert, H; Lebret, B

2013-01-01

Selection to decrease Residual Feed Intake (RFI) is a relevant way to improve feed efficiency in growing pigs. However, RFI criterion is correlated with body composition and muscle characteristics. Present study evaluated adaptive responses to divergent selection on RFI on muscle metabolism and homeostasis through AMP-activated protein kinase pathway. Consequences on technological and sensory meat quality were also analyzed in two lines of Large White pigs after six generations of divergent selection on RFI. RFI(-) pigs (n=60) exhibited similar growth rate but lower feed intake and conversion ratio, and were leaner than RFI(+) pigs (n=57). Despite higher glycogen content, metabolic enzyme capacities involved in glycolytic, fatty acid oxidation pathway and energy balance were reduced in the Longissimus muscle of the RFI(-) pigs. Reduced muscle homeostasis in the RFI(-) line influenced post-mortem metabolism and impaired technological quality traits of loin and ham but had only slight effects on meat eating quality. Copyright © 2012 Elsevier Ltd. All rights reserved.

The development of a new breast feeding assessment tool and the relationship with breast feeding self-efficacy

PubMed Central

Ingram, Jenny; Johnson, Debbie; Copeland, Marion; Churchill, Cathy; Taylor, Hazel

2015-01-01

Objective to develop a breast feeding assessment tool to facilitate improved targeting of optimum positioning and attachment advice and to describe the changes seen following the release of a tongue-tie. Design development and validation of the Bristol Breastfeeding Assessment Tool (BBAT) and correlation with breast feeding self-efficacy. Setting maternity hospital in South West England. Participants 218 breast feeds (160 mother–infant dyads); seven midwife assessors. Findings the tool has more explanation than other tools to remind those supporting breast-feeding women about the components of an efficient breast feed. There was good internal reliability for the final 4-item BBAT (Cronbach׳s alpha=0.668) and the midwives who used it showed a high correlation in the consistency of its use (ICC=0.782). Midwives were able to score a breast feed consistently using the BBAT and felt that it helped them with advice to mothers about improving positioning and attachment to make breast feeding less painful, particularly with a tongue-tied infant. The tool showed strong correlation with breast feeding self-efficacy, indicating that more efficient breast feeding technique is associated with increased confidence in breast feeding an infant. Conclusions the BBAT is a concise breast feeding assessment tool facilitating accurate, rapid breast feeding appraisal, and targeting breast feeding advice to mothers acquiring early breast feeding skills or for those experiencing problems with an older infant. Accurate assessment is essential to ensure enhanced breast feeding efficiency and increased maternal self-confidence. Implications for practice the BBAT could be used both clinically and in research to target advice to improve breast feeding efficacy. Further research is needed to establish its wider usefulness. PMID:25061006

The development of a new breast feeding assessment tool and the relationship with breast feeding self-efficacy.

PubMed

Ingram, Jenny; Johnson, Debbie; Copeland, Marion; Churchill, Cathy; Taylor, Hazel

2015-01-01

to develop a breast feeding assessment tool to facilitate improved targeting of optimum positioning and attachment advice and to describe the changes seen following the release of a tongue-tie. development and validation of the Bristol Breastfeeding Assessment Tool (BBAT) and correlation with breast feeding self-efficacy. maternity hospital in South West England. 218 breast feeds (160 mother-infant dyads); seven midwife assessors. the tool has more explanation than other tools to remind those supporting breast-feeding women about the components of an efficient breast feed. There was good internal reliability for the final 4-item BBAT (Cronbach's alpha=0.668) and the midwives who used it showed a high correlation in the consistency of its use (ICC=0.782). Midwives were able to score a breast feed consistently using the BBAT and felt that it helped them with advice to mothers about improving positioning and attachment to make breast feeding less painful, particularly with a tongue-tied infant. The tool showed strong correlation with breast feeding self-efficacy, indicating that more efficient breast feeding technique is associated with increased confidence in breast feeding an infant. the BBAT is a concise breast feeding assessment tool facilitating accurate, rapid breast feeding appraisal, and targeting breast feeding advice to mothers acquiring early breast feeding skills or for those experiencing problems with an older infant. Accurate assessment is essential to ensure enhanced breast feeding efficiency and increased maternal self-confidence. the BBAT could be used both clinically and in research to target advice to improve breast feeding efficacy. Further research is needed to establish its wider usefulness. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Groundnut shell gasification performance in a fluidized bed gasifier with bubbling air as gasification medium.

PubMed

Singh, Dharminder; Yadav, Sanjeev; Rajesh, V M; Mohanty, Pravakar

2018-05-24

This work was focused on finding the groundnut shell (GNS) gasification performance in a fluidized bed gasifier with bubbling air as gasification medium. GNS in powder form (a mixture of different particle size as given in table 8 in the article) was gasified using naturally available river sand as bed material, top of the bed feeding, conventional charcoal as bed heating medium, and two cyclones for proper cleaning and cooling the product gas. Experiments were performed using different operating conditions such as equivalence ratio (ER) between 0.29 and 0.33, bed temperature between 650°C and 800°C, and feedstock feeding rate between 36 and 31.7 kg/h. Different parameters were evaluated to study the gasifier performance such as gas yield, cold gas efficiency, carbon conversion efficiency (CCE), and high heating value. The most suitable ER value was found to be 0.31, giving the most stable bed temperature profile at 714.4°C with 5-10% fluctuation. Cold gas efficiency and CCE at optimal ER of 0.31 was found to be 71.8% and 91%, respectively.

Genetic and phenotypic relationships of feeding behavior and temperament with performance, feed efficiency, ultrasound, and carcass merit of beef cattle.

PubMed

Nkrumah, J D; Crews, D H; Basarab, J A; Price, M A; Okine, E K; Wang, Z; Li, C; Moore, S S

2007-10-01

Feeding behavior and temperament may be useful in genetic evaluations either as indicator traits for other economically relevant traits or because the behavior traits may have a direct economic value. We determined the variation in feeding behavior and temperament of beef cattle sired by Angus, Charolais, or Hybrid bulls and evaluated their associations with performance, efficiency, and carcass merit. The behavior traits were daily feeding duration, feeding head down (HD) time, feeding frequency (FF), and flight speed (FS, as a measure of temperament). A pedigree file of 813 animals forming 28 paternal half-sib families with about 20 progeny per sire was used. Performance, feeding behavior, and efficiency records were available on 464 animals of which 381 and 302 had records on carcass merit and flight speed, respectively. Large SE reflect the number of animals used. Direct heritability estimates were 0.28 +/- 0.12 for feeding duration, 0.33 +/- 0.12 for HD, 0.38 +/- 0.13 for FF, and 0.49 +/- 0.18 for FS. Feeding duration had a weak positive genetic (r(g)) correlation with HD (r(g) = 0.25 +/- 0.32) and FS (r(g) = 0.42 +/- 0.26) but a moderate negative genetic correlation with FF (r(g) = -0.40 +/- 0.30). Feeding duration had positive phenotypic (r(p)) and genetic correlations with DMI (r(p) = 0.27; r(g) = 0.56 +/- 0.20) and residual feed intake (RFI; r(p) = 0.49; r(g) = 0.57 +/- 0.28) but was unrelated phenotypically with feed conversion ratio [FCR; which is the reciprocal of the efficiency of growth (G:F)]. Feeding duration was negatively correlated with FCR (r(g) = -0.25 +/- 0.29). Feeding frequency had a moderate to high negative genetic correlation with DMI (r(g) = -0.74 +/- 0.15), FCR (r(g) = -0.52 +/- 0.21), and RFI (r(g) = -0.77 +/- 0.21). Flight speed was negatively correlated phenotypically with DMI (r(p) = -0.35) but was unrelated phenotypically with FCR or RFI. On the other hand, FS had a weak negative genetic correlation with DMI (r(g) = -0.11 +/- 0.26), a moderate genetic correlation with FCR (r(g) = 0.40 +/- 0.26), and a negative genetic correlation with RFI (r(g) = -0.59 +/- 0.45). The results indicate that behavior traits may contribute to the variation in the efficiency of growth of beef cattle, and there are potential correlated responses to selection to improve efficiency. Feeding behavior and temperament may need to be included in the definition of beef cattle breeding goals, and approaches such as the culling of unmanageable cattle and the introduction of correct handling facilities or early life provision of appropriate experiences to improve handling will be useful.

Cooling cows efficiently with water spray: Behavioral, physiological, and production responses to sprinklers at the feed bunk.

PubMed

Chen, Jennifer M; Schütz, Karin E; Tucker, Cassandra B

2016-06-01

Dairies commonly mount nozzles above the feed bunk that intermittently spray cows to dissipate heat. These sprinklers use potable water-an increasingly scarce resource-but there is little experimental evidence for how much is needed to cool cows in loose housing. Sprinkler flow rate may affect the efficacy of heat abatement, cattle avoidance of spray (particularly on the head), and water waste. Our objectives were to determine how sprinkler flow rate affects cattle behavioral, physiological, and production responses when cows are given 24-h access to spray in freestall housing, and to evaluate heat abatement in relation to water use. We compared 3 treatments: sprinklers that delivered 1.3 or 4.9L/min (both 3min on and 9min off, 24h/d) and an unsprayed control. Nine pairs of high-producing lactating Holstein cows received each treatment at a shaded feed bunk for 2d in a replicated 3×3 Latin square design [air temperature (T): 24-h maximum=33±3°C, mean ± SD]. Cows spent 5.8±0.9h/24h (mean ± SD) at the feed bunk overall, regardless of treatment. With few exceptions, cows responded similarly to the 1.3 and 4.9L/min flow rates. Sprinklers resulted in visits to the feed bunk that were on average 23 to 27% longer and 13 to 16% less frequent compared with the control, perhaps because cows avoided walking through spray. Indeed, when the sprinklers were on, cows left the feed bunk half as often as expected by chance, and when cows chose to walk through spray, they lowered their heads on average 1.7- to 3-fold more often than in the control. Despite possible reluctance to expose their heads to spray, cows did not avoid sprinklers overall. In warmer weather, cows spent more time at the feed bunk when it had sprinklers (on average 19 to 21min/24h for each 1°C increase in T), likely for heat abatement benefits. Compared with the control, sprinklers resulted in 0.3 to 0.7°C lower body temperature from 1300 to 1500h and 1700 to 2000h overall and attenuated the rise in this measure on warmer days (for each 10°C increase in T, body temperature increased by on average 0.5 to 0.7°C with sprinklers vs. 1.6°C without). Sprinkler access also resulted in milk yield that was, on average, 3.3 to 3.7kg/24h higher than in the control treatment. In this hot and dry climate, 1.3L/min cooled cows more efficiently than 4.9L/min, as the lower flow rate achieved equivalent reduction in body temperature and increase in milk yield relative to no spray, despite using 73% less water. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

The effects of temperature and food availability on growth, flexibility in metabolic rates and their relationships in juvenile common carp.

PubMed

Zeng, Ling-Qing; Fu, Cheng; Fu, Shi-Jian

2018-03-01

Flexibility in phenotypic traits can allow organisms to handle environmental changes. However, the ecological consequences of flexibility in metabolic rates are poorly understood. Here, we investigated whether the links between growth and flexibility in metabolic rates vary between two temperatures. Common carp Cyprinus carpio were raised in three temperature treatments [the 18°C, 28°C and 28°C-food control (28°C-FC)] and fed to satiation of receiving food either once or twice daily for 4weeks. The morphology and metabolic rates (standard metabolic rate, SMR; maximum metabolic rate, MMR) were measured at the beginning and end of the experiment. The mean total food ingested by fish in the 28°C-FC treatment was the same as that by fish in the 18°C treatment at each food availability. The final SMR (not MMR and aerobic scope, AS=MMR-SMR) increased more in the 28°C and 28°C-FC treatments with twice-daily feedings than once-daily feedings. Fish in the 28°C treatment had a higher specific growth rate (SGR) than fish in the 28°C-FC and 18°C treatments at both food availabilities. However, no differences in feeding efficiency (FE) were found among the three treatments in fish fed twice daily. The flexibility in SMR was related to individual differences in SGR, not with food intake and FE; individuals who increased their SMR more had a smaller growth performance with twice-daily feedings at 28°C, but it did not exist at 18°C. Flexibility in SMR provides a growth advantage in juvenile common carp experiencing changes in food availability and this link is temperature-dependent. Copyright © 2017 Elsevier Inc. All rights reserved.

Combustion in a multiburner furnace with selective flow of oxygen

DOEpatents

Bool, III, Lawrence E.; Kobayashi, Hisashi

2004-03-02

Improved operational characteristics such as improved fuel efficiency, reduction of NOx formation, reduction of the amount of unburned carbon in the ash, and lessened tendency to corrosion at the tube wall, in a multi-burner furnace are obtained by reducing the flow rate of combustion air to the burners and selectively individually feeding oxidant to only some of the burners.

Trophic accumulation and depuration of mercury by blue crabs (Callinectes sapidus) and pink shrimp (Penaeus duorarum).

PubMed

Evans, D W; Kathman, R D; Walker, W W

2000-06-01

Mercury concentrations in blue crabs (Callinectes sapidus) collected from an area of mercury-contaminated sediments in Lavaca Bay, TX, USA, are more than an order of magnitude greater than concentrations in penaeid shrimp from the same area. Laboratory feeding experiments using mercury-contaminated fish as food showed that both blue crabs and pink shrimp (Penaeus duorarum) could accumulate mercury concentrations comparable to those in their food in 28 days. Calculated mercury assimilation efficiencies averaged 76% for blue crabs and 72% for pink shrimp. Significant depuration of mercury by blue crabs was not observed during a subsequent 28-day period, but pink shrimp lost mercury at a rate of about 0.012 day-1. Model calculations predict biomagnification factors of mercury of about two to three at steady state for both species. The large difference in observed concentrations of mercury in field-collected blue crabs and penaeid shrimp does not result from differences in efficiency of mercury assimilation from their food or from differences in excretion rates. It is more likely the result of differences in residence times in the contaminated area and of differences in feeding habits.

Removal of unburned carbon from coal fly ash using a pneumatic triboelectrostatic separator.

PubMed

Kim, J K; Cho, H C; Kim, S C

2001-01-01

A pneumatic triboelectrostatic beneficiation system of fly ash was studied using a continuous, bench-scale electroseparator composed of two vertical electrode plates and an ejector-tribocharger. Tests were conducted to evaluate the charge density and the separation efficiency at various operating conditions. It was found that the higher charge densities were obtained at (1) the air flow rate of 1.75 m3/min. (2) the feed rate of less than 50 kg/h. and (3) the relative humidity of less than 30% with use of a stainless ejector tribocharger. With these optimum conditions, the clean ash of less than LOI 3% was recovered with a yield over 75% when operated at the diffuser slit gap of 4mm, the diffuser outlet velocity of 16.1-18.6 m/s, and the distance of 15 cm between diffuser slit and splitter. The optimum feed rate was found to be 740 kg/h per m2 of electrode surface area, which can be used as a scale-up factor of electroseparator.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes.

PubMed

Caillouët, Kevin A; Riggan, Anna E; Rider, Mark; Bulluck, Lesley P

2012-06-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. © 2012 The Society for Vector Ecology.

Nest Mosquito Trap quantifies contact rates between nesting birds and mosquitoes

PubMed Central

Caillouët, Kevin A.; Riggan, Anna E.; Rider, Mark; Bulluck, Lesley P.

2012-01-01

Accurate estimates of host-vector contact rates are required for precise determination of arbovirus transmission intensity. We designed and tested a novel mosquito collection device, the Nest Mosquito Trap (NMT), to collect mosquitoes as they attempt to feed on unrestrained nesting birds in artificial nest boxes. In the laboratory, the NMT collected nearly one-third of the mosquitoes introduced to the nest boxes. We then used these laboratory data to estimate our capture efficiency of field-collected bird-seeking mosquitoes collected over 66 trap nights. We estimated that 7.5 mosquitoes per trap night attempted to feed on nesting birds in artificial nest boxes. Presence of the NMT did not have a negative effect on avian nest success when compared to occupied nest boxes that were not sampled with the trap. Future studies using the NMT may elucidate the role of nestlings in arbovirus transmission and further refine estimates of nesting bird and vector contact rates. PMID:22548555

Genetic variance and covariance components for feed intake, average daily gain, and postweaning gain in growing beef cattle

USDA-ARS?s Scientific Manuscript database

Feed is the single most expensive cost related to a beef cattle production enterprise. Data collection to determine feed efficient animals is also costly. Currently a 70 d performance test is recommended for accurate calculation of efficiency. Previous research has suggested intake tests can be l...

Exploration of the genetic and biological basis of feed efficiency in mid-lactation Holstein dairy cows

USDA-ARS?s Scientific Manuscript database

The purpose of this study was to characterize the genetic basis underlying variation in feed efficiency in mid-lactation Holstein dairy cows. A genome-wide association study was performed for residual feed intake (RFI) and related traits using a large data set, consisting of nearly 5,000 cows. It wa...

Relationship of feed efficiency of replacement beef heifers to subsequent feed efficiency as 3-year old suckled beef cows

USDA-ARS?s Scientific Manuscript database

We determined the correlaton between Residual Feed Intake (RFI) measured as post-weaned growing heifers (phase 1) and RFI measured as lactating beef cows (phase 2) in the same cohort. Individual performance and daily DMI were evaluated in 74 yearling heifers, and were subsequently reevaluated upon t...

Rumen fluid metabolomics analysis associated with feed efficiency on crossbred steers

USDA-ARS?s Scientific Manuscript database

The rumen plays a central role in the efficiency of digestion in ruminants. To identify potential differences in rumen function that lead to differences in feed efficiency, rumen metabolomic analysis by ultra-performance liquid chromatography/ time-of-flight mass spectrometry (MS) and multivariate/u...

Foraging decisions, patch use, and seasonality in egrets (Aves: ciconiiformes)

USGS Publications Warehouse

Erwin, R.M.

1985-01-01

Feeding snowy (Egretta thula) and great (Casmerodius albus) egrets were observed during 2 breeding seasons in coastal New Jersey and 2 brief winter periods in northeast Florida (USA). A number of tests based on assumptions of foraging models, predictions from foraging theory, and earlier empirical tests concerning time allocation and movement in foraging patches was made. Few of the expectations based on foraging theory and/or assumptions were supported by the empirical evidence. Snowy egrets fed with greater intensity and efficiency during the breeding season (when young were being fed) than during winter. They also showed some tendency to leave patches when their capture rate declined, and they spent more time foraging in patches when other birds were present nearby. Great egrets showed few of these tendencies, although they did leave patches when their intercapture intervals increased. Satiation differences had some influence on feeding rates in snowy egrets, but only at the end of feeding bouts. Some individuals of both species revisited areas in patches that had recently been exploited, and success rates were usually higher after the 2nd visit. Apparently, for predators of active prey, short-term changes in resource availability ('resource depression') may be more important than resource depletion, a common assumption in most optimal foraging theory models.

Effect of Feeding-Fasting Cycles on Oxygen Consumption and Bioenergetics of Yellow Perch

USGS Publications Warehouse

Chipps, Steven R.; Travis W. Schaeffer,; Daniel E. Spengler,; Casey W. Schoenebeck,; Michael L. Brown,

2012-01-01

We measured growth and oxygen consumption of age-1 yellow perch Perca flavescenssubjected to ad libitum (control) or variable feeding cycles of 2 (i.e., 2 d of feed, 2 d of deprivation), 6, or 12 d for a 72-d period. Individual, female yellow perch (initial weight = 51.9 ± 0.9 g [mean ± SE]) were stocked in 110-L aquaria to provide six replicates per treatment and fed measured rations of live fathead minnow Pimephales promelas. Consumption, absolute growth rate, growth efficiency, and oxygen consumption were similar among feeding regimens. However, growth trajectories for fish on the 2-d cycle were significantly lower than other feed–fast cycles. Hyperphagia occurred in all treatments. Bioenergetics model simulations indicated that consumption was significantly underestimated (t = 5.4, df = 4, P = 0.006), while growth was overestimated (t = −5.5, df = 4, P = 0.005) for fish on the 12-d cycle. However, model errors detected between observed and predicted values were low, ranging from −10.1% to +7.8%. We found that juvenile yellow perch exhibited compensatory growth (CG), but none of the feed–fast treatments resulted in growth overcompensation. Likewise, we found no evidence that respiration rates varied with CG, implying that yellow perch bioenergetics models could be used to predict the effects of feeding history and CG response on food consumption and fish growth.

The efficacy of using exogenous enzymes cocktail on production, egg quality, egg nutrients and blood metabolites of laying hens fed distiller's dried grains with solubles.

PubMed

Abd El-Hack, M E; Chaudhry, M T; Mahrose, K M; Noreldin, A; Emam, M; Alagawany, M

2018-04-01

An experiment was performed using 120 Hisex Brown laying hens for evaluating the effects of different inclusion levels of corn distiller's dried grains with solubles (DDGS) as a replacement of soybean meal (SBM) with or without enzyme cocktail on performance, egg quality, egg nutrients and blood metabolites in laying hens through 22-42 weeks of age. A 4 × 2 factorial design experiment was performed including four substitution levels of DDGS (0, 250, 500 and 750 g/kg respectively) and two enzyme cocktail levels (0 and 250 mg/kg diet). The used enzyme in this study "Gallazyme" composed of xylanase, Trichoderma longibrachiatum (600 units/g), protease, Bacillus subtilis (8,000 units/g) and amylase and Bacillus amyloliquofaciens (800 units/g). The control diet showed the best feed efficiency followed by the intermediate levels of DDGS. The lowest value of feed efficiency was found in the group fed the highest level of DDGS. Enzyme addition improved feed efficiency and decreased laying rate. Increasing DDGS levels was associated with albumin and shell thickness increases. Dietary DDGS depressed all egg components except the organic matter which maximised in enzyme-treated groups. Increasing DDGS level was accompanied by increase in yolk cholesterol and total lipids. No significant impacts were detected with enzymes supplementation on yolk lipids profile. Excepting serum calcium and phosphorous, all serum constituents increased with increasing level of DDGS. Using enzyme markedly depressed serum ammonia by 15.02% and increased calcium by 6.44% compared with enzyme-free diets. Interaction between DDGS and enzyme was significant on most of studied parameters. It could be concluded that using enzyme cocktail in DDGS-based diets may improve feed efficiency and egg quality, in addition to lowering blood ammonia and increasing blood calcium. It is recommended to substitute SBM by DDGS up to 500 g/kg diet. © 2017 Blackwell Verlag GmbH.

An Ultra-Precise Method for the Nano Thin-Film Removal

NASA Astrophysics Data System (ADS)

Pa, P. S.

In this research an electrode-set is used to investigate via an ultra-precise method for the removal of Indium Tin Oxide (ITO) thin-film microstructure from defective display panels to conquer the low yield rate in display panel production as to from imperfect Indium Tin Oxide layer deposition is well known. This process, which involves the removal of ITO layer substructure by means of an electrochemical removal (ECMR), is of major interest to the optoelectronics semiconductor industry. In this electro machining process a high current flow and high feed rate of the display (color filter) achieves complete and efficient removal of the ITO layer. The ITO thin-film can be removed completely by a proper combination of feed rate and electric power. A small gap between the diameter cathode virtual rotation circle and the diameter virtual rotation circle also corresponds to a higher removal rate. A small anode edge radius with a small cathode edge radius effectively improves dregs discharge and is an advantage when associated with a high workpiece feed rate. This precision method for the recycling of defective display screen color filters is presented as an effective tool for use in the screen manufacturing process. The defective Indium Tin Oxide thin-film can be removed easily and cleanly in a short time. The complete removal of the ITO layer makes it possible to put these panels back into the production line for reuse with a considerable reduction of both waste and production cost.

Xylose fermentation efficiency and inhibitor tolerance of the recombinant industrial Saccharomyces cerevisiae strain NAPX37.

PubMed

Li, Yun-Cheng; Mitsumasu, Kanako; Gou, Zi-Xi; Gou, Min; Tang, Yue-Qin; Li, Guo-Ying; Wu, Xiao-Lei; Akamatsu, Takashi; Taguchi, Hisataka; Kida, Kenji

2016-02-01

Industrial yeast strains with good xylose fermentation ability and inhibitor tolerance are important for economical lignocellulosic bioethanol production. The flocculating industrial Saccharomyces cerevisiae strain NAPX37, harboring the xylose reductase-xylitol dehydrogenase (XR-XDH)-based xylose metabolic pathway, displayed efficient xylose fermentation during batch and continuous fermentation. During batch fermentation, the xylose consumption rates at the first 36 h were similar (1.37 g/L/h) when the initial xylose concentrations were 50 and 75 g/L, indicating that xylose fermentation was not inhibited even when the xylose concentration was as high as 75 g/L. The presence of glucose, at concentrations of up to 25 g/L, did not affect xylose consumption rate at the first 36 h. Strain NAPX37 showed stable xylose fermentation capacity during continuous ethanol fermentation using xylose as the sole sugar, for almost 1 year. Fermentation remained stable at a dilution rate of 0.05/h, even though the xylose concentration in the feed was as high as 100 g/L. Aeration rate, xylose concentration, and MgSO4 concentration were found to affect xylose consumption and ethanol yield. When the xylose concentration in the feed was 75 g/L, a high xylose consumption rate of 6.62 g/L/h and an ethanol yield of 0.394 were achieved under an aeration rate of 0.1 vvm, dilution rate of 0.1/h, and 5 mM MgSO4. In addition, strain NAPX37 exhibited good tolerance to inhibitors such as weak acids, furans, and phenolics during xylose fermentation. These findings indicate that strain NAPX37 is a promising candidate for application in the industrial production of lignocellulosic bioethanol.

Effect of hydraulic loading rate on pollutant removal efficiency in subsurface infiltration system under intermittent operation and micro-power aeration.

PubMed

Yang, Yongqiang; Zhan, Xuan; Wu, Shijun; Kang, Mingliang; Guo, Jianan; Chen, Fanrong

2016-04-01

The low hydraulic loading rate (HLR) greatly restricts the wide application of subsurface wastewater infiltration system (SWIS) in densely populated areas. To increase the HLR, an innovative SWIS was developed using cyclic operation mode. In each cycle, a wastewater feeding period is followed by a drying period, in which the aeration is conducted by a medium-pressure fan. Results indicated that the removal rate of TOC and NH4(+)-N were more than 85% at HLR of 0.5m(3)/m(2)d, whereas the TN removal rate was lower than 20%, indicating that the aeration was efficient and denitrification process was largely limited in the SWIS. When HLR decreased from 0.5 to 0.2m(3)/m(2)d, the pollutant removal efficiency enhanced slightly except for TN. Overall, the intermittent operation and micro-power aeration, combined with shunting the pollutant loading were really helpful for SWIS to achieve higher HLR, which offers a reference for the design of innovative SWIS. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rumen fluid metabolomics analysis associated with feed efficiency on crossbred steers

USDA-ARS?s Scientific Manuscript database

The rumen has a central role in the efficiency of digestion in ruminants. To identify potential differences in rumen function that lead to differences in feed efficiency, rumen fluid metabolomic analysis by LC-MS and multivariate/univariate statistical analysis were used to identify differences in r...

Hierarchical Bayesian inference on genetic and non-genetic components of partial efficiencies determining feed efficiency in dairy cattle

USDA-ARS?s Scientific Manuscript database

Dairy cattle feed efficiency (FE) can be defined as the ability to convert DMI into milk energy (MILKE) and maintenance or metabolic body weight (MBW). In other words, DMI is conditional on MILKE and MBW (DMI|MILKE,MBW). These partial regressions or partial efficiencies (PE) of DMI on MILKE and MBW ...

The effect of a self-efficacy-based educational programme on maternal breast feeding self-efficacy, breast feeding duration and exclusive breast feeding rates: A longitudinal study.

PubMed

Chan, Man Yi; Ip, Wan Yim; Choi, Kai Chow

2016-05-01

breast feeding has a number of well-documented benefits. Numerous studies have been conducted to investigate an effective approach to increase the breast feeding rate, duration and exclusive breast feeding rate, in which maternal breast feeding self-efficacy was determined as one of the major contributors. Although numerous breast feeding educational programmes have been developed to enhance maternal breastfeeding self-efficacy, results on the effectiveness of these programmes remain inconclusive. this study aims to investigate the effectiveness of a self-efficacy-based breast feeding educational programme (SEBEP) in enhancing breast feeding self-efficacy, breast feeding duration and exclusive breast feeding rates among mothers in Hong Kong. eligible pregnant women were randomized to attend a 2.5-hour breast feeding workshop at 28-38 weeks of gestation and receive 30-60minutes of telephone counselling at two weeks post partum, whereas both intervention and control groups received usual care. At two weeks postpartum, the Breast feeding Self-Efficacy Scale-Short Form (BSES-SF) and a self-developed post partum questionnaire were completed via telephone interviews. The breast feeding duration, pattern of breast feeding and exclusive breast feeding rates were recorded at two weeks, four weeks, eight weeks and six months post partum. results of analyses based on an intention-to-treat (ITT) assumption showed a significant difference (p<0.01) in the change in BSES-SF mean scores between the mothers who received SEBEP and those who did not receive SEBEP at two weeks post partum. The exclusive breast feeding rate was 11.4% for the intervention group and 5.6% for the control group at six months post partum. the findings of this study highlight the feasibility of a major trial to implement breast feeding education targeted at increasing breast feeding self-efficacy and exclusive breast feeding rates in Hong Kong. Copyright © 2016 Elsevier Ltd. All rights reserved.

Modeling genetic and non-genetic variation of feed efficiency and its partial relationships between component traits as a function of management and environmental factors

USDA-ARS?s Scientific Manuscript database

Feed efficiency (FE), characterized as the ability to convert feed nutrients into saleable milk or meat directly affects the profitability of dairy production, is of increasing economic importance in the dairy industry. We conjecture that FE is a complex trait whose variation and relationships or pa...

Reducing the period of data collection for intake and gain to improve response to selection for feed efficiency in beef cattle

USDA-ARS?s Scientific Manuscript database

Shortening the period of recording individual feed intake may improve selection response for feed efficiency by increasing the number of cattle that can be recorded given facilities of fixed capacity. Individual DMI and ADG records of 3,462 steers and 2,869 heifers over the entire intake recording p...

Phenotypic and Genetic Correlations of Feed Efficiency Traits with Growth and Carcass Traits in Nellore Cattle Selected for Postweaning Weight.

PubMed

Ceacero, Thais Matos; Mercadante, Maria Eugênia Zerlotti; Cyrillo, Joslaine Noely Dos Santos Gonçalves; Canesin, Roberta Carrilho; Bonilha, Sarah Figueiredo Martins; de Albuquerque, Lucia Galvão

2016-01-01

This study evaluated phenotypic (rph) and genetic correlations (rg) between 8 feed efficiency traits and other traits of economic interest including weight at selection (WS), loin-eye area (LEA), backfat thickness (BF), and rump fat thickness (RF) in Nellore cattle. Feed efficiency traits were gain:feed, residual feed intake (RFI), residual feed intake adjusted for backfat thickness (RFIb) and for backfat and rump fat thickness (RFIsf), residual body weight gain (RG), residual intake and body weight gain (RIG), and residual intake and body weight gain using RFIb (RIGb) and RFIsf (RIGsf). The variance components were estimated by the restricted maximum likelihood method using a two-trait animal model. The heritability estimates (h2) were 0.14, 0.24, 0.20, 0.22, 0.19, 0.15, 0.11 and 0.11 for gain:feed, RFI, RFIb, RFIsf, RG, RIG, RIGb and RIGsf, respectively. All rph values between traits were close to zero, except for the correlation of feed efficiency traits with dry matter intake and average daily gain. High rg values were observed for the correlation of dry matter intake, average daily gain and metabolic weight with WS and hip height (>0.61) and low to medium values (0.15 to 0.48) with the carcass traits (LEA, BF, RF). Among the feed efficiency traits, RG showed the highest rg with WS and hip height (0.34 and 0.25) and the lowest rg with subcutaneous fat thickness (-0.17 to 0.18). The rg values of RFI, RFIb and RFIsf with WS (0.17, 0.23 and 0.22), BF (0.37, 0.33 and 0.33) and RF (0.30, 0.31 and 0.32) were unfavorable. The rg values of gain:feed, RIG, RIGb and RIGsf with WS were low and favorable (0.07 to 0.22), while medium and unfavorable (-0.22 to -0.45) correlations were observed with fat thickness. The inclusion of subcutaneous fat thickness in the models used to calculate RFI did not reduce the rg between these traits. Selecting animals for higher feed efficiency will result in little or no genetic change in growth and will decrease subcutaneous fat thickness in the carcass.

Direct measures of mechanical energy for knife mill size reduction of switchgrass, wheat straw, and corn stover.

PubMed

Bitra, Venkata S P; Womac, Alvin R; Igathinathane, C; Miu, Petre I; Yang, Yuechuan T; Smith, David R; Chevanan, Nehru; Sokhansanj, Shahab

2009-12-01

Lengthy straw/stalk of biomass may not be directly fed into grinders such as hammer mills and disc refiners. Hence, biomass needs to be preprocessed using coarse grinders like a knife mill to allow for efficient feeding in refiner mills without bridging and choking. Size reduction mechanical energy was directly measured for switchgrass (Panicum virgatum L.), wheat straw (Triticum aestivum L.), and corn stover (Zea mays L.) in an instrumented knife mill. Direct power inputs were determined for different knife mill screen openings from 12.7 to 50.8 mm, rotor speeds between 250 and 500 rpm, and mass feed rates from 1 to 11 kg/min. Overall accuracy of power measurement was calculated to be +/-0.003 kW. Total specific energy (kWh/Mg) was defined as size reduction energy to operate mill with biomass. Effective specific energy was defined as the energy that can be assumed to reach the biomass. The difference is parasitic or no-load energy of mill. Total specific energy for switchgrass, wheat straw, and corn stover chopping increased with knife mill speed, whereas, effective specific energy decreased marginally for switchgrass and increased for wheat straw and corn stover. Total and effective specific energy decreased with an increase in screen size for all the crops studied. Total specific energy decreased with increase in mass feed rate, but effective specific energy increased for switchgrass and wheat straw, and decreased for corn stover at increased feed rate. For knife mill screen size of 25.4 mm and optimum speed of 250 rpm, optimum feed rates were 7.6, 5.8, and 4.5 kg/min for switchgrass, wheat straw, and corn stover, respectively, and the corresponding total specific energies were 7.57, 10.53, and 8.87 kWh/Mg and effective specific energies were 1.27, 1.50, and 0.24 kWh/Mg for switchgrass, wheat straw, and corn stover, respectively. Energy utilization ratios were calculated as 16.8%, 14.3%, and 2.8% for switchgrass, wheat straw, and corn stover, respectively. These data will be useful for preparing the feed material for subsequent fine grinding operations and designing new mills.

Air gasification of rice husk in bubbling fluidized bed reactor with bed heating by conventional charcoal.

PubMed

Makwana, J P; Joshi, Asim Kumar; Athawale, Gaurav; Singh, Dharminder; Mohanty, Pravakar

2015-02-01

An experimental study of air gasification of rice husk was conducted in a bench-scale fluidized bed gasifier (FBG) having 210 mm diameter and 1600 mm height. Heating of sand bed material was performed using conventional charcoal fuel. Different operating conditions like bed temperature, feeding rate and equivalence ratio (ER) varied in the range of 750-850 °C, 25-31.3 kg/h, and 0.3-0.38, respectively. Flow rate of air was kept constant (37 m(3)/h) during FBG experiments. The carbon conversion efficiencies (CCE), cold gas efficiency, and thermal efficiency were evaluated, where maximum CCE was found as 91%. By increasing ER, the carbon conversion efficiency was decreased. Drastic reduction in electric consumption for initial heating of gasifier bed with charcoal compared to ceramic heater was ∼45%. Hence rice husk is found as a potential candidate to use directly (without any processing) in FBG as an alternative renewable energy source from agricultural field. Copyright © 2014 Elsevier Ltd. All rights reserved.

Energy and protein feed-to-food conversion efficiencies in the US and potential food security gains from dietary changes

NASA Astrophysics Data System (ADS)

Shepon, A.; Eshel, G.; Noor, E.; Milo, R.

2016-10-01

Feeding a growing population while minimizing environmental degradation is a global challenge requiring thoroughly rethinking food production and consumption. Dietary choices control food availability and natural resource demands. In particular, reducing or avoiding consumption of low production efficiency animal-based products can spare resources that can then yield more food. In quantifying the potential food gains of specific dietary shifts, most earlier research focused on calories, with less attention to other important nutrients, notably protein. Moreover, despite the well-known environmental burdens of livestock, only a handful of national level feed-to-food conversion efficiency estimates of dairy, beef, poultry, pork, and eggs exist. Yet such high level estimates are essential for reducing diet related environmental impacts and identifying optimal food gain paths. Here we quantify caloric and protein conversion efficiencies for US livestock categories. We then use these efficiencies to calculate the food availability gains expected from replacing beef in the US diet with poultry, a more efficient meat, and a plant-based alternative. Averaged over all categories, caloric and protein efficiencies are 7%-8%. At 3% in both metrics, beef is by far the least efficient. We find that reallocating the agricultural land used for beef feed to poultry feed production can meet the caloric and protein demands of ≈120 and ≈140 million additional people consuming the mean American diet, respectively, roughly 40% of current US population.

In vitro embryo production: growth performance, feed efficiency, and hematological, metabolic, and endocrine status in calves.

PubMed

Rérat, M; Zbinden, Y; Saner, R; Hammon, H; Blum, J W

2005-07-01

The potential management benefits of in vitro embryo production have been offset by an increased incidence of health-related problems in resulting calves [increased birth weight, congenital abnormalities, and peri- and postnatal mortality (large-offspring syndrome)] and of recipient cows (prolonged gestation, dystocia, increased hydroallantois, abortion). The aim of the present research was to determine whether relevant metabolic, endocrine, or hematological traits could be related to the causes of enhanced growth performance of in vitro fertilized calves. Growth performance and feed efficiency as well as hematological, metabolic, and endocrine traits studied in calves derived from in vitro-produced embryos (IVP; n = 11) and in calves derived from artificial insemination (AI; n = 8). Donor cows from which oocytes for in vitro fertilization were obtained had a heterogeneous background, thus excluding genetic maternal influences. On the other hand, semen for in vitro fertilization and for artificial insemination was from the same bull, and recipient cows were held under the same husbandry and feeding conditions as AI cows, thus reducing the variability. Blood samples were collected preprandially on d 1, 2, 3, 4, 7, 14, 28, 56, and 112 of life and every 20 min between 0830 and 1630 h on d 7 and 112 for the evaluation of growth hormone secretory patterns. Gestation of IVP cows was longer than that of AI cows, but birth weights were similar in both groups. Feed intake, average daily gain, and body length during the experimental period, body weight from wk 8 to 16, and gain/feed ratio during the first month of life were higher in IVP than in AI calves. At birth, potassium, 3,5,3'-triiodothyronine, and thyroxine concentrations were lower in IVP than in AI calves. Concentrations of sodium and potassium on d 7, of triglycerides on d 28, and of albumin on d 56 were higher in IVP than in AI calves. In conclusion, IVP calves had higher feed intake and growth rate during the entire growth period and improved feed efficiency in the first month of life than AI calves, but this was not mirrored by consistent changes of hematological, metabolic, or endocrine traits, whose concentrations were in the normal range. Additional work is needed to study IVP calves under field conditions.

Applicability of Perinereis aibuhitensis Grube for fish waste removal from fish cages in Sanggou Bay, P. R. China

NASA Astrophysics Data System (ADS)

Fang, Jinghui; Jiang, Zengjie; Jansen, Henrice M.; Hu, Fawen; Fang, Jianguang; Liu, Yi; Gao, Yaping; Du, Meirong

2017-04-01

The present study investigated the applicability of integrated polychaete-fish culture for fish waste removal to offset negative impact induced by organic benthic enrichment. A field study demonstrated that deposition rate was significantly higher underneath the fish farm than that in control area. The material settling under the farm was characterized by a high amount of fish feces (45%) and uneaten feed (27%). Both feeding rate (FR) and apparent digestibility rate (ADR) increased with decreasing body weight, as was indicated by significantly a higher rate observed for the groups containing smaller individuals in a lab study. The nutrient in fresh deposited material (De) was higher than that in sediments collected under the farm (Se), resulting in lower feces production but higher apparent digestibility rate for the De group as feeding rate was similar. Consequently, higher nutrient removal efficiency was observed in the De group. A mass balance approach indicated that approximately 400-500 individuals m-2 is required for removing all waste materials deposited underneath the fish farm, whereas abundance can be lower (about 300-350 individuals m-2) when only the fish waste needs to be removed. The results showed that a significant amount of waste had been accumulated in the fish cages in Sanggou Bay. The integration of fish with P. aibuhitensis seems promising for preventing organic pollution in the sediment and therefore is an effective strategy for mitigating negative effect of fish farms. Thus such integration can become a new IMTA (integrated multi-trophic aquaculture) model in Sanggou Bay.

Oropharyngeal dysphagia in preschool children with cerebral palsy: oral phase impairments.

PubMed

Benfer, Katherine A; Weir, Kelly A; Bell, Kristie L; Ware, Robert S; Davies, Peter S W; Boyd, Roslyn N

2014-12-01

This study aimed to document the prevalence and patterns of oral phase oropharyngeal dysphagia (OPD) in preschool children with cerebral palsy (CP), and its association with mealtime duration, frequency and efficiency. Cross-sectional population-based cohort study of 130 children diagnosed with CP at 18-36 months ca (mean = 27.4 months, 81 males) and 40 children with typical development (mean = 26.2, 18 males). Functional abilities of children with CP were representative of a population sample (GMFCS I = 57, II = 15, III = 23, IV = 12, V = 23). Oral phase impairment was rated from video using the Dyspahgia Disorders Survey, Schedule for Oral Motor Impairment, and Pre-Speech Assessment Scale. Parent-report was collected on a feeding questionnaire. Mealtime frequency, duration and efficiency were calculated from a three day weighed food record completed by parents. Gross motor function was classified using the Gross Motor Function Classification System (GMFCS). Overall, 93.8% of children had directly assessed oral phase impairments during eating or drinking, or in controlling saliva (78.5% with modified cut-points). Directly assessed oral phase impairments were associated with declining gross motor function, with children from GMFCS I having a 2-fold increased likelihood of oral phase impairment compared to the children with TD (OR = 2.0, p = 0.18), and all children from GMFCS II-V having oral phase impairments. Difficulty biting (70%), cleaning behaviours (70%) and chewing (65%) were the most common impairments on solids, and difficulty sipping from a cup (60%) for fluids. OPD severity and GMFCS were not related to mealtime frequency, duration or efficiency, although children on partial tube feeds had significantly reduced mealtime efficiency. Oral phase impairments were common in preschool children with CP, with severity increasing stepwise with declining gross motor function. The prevalence and severity of oral phase impairments were significantly greater for most tasks when compared to children with typical development, even for those with mild CP. Children who were partially tube fed had significantly lower feeding efficiency, so this could be a useful early indicator of children needing supplementation to their nutrition (through increasing energy density of foods/fluids, or tube feeds). Copyright © 2014 Elsevier Ltd. All rights reserved.

Optimal concentrations in nectar feeding

PubMed Central

Kim, Wonjung; Gilet, Tristan; Bush, John W. M.

2011-01-01

Nectar drinkers must feed quickly and efficiently due to the threat of predation. While the sweetest nectar offers the greatest energetic rewards, the sharp increase of viscosity with sugar concentration makes it the most difficult to transport. We here demonstrate that the sugar concentration that optimizes energy transport depends exclusively on the drinking technique employed. We identify three nectar drinking techniques: active suction, capillary suction, and viscous dipping. For each, we deduce the dependence of the volume intake rate on the nectar viscosity and thus infer an optimal sugar concentration consistent with laboratory measurements. Our results provide the first rationale for why suction feeders typically pollinate flowers with lower sugar concentration nectar than their counterparts that use viscous dipping. PMID:21949358

Nutrigenomic and Nutritional Analyses Reveal the Effects of Pelleted Feeds on Asian Seabass (Lates calcarifer).

PubMed

Ngoh, Si Yan; Tan, Daniel; Shen, Xueyan; Kathiresan, Purushothaman; Jiang, Junhui; Liew, Woei Chang; Thevasagayam, Natascha May; Kwan, Hsiao Yuen; Saju, Jolly M; Prakki, Sridatta R S; Goh, Chin Heng; Wong, Hong Ching; Chan, Tai Teck; Mézes, Miklós; Orbán, László

2015-01-01

As nutrition-related expenses constitute the majority of the costs for aquaculture farms, it is essential for them to use feeds that provide an ideal combination of nutrients for the species of choice. In this study, the relative effect of consuming three different pelleted feeds (B, C and D) in comparison to frozen baitfish (A; control) were compared on juvenile Asian seabass (77.3 ± 22.4g) that were selected for increased growth rate over two generations. Our objectives were: 1) to evaluate the effects of different pelleted feeds based on overall physiological changes and nutritional quality of fillets; 2) improve our understanding of the underlying mechanisms with transcriptomic analysis; 3) if possible, identify the feed type that supports the growth of these fishes without substantially reducing the nutritional quality of fillet. The growth performance, fatty acid composition of fillet, hepatic histology and transcriptome of the fishes (Groups A-D) were analyzed. The majority of fatty acids of the fillets, except γ-linolenic acid (GLA, C18:3n6), correlated significantly with the respective diets. Asian seabass fed Feed C showed highest specific growth rate (SGR) and feed conversion efficiency (FCE) with closest histology and transcriptomic profile to control, but their fillet contained the highest n6/n3 ratio. When the liver-based transcriptomes were analyzed, a complex set of differentially expressed genes were detected between groups fed pelleted feeds and controls as well as among the pellet-fed groups themselves. Significant enrichment of genes with growth-related function tallied with the morphological data measured. When compared with control (Group A), 'Biosynthesis of unsaturated fatty acids' and 'Steroid biosynthesis' pathways were significantly enriched in pellet-fed groups. Reduced goblet cell numbers were observed in the gut of pellet-fed fish compared to controls and fads6 was found to be a suitable candidate gene to separate wild-caught Asian seabass, from pellet-fed ones. These results provide insights for researchers on the various effects of feeds on the biochemistry and global gene expression of the fish and potentially for seabass farms to make more informed feed choices.

Nutrigenomic and Nutritional Analyses Reveal the Effects of Pelleted Feeds on Asian Seabass (Lates calcarifer)

PubMed Central

Shen, Xueyan; Kathiresan, Purushothaman; Jiang, Junhui; Liew, Woei Chang; Thevasagayam, Natascha May; Kwan, Hsiao Yuen; Saju, Jolly M.; Prakki, Sridatta R. S.; Goh, Chin Heng; Wong, Hong Ching; Chan, Tai Teck; Mézes, Miklós; Orbán, László

2015-01-01

As nutrition-related expenses constitute the majority of the costs for aquaculture farms, it is essential for them to use feeds that provide an ideal combination of nutrients for the species of choice. In this study, the relative effect of consuming three different pelleted feeds (B, C and D) in comparison to frozen baitfish (A; control) were compared on juvenile Asian seabass (77.3 ± 22.4g) that were selected for increased growth rate over two generations. Our objectives were: 1) to evaluate the effects of different pelleted feeds based on overall physiological changes and nutritional quality of fillets; 2) improve our understanding of the underlying mechanisms with transcriptomic analysis; 3) if possible, identify the feed type that supports the growth of these fishes without substantially reducing the nutritional quality of fillet. The growth performance, fatty acid composition of fillet, hepatic histology and transcriptome of the fishes (Groups A-D) were analyzed. The majority of fatty acids of the fillets, except γ-linolenic acid (GLA, C18:3n6), correlated significantly with the respective diets. Asian seabass fed Feed C showed highest specific growth rate (SGR) and feed conversion efficiency (FCE) with closest histology and transcriptomic profile to control, but their fillet contained the highest n6/n3 ratio. When the liver-based transcriptomes were analyzed, a complex set of differentially expressed genes were detected between groups fed pelleted feeds and controls as well as among the pellet-fed groups themselves. Significant enrichment of genes with growth-related function tallied with the morphological data measured. When compared with control (Group A), ‘Biosynthesis of unsaturated fatty acids’ and ‘Steroid biosynthesis’ pathways were significantly enriched in pellet-fed groups. Reduced goblet cell numbers were observed in the gut of pellet-fed fish compared to controls and fads6 was found to be a suitable candidate gene to separate wild-caught Asian seabass, from pellet-fed ones. These results provide insights for researchers on the various effects of feeds on the biochemistry and global gene expression of the fish and potentially for seabass farms to make more informed feed choices. PMID:26696533

Environmental effects on nutrient and energy metabolism in ruminants.

PubMed

Tamminga, S; Schrama, J W

1998-01-01

Domesticated animals all over the world are subjected to a wide variety of environmental conditions and challenges. Any deviation from "normal" may result in adaptive behavior of which changes in feed intake or feed intake pattern is by far the most important. Adaptive behavior may further include influences on passage rate of feed residues through the digestive tract, resulting in changes in digestibility. Adaptive behavior may also result in changes in heat production, either to maintain body temperature constant, or as a result of an elevated body temperature. Important environmental challenges are infectious diseases. Mild (sub-clinical) infections usually result in reduced performance, without affecting feed intake or digestibility. Severe infections may disrupt the barriers between the internal metabolism and the respiratory and/or digestive tract, resulting in severe losses of energy and protein. This situation is notably apparent in severe infections with parasites of the gastrointestinal tract and may be associated with severe protein losses. Feeding high protein diets may partly alleviate the negative effects. Contamination of air, water and feed may occasionally cause problems in farm animals. Such contamination may include pathogenic microbes, toxic secondary fungal metabolites and heavy metals. Negative effects associated with such contamination often show an impaired reproductive efficiency, but their influence on the utilization of energy and nutrients is not well documented.

Role of probiotics in nutrition and health of small ruminants.

PubMed

Abd El-Tawab, M M; Youssef, I M I; Bakr, H A; Fthenakis, G C; Giadinis, N D

2016-12-01

Small ruminants represent an important economic source in small farm systems and agriculture. Feed is the main component of livestock farming, which has gained special attention to improve animal performance. Many studies have been done to improve feed utilisation through addition of feed additives. For a long period, antibiotics have been widely used as growth promoters in livestock diets. Due to their ban in many countries, search for alternative feed additives has been intensified. Probiotics are one of these alternatives recognised to be safe to the animals. Use of probiotics in small ruminant nutrition has been confirmed to improve animal health, productivity and immunity. Probiotics improved growth performance through enhancing of rumen microbial ecosystem, nutrient digestibility and feed conversion rate. Moreover, probiotics have been reported to stabilise rumen pH, increase volatile fatty acids production and to stimulate lactic acid utilising protozoa, resulting in a highly efficient rumen function. Furthermore, use of probiotics has been found to increase milk production and can reduce incidence of neonatal diarrhea and mortality. However, actual mechanisms through which probiotics exert these functions are not known. Since research on application of probiotics in small ruminants is scarce, the present review attempts to discuss the potential roles of this class of feed additives on productive performance and health status of these animals.

Increased expressions of genes and proteins involved in mitochondrial oxidation and antioxidant pathway in adipose tissue of pigs selected for a low residual feed intake.

PubMed

Louveau, I; Vincent, A; Tacher, S; Gilbert, H; Gondret, F

2016-12-01

Adipose tissue is a primary sensor for nutrient availability and regulates many functions including feed intake and energy homeostasis. This study was undertaken to determine the molecular responses of adipose tissue to differences in feed intake and feed efficiency. Subcutaneous adipose tissue was collected from two lines of pigs divergently selected for residual feed intake (RFI), a measure of feed efficiency defined as the difference between actual and expected feed intake, and from a subset of high-RFI pigs that were feed-restricted at the level of the voluntary feed intake of low-RFI pigs during the growing-finishing period. Transcriptomics analyses indicated that the number of genes that were differentially expressed ( < 0.01) between low- and high-RFI pigs ( = 8 per group at each stage) in adipose tissue was much lower when pigs were considered at 19 kg (postweaning) than at 115 kg BW (market weight). Extended investigations were performed at 115 kg BW to compare low-RFI ( = 8), high-RFI ( = 8), and feed-restricted high-RFI ( = 8) pigs. They included in silico pathway analyses of the differentially expressed (DE) genes ( < 0.01) and a complementary proteomic investigation to list adipose proteins with a differential abundance ( < 0.10). Only 23% of the DE genes were affected by both RFI and feed restriction. This indicates that the responses of adipose tissue to RFI difference shared only some common mechanisms with feed intake modulation, notably the regulation of cell cycle (including ) and transferase activity pathway. Two carboxylesterase genes (, ) involved in lipolysis, were among the most overexpressed genes in the low-RFI pigs; they were also affected by feed restriction within the high-RFI line. About 60% of the molecular changes between low- and high-RFI pigs were specific to genetic divergence in feed efficiency, independently of feed intake. Different genes and proteins known to be associated with mitochondrial oxidative metabolism were overexpressed in adipose tissue of low-RFI pigs compared with high-RFI pigs; other proteins participating in the generation of energy were also affected by feed restriction within the high-RFI line. Finally, mitochondrial antioxidant genes were upregulated in low-RFI pigs vs. high-RFI pigs. Altogether, increased oxidative and antioxidant processes in adipose tissue might be associated with improved feed efficiency.

Direct and correlated responses to selection in two lines of rabbits selected for feed efficiency under ad libitum and restricted feeding: I. Production traits and gut microbiota characteristics.

PubMed

Drouilhet, L; Achard, C S; Zemb, O; Molette, C; Gidenne, T; Larzul, C; Ruesche, J; Tircazes, A; Segura, M; Bouchez, T; Theau-Clément, M; Joly, T; Balmisse, E; Garreau, H; Gilbert, H

2016-01-01

To get insights into selection criteria for feed efficiency, 2 rabbit lines have been created: the ConsoResidual line was selected for residual feed intake (RFI) with ad libitum feeding and the ADGrestrict line was selected for ADG under restricted feeding (-20% of voluntary intake). The first objective of this study was to evaluate, after 9 generations of selection, the direct and correlated responses to selection on production traits in the 2 lines for traits recorded during growth. Second, applying the 2 feeding conditions used for selection to both selected lines plus the control unselected line (generation 0, G0) in a 2 × 3 factorial trial, the line performances were compared and the gut microbiota of the lines was characterized. The correlated responses in feed conversion ratio (FCR) were remarkably equivalent in both selected lines (-2.74 genetic σ) but correlated responses in other traits were notably different. In the ConsoResidual line, selection for decreased RFI resulted in a small negative correlated response in BW at 63 d old (BW63) and in a null response in ADG. In the ADGrestrict line, on the contrary, the correlated response in BW63 was substantial (+1.59 σ). The 2 selected lines had a FCR reduced by 0.2 point compared with the G0 line, and the same difference was found in both feeding regimens ( < 0.001). Indeed, selection on ADG would lead to heavier animals with no significant reduction of feed costs, whereas selection on RFI leads to lower feed costs and no increase of animal BW under ad libitum feeding. Altogether, our results do not suggest any genotype × environment interaction in the response to feeding regimens. The intestinal microbial communities from efficient rabbits differed from their unselected counterparts in terms of fermentation end products and microbial phylotypes, suggesting a central role of these microbes in the better feed efficiency of the rabbits.

Characterization of tapered slot antenna feeds and feed arrays

NASA Technical Reports Server (NTRS)

Kim, Young-Sik; Yngvesson, K. Sigfrid

1990-01-01

A class of feed antennas and feed antenna arrays used in the focal plane of paraboloid reflectors and exhibiting higher than normal levels of cross-polarized radiation in the diagonal planes is addressed. A model which allows prediction of element gain and aperture efficiency of the feed/reflector system is presented. The predictions are in good agreement with experimental results. Tapered slot antenna (TSA) elements are used an example of an element of this type. It is shown that TSA arrays used in multibeam systems with small beam spacings are competitive in terms of aperture efficiency with other, more standard types of arrays incorporating waveguide type elements.

Organic Selenium, Probiotics, and Prebiotics Effects on Growth, Blood Biochemistry, and Carcass Traits of Growing Rabbits During Summer and Winter Seasons.

PubMed

Ayyat, Mohamed S; Al-Sagheer, Adham A; Abd El-Latif, Khaled M; Khalil, Bakry A

2018-03-07

The effect of organic selenium, prebiotics, or probiotics on productive performances, blood biochemistry, and carcass characteristics of growing rabbits was studied throughout summer and winter seasons. In an 8-week feeding trial, a total of 100 New Zealand White rabbits were randomly distributed to 10 groups. Two seasons (winter and summer) and five diets fortified with 0 (control), 0.03 mg selenium, 3 g Bio-Mos®, 1 g Bactocell® (1 × 10 10  CFU) or 3 g yeast/kg diet were used in 2 × 5 factorial design. Results indicated that growth performance, feed intake (FI), and blood components (red blood cells [RBCs], serum total protein [TP], globulin [GLOB], albumin [ALB]) decreased significantly in rabbits reared during summer than in those during winter. In contrast, white blood cells, urea-N, creatinine, alanine transaminase [ALT], and aspartate transaminase [AST] increased significantly in summer. However, growth performance indices, FI, blood hemoglobin, RBCs, TP, ALB, and GLOB increased significantly in rabbits when fed the tested feed additives. The respiration rate, rectal temperature, and heart rate of the animals were significantly decreased with all feed additives. Adjusted weight of carcass, liver, kidney fat, and carcass cuts were not affected by feed additives. Final margin and margin efficiency increased in rabbit fed diets supplemented with feed additives than those fed the basal diet without any supplementation. Results of the current study concluded that a supplementation of rabbit diets with organic selenium, probiotics, and prebiotics can promote rabbit performance during mild weather and also alleviate the adverse impact of heat stress during summer season.

Infant feeding practices within a large electronic medical record database.

PubMed

Bartsch, Emily; Park, Alison L; Young, Jacqueline; Ray, Joel G; Tu, Karen

2018-01-02

The emerging adoption of the electronic medical record (EMR) in primary care enables clinicians and researchers to efficiently examine epidemiological trends in child health, including infant feeding practices. We completed a population-based retrospective cohort study of 8815 singleton infants born at term in Ontario, Canada, April 2002 to March 2013. Newborn records were linked to the Electronic Medical Record Administrative data Linked Database (EMRALD™), which uses patient-level information from participating family practice EMRs across Ontario. We assessed exclusive breastfeeding patterns using an automated electronic search algorithm, with manual review of EMRs when the latter was not possible. We examined the rate of breastfeeding at visits corresponding to 2, 4 and 6 months of age, as well as sociodemographic factors associated with exclusive breastfeeding. Of the 8815 newborns, 1044 (11.8%) lacked breastfeeding information in their EMR. Rates of exclusive breastfeeding were 39.5% at 2 months, 32.4% at 4 months and 25.1% at 6 months. At age 6 months, exclusive breastfeeding rates were highest among mothers aged ≥40 vs. < 20 years (rate ratio [RR] 2.45, 95% confidence interval [CI] 1.62-3.68), urban vs. rural residence (RR 1.35, 95% CI 1.22-1.50), and highest vs. lowest income quintile (RR 1.18, 95% CI 1.02-1.36). Overall, immigrants had similar rates of exclusive breastfeeding as non-immigrants; yet, by age 6 months, among those residing in the lowest income quintile, immigrants were more likely to exclusively breastfeed than their non-immigrant counterparts (RR 1.43, 95% CI 1.12-1.83). We efficiently determined rates and factors associated with exclusive breastfeeding using data from a large EMR database.

Dietary accumulation efficiencies and biotransformation of polybrominated diphenyl ethers in farmed Atlantic salmon (Salmo salar).

PubMed

Isosaari, P; Lundebye, A-K; Ritchie, G; Lie, O; Kiviranta, H; Vartiainen, T

2005-09-01

The consumer safety of farm-raised salmon could be improved by determining the transfer efficiency of hazardous pollutants from fish feed to the salmon. A controlled feeding trial for 30 weeks was carried out to investigate the transfer of polybrominated diphenyl ethers (PBDEs) in Atlantic salmon (Salmo salar). Using three feed concentrations, an average of 95% of the total PBDE content of feed accumulated in whole salmon. Skinned fillet accumulated 42-59% of the PBDE intake. Equal partitioning according to the lipid content of the tissue was demonstrated. The formation of less brominated PBDEs via preferential debromination from the meta-position was thought to explain the exceptional accumulation efficiencies of BDE 47, BDE 66, BDE 75, BDE 119 and BDE 183 that were either >100% or else increasing with the exposure dose. Monitoring of a larger number of PBDE congeners is recommended to verify the biotransformation routes. The PBDE concentration in salmon of different ages, fed on a known concentration of PBDEs in fish feed, could be predicted by using the accumulation efficiencies determined in this study.

The combined effects of supplementing monensin and 3-nitrooxypropanol on methane emissions, growth rate, and feed conversion efficiency in beef cattle fed high forage and high grain diets.

PubMed

Vyas, Diwakar; Alemu, Aklilu W; McGinn, Sean M; Duval, Stephane M; Kindermann, Maik; Beauchemin, Karen A

2018-05-05

The study objective was to evaluate the combined effects of supplementing monensin (MON) and the methane (CH4) inhibitor 3-nitrooxypropanol (NOP) on enteric CH4 emissions, growth rate and feed conversion efficiency of backgrounding and finishing beef cattle. Two hundred and forty crossbred steers were used in a 238-d feeding study and fed a backgrounding diet for the first 105-d (backgrounding phase), transition diets for 28 d, followed by a finishing diet for 105-d (finishing phase). Treatments were: 1) Control (no additive); 2) MON (monensin supplemented at 33 mg/kg DM; 3) NOP (3-nitrooxypropanol supplemented at 200 mg/kg DM for backgrounding or 125 mg/kg DM for finishing phase); 4) MONOP (33 mg/kg DM MON supplemented with either 200 mg/kg DM or 125 mg/kg DM NOP). The experiment was a randomized complete block (weight: heavy and light) design with 2 (NOP) × 2 (MON) factorial arrangement of treatments using 24 pens (8 cattle/pen; 6 pens/treatment) at the main feedlot and 8 pens (6 cattle/pen; 2 pens/treatment) at the controlled environment building (CEB) feedlot. Five animals per treatment were moved to chambers for methane measurements during both phases. Data were analyzed using a Mixed procedure of SAS with pen as experimental unit (except CH4). Location (Main vs CEB) had no significant effect and was thus omitted from the final model. Overall, there were few interactions between MON and NOP indicating that the effects of the 2 compounds were independent. When cattle were fed the backgrounding diet, pen DMI was decreased by 7% while gain-to-feed ratio (G:F) was improved by 5% with NOP supplementation (P < 0.01). Similarly, MON improved G:F ratio by 4% (P < 0.01), but without affecting DMI. During the finishing phase, DMI tended (P = 0.06) to decrease by 5% with both MON (5%) and NOP (5%), while average daily gain tended (P = 0.08) to decrease by 3% with MON. Gain-to-feed ratio for finishing cattle was improved with NOP by 3% (P < 0.01); however, no effects were observed with MON. 3-Nitrooxypropanol decreased CH4 yield (g/kg DMI) by 42% and 37% with backgrounding and finishing diets (P ≤ 0.01), respectively, while MON did not lower CH4 yield. Overall, these results demonstrate efficacy of NOP in reducing enteric CH4 emissions and subsequently improving feed conversion efficiency in cattle fed high forage and high grain diets. Furthermore, effects of NOP did not depend upon whether MON was included in the diet.

Novel insights into iron regulation and requirement in marine medaka Oryzias melastigma

NASA Astrophysics Data System (ADS)

Wang, Jian; Wang, Wen-Xiong

2016-05-01

Iron (Fe) is an essential trace element for marine fish. However, our knowledge of Fe requirements at different development stages of marine fish is still limited. Here, we reported the efficient Fe absorption strategies adopted by larval fish under different dietary Fe supplementary levels (i.e., 0-640 mg/kg). Biokinetically, the larval fish controlled their dietary Fe assimilation efficiency (AE, 1.6-18.5%), and enhanced their waterborne Fe uptake (ca. 2.5 fold change of uptake rate constant) once the dietary Fe was deficient (i.e., 27.4 mg Fe/kg feed). Transcriptionally, the expression of hepcidin1 (hep1; Fe regulator; i.e., 2.3-15.7 fold change) in larval fish was positively correlated with the Fe supplementary levels. Comparatively, the female adult fish were poor in assimilating the added Fe source (i.e., ferric form) with similar life-sustainable levels of Fe (i.e., 0.046-0.12 μg/g/d assimilated for Fe supplementary levels of 27.4, 162 and 657 mg Fe/kg feed). The overall feeding experiments suggested that dietary net Fe flux sufficient for the normal growth of larval medaka was 0.71-1.75 μg/g/d (i.e., 83.9 mg Fe/kg feed), consistent with the modeled value (i.e., 1.09-2.16 μg/g/d). In female adults, the estimated essential net Fe flux was 0.88-0.90 μg/g/d.

Growth performance and meat quality of rabbits under different feeding regimes.

PubMed

Khan, Kamran; Khan, Sarzamin; Khan, Rajwali; Sultan, Asad; Khan, Nazir Ahmad; Ahmad, Naseer

2016-12-01

This study evaluated the growth, carcass characteristics and meat quality of indigenous rabbits in northern Pakistan. Weaned rabbits (age 35 days, weight 323 g) of four distinct phenotypes (white, black and white, brown and black) were fed four experimental diets: alfalfa hay (AH), berseem fodder (BF), BF supplemented with low-level concentrate (50 %; LLC) and high-level concentrate (75 %; HLC). Each experimental diet was fed to 48 rabbits, 12 of each phenotype, in a randomized complete block design. The duration of the experiment was 55 days, including 1 week of adaptation. Rabbits fed the BF and AH diets had poor body weight gain (P < 0.05) compared to rabbits fed the LLC and HLC diets. Feed conversion efficiency was best in the LLC (4.47) and HLC (4.58) groups. Average carcass yield (743 g) and carcass dressing percentage (56.2) were higher (P < 0.05) in LLC. Growth rate was not improved significantly by feeding HLC. Fat deposition in animals was higher (P < 0.05) in the groups supplemented with concentrate. Cost per kilogram of rabbit meat was lowest (P < 0.05) for BF, followed by AH, LLC and HLC. Brown phenotypes had the best (P < 0.05) feed conversion efficiency, body weight gain, carcass yield and carcass dressing. It was concluded that local rabbits do not necessarily need high levels of concentrates but can be well fattened with low-level concentrates along with forages.

Functional Response of Eretmocerus delhiensis on Trialeurodes vaporariorum by Parasitism and Host Feeding

PubMed Central

Ebrahimifar, Jafar; Allahyari, Hossein

2017-01-01

The parasitoid wasp, Eretmocerus delhiensis (Hymenoptera, Aphelinidae) is a thelytokous and syn-ovigenic parasitoid. To evaluate E. delhiensis as a biocontrol agent in greenhouse, the killing efficiency of this parasitoid by parasitism and host-feeding, were studied. Killing efficiency can be compared by estimation of functional response parameters. Laboratory experiments were performed in controllable conditions to evaluate the functional response of E. delhiensis at eight densities (2, 4, 8, 16, 32, 64, 100, and 120 third nymphal stage) of Trialeurodes vaporariorum (Hemiptera, Aleyrodidae) on two hosts including; tomato and prickly lettuce. The maximum likelihood estimates from regression logistic analysis revealed type II functional response for two host plants and the type of functional response was not affected by host plant. Roger’s model was used to fit the data. The attack rate (a) for E. delhiensis was 0.0286 and 0.0144 per hour on tomato and 0.0434 and 0.0170 per hour on prickly lettuce for parasitism and host feeding, respectively. Furthermore, estimated handling times (Th) were 0.4911 and 1.4453 h on tomato and 0.5713 and 1.5001 h on prickly lettuce for parasitism and host feeding, respectively. Based on 95% confidence interval, functional response parameters were significantly different between the host plants solely in parasitism. Results of this study opens new insight in the host parasitoid interactions, subsequently needs further investigation before utilizing it for management and reduction of greenhouse whitefly. PMID:28423420

Is domestication driven by reduced fear of humans? Boldness, metabolism and serotonin levels in divergently selected red junglefowl (Gallus gallus).

PubMed

Agnvall, Beatrix; Katajamaa, Rebecca; Altimiras, Jordi; Jensen, Per

2015-09-01

Domesticated animals tend to develop a coherent set of phenotypic traits. Tameness could be a central underlying factor driving this, and we therefore selected red junglefowl, ancestors of all domestic chickens, for high or low fear of humans during six generations. We measured basal metabolic rate (BMR), feed efficiency, boldness in a novel object (NO) test, corticosterone reactivity and basal serotonin levels (related to fearfulness) in birds from the fifth and sixth generation of the high- and low-fear lines, respectively (44-48 individuals). Corticosterone response to physical restraint did not differ between selection lines. However, BMR was higher in low-fear birds, as was feed efficiency. Low-fear males had higher plasma levels of serotonin and both low-fear males and females were bolder in an NO test. The results show that many aspects of the domesticated phenotype may have developed as correlated responses to reduced fear of humans, an essential trait for successful domestication. © 2015 The Author(s).

Relationship between residual feed intake and lymphocyte mitochondrial complex protein concentration and ratio in crossbred steers.

PubMed

Davis, M P; Brooks, M A; Kerley, M S

2016-04-01

Rate of oxygen uptake by muscle mitochondria and respiratory chain protein concentrations differed between high- and low-residual feed intake (RFI) animals. The hypothesis of this research was that complex I (CI), II (CII), and III (CIII) mitochondria protein concentrations in lymphocyte (blood) mitochondria were related to the RFI phenotype of beef steers. Daily feed intake (ADFI) was individually recorded for 92 Hereford-crossbreed steers over 63 d using GrowSafe individual feed intake system. Predicted ADFI was calculated as the regression of ADFI on ADG and midtest BW. Difference between ADFI and predicted ADFI was RFI. Lymphocytes were isolated from low-RFI (-1.32 ± 0.11 kg/d; = 10) and high-RFI (1.34 ± 0.18 kg/d; = 8) steers. Immunocapture of CI, CII, and CIII proteins from the lymphocyte was done using MitoProfile CI, CII, and CIII immunocapture kits (MitoSciences Inc., Eugene, OR). Protein concentrations of CI, CII, and CIII and total protein were quantified using bicinchoninic acid colorimetric procedures. Low-RFI steers consumed 30% less ( = 0.0004) feed and had a 40% improvement ( < 0.0001) in feed efficiency compared with high-RFI steers with similar growth ( = 0.78) and weight measurements ( > 0.65). High- and low-RFI steers did not differ in CI ( = 0.22), CII ( = 0.69), and CIII ( = 0.59) protein concentrations. The protein concentration ratios for CI to CII ( = 0.03) were 20% higher and the ratios of CI to CIII ( = 0.01) were 30% higher, but the ratios of CII to CIII ( = 0.89) did not differ when comparing low-RFI steers with high-RFI steers. The similar magnitude difference in feed intake, feed efficiency measurements, and CI-to-CIII ratio between RFI phenotypes provides a plausible explanation for differences between the phenotypes. We also concluded that mitochondria isolated from lymphocytes could be used to study respiratory chain differences among differing RFI phenotypes. Further research is needed to determine if lymphocyte mitochondrial complex proteins can be used for identification of RFI phenotype.

The role of dietary long chain fatty acids in mitochondrial structure and function. Effects on rat cardiac mitochondrial respiration.

PubMed

Clandinin, M T

1978-02-01

To evaluate the effect of dietary rapeseed oils on cardiac mitochondrial function and metabolic conservation of energy, male weanling rats derived from the Sprague-Dawley strain were fed three rations containing either 15% (w/w) soybean oil, low erucic acid rapeseed oil or a high erucic acid rapeseed oil. Cardiac mitochondria were isolated for measurement of mitochondrial respiratory functions. Pyruvate and malate plus malonate or succinate plus amytal, or alpha-ketoglutarate and malate plus malonate were utilized as substrates for oxidative phosphorylation. Net rates of state 3 oxygen uptake and therefore ATP synthesis were found to decline with chronic feeding of the 15% (w/w) oil containing diets. Significantly reduced ADP/O ratios were observed for groups fed high erucic acid rapeseed oil containing diets for 11 days. Decreased ADP/O ratios were also observed for groups fed high or low erucic acid rapeseed oils for 112 days. When pyruvate and malate plus malonate were utilized as substrates, reduced rates of ATP synthesis were observed after chronic feeding of high erucic acid rapeseed oil diets. Only prolonged feeding of low erucic acid rapeseed oils resulted in significant alterations in the efficiency of oxidative phosphorylation.

Model-based optimization and scale-up of multi-feed simultaneous saccharification and co-fermentation of steam pre-treated lignocellulose enables high gravity ethanol production.

PubMed

Wang, Ruifei; Unrean, Pornkamol; Franzén, Carl Johan

2016-01-01

High content of water-insoluble solids (WIS) is required for simultaneous saccharification and co-fermentation (SSCF) operations to reach the high ethanol concentrations that meet the techno-economic requirements of industrial-scale production. The fundamental challenges of such processes are related to the high viscosity and inhibitor contents of the medium. Poor mass transfer and inhibition of the yeast lead to decreased ethanol yield, titre and productivity. In the present work, high-solid SSCF of pre-treated wheat straw was carried out by multi-feed SSCF which is a fed-batch process with additions of substrate, enzymes and cells, integrated with yeast propagation and adaptation on the pre-treatment liquor. The combined feeding strategies were systematically compared and optimized using experiments and simulations. For high-solid SSCF process of SO2-catalyzed steam pre-treated wheat straw, the boosted solubilisation of WIS achieved by having all enzyme loaded at the beginning of the process is crucial for increased rates of both enzymatic hydrolysis and SSCF. A kinetic model was adapted to simulate the release of sugars during separate hydrolysis as well as during SSCF. Feeding of solid substrate to reach the instantaneous WIS content of 13 % (w/w) was carried out when 60 % of the cellulose was hydrolysed, according to simulation results. With this approach, accumulated WIS additions reached more than 20 % (w/w) without encountering mixing problems in a standard bioreactor. Feeding fresh cells to the SSCF reactor maintained the fermentation activity, which otherwise ceased when the ethanol concentration reached 40-45 g L(-1). In lab scale, the optimized multi-feed SSCF produced 57 g L(-1) ethanol in 72 h. The process was reproducible and resulted in 52 g L(-1) ethanol in 10 m(3) scale at the SP Biorefinery Demo Plant. SSCF of WIS content up to 22 % (w/w) is reproducible and scalable with the multi-feed SSCF configuration and model-aided process design. For simultaneous saccharification and fermentation, the overall efficiency relies on balanced rates of substrate feeding and conversion. Multi-feed SSCF provides the possibilities to balance interdependent rates by systematic optimization of the feeding strategies. The optimization routine presented in this work can easily be adapted for optimization of other lignocellulose-based fermentation systems.

Constant and changing photoperiods in the laying period for broiler breeders allowed [corrected] normal or accelerated growth during the rearing period.

PubMed

Lewis, P D; Gous, R M

2006-02-01

Broiler breeder pullets were grown on 8-h photoperiods to 2.23 or 2.42 kg of BW at 20 wk, and then transferred abruptly to 11- or 16-h photoperiods. Subsequently, some of the 11-h photoperiod birds were given 15-min increases in day length weekly or a 1-h increase every 4 wk to reach 16 h of light at 54 wk. The birds transferred abruptly to a 16-h photoperiod at 20 wk matured 4 d earlier than 11-h photoperiod birds, required 500 g less feed to reach 50% lay, but, because of a 3% lower rate of lay after peak, produced 5 fewer eggs to 60 wk. However, the number of settable eggs was similar for the 2 groups because the 11-h photoperiod birds laid more eggs on the floor, resulting in more cracked and dirty eggs. The 11-h photoperiod birds converted feed into egg more efficiently, and were 100 g heavier at end of lay. Increasing the photoperiod in 15-min or 1-h increments from 11 to 16 h during the laying cycle depressed egg production. Mean egg weight and mortality were similar for all lighting groups. The heavier BW birds at 20 wk reached maturity 1 d earlier, but used 1 kg more feed to reach maturity, laid 5 fewer total eggs (because of a 3% lower rate of lay after peak), produced 7 more unsettable eggs (because more eggs were laid on the floor), and converted feed into egg less efficiently than did the lighter BW birds. Mean egg weight, BW at 57 wk, and mortality were similar for both groups. There was no significant light x growth interaction for any performance parameter. It is concluded that there is no benefit to egg production from extending the photoperiod to 16 h when broiler breeders are kept in light-proofed housing, especially if they have access to illuminated nest boxes.

Historical trade-offs of livestock’s environmental impacts

NASA Astrophysics Data System (ADS)

Frankel Davis, Kyle; Yu, Kailiang; Herrero, Mario; Havlik, Petr; Carr, Joel A.; D'Odorico, Paolo

2015-12-01

Human demand for animal products has risen markedly over the past 50 years with important environmental impacts. Dairy and cattle production have disproportionately contributed to greenhouse gas (GHG) emissions and land use, while crop demands of more intensive systems have increased fertilizer use and competition for available crop calories. At the same time, chicken and pig production has grown more rapidly than for ruminants, indicating a change in the environmental burden per animal calorie (EBC) with time. How EBCs have changed and to what extent resource use efficiency (RUE), the composition of animal production and the trade of feed have played a role in these changes have not been examined to date. We employ a calorie-based perspective, distinguishing animal calorie production between calories produced from feedcrop sources—directly competing with humans for available calories—and those from non-feed sources—plant biomass unavailable for direct human consumption. Combining this information with data on agricultural resource use, we calculate EBCs in terms of land, GHG emissions and nitrogen. We find that EBCs have changed substantially for land (-62%), GHGs (-46%) and nitrogen (+188%). Changes in RUE (e.g., selective breeding, increased grain-feeding) have been the primary contributor to these EBC trends, but shifts in the composition of livestock production were responsible for 12%-41% of the total EBC changes. In addition, the virtual trade of land for feed has more than tripled in the past 25 years with 77% of countries currently relying on virtual land imports to support domestic livestock production. Our findings indicate that important tradeoffs have occurred as a result of livestock intensification, with more efficient land use and emission rates exchanged for greater nitrogen use and increased competition between feed and food. This study provides an integrated evaluation of livestock’s impact on food security and the environment.

Divergence for residual feed intake of Holstein-Friesian cattle during growth did not affect production and reproduction during lactation.

PubMed

Macdonald, K A; Thomson, B P; Waghorn, G C

2016-11-01

Residual feed intake (RFI) is the difference between actual and predicted dry matter intake (DMI) of individual animals. Recent studies with Holstein-Friesian calves have identified an ~20% difference in RFI during growth (calf RFI) and these groups remained divergent in RFI during lactation. The objective of the experiment described here was to determine if cows selected for divergent RFI as calves differed in milk production, reproduction or in the profiles of BW and body condition score (BCS) change during lactation, when grazing pasture. The cows used in the experiment (n=126) had an RFI of -0.88 and +0.75 kg DM intake/day for growth as calves (efficient and inefficient calf RFI groups, respectively) and were intensively grazed at four stocking rates (SR) of 2.2, 2.6, 3.1 and 3.6 cows/ha on self-contained farmlets, over 3 years. Each SR treatment had equal number of cows identified as low and high calf RFI, with 24, 28, 34 and 40/11 ha farmlet. The cows divergent for calf RFI were randomly allocated to each SR. Although SR affected production, calf RFI group (low or high) did not affect milk production, reproduction, BW, BCS or changes in these parameters throughout lactation. The most efficient animals (low calf RFI) lost similar BW and BCS as the least efficient (high calf RFI) immediately post-calving, and regained similar BW and BCS before their next calving. These results indicate that selection for RFI as calves to increase efficiency of feed utilisation did not negatively affect farm productivity variables (milk production, BCS, BW and reproduction) as adults when managed under an intensive pastoral grazing system.

Association analysis between feed efficiency studies and expression of hypothalamic neuropeptide genes in laying ducks.

PubMed

Zeng, T; Chen, L; Du, X; Lai, S J; Huang, S P; Liu, Y L; Lu, L Z

2016-10-01

Residual feed intake (RFI) is now considered a more reasonable metric to evaluate animal feed efficiency. In this study, the correlation between RFI and other feed efficiency traits was investigated and gene expression within the hypothalamus was determined in low RFI (LRFI) and high RFI (HRFI) ducks. Further, several hypothalamic neuropeptide genes were measured using quantitative real-time PCR. The mean feed intake value was 160 g/day, whereas the egg mass laid (EML) and body weight were approximately 62.4 g/day and 1.46 kg respectively. Estimates for heritability of RFI, feed conversion ratio (FCR) and feed intake were 0.26, 0.18 and 0.23 respectively. RFI is phenotypically positively correlated with feed intake and FCR (P < 0.01). The expression of neuropeptide Y (NPY) and neuropeptide Y receptor Y5 (NPY5R) mRNA was higher in HRFI ducks compared with LRFI ducks (P < 0.05), whereas that of proopiomelanocortin (POMC), melanocortin 4 receptor (MC4R) and cholecystokinin (CCK) was lower (P < 0.05). The mRNA expression of gonadotropin-releasing hormone 1 (luteinizing-releasing hormone) (GNRH1) and prolactin receptor (PRLR) was unchanged between LRFI and HRFI ducks. The results indicate that selection for LRFI could reduce feed intake without significant changes in EML, whereas selection on FCR will increase EML. © 2016 Stichting International Foundation for Animal Genetics.

Effect of the squid viscera hydrolysate on growth performance and digestion in the red sea bream Pagrus major.

PubMed

Kondo, Fumitaka; Ohta, Takashi; Iwai, Toshiharu; Ido, Atsushi; Miura, Chiemi; Miura, Takeshi

2017-12-01

The improvement in feed efficiency is one of the most important subjects in fish culture. The development of feed, in terms of good intake, high growth performance, and high feed efficiency is needed. Squid viscera are one of the candidates for alternative material in improving feed efficiency in fish culture. In the present study, we described the dietary effect of the squid viscera hydrolysate (SVH) on the growth performance of the red sea bream. The addition of SVH to feed caused significant increases in feed intake, fork length, and body weight and produced a marked improvement in feed conversion after 4 weeks of feeding. Furthermore, the results of this feeding revealed that low dietary levels of SVH promote growth performance in the red sea bream. We physiologically analyzed digestion and appetite in fish fed diet containing SVH. SVH promoted the activity of hepatic trypsin and lipase, gene expression of stomach pepsin, hepatic lipase, and pyloric caeca trypsin, thereby improving the nutrient availability in red sea bream. Moreover, the mRNA expression of appetite regulating factor, such as brain NPY and stomach ghrelin was significantly improved by dietary SVH. Our current results indicate that dietary SVH as alternative material produced excellent effects on growth performance, which is dependent on the promoting effect on digestion and appetite in red sea bream.

Economic values for health and feed efficiency traits of dual-purpose cattle in marginal areas.

PubMed

Krupová, Z; Krupa, E; Michaličková, M; Wolfová, M; Kasarda, R

2016-01-01

Economic values of clinical mastitis, claw disease, and feed efficiency traits along with 16 additional production and functional traits were estimated for the dairy population of the Slovak Pinzgau breed using a bioeconomic approach. In the cow-calf population (suckler cow population) of the same breed, the economic values of feed efficiency traits along with 15 further production and functional traits were calculated. The marginal economic values of clinical mastitis and claw disease incidence in the dairy system were -€ 70.65 and -€ 26.73 per case per cow and year, respectively. The marginal economic values for residual feed intake were -€ 55.15 and -€ 54.64/kg of dry matter per day for cows and breeding heifers in the dairy system and -€ 20.45, -€ 11.30, and -€ 6.04/kg of dry matter per day for cows, breeding heifers, and fattened animals in the cow-calf system, respectively, all expressed per cow and year. The sums of the relative economic values for the 2 new health traits in the dairy system and for residual feed intake across all cattle categories in both systems were 1.4 and 8%, respectively. Within the dairy production system, the highest relative economic values were for milk yield (20%), daily gain of calves (20%), productive lifetime (10%), and cow conception rate (8%). In the cow-calf system, the most important traits were weight gain of calves from 120 to 210 d and from birth to 120 d (19 and 14%, respectively), productive lifetime (17%), and cow conception rate (13%). Based on the calculation of economic values for traits in the dual-purpose Pinzgau breed, milk production and growth traits remain highly important in the breeding goal, but their relative importance should be adapted to new production and economic conditions. The economic importance of functional traits (especially of cow productive lifetime and fertility) was sufficiently high to make the inclusion of these traits into the breeding goal necessary. An increased interest of consumers in animal welfare and quality of dairy farm products should probably lead to the incorporation of health traits (clinical mastitis incidence and somatic cells score) into the breeding goal. However, keeping carcass traits in the breeding goal of the Slovak Pinzgau breed does not seem to be relevant to the long-term market situation. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

An Experimental Investigation of Sewage Sludge Gasification in a Fluidized Bed Reactor

PubMed Central

Calvo, L. F.; García, A. I.; Otero, M.

2013-01-01

The gasification of sewage sludge was carried out in a simple atmospheric fluidized bed gasifier. Flow and fuel feed rate were adjusted for experimentally obtaining an air mass : fuel mass ratio (A/F) of 0.2 < A/F < 0.4. Fuel characterization, mass and power balances, produced gas composition, gas phase alkali and ammonia, tar concentration, agglomeration tendencies, and gas efficiencies were assessed. Although accumulation of material inside the reactor was a main problem, this was avoided by removing and adding bed media along gasification. This allowed improving the process heat transfer and, therefore, gasification efficiency. The heating value of the produced gas was 8.4 MJ/Nm, attaining a hot gas efficiency of 70% and a cold gas efficiency of 57%. PMID:24453863

Comparison of dairy beef genetics and dietary roughage levels.

PubMed

Lehmkuhler, J W; Ramos, M H

2008-06-01

The objectives of these trials were to investigate the performance of Jersey steers in relation to Holsteins under current management practices when fed diets differing in energy density and subsequent effects on carcass characteristics. In experiment 1, twelve Jersey and 12 Holstein steers were offered dietary treatments with differing roughage levels. Roughage levels investigated on a dry matter basis were 55% reduced to 25% versus 25% followed by 12.5% (HIGH and LOW, respectively) with all animals receiving the same finishing diet containing 6.5% roughage. Holstein steers were heavier than Jerseys at the initiation of the trial (228 vs. 116 kg). A diet response was observed for gain efficiency during the first period in which LOW was greater than HIGH. Holstein steers had higher dry matter intakes and rates of gain than Jerseys. However, gain efficiency was better for Jersey steers during the first and last periods. Carcass traits were influenced by breed but not diet. Holsteins had heavier hot carcass weights, greater dressing percentages, more backfat, and larger longissimus muscle area, whereas marbling scores were similar to Jerseys. The increased efficiency of Jersey steers and significant reduction in carcass value due to light carcass weights suggested that Jersey steers should be fed to heavier live weights. Experiment 2 utilized 85 steers to investigate continuous feeding of a low-roughage, high-concentrate diet versus a phase-feeding strategy. Jersey (n = 40) and Holstein (n = 45) steers were assigned to a diet containing 20% corn silage on a dry matter basis (HEN) or a phase-feeding program (PHASE) in which corn silage was reduced from 60 to 40% followed by the same diet as HEN. Initial body weights were similar for dietary treatments but differed by breed. A diet response was observed for live weight at the end of the first and second period, first period average daily gain (ADG), overall ADG, and days on feed with HEN having higher ADG than PHASE and fewer days on feed. Breed affected all body weight and gain variables with Holsteins being heavier and gaining more rapidly than Jersey steers. Jersey carcasses were lighter, had the highest percentage trim loss, least amount of backfat, and lowest numerical yield grade. Holstein steers had a greater propensity for gain, whereas the Jersey steers were equally or more efficient. These findings suggest that phase feeding Jersey steers higher-roughage diets has minimal effect on carcass traits.

Effects of dietary stachyose on growth performance, digestive enzyme activities and intestinal morphology of juvenile turbot ( Scophthalmus maximus L)

NASA Astrophysics Data System (ADS)

Hu, Haibin; Zhang, Yanjiao; Mai, Kangsen; Ai, Qinghui; Xu, Wei; Zhang, Wenbing; Li, Yanxian; Liu, Jintao

2015-10-01

A 12-week feeding trial was conducted to evaluate the effects of dietary stachyose on the growth performance, digestive enzymes activities and intestinal structures of juvenile turbot ( Scophthalmus maximus L). Five isonitrogenous (49.58% crude protein) and isolipidic (10.50% crude lipid) diets were formulated to contain 0 (Control), 0.625% (S-0.625), 1.25% (S-1.25), 2.5% (S-2.5) and 5% (S-5) stachyose, respectively. With the increase of stachyose level, the growth performance and feed utilization of turbot, such as the specific growth rate, final mean body weight, weight gain rate and feed efficiency, increased significantly ( P< 0.05) and then stabilized. The feed intake of fish fed S-5 was significantly higher ( P< 0.05) than that of fish in other groups. The activities of trypsin, intestinal caseinolytic, stomach and intestinal amylase were significantly influenced by stachyose ( P<0.05). The highest values of trypsin and intestinal caseinolytic activities were observed in group S-1.25, while the highest activity of stomach amylase and the lowest activity of intestine amylase were observed in group S-5. No lesion or damage was found on the distal intestine structures of fish from all treatments, while the height of simple folds in the distal intestine was significantly increased ( P< 0.05) when 1.25% or 2.5% stachyose was added in the diets. These results indicated that moderate level of stachyose (1.25%) improves the growth performance, feed utilization, digestive enzyme activities and the distal intestine structures of juvenile turbot.

Phenotypic and genetic relationships of feeding behavior with feed intake, growth performance, feed efficiency, and carcass merit traits in Angus and Charolais steers.

PubMed

Chen, L; Mao, F; Crews, D H; Vinsky, M; Li, C

2014-03-01

Feeding behavior traits including daily feeding duration (FD), daily feeding head down time (HD), average feeding duration per feeding event (FD_AVE), average feeding head down time per feeding event (HD_AVE), feeding frequency (FF), and meal eating rate (ER) were analyzed to estimate their phenotypic and genetic correlations with feed intake, growth performance, residual feed intake (RFI), ultrasound, and carcass merit traits in Angus and Charolais finishing steers. Heritability estimates for FD, HD, FD_AVE, HD_AVE, FF, and ER were 0.27 ± 0.09 (SE), 0.25 ± 0.09, 0.19 ± 0.06, 0.11 ± 0.05, 0.24 ± 0.08, and 0.38 ± 0.10, respectively, in the Angus population and 0.49 ± 0.12, 0.38 ± 0.11, 0.31 ± 0.09, 0.29 ± 0.10, 0.43 ± 0.11, and 0.56 ± 0.13, respectively, in the Charolais population. In both the Angus and Charolais steer populations, FD and HD had relatively stronger phenotypic (0.17 ± 0.06 to 0.32 ± 0.04) and genetic (0.29 ± 0.17 to 0.54 ± 0.18) correlations with RFI in comparison to other feeding behavior traits investigated, suggesting the potential of FD and HD as indicators in assessing variation of RFI. In general, feeding behavior traits had weak phenotypic correlations with most of the ultrasound and carcass merit traits; however, estimated genetic correlations of the feeding behavior traits with some fat deposition related traits were moderate to moderately strong but differed in magnitude or sign between the Angus and Charolais steer populations, likely reflecting their different biological types. Genetic parameter estimation studies involving feeding behavior traits in beef cattle are lacking and more research is needed to better characterize the relationships between feeding behavior and feed intake, growth, feed utilization, and carcass merit traits, in particular with respect to different biological types of cattle.

An innovative sewage sludge reduction by using a combined mesophilic anaerobic and thermophilic aerobic process with thermal-alkaline treatment and sludge recirculation.

PubMed

Cho, Hyun Uk; Park, Sang Kyu; Ha, Jeong Hyub; Park, Jong Moon

2013-11-15

Lab-scale High Efficiency Digestion (HED) systems containing a Mesophilic Anaerobic Reactor (MAR), Thermophilic Aerobic Reactor (TAR), liquid/solid separation unit, and thermal-alkaline treatment were developed to evaluate the efficiencies of sludge reduction and methane production. The HED process was divided into three phases to examine the influence of sludge pretreatment and pretreated sludge recirculation using TCOD and VSS reduction, COD solubilization, and methane production. The VSS removal with a solid/liquid separation unit, sludge recirculation, and thermal-alkaline treatment drastically increased up to 95% compared to the feed concentration. In addition, the results of COD solubilization and VSS/TSS showed that the solubilization of cells and organic matters by the thermal-alkaline treatment was highly increased, which was also consistent with the SEM images. In particular, the methane production rate increased 24-fold when the feed sludge and recirculated sludge were pretreated together. Collectively, the HED experiments performed with sludge recirculation and thermal-alkaline treatment demonstrated that the HED systems can be successfully employed for highly efficient sewage sludge reduction and methane gas production. Copyright © 2013 Elsevier Ltd. All rights reserved.

Feed efficiency differences and reranking in beef steers fed grower and finisher diets.

PubMed

Durunna, O N; Mujibi, F D N; Goonewardene, L; Okine, E K; Basarab, J A; Wang, Z; Moore, S S

2011-01-01

This 3-yr study used 490 steers to determine whether feedlot steers changed their feed efficiency (FE) ranking when fed a grower diet, then a finisher diet. The steers were crossbreds and were between 5 to 7 mo of age. There were 2 feeding periods each year. Within each year, approximately 90 steers had their diet switched from a grower to a finisher diet (feed-swap group), whereas another 90 steers were fed either the grower (grower-fed group) or the finisher (finisher-fed group) diet throughout the feeding trial. Each feeding test lasted for a minimum of 10 wk, and all steers were fed ad libitum. Individual animal feed intakes were collected using the GrowSafe feeding system, and BW were measured every 2 wk. Residual feed intake (RFI), G:F, and Kleiber ratio (KR) were computed at the end of each feeding period. For each measure of efficiency, animals were classified as low, medium, or high based on 0.5 SD from the mean. The majority of steers did not maintain the previous efficiency class in the second period. Approximately 58, 51, and 51% of steers in the feed-swap group, finisher-fed group, and the grower-fed group, respectively, changed their RFI measure by 0.5 SD. A low rank correlation occurred in all test groups but was less in the feed-swap group. Spearman rank correlations between the 2 feeding periods in the feed-swap group were 0.33, 0.20, and 0.31 for RFI, G:F, and KR, respectively. Classifications based on G:F and KR showed that a greater number of steers (P < 0.05) in the feed-swap group did not maintain their FE class from 1 feeding regimen to the other, whereas classification based on RFI did not show any difference (P > 0.05) between the proportions of individuals that changed or maintained their FE class. In the groups without a feed-swap, there was no difference (P > 0.05) in the proportion of steers that changed or maintained the same FE class for all FE measures. Our results suggest that diet type and feeding period affect the FE ranking in beef steers. A feedlot diet is ideal for evaluating the FE potential of steers for feedlot profitability; however, we suggest that tests involving less dense diets should be examined in an effort to understand the relationships between FE and feeder profitability.

Evaluation of limit feeding corn and distillers dried grains with solubles in non-feed-withdrawal molt programs for laying hens.

PubMed

Mejia, L; Meyer, E T; Utterback, P L; Utterback, C W; Parsons, C M; Koelkebeck, K W

2010-03-01

An experiment was conducted using 504 Hy-Line W-36 Single Comb White Leghorn hens (69 wk of age) randomly assigned to 1 of 7 treatments. These treatments consisted of a 47% corn:47% soy hulls diet (C:SH) fed ad libitum; a 94% corn diet fed at a rate of 36.3, 45.4, or 54.5 g/hen per day (CORN 36, CORN 45, and CORN 54, respectively); and a 94% corn distillers dried grains with solubles (DDGS) diet fed at the same rates as the previous corn diets (DDGS 36, DDGS 45, and DDGS 54, respectively) during the molt period of 28 d. The intent was to feed the DDGS diets for 28 d; however, all hens on these diets had very low feed intakes and greater than anticipated BW loss. Thus, they were switched to a 16% CP corn-soybean meal layer diet on d 19 of the molt period. At d 28, hens on all treatments were fed the same corn-soybean meal layer diet for 39 wk (73 to 112 wk of age). All DDGS diets and the CORN 36 diet resulted in total cessation of egg production during the molt period and egg production of hens fed the CORN 45, CORN 54, and C:SH diets had decreased to 3 and 4%, respectively, by d 28. Body weight loss during the 28-d molt period ranged from 14% for the CORN 54 diet to approximately 23% for the 3 DDGS diets. Postmolt egg production (5 to 43 wk) was higher for hens fed the DDGS molt diets than those fed the corn diets. There were no consistent differences in egg mass, egg-specific gravity, feed efficiency, or layer feed consumption among molt treatments for the postmolt period. These results indicate that limit feeding corn diet and DDGS diet in non-feed-withdrawal molt programs will yield long-term postmolt performance that is comparable to that observed by ad libitum feeding a C:SH diet.

Methane production by anaerobic digestion of water hyacinth (Eichhornia crassipes)

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

Klass, D.L.; Ghosh, S.

1980-01-01

Water hyacinth under conventional high-rate digestion conditions exhibited higher CH4 yields and energy recovery efficiencies when grown in sewage-fed lagoons than when grown in a fresh water pond. Mesophilic digestion provided the highest recovery of feed energy in the product gas as CH4, while thermophilic digestion, when operated at sufficiently high loading rates and reduced detention times, gave the highest specific CH4 production rates. CH4 yields, volatile solids reduction, and energy recovery as CH4 from the sewage-grown water hyacinth were in the same range as those observed for other biomass substrates when digested under similar conditions.

Effect of light, prey density, and prey type on the feeding rates of Hemimysis anomala

USGS Publications Warehouse

Halpin, Kathleen E.; Boscarino, Brent T.; Rudstam, Lars G.; Walsh, Mureen G.; Lantry, Brian F.

2013-01-01

Hemimysis anomala is a near-shore mysid native to the Ponto-Caspian region that was discovered to have invaded Great Lakes ecosystems in 2006. We investigated feeding rates and prey preferences of adult and juvenile Hemimysis in laboratory experiments to gain insight on the potential for Hemimysis to disrupt food webs. For both age groups (AGs), we measured feeding rates as a function of prey abundance (Bosmina longirostris as prey), prey type (B. longirostris, Daphnia pulex, and Mesocyclops sp.), and light levels (no light and dim light). Mean feeding rates on Bosmina increased with prey density and reached 23 ind. (2 h)−1 for adults and 17 ind. (2 h)−1 for juveniles. Dim light had little effect on prey selection or feeding rate compared to complete darkness. When feeding rates on alternate prey were compared, both AGs fed at higher rates on Bosmina than Daphnia, but only juveniles fed at significantly higher rates on Bosmina relative to Mesocyclops. No significant differences were observed between feeding rates on Mesocyclops and on Daphnia. Hemimysis feeding rates were on the order of 30–60% of their body weight per day, similar to predatory cladocerans that have been implicated in zooplankton declines in Lakes Huron and Ontario.

Loblolly pine grown under elevated CO2 affects early instar pine sawfly performance.

PubMed

Williams, R S; Lincoln, D E; Thomas, R B

1994-06-01

Seedlings of loblolly pine Pinus taeda (L.), were grown in open-topped field chambers under three CO 2 regimes: ambient, 150 μl l -1 CO 2 above ambient, and 300 μl l -1 CO 2 above ambient. A fourth, non-chambered ambient treatment was included to assess chamber effects. Needles were used in 96 h feeding trials to determine the performance of young, second instar larvae of loblolly pine's principal leaf herbivore, red-headed pine sawfly, Neodiprion lecontei (Fitch). The relative consumption rate of larvae significantly increased on plants grown under elevated CO 2 , and needles grown in the highest CO 2 regime were consumed 21% more rapidly than needles grown in ambient CO 2 . Both the significant decline in leaf nitrogen content and the substantial increase in leaf starch content contributed to a significant increase in the starch:nitrogen ratio in plants grown in elevated CO 2 . Insect consumption rate was negatively related to leaf nitrogen content and positively related to the starch:nitrogen ratio. Of the four volatile leaf monoterpenes measured, only β-pinene exhibited a significant CO 2 effect and declined in plants grown in elevated CO 2 . Although consumption changed, the relative growth rates of larvae were not different among CO 2 treatments. Despite lower nitrogen consumption rates by larvae feeding on the plants grown in elevated CO 2 , nitrogen accumulation rates were the same for all treatments due to a significant increase in nitrogen utilization efficiency. The ability of this insect to respond at an early, potentially susceptible larval stage to poorer food quality and declining levels of a leaf monoterpene suggest that changes in needle quality within pines in future elevated-CO 2 atmospheres may not especially affect young insects and that tree-feeding sawflies may respond in a manner similar to herb-feeding lepidopterans.

Fabrication and test of a space power boiler feed electromagnetic pump. 3: Endurance and final performance tests

NASA Technical Reports Server (NTRS)

Powell, A. H.; Amos, J. C.

1972-01-01

A three-phase helical induction electromagnetic pump designed for the boiler feed pump of a potassium Rankine cycle space power system was developed and built. It was mounted in a liquid metal test loop and successfully tested over a range of potassium temperatures from 900 to 1400 F, flow rates from 0.75 to 4.85 lb/sec, developed pressures up to 340 psi, net positive suction head from 1 to 22 psi, and NaK coolant temperatures from 800 to 950 F. Maximum efficiency at design point conditions of 3.25 lb/sec flow rate, 240 psi developed head, 1000 F potassium inlet temperature, and 800 F NaK coolant inlet temperature was 16.3 percent. After the performance tests the pump was operated without any difficulty at design point for 10,000 hours, and then a limited number of repeat performance tests were made. There was no appreciable change in pump performance after 10,000 hours of operation. A supplementary series of tests using the quasi-square wave power output of a dc to three-phase ac inverter showed that the pump would operate without difficulty at a frequency as low as 25 Hz, with little loss in efficiency.

Removal of arsenic from drinking water using rice husk

NASA Astrophysics Data System (ADS)

Asif, Zunaira; Chen, Zhi

2017-06-01

Rice husk adsorption column method has proved to be a promising solution for arsenic (As) removal over the other conventional methods. The present work investigates the potential of raw rice husk as an adsorbent for the removal of arsenic [As(V)] from drinking water. Effects of various operating parameters such as diameter of column, bed height, flow rate, initial arsenic feed concentration and particle size were investigated using continuous fixed bed column to check the removal efficiency of arsenic. This method shows maximum removal of As, i.e., 90.7 % under the following conditions: rice husk amount 42.5 g; 7 mL/min flow rate in 5 cm diameter column at the bed height of 28 cm for 15 ppb inlet feed concentration. Removal efficiency was increased from 83.4 to 90.7 % by reducing the particle size from 1.18 mm to 710 µm for 15 ppb concentration. Langmuir and Freundlich isotherm models were employed to discuss the adsorption behavior. The effect of different operating parameters on the column adsorption was determined using breakthrough curves. In the present study, three kinetic models Adam-Bohart, Thomas and Yoon-Nelson were applied to find out the saturated concentration, fixed bed adsorption capacity and time required for 50 % adsorbate breakthrough, respectively. At the end, solidification was done for disposal of rice husk.

Risk aversion affects economic values of blue fox breeding scheme.

PubMed

Peura, J; Kempe, R; Strandén, I; Rydhmer, L

2016-12-01

The profit and production of an average Finnish blue fox farm was simulated using a deterministic bio-economic farm model. Risk was included using Arrow-Prat absolute risk aversion coefficient and profit variance. Risk-rated economic values were calculated for pregnancy rate, litter loss, litter size, pelt size, pelt quality, pelt colour clarity, feed efficiency and eye infection. With high absolute risk aversion, economic values were lower than with low absolute risk aversion. Economic values were highest for litter loss (18.16 and 26.42 EUR), litter size (13.27 and 19.40 EUR), pregnancy (11.99 and 18.39 EUR) and eye infection (12.39 and 13.81 EUR). Sensitivity analysis showed that selection pressure for improved eye health depended strongly on proportion of culled animals among infected animals and much less on the proportion of infected animals. The economic value of feed efficiency was lower than expected (6.06 and 8.03 EUR). However, it was almost the same magnitude as pelt quality (7.30 and 7.30 EUR) and higher than the economic value of pelt size (3.37 and 5.26 EUR). Risk factors should be considered in blue fox breeding scheme because they change the relative importance of traits. © 2016 Blackwell Verlag GmbH.

Growth and development of male "little" mice assessed with Parks' theory of feeding and growth.

PubMed

Puche, Rodolfo C; Alloatti, Rosa; Chapo, Gustavo

2002-01-01

This work was designed to characterize the appetite kinetics and growth of male C57BL/6J (lit) mice. Those variables were assessed with Parks' function of ad libitum feeding and growth. Heterozygous mice (lit/+) attained their mature weight at 12-15 weeks of age, peak growth rate (3.5 g/week) at 5 weeks and displayed the normal decay of food conversion efficiency as a function of age. The homozygous genotype has a chronic defect in the synthesis and secretion of growth hormone (GH). Homozygous mice could not be assessed with Park's function. From the 4th to the 15th week of age, body weight increased linearly and exhibited constant food conversion efficiency. Food intake of both genotypes was commensurate with their body weights. Lit/lit mice became progressively obese. At 40 weeks of age, body fat of lit/lit mice was fivefold that of lit/+ and their body weight was similar to their heterozygous controls. The chronic deficiency of growth hormone produced a lower bone mass (compared to heterozygous controls). Bone mass of both genotypes attained maturity at 12-15 weeks with a maximum growth rate at 5 weeks. Body weight and bone mass grow harmoniously in lit/+ but not in lit/lit mice.

Longer guts and higher food quality increase energy intake in migratory swans.

PubMed

van Gils, Jan A; Beekman, Jan H; Coehoorn, Pieter; Corporaal, Els; Dekkers, Ten; Klaassen, Marcel; van Kraaij, Rik; de Leeuw, Rinze; de Vries, Peter P

2008-11-01

1. Within the broad field of optimal foraging, it is increasingly acknowledged that animals often face digestive constraints rather than constraints on rates of food collection. This therefore calls for a formalization of how animals could optimize food absorption rates. 2. Here we generate predictions from a simple graphical optimal digestion model for foragers that aim to maximize their (true) metabolizable food intake over total time (i.e. including nonforaging bouts) under a digestive constraint. 3. The model predicts that such foragers should maintain a constant food retention time, even if gut length or food quality changes. For phenotypically flexible foragers, which are able to change the size of their digestive machinery, this means that an increase in gut length should go hand in hand with an increase in gross intake rate. It also means that better quality food should be digested more efficiently. 4. These latter two predictions are tested in a large avian long-distance migrant, the Bewick's swan (Cygnus columbianus bewickii), feeding on grasslands in its Dutch wintering quarters. 5. Throughout winter, free-ranging Bewick's swans, growing a longer gut and experiencing improved food quality, increased their gross intake rate (i.e. bite rate) and showed a higher digestive efficiency. These responses were in accordance with the model and suggest maintenance of a constant food retention time. 6. These changes doubled the birds' absorption rate. Had only food quality changed (and not gut length), then absorption rate would have increased by only 67%; absorption rate would have increased by only 17% had only gut length changed (and not food quality). 7. The prediction that gross intake rate should go up with gut length parallels the mechanism included in some proximate models of foraging that feeding motivation scales inversely to gut fullness. We plea for a tighter integration between ultimate and proximate foraging models.

Application of Biological Simulation Models in Estimating Feed Efficiency of Finishing Steers

USDA-ARS?s Scientific Manuscript database

Data on individual daily feed intake, bi-weekly BW, and carcass composition were obtained on 1,212 crossbred steers. Within animal regressions of cumulative feed intake and BW on linear and quadratic days on feed were used to quantify initial and ending BW, average daily feed intake (OFI) and ADG o...

Primary genome scan to identify putative quantitative trait loci for feedlot growth rate, feed intake, and feed efficiency of beef cattle.

PubMed

Nkrumah, J D; Sherman, E L; Li, C; Marques, E; Crews, D H; Bartusiak, R; Murdoch, B; Wang, Z; Basarab, J A; Moore, S S

2007-12-01

Feed intake and feed efficiency of beef cattle are economically relevant traits. The study was conducted to identify QTL for feed intake and feed efficiency of beef cattle by using genotype information from 100 microsatellite markers and 355 SNP genotyped across 400 progeny of 20 Angus, Charolais, or Alberta Hybrid bulls. Traits analyzed include feedlot ADG, daily DMI, feed-to-gain ratio [F:G, which is the reciprocal of the efficiency of gain (G:F)], and residual feed intake (RFI). A mixed model with sire as random and QTL effects as fixed was used to generate an F-statistic profile across and within families for each trait along each chromosome, followed by empirical permutation tests to determine significance thresholds for QTL detection. Putative QTL for ADG (chromosome-wise P < 0.05) were detected across families on chromosomes 5 (130 cM), 6 (42 cM), 7 (84 cM), 11 (20 cM), 14 (74 cM), 16 (22 cM), 17 (9 cM), 18 (46 cM), 19 (53 cM), and 28 (23 cM). For DMI, putative QTL that exceeded the chromosome-wise P < 0.05 threshold were detected on chromosomes 1 (93 cM), 3 (123 cM), 15 (31 cM), 17 (81 cM), 18 (49 cM), 20 (56 cM), and 26 (69 cM) in the across-family analyses. Putative across-family QTL influencing F:G that exceeded the chromosome-wise P < 0.05 threshold were detected on chromosomes 3 (62 cM), 5 (129 cM), 7 (27 cM), 11 (16 cM), 16 (30 cM), 17 (81 cM), 22 (72 cM), 24 (55 cM), and 28 (24 cM). Putative QTL influencing RFI that exceeded the chromosome-wise P < 0.05 threshold were detected on chromosomes 1 (90 cM), 5 (129 cM), 7 (22 cM), 8 (80 cM), 12 (89 cM), 16 (41 cM), 17 (19 cM), and 26 (48 cM) in the across-family analyses. In addition, a total of 4, 6, 1, and 8 chromosomes showed suggestive evidence (chromosome-wise, P < 0.10) for putative ADG, DMI, F:G, and RFI QTL, respectively. Most of the QTL detected across families were also detected within families, although the locations across families were not necessarily the locations within families, which is likely because of differences among families in marker informativeness for the different linkage groups. The locations and direction of some of the QTL effects reported in this study suggest potentially favorable pleiotropic effects for the underlying genes. Further studies will be required to confirm these QTL in other populations so that they can be fine-mapped for potential applications in marker-assisted selection and management of beef cattle.

21 CFR 558.55 - Amprolium.

Code of Federal Regulations, 2010 CFR

2010-04-01

... obsignata) Feed according to subtable in item (i) Penicillin 2.4 to 50 Replacement chickens; development of active immunity to coccidiosis; growth promotion and feed efficiency As procaine penicillin. Feed... worms (Capillaria obsignata) Feed according to subtable in item (i) Penicillin 2.4 to 50 Broiler...

A study on porous super austenitic stainless steel coating for improvement of bone ingrowth

NASA Astrophysics Data System (ADS)

Oh, Keun Taek; Park, Yong Soo

1998-02-01

In this study, the prostheses were provided with the bone ingrowth site by coating the super stainless steel powder on the same substrate (S32050) using plasma spraying method. Plasma current and powder feed rate varied in this study based on the optimum conditions of previous experiments. The optimum conditions for satisfying the requirements of the porous coatings were found. The characteristics of the coatings were observed according to the experimental parameters. It was found that plasma current influenced the chemical composition (the oxides, Cr component), melting and flattening degree of the sprayed particle (surface roughness, thickness of the splat, pores) and corrosion -resistance. The powder feed rate also influenced the coating thickness and efficiency. The amount of Cr was increased, but Ni, Mo, Fe were decreased with plasma current. An increase of Cr in the coating surface corresponded to an increase in the amount of the formed oxides. The coated specimen in 400A had a high corrosion-resistance owing to a dense coating. The coated specimen in 500A formed many types of oxides. In 300A current, the coating was rough with many pores, and corrosion-resistance of the coating showed a large variation according to the oxidation and compositional change. Specifically at 100 g/min powder feed rate in a 300A current, the coating was rough and porous, nevertheless, it had high corrosion resistance.

Assessment of the safety and efficacy of low pathogenic avian influenza (H9N2) virus in inactivated oil emulsion vaccine in laying hens.

PubMed

Shin, Jeong-Hwa; Mo, Jong Seo; Kim, Jong-Nyeo; Mo, In-pil; Ha, Bong-Do

2016-03-01

In Korea, several outbreaks of low pathogenic AI (H9N2) viral infections leading to decreased egg production and increased mortality have been reported on commercial farms since 1996, resulting in severe economic losses. To control the H9N2 LPAI endemic, the Korea Veterinary Authority has permitted the use of the inactivated H9N2 LPAI vaccine since 2007. In this study, we developed a killed vaccine using a low pathogenic H9N2 AI virus (A/chicken/Korea/ADL0401) and conducted safety and efficacy tests in commercial layer farms while focusing on analysis of factors that cause losses to farms, including egg production rate, egg abnormality, and feed efficiency. The egg production rate of the control group declined dramatically 5 days after the challenge. There were no changes in feed consumption of all three groups before the challenge, but rates of the control declined afterward. Clinical signs in the vaccinated groups were similar, and a slight decline in feed consumption was observed after challenge; however, this returned to normal more rapidly than the control group and commercial layers. Overall, the results of this study indicate that the safety and efficacy of the vaccine are adequate to provide protection against the AI field infection (H9N2) epidemic in Korea.

Jewish and Celtic attitudes to breast feeding compared.

PubMed

Ineichen, B; Pierce, M; Lawrenson, R

1997-03-01

To examine reasons for the high rate of breast feeding among one UK ethnic group (Jews) and the low rate among Celtic (Scots and Irish) populations. A manual literature search of ethnic variation in breast feeding rates in the UK was conducted over several years. A computerised search yielded 31 additional references. Seven of these were added. Positive Jewish attitudes to breast feeding were underpinned by scriptural references, and rates of breast feeding were found to be especially high among Orthodox samples in the UK and Israel. Low Scottish and Irish rates appear to reflect prudishness, fashion, and possibly poor health. Reasons for falling rates among these populations in the twentieth century were not clear. Health education needs to address cultural attitudes throughout society if effective change is to be introduced, and the overall rate of breast feeding is to be increased.

Genetic Determinism of Fearfulness, General Activity and Feeding Behavior in Chickens and Its Relationship with Digestive Efficiency.

PubMed

Mignon-Grasteau, Sandrine; Chantry-Darmon, Céline; Boscher, Marie-Yvonne; Sellier, Nadine; Le Bihan-Duval, Elisabeth; Bertin, Aline

2017-01-01

The genetic relationships between behavior and digestive efficiency were studied in 860 chickens from a cross between two lines divergently selected on digestive efficiency. At 2 weeks of age each chick was video-recorded in the home pen to characterize general activity and feeding behavior. Tonic immobility and open-field tests were also carried out individually to evaluate emotional reactivity (i.e. the propensity to express fear responses). Digestive efficiency was measured at 3 weeks. Genetic parameters of behavior traits were estimated. Birds were genotyped on 3379 SNP markers to detect QTLs. Heritabilities of behavioral traits were low, apart from tonic immobility (0.17-0.18) and maximum meal length (0.14). The genetic correlations indicated that the most efficient birds fed more frequently and were less fearful. We detected 14 QTL (9 for feeding behavior, 3 for tonic immobility, 2 for frequency of lying). Nine of them co-localized with QTL for efficiency, anatomy of the digestive tract, feed intake or microbiota composition. Four genes involved in fear reactions were identified in the QTL for tonic immobility on GGA1.

Micro-feeding and dosing of powders via a small-scale powder pump.

PubMed

Besenhard, M O; Fathollahi, S; Siegmann, E; Slama, E; Faulhammer, E; Khinast, J G

2017-03-15

Robust and accurate powder micro-feeding (<100mg/s) and micro-dosing (<5 mg) are major challenges, especially with regard to regulatory limitations applicable to pharmaceutical development and production. Since known micro-feeders that yield feed rates below 5mg/s use gravimetric feeding principles, feed rates depend primarily on powder properties. In contrast, volumetric powder feeders do not require regular calibration because their feed rates are primarily determined by the feeder's characteristic volume replacement. In this paper, we present a volumetric micro-feeder based on a cylinder piston system (i.e., a powder pump), which allows accurate micro-feeding and feed rates of a few grams per hours even for very fine powders. Our experimental studies addressed the influence of cylinder geometries, the initial conditions of bulk powder, and the piston speeds. Additional computational studies via Discrete Element Method simulations offered a better understanding of the feeding process, its possible limitations and ways to overcome them. The powder pump is a simple yet valuable tool for accurate powder feeding at feed rates of several orders of magnitude. Copyright © 2016 Elsevier B.V. All rights reserved.

Metabolic expenditures of lunge feeding rorquals across scale: implications for the evolution of filter feeding and the limits to maximum body size.

PubMed

Potvin, Jean; Goldbogen, Jeremy A; Shadwick, Robert E

2012-01-01

Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti) and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae) exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals), the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae), fin (Balaenoptera physalus), blue (Balaenoptera musculus) and minke (Balaenoptera acutorostrata) whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum VO2 at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half VO2|max. These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting individual prey items to filter feeding on prey aggregations.

Heterogeneous Feeding Patterns of the Dengue Vector, Aedes aegypti, on Individual Human Hosts in Rural Thailand

PubMed Central

Harrington, Laura C.; Fleisher, Andrew; Ruiz-Moreno, Diego; Vermeylen, Francoise; Wa, Chrystal V.; Poulson, Rebecca L.; Edman, John D.; Clark, John M.; Jones, James W.; Kitthawee, Sangvorn; Scott, Thomas W.

2014-01-01

Background Mosquito biting frequency and how bites are distributed among different people can have significant epidemiologic effects. An improved understanding of mosquito vector-human interactions would refine knowledge of the entomological processes supporting pathogen transmission and could reveal targets for minimizing risk and breaking pathogen transmission cycles. Methodology and principal findings We used human DNA blood meal profiling of the dengue virus (DENV) vector, Aedes aegypti, to quantify its contact with human hosts and to infer epidemiologic implications of its blood feeding behavior. We determined the number of different people bitten, biting frequency by host age, size, mosquito age, and the number of times each person was bitten. Of 3,677 engorged mosquitoes collected and 1,186 complete DNA profiles, only 420 meals matched people from the study area, indicating that Ae. aegypti feed on people moving transiently through communities to conduct daily business. 10–13% of engorged mosquitoes fed on more than one person. No biting rate differences were detected between high- and low-dengue transmission seasons. We estimate that 43–46% of engorged mosquitoes bit more than one person within each gonotrophic cycle. Most multiple meals were from residents of the mosquito collection house or neighbors. People ≤25 years old were bitten less often than older people. Some hosts were fed on frequently, with three hosts bitten nine times. Interaction networks for mosquitoes and humans revealed biologically significant blood feeding hotspots, including community marketplaces. Conclusion and significance High multiple-feeding rates and feeding on community visitors are likely important features in the efficient transmission and rapid spread of DENV. These results help explain why reducing vector populations alone is difficult for dengue prevention and support the argument for additional studies of mosquito feeding behavior, which when integrated with a greater understanding of human behavior will refine estimates of risk and strategies for dengue control. PMID:25102306

Fouling resilient perforated feed spacers for membrane filtration.

PubMed

Kerdi, Sarah; Qamar, Adnan; Vrouwenvelder, Johannes S; Ghaffour, Noreddine

2018-04-24

The improvement of feed spacers with optimal geometry remains a key challenge for spiral-wound membrane systems in water treatment due to their impact on the hydrodynamic performance and fouling development. In this work, novel spacer designs are proposed by intrinsically modifying cylindrical filaments through perforations. Three symmetric perforated spacers (1-Hole, 2-Hole, and 3-Hole) were in-house 3D-printed and experimentally evaluated in terms of permeate flux, feed channel pressure drop and membrane fouling. Spacer performance is characterized and compared with standard no perforated (0-Hole) design under constant feed pressure and constant feed flow rate. Perforations in the spacer filaments resulted in significantly lowering the net pressure drop across the spacer filled channel. The 3-Hole spacer was found to have the lowest pressure drop (50%-61%) compared to 0-Hole spacer for various average flow velocities. Regarding permeate flux production, the 0-Hole spacer produced 5.7 L m -2 .h -1 and 6.6 L m -2 .h -1 steady state flux for constant pressure and constant feed flow rate, respectively. The 1-Hole spacer was found to be the most efficient among the perforated spacers with 75% and 23% increase in permeate production at constant pressure and constant feed flow, respectively. Furthermore, membrane surface of 1-Hole spacer was found to be cleanest in terms of fouling, contributing to maintain higher permeate flux production. Hydrodynamic understanding of these perforated spacers is also quantified by performing Direct Numerical Simulation (DNS). The performance enhancement of these perforated spacers is attributed to the formation of micro-jets in the spacer cell that aided in producing enough unsteadiness/turbulence to clean the membrane surface and mitigate fouling phenomena. In the case of 1-Hole spacer, the unsteadiness intensity at the outlet of micro-jets and the shear stress fluctuations created inside the cells are higher than those observed with other perforated spacers, resulting in the cleanest membrane surface. Copyright © 2018 Elsevier Ltd. All rights reserved.

Metabolic Expenditures of Lunge Feeding Rorquals Across Scale: Implications for the Evolution of Filter Feeding and the Limits to Maximum Body Size

PubMed Central

Potvin, Jean; Goldbogen, Jeremy A.; Shadwick, Robert E.

2012-01-01

Bulk-filter feeding is an energetically efficient strategy for resource acquisition and assimilation, and facilitates the maintenance of extreme body size as exemplified by baleen whales (Mysticeti) and multiple lineages of bony and cartilaginous fishes. Among mysticetes, rorqual whales (Balaenopteridae) exhibit an intermittent ram filter feeding mode, lunge feeding, which requires the abandonment of body-streamlining in favor of a high-drag, mouth-open configuration aimed at engulfing a very large amount of prey-laden water. Particularly while lunge feeding on krill (the most widespread prey preference among rorquals), the effort required during engulfment involve short bouts of high-intensity muscle activity that demand high metabolic output. We used computational modeling together with morphological and kinematic data on humpback (Megaptera noveaangliae), fin (Balaenoptera physalus), blue (Balaenoptera musculus) and minke (Balaenoptera acutorostrata) whales to estimate engulfment power output in comparison with standard metrics of metabolic rate. The simulations reveal that engulfment metabolism increases across the full body size of the larger rorqual species to nearly 50 times the basal metabolic rate of terrestrial mammals of the same body mass. Moreover, they suggest that the metabolism of the largest body sizes runs with significant oxygen deficits during mouth opening, namely, 20% over maximum at the size of the largest blue whales, thus requiring significant contributions from anaerobic catabolism during a lunge and significant recovery after a lunge. Our analyses show that engulfment metabolism is also significantly lower for smaller adults, typically one-tenth to one-half . These results not only point to a physiological limit on maximum body size in this lineage, but also have major implications for the ontogeny of extant rorquals as well as the evolutionary pathways used by ancestral toothed whales to transition from hunting individual prey items to filter feeding on prey aggregations. PMID:23024769

Variable food absorption by Antarctic krill: Relationships between diet, egestion rate and the composition and sinking rates of their fecal pellets

NASA Astrophysics Data System (ADS)

Atkinson, A.; Schmidt, K.; Fielding, S.; Kawaguchi, S.; Geissler, P. A.

2012-01-01

The kinetics of food processing by zooplankton affects both their energy budgets and the biogeochemical fate of their fecal pellets. We sampled 40 schools of krill across the Scotia Sea during spring, summer and autumn and found that in all 3 seasons, every aspect of their absorption and defecation varied greatly. The C content of fecal pellets varied from 0.85% to 29% of their dry mass (median 9.8%) and C egestion rates varied 75-fold. C:N mass ratios of pellets ranged from 4.9 to 13.2 (median 7.8), higher than values of 3.9 in the krill and 5.4 in their food, pointing to enhanced uptake of N. Pellet sinking rates equated to 27-1218 m d -1 (median 304 m d -1), being governed mainly by pellet diameter (80-600 μm, mean 183 μm) and density (1.038-1.391 g cm -3, mean 1.121 g cm -3). Pellets showed little loss of C or N in filtered seawater over the first 2 days and were physically robust. When feeding rates were low, slow gut passage time and high absorption efficiency resulted in low egestion rates of pellets that were low in C and N content. These pellets were compact, dense and fast-sinking. Conversely, in good feeding conditions much food tended to pass quickly through the gut and was not efficiently absorbed, producing C and N-rich, slow-sinking pellets. Such "superfluous feeding" probably maximises the absolute rates of nutrient absorption. Food composition was also important: diatom-rich diets depressed the C content of the pellets but increased their sinking rates, likely due to silica ballasting. So depending on how krill process food, their pellets could represent both vehicles for rapid export and slow sinking, C and N-rich food sources for pelagic scavengers. C egestion rates by krill averaged 3.4% of summer primary production (and ingestion rates would be 2-10-fold higher than this) so whatever the fate of the pellets, krill are an important re-packager within the food web. While salp pellets tend to sink faster than those of krill, it is the latter that tend to prevail in sediment traps. We suggest that this is because krill schools are more compact, producing "rain showers" of pellets that exceed the capacity of pelagic scavengers to reprocess them.

Liver metabolomics analysis associated with feed efficiency on steers

USDA-ARS?s Scientific Manuscript database

The liver represents a metabolic crossroad regulating and modulating nutrients available from digestive tract absorption to the peripheral tissues. To identify potential differences in liver function that lead to differences in feed efficiency, liver metabolomic analysis was conducted using ultra-pe...

LOW EMISSION AND HIGH EFFICIENCY RESIDENTIAL PELLET-FIRED HEATERS

EPA Science Inventory

The paper gives results of air emissions testing and efficiency testing on new commercially available under-feed and top-feed residential heaters burning hardwood- and softwood-based pellets. The results were compared with data from earlier models. Reductions in air emissions w...

Identification of biological traits associated with differences in residual energy intake among lactating Holstein cows.

PubMed

Fischer, A; Delagarde, R; Faverdin, P

2018-05-01

Residual feed intake, which is usually used to estimate individual variation of feed efficiency, requires frequent and accurate measurements of individual feed intake to be carried out. Developing a breeding scheme based on residual feed intake in dairy cows is therefore complicated, especially because feed intake is not measurable for a large population. Another solution could be to focus on biological determinants of feed efficiency, which could potentially be directly and broadband measurable on farm. Several phenotypes have been identified in literature as being associated with differences in feed efficiency. The present study therefore aims to identify which biological mechanisms are associated with residual energy intake (REI) differences among dairy cows. Several candidate phenotypes were recorded frequently and simultaneously throughout the first 238 d in milk for 60 Holstein cows fed on a constant diet based on maize silage. A multiple linear regression of the 238 d in milk average of net energy intake was fitted on the 238 d in milk averages for milk energy output, metabolic body weight, the sum over the 238 d in milk of both, body condition score loss and gain, and the residuals were defined as REI. A partial least square regression was fitted over all biological traits to explain REI variability. Linear multiple regression explained 93.6% of net energy intake phenotypic variation, with 65.5% associated with lactation requirement, 23.2% with maintenance, and 4.9% with body reserves change; the 6.4% residuals represented REI. Overall, measured biological traits contributed to 58.9% of REI phenotypic variability, which were mainly explained by activity (26.5%) and feeding behavior (21.3%). However, apparent confounding was observed between behavior, activity, digestibility, and rumen-temperature variables. Drawing a conclusion on biological traits that explain feed efficiency differences among dairy cows was not possible due to this apparent confounding between the measured variables. Further investigation is needed to validate these results and to characterize the causal relationship of feed efficiency with feeding behavior, digestibility, body reserves change, activity, and rumen temperature. The Authors. Published by FASS Inc. and Elsevier Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/3.0/).

Domestic animal hosts strongly influence human-feeding rates of the Chagas disease vector Triatoma infestans in Argentina.

PubMed

Gürtler, Ricardo E; Cecere, María C; Vázquez-Prokopec, Gonzalo M; Ceballos, Leonardo A; Gurevitz, Juan M; Fernández, María Del Pilar; Kitron, Uriel; Cohen, Joel E

2014-01-01

The host species composition in a household and their relative availability affect the host-feeding choices of blood-sucking insects and parasite transmission risks. We investigated four hypotheses regarding factors that affect blood-feeding rates, proportion of human-fed bugs (human blood index), and daily human-feeding rates of Triatoma infestans, the main vector of Chagas disease. A cross-sectional survey collected triatomines in human sleeping quarters (domiciles) of 49 of 270 rural houses in northwestern Argentina. We developed an improved way of estimating the human-feeding rate of domestic T. infestans populations. We fitted generalized linear mixed-effects models to a global model with six explanatory variables (chicken blood index, dog blood index, bug stage, numbers of human residents, bug abundance, and maximum temperature during the night preceding bug catch) and three response variables (daily blood-feeding rate, human blood index, and daily human-feeding rate). Coefficients were estimated via multimodel inference with model averaging. Median blood-feeding intervals per late-stage bug were 4.1 days, with large variations among households. The main bloodmeal sources were humans (68%), chickens (22%), and dogs (9%). Blood-feeding rates decreased with increases in the chicken blood index. Both the human blood index and daily human-feeding rate decreased substantially with increasing proportions of chicken- or dog-fed bugs, or the presence of chickens indoors. Improved calculations estimated the mean daily human-feeding rate per late-stage bug at 0.231 (95% confidence interval, 0.157-0.305). Based on the changing availability of chickens in domiciles during spring-summer and the much larger infectivity of dogs compared with humans, we infer that the net effects of chickens in the presence of transmission-competent hosts may be more adequately described by zoopotentiation than by zooprophylaxis. Domestic animals in domiciles profoundly affect the host-feeding choices, human-vector contact rates and parasite transmission predicted by a model based on these estimates.

Control of nitrification/denitrification in an onsite two-chamber intermittently aerated membrane bioreactor with alkalinity and carbon addition: Model and experiment.

PubMed

Perera, Mahamalage Kusumitha; Englehardt, James D; Tchobanoglous, George; Shamskhorzani, Reza

2017-05-15

Denitrifying membrane bioreactors (MBRs) are being found useful in water reuse treatment systems, including net-zero water (nearly closed-loop), non-reverse osmosis-based, direct potable reuse (DPR) systems. In such systems nitrogen may need to be controlled in the MBR to meet the nitrate drinking water standard in the finished water. To achieve efficient nitrification and denitrification, the addition of alkalinity and external carbon may be required, and control of the carbon feed rate is then important. In this work, an onsite, two-chamber aerobic nitrifying/denitrifying MBR, representing one unit process of a net-zero water, non-reverse osmosis-based DPR system, was modeled as a basis for control of the MBR internal recycling rate, aeration rate, and external carbon feed rate. Specifically, a modification of the activated sludge model ASM2dSMP was modified further to represent the rate of recycling between separate aerobic and anoxic chambers, rates of carbon and alkalinity feed, and variable aeration schedule, and was demonstrated versus field data. The optimal aeration pattern for the modeled reactor configuration and influent matrix was found to be 30 min of aeration in a 2 h cycle (104 m 3 air/d per 1 m 3 /d average influent), to ultimately meet the nitrate drinking water standard. Optimal recycling ratios (inter-chamber flow to average daily flow) were found to be 1.5 and 3 during rest and mixing periods, respectively. The model can be used to optimize aeration pattern and recycling ratio in such MBRs, with slight modifications to reflect reactor configuration, influent matrix, and target nitrogen species concentrations, though some recalibration may be required. Copyright © 2017 Elsevier Ltd. All rights reserved.

The effect of autoclaving and enzyme supplementation of guar meal on the performance of chicks and laying hens.

PubMed

Patel, M B; McGinnis, J

1985-06-01

Four experiments with broilers and one with laying hens were conducted to study the effects of processing and hemicellulase supplementation of guar meal (37.0% protein) on growth, feed efficiency, and egg production. Guar meal at 0, 10, and 15%, either in raw form or autoclaved at 100, 102, or 132 C for 3, 15, or 30 min, was fed alone or in the presence of 0 to 250 ppm hemicellulase. In an experiment utilizing full-term broilers, 10 and 15% autoclaved guar meal was fed in the presence of lincomycin (3.3 ppm) or in combination with lincomycin and hemicellulase (25 ppm). The laying hen experiment was conducted with 36-week-old hens for 8 weeks. They were fed the raw or autoclaved meal (102 C, 15 min) alone and in combination with 30 ppm hemicellulase. The raw guar meal depressed growth and the depression was dose-related. Autoclaving at 102 C for 15 min increased growth and feed efficiency. A higher temperature or a longer time of autoclaving failed to give any further increase in growth or feed efficiency. The lowest (16.5 ppm) hemicellulase was as effective as the highest (250 ppm) in increasing growth and feed efficiency of chicks when added to guar meal diets. Penicillin had no effect on growth or feed efficiency when added to the diet containing autoclaved guar meal in the presence of hemicellulase. Dry heating at 150 C for 6 hr or water treatment of guar meal was not effective in stimulating growth or feed efficiency. Guar meal also increased stickiness of droppings; autoclaving enhanced the effect, whereas hemicellulase prevented the sticky droppings.(ABSTRACT TRUNCATED AT 250 WORDS)

Oxygen saturation and heart rate during feeding in breast-fed infants at 1 week and 2 months of age.

PubMed

Suiter, Debra M; Ruark-McMurtrey, Jacki

2007-12-01

To gather normative data about cardiopulmonary changes during feeding in breast-fed infants at 1 week and 2 months of age. Prospective cohort study. General community. Twenty-two term-born, breast-fed infants. Not applicable. Oxygen saturation (SpO2), the percentage of oxygenized hemoglobin, and heart rate were monitored and recorded every 30 seconds for 5 minutes before oral feeding, during the first 10 minutes of feeding, and the first 10 minutes immediately after feeding. The observations were made at 1 week and 2 months of age. Mean SpO2 levels were significantly higher in 2-month-old infants (mean, 97.57) than in 1-week-old infants (mean, 96.35) (P=.001). SpO2 was not affected by any of the 3 trials (before, during, and after feeding). Heart rate was significantly affected by trial. Mean heart rate during feeding (mean, 152.45) was significantly higher than heart rate prefeeding (mean, 146.51) (P<.001), and heart rate postfeeding (mean, 147.12) (P=.002). Heart rate was not affected by age. Little is known about the association between feeding and cardiopulmonary status in term-born, breast-fed infants. This longitudinal study contributes to our knowledge about feeding-related cardiopulmonary changes in term-born, breast-fed infants.

The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish

PubMed Central

Lawrence, Christian; Best, Jason; Cockington, Jason; Henry, Eric C.; Hurley, Shane; James, Althea; Lapointe, Christopher; Maloney, Kara; Sanders, Erik

2016-01-01

The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding. PMID:26863035

The Complete and Updated "Rotifer Polyculture Method" for Rearing First Feeding Zebrafish.

PubMed

Lawrence, Christian; Best, Jason; Cockington, Jason; Henry, Eric C; Hurley, Shane; James, Althea; Lapointe, Christopher; Maloney, Kara; Sanders, Erik

2016-01-17

The zebrafish (Danio rerio) is a model organism of increasing importance in many fields of science. One of the most demanding technical aspects of culture of this species in the laboratory is rearing first-feeding larvae to the juvenile stage with high rates of growth and survival. The central management challenge of this developmental period revolves around delivering highly nutritious feed items to the fish on a nearly continuous basis without compromising water quality. Because larval zebrafish are well-adapted to feed on small zooplankton in the water column, live prey items such as brachionid rotifers, Artemia, and Paramecium are widely recognized as the feeds of choice, at least until the fish reach the juvenile stage and are able to efficiently feed on processed diets. This protocol describes a method whereby newly hatched zebrafish larvae are cultured together with live saltwater rotifers (Brachionus plicatilis) in the same system. This polyculture approach provides fish with an "on-demand", nutrient-rich live food source without producing chemical waste at levels that would otherwise limit performance. Importantly, because the system harnesses both the natural high productivity of the rotifers and the behavioral preferences of the fish, the labor involved with maintenance is low. The following protocol details an updated, step-by-step procedure that incorporates rotifer production (scalable to any desired level) for use in a polyculture of zebrafish larvae and rotifers that promotes maximal performance during the first 5 days of exogenous feeding.

Effects of meal size, clutch, and metabolism on the energy efficiencies of juvenile Burmese pythons, Python molurus.

PubMed

Cox, Christian L; Secor, Stephen M

2007-12-01

We explored meal size and clutch (i.e., genetic) effects on the relative proportion of ingested energy that is absorbed by the gut (apparent digestive efficiency), becomes available for metabolism and growth (apparent assimilation efficiency), and is used for growth (production efficiency) for juvenile Burmese pythons (Python molurus). Sibling pythons were fed rodent meals equaling 15%, 25%, and 35% of their body mass and individuals from five different clutches were fed rodent meals equaling 25% of their body mass. For each of 11-12 consecutive feeding trials, python body mass was recorded and feces and urate of each snake was collected, dried, and weighed. Energy contents of meals (mice and rats), feces, urate, and pythons were determined using bomb calorimetry. For siblings fed three different meal sizes, growth rate increased with larger meals, but there was no significant variation among the meal sizes for any of the calculated energy efficiencies. Among the three meal sizes, apparent digestive efficiency, apparent assimilation efficiency, and production efficiency averaged 91.0%, 84.7%, and 40.7%, respectively. In contrast, each of these energy efficiencies varied significantly among the five different clutches. Among these clutches production efficiency was negatively correlated with standard metabolic rate (SMR). Clutches containing individuals with low SMR were therefore able to allocate more of ingested energy into growth.

Feed efficiency and the liver proteome of fattening lambs are modified by feed restriction during the suckling period.

PubMed

Santos, A; Valdés, C; Giráldez, F J; López, S; France, J; Frutos, J; Fernández, M; Andrés, S

2018-01-24

The present study was designed to describe the effects of early feed restriction of Merino lambs on feed efficiency during the fattening period by examining ruminal microbiota and fermentation parameters, gastrointestinal morphology, digestibility or liver proteome. In total, 24 male Merino lambs were randomly assigned to two experimental treatments (n=12 per treatment). Lambs of the first group (ad libitum (ADL)) were kept permanently with the dams, whereas the other 12 lambs (restricted (RES)) were milk restricted. When lambs reached a live BW (LBW) of 15 kg, all the animals were offered the same complete pelleted diet (35 g dry matter/kg LBW per day) until slaughter at a LBW of 27 kg. The RES lambs showed poorer feed efficiency during the fattening period when compared with the ADL group (feed to gain ratio, 3.69 v. 3.05, P<0.001). No differences were observed in ruminal microbiota, fermentation parameters or apparent digestibility. However, the proportion of the small intestine and the length of ileal villi were reduced in the RES lambs. In total, 26 spots/proteins were identified in the liver proteomic profile, with significant differences (P<0.05) between experimental treatments, suggesting a higher catabolism of proteins and a reduction in β-oxidation of fatty acids in RES lambs when compared with the ADL animals. In conclusion, early feed restriction of Merino lambs during the suckling period promotes long-term effects on the small intestine and the proteomic profile of the liver, which may influence the metabolic use of nutrients, thus negatively affecting feed efficiency during the fattening phase.

Life cycle biological efficiency of mice divergently selected for heat loss.

PubMed

Bhatnagar, A S; Nielsen, M K

2014-08-01

Divergent selection in mice for heat loss was conducted in 3 independent replicates creating a high maintenance, high heat loss (MH) and low maintenance, low heat loss (ML) line and unselected control (MC). Improvement in feed efficiency was observed in ML mice due to a reduced maintenance energy requirement but there was also a slight decline in reproductive performance, survivability, and lean content, particularly when compared to MC animals. The objective of this study was to model a life cycle scenario similar to a livestock production system and calculate total inputs and outputs to estimate overall biological efficiency of these lines and determine if reduced feed intake resulted in improved life cycle efficiency. Feed intake, reproductive performance, growth, and body composition were recorded on 21 mating pairs from each line × replicate combination, cohabitated at 7 wk of age and maintained for up to 1 yr unless culled. Proportion of animals at each parity was calculated from survival rates estimated from previous research when enforcing a maximum of 4, 8, or 12 allowed parities. This parity distribution was then combined with values from previous studies to calculate inputs and outputs of mating pairs and offspring produced in a single cycle at equilibrium. Offspring output was defined as kilograms of lean output of offspring at 49 d. Offspring input was defined as megacalories of energy intake for growing offspring from 21 to 49 d. Parent output was defined as kilograms of lean output of culled parents. Parent input was defined as megacalories of energy intake for mating pairs from weaning of one parity to weaning of the next. Offspring output was greatest in MC mice due to superior BW and numbers weaned, while output was lowest in ML mice due to smaller litter sizes and lean content. Parent output did not differ substantially between lines but was greatest in MH mice due to poorer survival rates resulting in more culled animals. Input was greatest in MH and lowest for ML mice for both offspring and parent pairs, consistent with previous results in these lines. Life cycle efficiency was similar in MC and ML mice, while MH mice were least efficient. Ultimately, superior output in MC mice slightly outweighed the lower inputs in ML animals resulting from decreased maintenance energy requirements. Therefore, selection to reduce maintenance energy requirements may be more useful in terminal crosses or in a selection index to reduce possible negative effects on output, especially reproductive performance.

Effects of feed restriction to enhance the profitable farming of blackhead seabream Acanthopagrus schlegelii schlegelii in sea cages

NASA Astrophysics Data System (ADS)

Oh, Sung-Yong; Kim, Min-Suk; Kwon, Joon Yeong; Maran, B. A. Venmathi

2013-09-01

The feed intake, growth and body composition of juvenile blackhead seabream Acanthopagrus schlegelii schlegelii (Sparidae) (5.6 g fish-1) were investigated for 16 weeks in sea cages under seven repetitive feeding cycles: every day feeding (control), 6-day feeding and 1-day fasting (F6.1), 5-day feeding and 1-day fasting (F5.1), 4-day feeding and 1-day fasting (F4.1), 3-day feeding and 1-day fasting (F3.1), 2-day feeding and 1-day fasting (F2.1), and 1-day feeding and 1-day fasting (F1.1). The survival of the fish during the experimental period was not different among the feeding cycles. The greatest weight gain of fish was observed in the control, but not significantly different from that of the F6.1 and F5.1 groups (p > 0.05). Total feed intake and daily feed intake decreased with the increase of fasting frequency, however, actual feed intake, feed efficiency and protein efficiency ratio increased with the increase of the fasting frequency. Proximate composition of the whole body of fish was not affected by different feeding cycles. These results suggest that juvenile blackhead seabreams subjected to repetitive feeding cycles of 6- or 5-days feeding and 1 day fasting for 16 weeks could achieve compensatory growth, and that such mild feeding deprivation could save significant amounts of feed without causing any profit reduction that might result from a decrease in fish size or quality.

[Breast feeding rates and factors influencing breast feeding practice in late preterm infants: comparison with preterm born at less than 34 weeks of gestational age].

PubMed

Jang, Gun Ja; Lee, Sang Lak; Kim, Hyeon Mi

2012-04-01

This study was done to compare breast feeding rates and factors influencing feeding practice between late preterm (34 ≤ GA < 37) and preterm infants (GA<34). A survey was done of 207 late preterm and 117 preterm infants in neonatal intensive care units (NICU) of 4 university hospitals in D city. Data were collected from July 2009 to June 2010 from 324 medical records in the NICU. Breast-feeding at home was checked either by telephone survey or questioning during hospital visits. Rate of breast feeding for late preterm infants was significantly lower than for preterm infants. There was no significant difference in breast-feeding at home. We found differences in factors influencing breast feeding between the two groups. Factors influencing feeding for late preterm infants were type of delivery, mothers' occupation, feeding type during hospitalization, time elapse from hospital discharge, total admission days, infant's body weight at first feeding and length of NPO (nothing by mouth). Factors influencing feeding for preterm infants were birth order, maternal disease and obstetric complications, and one-minute Apgar score. Results of the study show low rates of breast-feeding for late preterm infants indicating a need for breast-feeding education for mothers of these infants.

Palm kernel cake obtained from biodiesel production in diets for goats: feeding behavior and physiological parameters.

PubMed

de Oliveira, R L; de Carvalho, G G P; Oliveira, R L; Tosto, M S L; Santos, E M; Ribeiro, R D X; Silva, T M; Correia, B R; de Rufino, L M A

2017-10-01

The objective of this study was to evaluate the effects of the inclusion of palm kernel (Elaeis guineensis) cake in diets for goats on feeding behaviors, rectal temperature, and cardiac and respiratory frequencies. Forty crossbred Boer male, non-castrated goats (ten animals per treatment), with an average age of 90 days and an initial body weight of 15.01 ± 1.76 kg, were used. The goats were fed Tifton 85 (Cynodon spp.) hay and palm kernel supplemented at the rates of 0, 7, 14, and 21% of dry matter (DM). The feeding behaviors (rumination, feeding, and idling times) were observed for three 24-h periods. DM and neutral detergent fiber (NDF) intake values were estimated as the difference between the total DM and NDF contents of the feed offered and the total DM and NDF contents of the orts. There was no effect of palm kernel cake inclusion in goat diets on DM intake (P > 0.05). However, palm kernel cake promoted a linear increase (P < 0.05) in NDF intake and time spent feeding and ruminating (min/day; %; period) and a linear decrease in time spent idling. Palm kernel cakes had no effects (P > 0.05) on the chewing, feeding, and rumination efficiency (DM and NDF) or on physiological variables. The use up to 21% palm kernel cake in the diet of crossbred Boer goats maintained the feeding behaviors and did not change the physiological parameters of goats; therefore, its use is recommended in the diet of these animals.

Potential of using tropical brown macroalgae sargassum cristaefolium meal in the diets for juvenile white shrimp (litopenaeus vannamei)

NASA Astrophysics Data System (ADS)

Sudaryono, A.; Sukardi, P.; Yudiarti, E.; Hardi, E. H.; Hastuti, S.; Susilowati, T.

2018-04-01

The objectives of this study were to evaluate the effect of different dietary levels of tropical marine brown macroalgae, Sargassum cristaefolium meal (SCM) on growth performance and feed utilization efficiency of juvenile white shrimp, Litopenaeus vannamei (mean initial weight 2.65±0.1 g). The algae were collected from Bandengan Coast, Jepara, Indonesia. The study used a completely randomized design with 5 treatments of dietary different S. cristaefolium meal levels (0, 10, 20, 30, and 40 g algae meal/kg feed) in triplicates. The results showed that the different levels of dietary SCM did not significantly affect (P>0.05) average daily growth (ADG;.204-224 mg/day) and survival (80-97%) of the shrimp after a 42-day feeding period. However, the test diets significantly affected (P<0.05) feed intake (FI), feed conversion ratio (FCR), and protein efficiency ratio (PER). Better FCR (2.13) and PER (1.34) was found by the diet with 2% SCM compared to the control diet (no SCM) (FCR 3.42 and PER 0.81). This finding indicates that the supplement of dietary 2% SCM (20 g/kg feed) can increase the feed utilization efficiency up to 62% or reduce the FCR up to 38% without any adverse in growth performance.

Dietary phosphatidylcholine impacts on growth performance and lipid metabolism in adult Genetically Improved Farmed Tilapia (GIFT) strain of Nile tilapia Oreochromis niloticus.

PubMed

Tian, Juan; Wen, Hua; Lu, Xing; Liu, Wei; Wu, Fan; Yang, Chang-Geng; Jiang, Ming; Yu, Li-Juan

2018-01-01

This study aimed to determine the effects of supplementing the diet of adult Nile tilapia Oreochromis niloticus with phosphatidylcholine (PC) on growth performance, body composition, fatty acid composition and gene expression. Genetically Improved Farmed Tilapia fish with an initial body weight of 83·1 (sd 2·9) g were divided into six groups. Each group was hand-fed a semi-purified diet containing 1·7 (control diet), 4·0, 6·5, 11·5, 21·3 or 41·0 g PC/kg diet for 68 d. Supplemental PC improved the feed efficiency rate, which was highest in the 11·5 g PC/kg diet. Weight gain and specific growth rate were unaffected. Dietary PC increased PC content in the liver and decreased crude fat content in the liver, viscera and body. SFA and MUFA increased and PUFA decreased in muscle with increasing dietary PC. Cytoplasmic phospholipase A 2 and secreted phospholipase A 2 mRNA expression were up-regulated in the brain and heart in PC-supplemented fish. PC reduced fatty acid synthase mRNA expression in the liver and visceral tissue but increased expression in muscle. Hormone-sensitive lipase and lipoprotein lipase expression increased in the liver with increasing dietary PC. Growth hormone mRNA expression was reduced in the brain and insulin-like growth factor-1 mRNA expression in liver reduced with PC above 6·5 g/kg. Our results demonstrate that dietary supplementation with PC improves feed efficiency and reduces liver fat in adult Nile tilapia, without increasing weight gain, representing a novel dietary approach to reduce feed requirements and improve the health of Nile tilapia.

Protective efficacy of Mucuna pruriens (L.) seed meal enriched diet on growth performance, innate immunity, and disease resistance in Oreochromis mossambicus against Aeromonas hydrophila.

PubMed

Saiyad Musthafa, Mohamed; Asgari, Syed Mohideen; Kurian, Amitha; Elumalai, Preetham; Jawahar Ali, Abdul Rahman; Paray, Bilal Ahmad; Al-Sadoon, Mohammad K

2018-04-01

The impact of Mucuna pruriens (L.) seed meal diet on growth performance, innate immune response, and disease resistance in Oreochromis mossambicus against Aeromonas hydrophila is reported for the first time. Infected O. mossambicus was fed with 2 g kg -1 , 4 g kg -1 , and 6 g kg -1 of M. pruriens seed meal diets significantly increased initial body weight (IBW) and final body weight (FBW) over control, for a period of 4 weeks. At 4 g kg -1 and 6 g kg -1 the enriched diet significantly (P < 0.05) enhanced the survival rate, weight gain (WG), protein efficiency ratio (PER), specific growth rate (SGR), feed conversion ratio (FCR), and feed efficiency (FE) when compared to the control; besides, from weeks 2-4 these diets significantly (P < 0.05) enhanced the complement activity, phagocytic activity, respiratory burst activity, and lysosome activity. On being fed with 4 g kg -1 and 6 g kg -1- enriched diets the cumulative mortality was lower (10% and 12%) than with 2 g kg -1 diet (24%). The present investigation suggests that the enriched diet at 4 g kg -1 and 6 g kg -1 improved the growth performance more than that of the control and negative control; it also positively enhanced the innate immunity and disease resistance against A. hydrophilla in O. mossambicus. Hence M. pruriens can be used as a feed additive to stimulate immunity for effective production of economically valuable freshwater fish, O. mossambicus. Copyright © 2018 Elsevier Ltd. All rights reserved.

Density of Key-Species Determines Efficiency of Macroalgae Detritus Uptake by Intertidal Benthic Communities

PubMed Central

Karlson, Agnes M. L.; Niemand, Clarisse; Savage, Candida; Pilditch, Conrad A

2016-01-01

Accumulating evidence shows that increased biodiversity has a positive effect on ecosystem functioning, but the mechanisms that underpin this positive relationship are contentious. Complete extinctions of regional species pools are comparatively rare whereas compositional changes and reductions in abundance and biomass are common, although seldom the focus of biodiversity-ecosystem functioning studies. We use natural, small-scale patchiness in the density of two species of large bivalves with contrasting feeding modes (the suspension-feeding Austrovenus stutchburyi and deposit-feeding Macomona liliana) to examine their influence on the uptake of nitrogen from macroalgae detritus (i.e. measure of ecosystem function and food web efficiency) by other infauna in a 10-d laboratory isotope-tracer experiment. We predicted that densities of these key bivalve species and functional group diversity (calculated as Shannons H, a density-independent measure of community composition) of the intact infaunal community will be critical factors explaining variance in macroalgal per capita uptake rates by the community members and hence determine total uptake by the community. Results show that only two species, M. liliana and a large orbiniid polychaete (Scoloplos cylindrifer) dominated macroalgal nitrogen taken up by the whole community due to their large biomass. However, their densities were mostly not important or negatively influenced per capita uptake by other species. Instead, the density of a head-down deposit-feeder (the capitellid Heteromastus filiformis), scavengers (mainly nemertines and nereids) and species and functional group diversity, best explained per capita uptake rates in community members. Our results demonstrate the importance of species identity, density and large body size for ecosystem functioning and highlight the complex interactions underlying loss of ecological functions with declining biodiversity and compositional changes. PMID:27414032

Impact of Feed Delivery Pattern on Aerial Particulate Matter and Behavior of Feedlot Cattle †

PubMed Central

Mitloehner, Frank M.; Dailey, Jeff W.; Morrow, Julie L.; McGlone, John J.

2017-01-01

Simple Summary Fine particulate matter (with less than 2.5 microns diameter; aka PM2.5) are a human and animal health concern because they can carry microbes and chemicals into the lungs. Particulate matter (PM) in general emitted from cattle feedlots can reach high concentrations. When feedlot cattle were given an altered feeding schedule (ALT) that more closely reflected their biological feeding times compared with conventional morning feeding (CON), PM2.5 generation at peak times was substantially lowered. Average daily generation of PM2.5 was decreased by 37% when cattle behavior was redirected away from PM-generating behaviors and toward evening feeding behaviors. Behavioral problems such as agonistic (i.e., aggressive) and bulling (i.e., mounting each other) behaviors also were reduced several fold among ALT compared with CON cattle. Intake of feed was less and daily body weight gain tended to be less with the altered feeding schedule while efficiency of feed utilization was not affected. Although ALT may pose a challenge in feed delivery and labor scheduling, cattle had fewer behavioral problems and reduced PM2.5 generation when feed delivery times matched with the natural drive to eat in a crepuscular pattern. Abstract Fine particulate matter with less than 2.5 microns diameter (PM2.5) generated by cattle in feedlots is an environmental pollutant and a potential human and animal health issue. The objective of this study was to determine if a feeding schedule affects cattle behaviors that promote PM2.5 in a commercial feedlot. The study used 2813 crossbred steers housed in 14 adjacent pens at a large-scale commercial West Texas feedlot. Treatments were conventional feeding at 0700, 1000, and 1200 (CON) or feeding at 0700, 1000, and 1830 (ALT), the latter feeding time coincided with dusk. A mobile behavior lab was used to quantify behaviors of steers that were associated with generation of PM2.5 (e.g., fighting, mounting of peers, and increased locomotion). PM2.5 samplers measured respirable particles with a mass median diameter ≤2.5 μm (PM2.5) every 15 min over a period of 7 d in April and May. Simultaneously, the ambient temperature, humidity, wind speed and direction, precipitation, air pressure, and solar radiation were measured with a weather station. Elevated downwind PM2.5 concentrations were measured at dusk, when cattle that were fed according to the ALT vs. the CON feeding schedule, demonstrated less PM2.5-generating behaviors (p < 0.05). At dusk, steers on ALT vs. CON feeding schedules ate or were waiting to eat (standing in second row behind feeding cattle) at much greater rates (p < 0.05). Upwind PM2.5 concentrations were similar between the treatments. Downwind PM2.5 concentrations averaged over 24 h were lower from ALT compared with CON pens (0.072 vs. 0.115 mg/m3, p < 0.01). However, dry matter intake (DMI) was less (p < 0.05), and average daily gain (ADG) tended to be less (p < 0.1) in cattle that were fed according to the ALT vs. the CON feeding schedules, whereas feed efficiency (aka gain to feed, G:F) was not affected. Although ALT feeding may pose a challenge in feed delivery and labor scheduling, cattle exhibited fewer PM2.5-generating behaviors and reduced generation of PM2.5 when feed delivery times matched the natural desires of cattle to eat in a crepuscular pattern. PMID:28257061

Evidence for loss of nepotism in the evolution of permanent sociality

PubMed Central

Berger-Tal, Reut; Lubin, Yael; Settepani, Virginia; Majer, Marija; Bilde, Trine; Tuni, Cristina

2015-01-01

Kin selected benefits of cooperation result in pronounced kin discrimination and nepotism in many social species and favour the evolution of sociality. However, low variability in relatedness among group members, infrequent competitive interactions with non-relatives, and direct benefits of cooperation may relax selection for nepotism. We tested this prediction in a permanently social spider, Stegodyphus dumicola that appears to fulfil these conditions. Sociality is a derived trait, and kin discrimination exists in sub-social closely related congeners and is likely a selective force in the sub-social route to permanent sociality in spiders. We examined whether social spiders show nepotism in cooperative feeding when genetic relatedness among group members was experimentally varied. We found no effect of relatedness on feeding efficiency, growth rate or participation in feeding events. Previous studies on sub-social species showed benefits of communal feeding with kin, indicating nepotistic cooperation. The lack of evidence for nepotism in the social species suggests that kin discrimination has been lost or is irrelevant in communal feeding. Our results are consistent with the hypothesis that the role of nepotism is diminished when cooperation evolves in certain genetic and ecological contexts, e.g. when intra-group genetic relatedness is homogeneous and encounters with competitors are rare. PMID:26333675

Effects of dietary forage level and monensin on lactation performance, digestibility and fecal excretion of nutrients, and efficiency of feed nitrogen utilization of Holstein dairy cows.

PubMed

Martinez, C M; Chung, Y-H; Ishler, V A; Bailey, K W; Varga, G A

2009-07-01

Two experiments (Exp. 1 and 2) were conducted using a 4 x 4 Latin square design with 2 replications (n = 8) to evaluate effects of feeding Holstein dairy cows a total mixed ration containing 50 or 60% of ration dry matter (DM) from forages with or without supplementation of monensin. In Exp. 1, alfalfa silage (AS) was used as the major forage (55% forage DM), and corn silage (CS; 45% forage DM) was used to make up the rest of the forage portion of diets (55AS:45CS). In Exp. 2, CS was used as the major forage (70% forage DM) and alfalfa hay (AH; 30% forage DM) was used to make up the rest of the forage portion of diets (70CS:30AH). Experimental diets were arranged in a 2 x 2 factorial with 50 or 60% ration DM from forages and monensin supplemented at 0 or 300 mg/cow daily. In Exp. 1 (55AS:45CS), feeding 60% forage diets decreased DM intake (DMI; 27.3 vs. 29.6 kg/d) but maintained the same levels of milk (45.8 vs. 47.0 kg/d) compared with 50% forage diets. The efficiency of converting feed to milk or 3.5% fat-corrected milk was greater for cows fed 60% compared with 50% forage diets (1.7 vs. 1.6 kg milk or 3.5% fat-corrected milk/kg of DMI, respectively). Increasing dietary forage level from 50 to 60% of ration DM increased milk fat percentage (3.4 to 3.5%); however, adding monensin to the 60% forage diet inhibited the increase in milk fat percentage. Feeding 60% forage diets decreased feed cost, but this decrease ($0.5/head per day) in feed cost did not affect income over feed cost. Feeding 60% forage diets decreased fecal excretion of DM (10.6 to 9.6 kg/d) and nitrogen (N; 354 to 324 g/d) and improved apparent digestibility of neutral detergent fiber from 43 to 49% and apparent efficiency of feed N utilization from 32.3 to 35.9% compared with 50% forage diets. In Exp. 2 (70CS:30AH), feeding 60% forage diets decreased DMI from 29.6 to 28.2 kg but maintained the same level of milk (41.1 vs. 40.8 kg/d) and therefore increased the efficiency of converting feed to milk (1.46 vs. 1.38 kg milk/kg DMI) compared with 50% forage diets. Daily feed cost for feeding 60% forage diets was $0.3/head lower than for the 50% forage diets. Fecal excretion of DM (10.3 vs. 11.5 kg/d) was lower and fecal excretion of N (299 vs. 328 g/d) tended to be lower for 60% compared with 50% forage diets. Results from these 2 experiments suggest that a 60% forage diet consisting of either AS or CS as the major forage can be fed to high producing Holstein dairy cows without affecting milk production while improving or maintaining the efficiency of converting feed to milk and the apparent efficiency of utilization of feed N. Cows receiving a 60% forage diet had a similar or improved digestibility of nutrients with a similar or reduced fecal excretion of nutrients. Effects of monensin under the conditions of the current experiments were minimal.

Effects of feeding different varieties of faba bean (Vicia faba L.) straws with concentrate supplement on feed intake, digestibility, body weight gain and carcass characteristics of Arsi-Bale sheep.

PubMed

Wegi, Teklu; Tolera, Adugna; Wamatu, Jane; Animut, Getachew; Rischkowsky, Barbara

2017-12-19

A study was conducted to evaluate the varietal differences among faba bean straws and also to assess the potentials of faba bean straws supplemented with concentrate fed at the rate 70% straws and 30% concentrate mixture on feed intake, digestibility, body weight gain and carcass characteristics of the animals. Forty yearling Arsi-Bale sheep with initial body weight of 19.85+0.29 kg (mean + SD were grouped in a randomized complete block design into eight blocks of five animals each based on their initial body weight. Straws include in the study were from Mosisa (T1M), Walki (T2W), Degaga (T3D), Shallo (T4S) and local (T5L) varieties of faba bean and concentrate (2:1 ratio of wheat bran to "noug" seed cake). The experiment consisted of seven days of digestibility and 90 days of feeding trials followed by evaluation of carcass parameters at the end. Local variety had lower (P<0.05) in grain and straw yield compared to improved varieties but higher in crude protein, metabolizable energy contents and in vitro organic matter digestibility. The apparent digestibility of dry matter and crude protein of sheep fed Walki and Mosisa straws were higher than (P<0.05) straws from Shallo varieties. Sheep fed Walki straw had greater (P<0.05) dry matter intake, average daily gain and feed conversion efficiency than sheep fed local and Shallo straws. Slaughter body weight and empty body weight were higher (P<0.05) for sheep fed Mosisa and Walki straws as compared to sheep fed Shallo straws. Apart from this, the other carcass components were not affected (P>0.05) by variety of the faba bean straws. There is significant varietal differences between faba bean straws both in quality and quantity. Similarly, significant variation observed among sheep in feed intake, digestibility, body weight gain and feed conversion efficiency among sheep fed different straws of faba bean varieties with concentrate supplement. Based on these results, Walki and Mosisa varieties could be recommended as pulse crop rotation with cereals in the study area.

Improvement of specific growth rate of Pichia pastoris for effective porcine interferon-α production with an on-line model-based glycerol feeding strategy.

PubMed

Gao, Min-Jie; Zheng, Zhi-Yong; Wu, Jian-Rong; Dong, Shi-Juan; Li, Zhen; Jin, Hu; Zhan, Xiao-Bei; Lin, Chi-Chung

2012-02-01

Effective expression of porcine interferon-α (pIFN-α) with recombinant Pichia pastoris was conducted in a bench-scale fermentor. The influence of the glycerol feeding strategy on the specific growth rate and protein production was investigated. The traditional DO-stat feeding strategy led to very low cell growth rate resulting in low dry cell weight (DCW) of about 90 g/L during the subsequent induction phase. The previously reported Artificial Neural Network Pattern Recognition (ANNPR) model-based glycerol feeding strategy improved the cell density to 120 g DCW/L, while the specific growth rate decreased from 0.15 to 0.18 to 0.03-0.08 h(-1) during the last 10 h of the glycerol feeding stage leading to a variation of the porcine interferon-α production, as the glycerol feeding scheme had a significant effect on the induction phase. This problem was resolved by an improved ANNPR model-based feeding strategy to maintain the specific growth rate above 0.11 h(-1). With this feeding strategy, the pIFN-α concentration reached a level of 1.43 g/L, more than 1.5-fold higher than that obtained with the previously adopted feeding strategy. Our results showed that increasing the specific growth rate favored the target protein production and the glycerol feeding methods directly influenced the induction stage. Consequently, higher cell density and specific growth rate as well as effective porcine interferon-α production have been achieved by our novel glycerol feeding strategy.

Experimental study of surface integrity and fatigue life in the face milling of inconel 718

NASA Astrophysics Data System (ADS)

Wang, Xiangyu; Huang, Chuanzhen; Zou, Bin; Liu, Guoliang; Zhu, Hongtao; Wang, Jun

2018-06-01

The Inconel 718 alloy is widely used in the aerospace and power industries. The machining-induced surface integrity and fatigue life of this material are important factors for consideration due to high reliability and safety requirements. In this work, the milling of Inconel 718 was conducted at different cutting speeds and feed rates. Surface integrity and fatigue life were measured directly. The effects of cutting speed and feed rate on surface integrity and their further influences on fatigue life were analyzed. Within the chosen parameter range, the cutting speed barely affected the surface roughness, whereas the feed rate increased the surface roughness through the ideal residual height. The surface hardness increased as the cutting speed and feed rate increased. Tensile residual stress was observed on the machined surface, which showed improvement with the increasing feed rate. The cutting speed was not an influencing factor on fatigue life, but the feed rate affected fatigue life through the surface roughness. The high surface roughness resulting from the high feed rate could result in a high stress concentration factor and lead to a low fatigue life.

Modulation of digestive physiology and biochemistry in Mytilus californianus in response to feeding level acclimation and microhabitat

PubMed Central

Sung, Aaron; Garcia, Nathan S.; Gracey, Andrew Y.; German, Donovan P.

2016-01-01

ABSTRACT The intertidal mussel Mytilus californianus is a critical foundation species that is exposed to fluctuations in the environment along tidal- and wave-exposure gradients. We investigated feeding and digestion in mussels under laboratory conditions and across environmental gradients in the field. We assessed whether mussels adopt a rate-maximization (higher ingestion and lower assimilation) or a yield-maximization acquisition (lower ingestion and higher assimilation) strategy under laboratory conditions by measuring feeding physiology and digestive enzyme activities. We used digestive enzyme activity to define resource acquisition strategies in laboratory studies, then measured digestive enzyme activities in three microhabitats at the extreme ends of the tidal- and wave-exposure gradients within a stretch of shore (<20 m) projected sea-ward. Our laboratory results indicated that mussels benefit from a high assimilation efficiency when food concentration is low and have a low assimilation efficiency when food concentration is high. Additionally, enzyme activities of carbohydrases amylase, laminarinase and cellulase were elevated when food concentration was high. The protease trypsin, however, did not increase with increasing food concentration. In field conditions, low-shore mussels surprisingly did not have high enzyme activities. Rather, high-shore mussels exhibited higher cellulase activities than low-shore mussels. Similarly, trypsin activity in the high-shore-wave-sheltered microhabitat was higher than that in high-shore-wave-exposed. As expected, mussels experienced increasing thermal stress as a function of reduced submergence from low to high shore and shelter from wave-splash. Our findings suggest that mussels compensate for limited feeding opportunities and thermal stress by modulating digestive enzyme activities. PMID:27402963

Feeding and energetics of the great scallop, Pecten maximus, through a DEB model

NASA Astrophysics Data System (ADS)

Lavaud, Romain; Flye-Sainte-Marie, Jonathan; Jean, Fred; Emmery, Antoine; Strand, Øivind; Kooijman, Sebastiaan A. L. M.

2014-11-01

We developed a full life-cycle bioenergetic model for the great scallop Pecten maximus relying on the concepts of the Dynamic Energy Budget (DEB) theory. The covariation method was implemented to estimate the parameters of a standard DEB model. Such models are able to predict various metabolic processes from a food availability marker and temperature in the environment. However, suspension-feeders are likely to feed on various trophic sources, from microalgae cells to detritus. They are also able to sort and select food particles very efficiently, depending on their size, energetic value or quality. The present model includes a mechanistic description of the feeding processes, based on Kooijman's Synthesizing Unit principle which allows to deal with several food sources. Moreover we tested the hypothesis of a differential selectivity between two potential substrates (phytoplankton cell and the remaining particulate organic matter). Simulations of shell length, daily shell growth rate, dry weight and gonado-somatic index (GSI) variations were realized and compared to field data from a monitoring conducted in the Bay of Brest (Brittany, France) for six years. The model shows its capacity to efficiently reproduce all life history traits of the wild great scallops. Predicted length data were estimated to the nearest millimeter. The fit of simulated weights to observed data was very satisfactory. GSI predictions were also in accordance with observations but improvements are required to better capture the sharp increase of gametogenesis at the beginning of the year. Finally, results bring evidences that P. maximus is actually preferentially feed on living algae cells rather than on the rest of organic particles.

Analysis of Nitrification Efficiency and Microbial Community in a Membrane Bioreactor Fed with Low COD/N-Ratio Wastewater

PubMed Central

Ma, Jinxing; Wang, Zhiwei; Zhu, Chaowei; Liu, Shumeng; Wang, Qiaoying; Wu, Zhichao

2013-01-01

In this study, an approach using influent COD/N ratio reduction was employed to improve process performance and nitrification efficiency in a membrane bioreactor (MBR). Besides sludge reduction, membrane fouling alleviation was observed during 330 d operation, which was attributed to the decreased production of soluble microbial products (SMP) and efficient carbon metabolism in the autotrophic nitrifying community. 454 high-throughput 16S rRNA gene pyrosequencing revealed that the diversity of microbial sequences was mainly determined by the feed characteristics, and that microbes could derive energy by switching to a more autotrophic metabolism to resist the environmental stress. The enrichment of nitrifiers in an MBR with a low COD/N-ratio demonstrated that this condition stimulated nitrification, and that the community distribution of ammonia oxidizing bacteria (AOB) and nitrite oxidizing bacteria (NOB) resulted in faster nitrite uptake rates. Further, ammonia oxidation was the rate-limiting step during the full nitrification. PMID:23667573

Effect of diet energy level and genomic residual feed intake on pre-bred dairy heifer feed intake and growth

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine the growth, feed intake, and feed efficiency of pre-bred dairy heifers with different predicted genomic residual feed intakes as lactating cows (RFI), and offered diets with different energy levels. Pre-bred heifers (128, ages 4-9 months) were blocked by ...

The economics of the law of effect.

PubMed Central

Collier, G H; Johnson, D F; Hill, W L; Kaufman, L W

1986-01-01

A corollary of the law of effect predicts that the larger the reinforcement, the greater the rate of responding. However, an animal must eat more small portions than large portions to obtain the same daily intake, and one would predict, therefore, that when eating smaller portions an efficient animal would eat less (conserving time and energy) and/or respond faster (conserving time). The latter of these predictions was supported by the present experiments with free-feeding rats for which portion size (pellet size or duration of feeder presentation) and portion price within meals were varied. Response rate was a function of the unit price (responses/g) of food: Rats responded faster when portions were smaller or when prices were higher. Meal size and frequency were relatively unaffected by unit price, but were influenced by the price of meal initiation. The results are discussed in relation to the economic differences between traditional operant and free-feeding paradigms and to both traditional and more recent formulations of the law of effect. PMID:3760748

Research on subsurface defects of potassium dihydrogen phosphate crystals fabricated by single point diamond turning technique

NASA Astrophysics Data System (ADS)

Tie, Guipeng; Dai, Yifan; Guan, Chaoliang; Chen, Shaoshan; Song, Bing

2013-03-01

Potassium dihydrogen phosphate (KDP) crystals, which are widely used in high-power laser systems, are required to be free of defects on fabricated subsurfaces. The depth of subsurface defects (SSD) of KDP crystals is significantly influenced by the parameters used in the single point diamond turning technique. In this paper, based on the deliquescent magnetorheological finishing technique, the SSD of KDP crystals is observed and the depths under various cutting parameters are detected and discussed. The results indicate that no SSD is generated under small parameters and with the increase of cutting parameters, SSD appears and the depth rises almost linearly. Although the ascending trends of SSD depths caused by cutting depth and feed rate are much alike, the two parameters make different contributions. Taking the same material removal efficiency as a criterion, a large cutting depth generates shallower SSD depth than a large feed rate. Based on the experiment results, an optimized cutting procedure is obtained to generate defect-free surfaces.

Effect of cellooligosaccharide or synbiotic feeding on growth performance, fecal condition and hormone concentrations in Holstein calves.

PubMed

Hasunuma, Toshiya; Kawashima, Kenji; Nakayama, Hirofumi; Murakami, Toshiaki; Kanagawa, Hiroyuki; Ishii, Takashige; Akiyama, Kiyoshi; Yasuda, Kenji; Terada, Fuminori; Kushibiki, Shiro

2011-08-01

We investigated the effect of cellooligosaccharide (CE) or a combination of dextran and Lactobacillus casei ssp. casei strain JCM1134(T) (synbiotic; SB) feeding on growth performance, fecal condition and hormone concentrations in Holstein calves. Fifty-two female Holstein calves were randomly assigned to three treatment groups: CE feeding group (n = 16), SB feeding group (n = 18), and control group (n = 18). Body weight at 90 days of age, as well as daily body weight gain (DG) and feed efficiency after weaning to 90 days of age were greater (P < 0.05) in the CE feeding group than in the control group. The total fecal score tended to be lower (P < 0.1) in the SB feeding group than in the control group. Plasma insulin concentration was higher (P < 0.05) in the CE feeding group than in the control group at 90 days of age. Our results indicate that CE feeding improved DG and feed efficiency in calves. On the other hand, there was less effect on growth performance and fecal Escherichia coli counts in calves fed SB. 2011 The Authors. Animal Science Journal © 2011 Japanese Society of Animal Science.

Kinetics of Cold-Cap Reactions for Vitrification of Nuclear Waste Glass Based on Simultaneous Differential Scanning Calorimetry - Thermogravimetry (DSC-TGA) and Evolved Gas Analysis (EGA)

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

Rodriguez, Carmen P.; Pierce, David A.; Schweiger, Michael J.

2013-12-03

For vitrifying nuclear waste glass, the feed, a mixture of waste with glass-forming and modifying additives, is charged onto the cold cap that covers 90-100% of the melt surface. The cold cap consists of a layer of reacting molten glass floating on the surface of the melt in an all-electric, continuous glass melter. As the feed moves through the cold cap, it undergoes chemical reactions and phase transitions through which it is converted to molten glass that moves from the cold cap into the melt pool. The process involves a series of reactions that generate multiple gases and subsequent massmore » loss and foaming significantly influence the mass and heat transfers. The rate of glass melting, which is greatly influenced by mass and heat transfers, affects the vitrification process and the efficiency of the immobilization of nuclear waste. We studied the cold-cap reactions of a representative waste glass feed using both the simultaneous differential scanning calorimetry thermogravimetry (DSC-TGA) and the thermogravimetry coupled with gas chromatography-mass spectrometer (TGA-GC-MS) as complementary tools to perform evolved gas analysis (EGA). Analyses from DSC-TGA and EGA on the cold-cap reactions provide a key element for the development of an advanced cold-cap model. It also helps to formulate melter feeds for higher production rate.« less

Recycle food wastes into high quality fish feeds for safe and quality fish production.

PubMed

Wong, Ming-Hung; Mo, Wing-Yin; Choi, Wai-Ming; Cheng, Zhang; Man, Yu-Bon

2016-12-01

The amount of food waste generated from modern societies is increasing, which has imposed a tremendous pressure on its treatment and disposal. Food waste should be treated as a valuable resource rather than waste, and turning it into fish feeds would be a viable alternative. This paper attempts to review the feasibility of using food waste to formulate feed pellets to culture a few freshwater fish species, such as grass carp, grey mullet, and tilapia, under polyculture mode (growing different species in the same pond). These species occupy different ecological niches, with different feeding modes (i.e., herbivorous, filter feeding, etc.), and therefore all the nutrients derived from the food waste could be efficiently recycled within the ecosystem. The problems facing environmental pollution and fish contamination; the past and present situation of inland fish culture (focusing on South China); upgrade of food waste based feed pellets by adding enzymes, vitamin-mineral premix, probiotics (yeast), prebiotics, and Chinese medicinal herbs into feeds; and potential health risks of fish cultivated by food waste based pellets are discussed, citing some local examples. It can be concluded that appropriate portions of different types of food waste could satisfy basic nutritional requirements of lower trophic level fish species such as grass carp and tilapia. Upgrading the fish pellets by adding different supplements mentioned above could further elevated the quality of feeds, leading to higher growth rates, and enhanced immunity of fish. Health risk assessments based on the major environmental contaminants (mercury, PAHs and DDTs) in fish flesh showed that fish fed food waste based pellets are safer for consumption, when compared with those fed commercial feed pellets. Copyright © 2016 Elsevier Ltd. All rights reserved.

Components of feed efficiency in broiler breeding stock: energetics, performance, carcass composition, metabolism, and body temperature.

PubMed

Skinner-Noble, D O; Teeter, R G

2003-07-01

Two experiments were conducted to identify factors influencing feed conversion in broilers. The first experiment was conducted to develop a test for body temperature (BT) under mild handling stress. In the first experiment, BT was recorded periodically with birds briefly restrained after they had been removed from feed with either continuous lighting or 16L:8D. Body temperature was affected by photoperiod and declined following feed removal. The second experiment was conducted to investigate metabolic-physiologic differences existing between good (G) and poor (P) converting broilers, initially classified in a commercial breeding company's feed conversion (FCR) test. Basal metabolic rate (BMR) and BT were measured at the beginning and end of the FCR test following appropriate time without feed. Heat production (HP) was recorded throughout the study both for BMR calculations and to measure net energy (NE). Excreta were collected for measurement of AME, and at study termination, birds were analyzed for carcass composition. The G and P converters, however, had similar BMR and feed consumption but differed in AME (58 kcal/kg) and total NE (184 kcal/kg). Generally, G and P broilers had similar starting BW, but the G broilers gained more weight on the same amount of feed than did P broilers. The two BT measurements recorded in the present study were correlated with each other. The BT was also correlated with subsequent gain and FCR, indicating potential use as an indicator trait for feed conversion. Further, the data indicated that processes other than basal metabolism (measured as average hourly HP) may impact FCR. These might include variability in fear response during BT measurement or variations in bird activity level.

Effect of production quotas on economic and environmental values of growth rate and feed efficiency in sea cage fish farming.

PubMed

Besson, M; de Boer, I J M; Vandeputte, M; van Arendonk, J A M; Quillet, E; Komen, H; Aubin, J

2017-01-01

In sea cage fish farming, production quotas aim to constrain the impact of fish farming on the surrounding ecosystem. It is unknown how these quotas affect economic profitability and environmental impact of genetic improvement. We combined bioeconomic modelling with life cycle assessment (LCA) to calculate the economic (EV) and environmental (ENV) values of thermal growth coefficient (TGC) and feed conversion ratio (FCR) of sea bass reared in sea cages, given four types of quota commonly used in Europe: annual production (Qprod), annual feed distributed (Qannual_feed), standing stock (Qstock), and daily feed distributed (Qdaily_feed). ENV were calculated for LCA impact categories climate change, eutrophication and acidification. ENV were expressed per ton of fish produced per year (ENV(fish)) and per farm per year (ENV(farm)). Results show that irrespective of quota used, EV of FCR as well as ENV(fish) and ENV(farm) were always positive, meaning that improving FCR increased profit and decreased environmental impacts. However, the EV and the ENV(fish) of TGC were positive only when quota was Qstock or Qdaily_feed. Moreover, the ENV(farm) of TGC was negative in Qstock and Qdaily_feed quotas, meaning that improving TGC increased the environmental impact of the farm. We conclude that Qstock quota and Qdaily_feed quota are economically favorable to a genetic improvement of TGC, a major trait for farmers. However, improving TGC increases the environmental impact of the farm. Improving FCR represents a good opportunity to balance out this increase but more information on its genetic background is needed to develop breeding programs improving FCR.

Hydrodynamic starvation in first-feeding larval fishes

PubMed Central

China, Victor; Holzman, Roi

2014-01-01

Larval fishes suffer prodigious mortality rates, eliminating 99% of the brood within a few days after first feeding. Hjort (1914) famously attributed this “critical period” of low survival to the larvae’s inability to obtain sufficient food [Hjort (1914) Rapp P-v Réun Cons Int Explor Mer 20:1–228]. However, the cause of this poor feeding success remains to be identified. Here, we show that hydrodynamic constraints on the ubiquitous suction mechanism in first-feeding larvae limit their ability to capture prey, thereby reducing their feeding rates. Dynamic-scaling experiments revealed that larval size is the primary determinant of feeding rate, independent of other ontogenetic effects. We conclude that first-feeding larvae experience “hydrodynamic starvation,” in which low Reynolds numbers mechanistically limit their feeding performance even under high prey densities. Our results provide a hydrodynamic perspective on feeding of larval fishes that focuses on the physical properties of the larvae and prey, rather than on prey concentration and the rate of encounters. PMID:24843180

Opportunities for improving milk production efficiency in dairy cattle

USDA-ARS?s Scientific Manuscript database

Increasing feed costs and the desire to improve environmental stewardship have stimulated renewed interest in improving feed efficiency of livestock, including that of U.S. dairy herds. For instance, USDA cost projections for corn and soybean meal suggest a 20% increase over 2010 pricing for a 16% p...

Opportunities for improving milk production efficiency in dairy cattle

USDA-ARS?s Scientific Manuscript database

Increasing feed costs and the desire to improve environmental stewardship have stimulated interest in improving feed efficiency of livestock, including that of U.S. dairy herds. For instance, USDA cost projections for corn and soybean meal suggest a 20% increase over 2010 pricing for a 16% protein ...

Genome wide association analyses based on a multiple trait approach for modeling feed efficiency

USDA-ARS?s Scientific Manuscript database

Genome wide association (GWA) of feed efficiency (FE) could help target important genomic regions influencing FE. Data provided by an international dairy FE research consortium consisted of phenotypic records on dry matter intakes (DMI), milk energy (MILKE), and metabolic body weight (MBW) on 6,937 ...

Rumen bacterial community structure impacts feed efficiency in beef cattle

USDA-ARS?s Scientific Manuscript database

The importance of the rumen microbiota on nutrient cycling to the animal is well recognized; however, our understanding of the influence of the rumen microbiome composition on feed efficiency is limited. The rumen microbiomes of two large animal cohorts (125 heifers and 122 steers) were characterize...

Feeding on dispersed vs. aggregated particles: The effect of zooplankton feeding behavior on vertical flux.

PubMed

Koski, Marja; Boutorh, Julia; de la Rocha, Christina

2017-01-01

Zooplankton feeding activity is hypothesized to attenuate the downward flux of elements in the ocean. We investigated whether the zooplankton community composition could influence the flux attenuation, due to the differences of feeding modes (feeding on dispersed vs. aggregated particles) and of metabolic rates. We fed 5 copepod species-three calanoid, one harpacticoid and one poecilamastoid-microplankton food, in either dispersed or aggregated form and measured rates of respiration, fecal pellet production and egg production. Calanoid copepods were able to feed only on dispersed food; when their food was introduced as aggregates, their pellet production and respiration rates decreased to rates observed for starved individuals. In contrast, harpacticoids and the poecilamastoid copepod Oncaea spp. were able to feed only when the food was in the form of aggregates. The sum of copepod respiration, pellet production and egg production rates was equivalent to a daily minimum carbon demand of ca. 10% body weight-1 for all non-feeding copepods; the carbon demand of calanoids feeding on dispersed food was 2-3 times greater, and the carbon demand of harpacticoids and Oncaea spp. feeding on aggregates was >7 times greater, than the resting rates. The zooplankton species composition combined with the type of available food strongly influences the calculated carbon demand of a copepod community, and thus also the attenuation of vertical carbon flux.

Feeding on dispersed vs. aggregated particles: The effect of zooplankton feeding behavior on vertical flux

PubMed Central

Boutorh, Julia; de la Rocha, Christina

2017-01-01

Zooplankton feeding activity is hypothesized to attenuate the downward flux of elements in the ocean. We investigated whether the zooplankton community composition could influence the flux attenuation, due to the differences of feeding modes (feeding on dispersed vs. aggregated particles) and of metabolic rates. We fed 5 copepod species—three calanoid, one harpacticoid and one poecilamastoid–microplankton food, in either dispersed or aggregated form and measured rates of respiration, fecal pellet production and egg production. Calanoid copepods were able to feed only on dispersed food; when their food was introduced as aggregates, their pellet production and respiration rates decreased to rates observed for starved individuals. In contrast, harpacticoids and the poecilamastoid copepod Oncaea spp. were able to feed only when the food was in the form of aggregates. The sum of copepod respiration, pellet production and egg production rates was equivalent to a daily minimum carbon demand of ca. 10% body weight-1 for all non-feeding copepods; the carbon demand of calanoids feeding on dispersed food was 2–3 times greater, and the carbon demand of harpacticoids and Oncaea spp. feeding on aggregates was >7 times greater, than the resting rates. The zooplankton species composition combined with the type of available food strongly influences the calculated carbon demand of a copepod community, and thus also the attenuation of vertical carbon flux. PMID:28545095

Cardiorespiratory parameters and their relation with gestational age and level of oral feeding skills in preterm infants.

PubMed

Yamamoto, Raquel Coube de Carvalho; Prade, Leila Sauer; Berwig, Luana Cristina; Weinmann, Angela Regina Maciel; Keske-Soares, Márcia

2016-01-01

To correlate cardiorespiratory parameters with gestational age and level of oral feeding skills in the first oral feeding in preterm infants. Study participants were 37 clinically stable preterm infants. Cardiorespiratory rate was assessed before and after introduction of oral feeding. The newborns were divided into three strata according to gestational age at birth. Oral skill was classified into four levels: I - low oral skill and low resistance to feeding; II - low oral skill and high resistance to feeding; III - high oral skill and low resistance to feeding; IV - high oral skill and high resistance to feeding. No difference was observed in heart and respiratory rate between the strata of gestational age at birth and between the levels of oral skill. Comparison between pre- and post-cardiorespiratory rates within each level of oral skill and stratum of gestational age showed difference between heart rate in the strata of gestational ages of 30 to 33 weeks and of 34 to 36 weeks, as well as between oral skill of levels I, II, and IV. With regard to the comparison between pre- and post- respiratory rates, difference was found in the oral skill of level I. Differences were observed between pre- and post-prandial cardiorespiratory rates regarding the first oral feeding, as well as between strata of gestational age at birth and levels of oral feeding skills.

Inter-relationships among alternative definitions of feed efficiency in grazing lactating dairy cows.

PubMed

Hurley, A M; López-Villalobos, N; McParland, S; Kennedy, E; Lewis, E; O'Donovan, M; Burke, J L; Berry, D P

2016-01-01

International interest in feed efficiency, and in particular energy intake and residual energy intake (REI), is intensifying due to a greater global demand for animal-derived protein and energy sources. Feed efficiency is a trait of economic importance, and yet is overlooked in national dairy cow breeding goals. This is due primarily to a lack of accurate data on commercial animals, but also a lack of clarity on the most appropriate definition of the feed intake and utilization complex. The objective of the present study was to derive alternative definitions of energetic efficiency in grazing lactating dairy cows and to quantify the inter-relationships among these alternative definitions. Net energy intake (NEI) from pasture and concentrate intake was estimated up to 8 times per lactation for 2,693 lactations from 1,412 Holstein-Friesian cows. Energy values of feed were based on the French Net Energy system where 1 UFL is the net energy requirements for lactation equivalent of 1kg of air-dry barley. A total of 8,183 individual feed intake measurements were available. Energy balance was defined as the difference between NEI and energy expenditure. Efficiency traits were either ratio-based or residual-based; the latter were derived from least squares regression models. Residual energy intake was defined as NEI minus predicted energy to fulfill the requirements for the various energy sinks. The energy sinks (e.g., NEL, metabolic live weight) and additional contributors to energy kinetics (e.g., live weight loss) combined, explained 59% of the variation in NEI, implying that REI represented 41% of the variance in total NEI. The most efficient 10% of test-day records, as defined by REI (n=709), on average were associated with a 7.59 UFL/d less NEI (average NEI of the entire population was 16.23 UFL/d) than the least efficient 10% of test-day records based on REI (n=709). Additionally, the most efficient 10% of test-day records, as defined by REI, were associated with superior energy conversion efficiency (ECE, i.e., NEL divided by NEI; ECE=0.55) compared with the least efficient 10% of test-day records (ECE=0.33). Moreover, REI was positively correlated with energy balance, implying that more negative REI animals (i.e., deemed more efficient) are expected to be, on average, in greater negative energy balance. Many of the correlations among the 14 defined efficiency traits differed from unity, implying that each trait is measuring a different aspect of efficiency. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Domestic Animal Hosts Strongly Influence Human-Feeding Rates of the Chagas Disease Vector Triatoma infestans in Argentina

PubMed Central

Gürtler, Ricardo E.; Cecere, María C.; Vázquez-Prokopec, Gonzalo M.; Ceballos, Leonardo A.; Gurevitz, Juan M.; Fernández, María del Pilar; Kitron, Uriel; Cohen, Joel E.

2014-01-01

Background The host species composition in a household and their relative availability affect the host-feeding choices of blood-sucking insects and parasite transmission risks. We investigated four hypotheses regarding factors that affect blood-feeding rates, proportion of human-fed bugs (human blood index), and daily human-feeding rates of Triatoma infestans, the main vector of Chagas disease. Methods A cross-sectional survey collected triatomines in human sleeping quarters (domiciles) of 49 of 270 rural houses in northwestern Argentina. We developed an improved way of estimating the human-feeding rate of domestic T. infestans populations. We fitted generalized linear mixed-effects models to a global model with six explanatory variables (chicken blood index, dog blood index, bug stage, numbers of human residents, bug abundance, and maximum temperature during the night preceding bug catch) and three response variables (daily blood-feeding rate, human blood index, and daily human-feeding rate). Coefficients were estimated via multimodel inference with model averaging. Findings Median blood-feeding intervals per late-stage bug were 4.1 days, with large variations among households. The main bloodmeal sources were humans (68%), chickens (22%), and dogs (9%). Blood-feeding rates decreased with increases in the chicken blood index. Both the human blood index and daily human-feeding rate decreased substantially with increasing proportions of chicken- or dog-fed bugs, or the presence of chickens indoors. Improved calculations estimated the mean daily human-feeding rate per late-stage bug at 0.231 (95% confidence interval, 0.157–0.305). Conclusions and Significance Based on the changing availability of chickens in domiciles during spring-summer and the much larger infectivity of dogs compared with humans, we infer that the net effects of chickens in the presence of transmission-competent hosts may be more adequately described by zoopotentiation than by zooprophylaxis. Domestic animals in domiciles profoundly affect the host-feeding choices, human-vector contact rates and parasite transmission predicted by a model based on these estimates. PMID:24852606

The Role of Biofuels Coproducts in Feeding the World Sustainably.

PubMed

Shurson, Gerald C

2017-02-08

One of the grand challenges facing our society today is finding solutions for feeding the world sustainably. The food-versus-fuel debate is a controversy embedded in this challenge, involving the trade-offs of using grains and oilseeds for biofuels production versus animal feed and human food. However, only 6% of total global grain produced is used to produce ethanol. Furthermore, biofuels coproducts contribute to sustainability of food production because only 1% to 2.5% of the overall energy efficiency is lost from converting crops into biofuels and animal feed, and approximately one-third of the corn used to produce ethanol is recovered as feed coproducts. Extensive research has been conducted over the past 15 years on biofuels coproducts to (a) optimize their use for improving caloric and nutritional efficiency in animal feeds, (b) identify benefits and limitations of use in various animal diets, (c) characterize their unique nutraceutical properties, and (d) evaluate their environmental impacts.

Effect of probiotic supplementation on organic feed to alternative antibiotic growth promoter on production performance and economics analysis of quail.

PubMed

Lokapirnasari, W P; Dewi, A R; Fathinah, A; Hidanah, S; Harijani, N; Soeharsono; Karimah, B; Andriani, A D

2017-12-01

The purpose of this study was to know the production performance and economic analysis in quail which use probiotic supplementation to alternate antibiotic growth promoter (AGP) to feed consumption, water consumption, egg production, egg mass, feed conversion, and feed efficiency. About 240 quails ( Coturnix coturnix japonica) at 14 weeks of age were completely randomized into four treatments, each treatment consisted of six replications and each replication consisted by 10 heads. The treatment was T0 (organic feed without AGP and without probiotic), T1 (organic feed + 0.001% AGP), T2 (organic feed + 0.005% probiotic in feed), and T3 (organic feed + 0.005% probiotic in drinking water). The probiotic consist of 1.2×10 5 CFU/g of Lactobacillus casei and Lactobacillus rhamnosus . The results showed that the probiotic supplementation both in feed and water give a significant impact to feed consumption, water intake, feed conversion, feed efficiency, and quail day production, but no statistical difference of egg mass. The T3 also show the most profitable business analysis, which has the best result in income, profit, break-even point, return cost ratio, benefit-cost ratio, and return on investment. It can be concluded that giving 0.005% probiotic in drinking water to get the best egg production and profit.

Differential response to stocking rates and feeding by two genotypes of Holstein-Friesian cows in a pasture-based automatic milking system.

PubMed

Nieman, C C; Steensma, K M; Rowntree, J E; Beede, D K; Utsumi, S A

2015-12-01

The throughput of automatic milking systems (AMS) is likely affected by differential traffic behavior and subsequent effects on the milking frequency and milk production of cows. This study investigated the effect of increasing stocking rate and partial mixed ration (PMR) on the milk production, dry matter intake (DMI), feed conversion efficiency (FCE) and use of AMS by two genotypes of Holstein-Friesian cows in mid-lactation. The study lasted 8 weeks and consisted in a factorial arrangement of two genotypes of dairy cattle, United States Holstein (USH) or New Zealand Friesian (NZF), and two pasture-based feeding treatments, a low stocking rate system (2 cows/ha) fed temperate pasture and concentrate, or a high stocking rate system (HSR; 3 cows/ha) fed same pasture and concentrate plus PMR. A total of 28 cows, 14 USH and 14 NZF, were used for comparisons, with 12 cows, six USH and six NZF, also used for tracking of animal movements. Data were analyzed by repeated measure mixed models for a completely randomized design. No differences (P>0.05) in pre- or post-grazing herbage mass, DMI and FCE were detected in response to increases in stocking rate and PMR feeding in HSR. However, there was a significant (P<0.05) grazing treatment×genotype×week interaction on milk production, explained by differential responses of genotypes to changes in herbage mass over time (P<0.001). A reduction (P<0.01) in hours spent on pasture was detected in response to PMR supplementation in HSR; this reduction was greater (P=0.01) for USH than NZF cows (6 v. 2 h, respectively). Regardless of the grazing treatment, USH cows had greater (P=0.02) milking frequency (2.51 v. 2.26±0.08 milkings/day) and greater (P<0.01) milk yield (27.3 v. 16.0±1.2 kg/day), energy-corrected milk (24.8 v. 16.5±1.0 kg/day), DMI (22.1 v. 16.6±0.8 kg/day) and FCE (1.25 v. 1.01±0.06 kg/kg) than NZF cows. There was also a different distribution of milkings/h between genotypes (P<0.001), with patterns of milkings/h shifting (P<0.001) as a consequence of PMR feeding in HSR. Results confirmed the improved FCE of grazing dairy cows with greater milk production and suggested the potential use of PMR feeding as a tactical decision to managing HSR and milkings/day in AMS farms.

Susceptibility of adult female Aedes aegypti (Diptera: Culicidae) to the entomopathogenic fungus Metarhizium anisopliae is modified following blood feeding.

PubMed

Paula, Adriano R; Carolino, Aline T; Silva, Carlos P; Samuels, Richard I

2011-05-26

The mosquito Aedes aegypti, vector of dengue fever, is a target for control by entomopathogenic fungi. Recent studies by our group have shown the susceptibility of adult A. aegypti to fungal infection by Metarhizium anisopliae. This fungus is currently being tested under field conditions. However, it is unknown whether blood-fed A. aegypti females are equally susceptible to infection by entomopathogenic fungi as sucrose fed females. Insect populations will be composed of females in a range of nutritional states. The fungus should be equally efficient at reducing survival of insects that rest on fungus impregnated surfaces following a blood meal as those coming into contact with fungi before host feeding. This could be an important factor when considering the behavior of A. aegypti females that can blood feed on multiple hosts over a short time period. Female A. aegypti of the Rockefeller strain and a wild strain were infected with two isolates of the entomopathogenic fungus M. anisopliae (LPP 133 and ESALQ 818) using an indirect contact bioassay at different times following blood feeding. Survival rates were monitored on a daily basis and one-way analysis of variance combined with Duncan's post-hoc test or Log-rank survival curve analysis were used for statistical comparisons of susceptibility to infection. Blood feeding rapidly reduced susceptibility to infection, determined by the difference in survival rates and survival curves, when females were exposed to either of the two M. anisopliae isolates. Following a time lag which probably coincided with digestion of the blood meal (96-120 h post-feeding), host susceptibility to infection returned to pre-blood fed (sucrose fed) levels. Reduced susceptibility of A. aegypti to fungi following a blood meal is of concern. Furthermore, engorged females seeking out intra-domicile resting places post-blood feeding, would be predicted to rest for prolonged periods on fungus impregnated black cloths, thus optimizing infection rates. It should be remembered that lowered susceptibility was only a temporary phenomenon and this may not necessarily occur when mosquitoes are infected with other fungal isolates. These results may have implications for field testing of entomopathogenic fungi by our group and further studies should be carried out to better understand the insect-fungus interaction.

Breast-feeding rates at an inner-city pediatric practice.

PubMed

Furman, Lydia; Combs, Bridget C; Alexander, Ashley D; O'Riordan, Mary Ann

2008-11-01

To determine rates of breast-feeding in the first 2 months of life at an inner-city pediatric practice. Using retrospective chart reviews, we examined all visits through 2 months of age for infants seen from April 1, 2007, to June 29, 2007, at the Pediatric Practice of Rainbow Babies and Children's Hospital, Cleveland, Ohio, which serves a low-income urban population. Rates of breast-feeding were analyzed by visit number and by infant age category. We reviewed all 557 visits occurring between birth and 2 months of age for all 223 eligible infants. At visit 1 (median age 5 days), the rates of exclusive and any breast-feeding were 22.0% and 40.8%, respectively. By visit 3 (median age 43 days), the rates of exclusive and any breast-feeding were 10.6% and 24.5%, respectively. These inner-city breast-feeding rates are substantially below reported regional and national rates. Barriers to implementing urgently needed interventions are discussed.

Sublethal responses of largemouth bass to parasites and organochlorines

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

MacRury, N.K.; Johnson, B.M.

1999-05-01

Largemouth bass (Micropterus salmoides) at the Rocky Mountain Arsenal National Wildlife Refuge (RMA) experience chronic organochlorine exposures and parasitism by nematodes (Contracaecum spiculigerum) and digenean flukes (Posthodiplostomum minimum centrarchi). The authors investigated the influences of nematode intensity, fluke intensity, and whole-body organochlorine concentrations on growth of juvenile RMA bass. Lifetime growth, or age-specific lengths, of bass in three RMA lakes were within the range observed for bass in five reference lakes. However, interlake comparisons can be confounded by differing environmental conditions. Therefore, they conducted mesocosm and laboratory studies to compare growth, consumption, and feeding behavior between RMA bass and bassmore » that had little contaminant or parasite exposure. Mean growth rates of RMA bass were 45% lower compared with hatchery bass in experimental ponds. However, regression analysis revealed that parasite and organochlorine burdens were not negatively associated with either short-term growth or age-specific lengths of RMA bass. Hatchery bass growth was likely higher due to their experience with culture pond conditions. In feeding trials, RMA bass exhibited similar food conversion efficiency and consumption rates and significantly elevated feeding activity compared with hatchery bass. This research demonstrates that current parasite and organochlorine loads had benign influences on growth of juvenile RMA bass.« less

Estimation of Scale Deposition in the Water Walls of an Operating Indian Coal Fired Boiler: Predictive Modeling Approach Using Artificial Neural Networks

NASA Astrophysics Data System (ADS)

Kumari, Amrita; Das, Suchandan Kumar; Srivastava, Prem Kumar

2016-04-01

Application of computational intelligence for predicting industrial processes has been in extensive use in various industrial sectors including power sector industry. An ANN model using multi-layer perceptron philosophy has been proposed in this paper to predict the deposition behaviors of oxide scale on waterwall tubes of a coal fired boiler. The input parameters comprises of boiler water chemistry and associated operating parameters, such as, pH, alkalinity, total dissolved solids, specific conductivity, iron and dissolved oxygen concentration of the feed water and local heat flux on boiler tube. An efficient gradient based network optimization algorithm has been employed to minimize neural predictions errors. Effects of heat flux, iron content, pH and the concentrations of total dissolved solids in feed water and other operating variables on the scale deposition behavior have been studied. It has been observed that heat flux, iron content and pH of the feed water have a relatively prime influence on the rate of oxide scale deposition in water walls of an Indian boiler. Reasonably good agreement between ANN model predictions and the measured values of oxide scale deposition rate has been observed which is corroborated by the regression fit between these values.

Improved fed-batch production of high-purity PHB (poly-3 hydroxy butyrate) by Cupriavidus necator (MTCC 1472) from sucrose-based cheap substrates under response surface-optimized conditions.

PubMed

Dey, Pinaki; Rangarajan, Vivek

2017-10-01

Experimental investigations were carried out for Cupriavidus necator (MTCC 1472)-based improved production of poly-3 hydroxy butyrate (PHB) through induced nitrogen limiting fed-batch cultivation strategies. Initially Plackett-Burman design and response surface methodology were implemented to optimize most influencing process parameters. With optimized process parameter values, continuous feeding strategies ware applied in a 5-l fermenter with table sugar concentration of 100 g/l, nitrogen concentration of 0.12 g/l for fed-batch fermentation with varying dilution rates of 0.02 and 0.046 1/h. To get enriched production of PHB, concentration of the sugar was further increased to 150 and 200 g/l in feeding. Maximum concentrations of PHB achieved were 22.35 and 23.07 g/l at those dilution rates when sugar concentration maintains at 200 g/l in feeding. At maximum concentration of PHB (23.07 g/l), productivity of 0.58 g/l h was achieved with maximum PHB accumulation efficiency up to 64% of the dry weight of biomass. High purity of PHB, close to medical grade was achieved after surfactant hypochlorite extraction method, and it was further confirmed by SEM, EDX, and XRD studies.

Understanding the Effects of Diet on Larval Crassostrea virginica: A Comparison of Commercial Concentrates and Live Algal Feed

NASA Astrophysics Data System (ADS)

Williams, C. T.; Krause, J. W.; Walton, W. C.

2016-02-01

Traditionally shellfish hatcheries produce live microalgal cultures to feed larvae. This process is time consuming, labor intensive, expensive, and requires a large and sterile environment. The use of commercial microalgal concentrates allows hatcheries to reduce operational costs and optimize floor space; however, there have been no systematic studies examining the relative yields from live algal vs. concentrate-based diets. The effects of diet type on the growth-rate, survival, and settling efficiency of Crassostrea virginica were explored by varying diet proportions in two-day old spawned larvae through metamorphosis and settlement. Live microalgal feed was blended from axenic Isochrysis, Tetraselmis, Pavlova, and Chaetoceros cultures to mimic typical hatchery recipes. The live microalgae was supplemented with variable amounts of the concentrate, Reed Mariculture Shellfish Diet 1800™, across multiple treatments ranging from 100% concentrate vs. 100% live diet. Caloric content was used to normalize between the diet types to achieve treatments with 25, 50 and 75% live diet supplemented with proportional amounts of concentrate (e.g. 75, 50, and 25% concentrate, respectively). The goal of this method was to show whether survival and settling rates depend on the proportion of live microalgal diet. Such data will inform a cost-benefit analysis of whether concentrates are a financially viable alternative for oyster hatcheries.

Methane production by anaerobic digestion of water hyacinth (Eichhornia crassipes)

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

Klass, D.L.; Ghosh, S.

1980-01-01

Water hyacinth under conventional high-rate digestion conditions exhibited higher methane yields and energy recovery efficiencies when grown in sewage-fed lagoons as compared to the corresponding values obtained with water hyacinth grown in a fresh-water pond. Mesophilic digestion provided the highest feed energy recovered in the product gas as methane while thermophilic digestion, when operated at sufficiently high loading rates and reduced detention times, gave the highest specific methane production rates. Methane yields, volatile solids reduction, and energy recovery as methane for the sewage-grown water hyacinth were in the same range as those observed for other biomass substrates when digested undermore » similar conditions.« less

Effect of limit feeding and genomic residual feed intake on bred dairy heifer performance

USDA-ARS?s Scientific Manuscript database

The objective of this study was to evaluate growth, intake, and feed efficiency of dairy heifers with different predicted genomic residual feed intakes as lactating cows (RFI) offered diets for ad-libitum intake or limit-fed. Post-bred Holstein heifers (128, ages 14-20 months), were blocked by initi...

Effect of diet energy level and genomic residual feed intake on dairy heifer performance

USDA-ARS?s Scientific Manuscript database

The objective of this study was to determine the growth, feed intake, and feed efficiency of dairy heifers with different genomically predicted residual feed intakes (RFI), and offered diets differing in energy density. Post-bred Holstein heifers (N=128; ages 14-20 months) were blocked by initial we...

Evaluation of formulated feed for juvenile lake sturgeon (Acipenser fulvescens) based on growth performance and nutrient retention

USDA-ARS?s Scientific Manuscript database

This study evaluated the potential of giving formulated feed to juvenile lake sturgeon (Acipenser fulvescens) and determined the optimal feeding rate of a soft-moist feed on the growth performance and whole-body composition of this fish. Six feeding rates (% body weight per day: % BW/d) of a soft-mo...

Effects of low-density feeding on elk–fetus contact rates on Wyoming feedgrounds

USGS Publications Warehouse

Creech, Tyler G.; Cross, Paul C.; Scurlock, Brandon M.; Maichak, Eric J.; Rogerson, Jared D.; Henningsen, John C.; Creel, Scott

2012-01-01

High seroprevalance for Brucella abortus among elk on Wyoming feedgrounds suggests that supplemental feeding may influence parasite transmission and disease dynamics by altering the rate at which elk contact infectious materials in their environment. We used proximity loggers and video cameras to estimate rates of elk-to-fetus contact (the primary source of brucellosis transmission) during winter supplemental feeding. We compared contact rates during high-density and low-density (LD) feeding treatments that provided the same total amount of food distributed over different areas. Low-density feeding led to >70% reductions in total number of contacts and number of individuals contacting a fetus. Proximity loggers and video cameras provided similar estimates of elk–fetus contact rates. Elk contacted fetuses and random control points equally, suggesting that elk were not attracted to fetuses but encountered them incidentally while feeding. The modeled relationship between contact rate and disease prevalence is nonlinear and LD feeding may result in large reductions in brucellosis prevalence, but this depends on the amount of transmission that occurs on and off feedgrounds.

What drives interaction strengths in complex food webs? A test with feeding rates of a generalist stream predator.

PubMed

Preston, Daniel L; Henderson, Jeremy S; Falke, Landon P; Segui, Leah M; Layden, Tamara J; Novak, Mark

2018-05-08

Describing the mechanisms that drive variation in species interaction strengths is central to understanding, predicting, and managing community dynamics. Multiple factors have been linked to trophic interaction strength variation, including species densities, species traits, and abiotic factors. Yet most empirical tests of the relative roles of multiple mechanisms that drive variation have been limited to simplified experiments that may diverge from the dynamics of natural food webs. Here, we used a field-based observational approach to quantify the roles of prey density, predator density, predator-prey body-mass ratios, prey identity, and abiotic factors in driving variation in feeding rates of reticulate sculpin (Cottus perplexus). We combined data on over 6,000 predator-prey observations with prey identification time functions to estimate 289 prey-specific feeding rates at nine stream sites in Oregon. Feeding rates on 57 prey types showed an approximately log-normal distribution, with few strong and many weak interactions. Model selection indicated that prey density, followed by prey identity, were the two most important predictors of prey-specific sculpin feeding rates. Feeding rates showed a positive relationship with prey taxon densities that was inconsistent with predator saturation predicted by current functional response models. Feeding rates also exhibited four orders-of-magnitude in variation across prey taxonomic orders, with the lowest feeding rates observed on prey with significant anti-predator defenses. Body-mass ratios were the third most important predictor variable, showing a hump-shaped relationship with the highest feeding rates at intermediate ratios. Sculpin density was negatively correlated with feeding rates, consistent with the presence of intraspecific predator interference. Our results highlight how multiple co-occurring drivers shape trophic interactions in nature and underscore ways in which simplified experiments or reliance on scaling laws alone may lead to biased inferences about the structure and dynamics of species-rich food webs. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Diminution in energy expenditure during lactation.

PubMed Central

Illingworth, P J; Jung, R T; Howie, P W; Leslie, P; Isles, T E

1986-01-01

Energy expenditure at rest and in response to a meal and to an infusion of noradrenaline was measured in 12 lactating women and compared with that in seven bottle feeding women and seven non-pregnant, non-lactating controls. The energy response of the lactating women was remeasured after lactation stopped. During lactation the resting metabolic rate was unaltered but there was a reduced response to infusion of noradrenaline and to a meal, which increased to normal control values after lactation stopped. Such reductions in expenditure were not found in women who had been bottle feeding and were tested at a similar six to eight weeks post partum. These findings suggest that metabolic efficiency is enhanced in lactating women, who may not need to increase energy intake to the extent suggested by current recommended dietary allowances. PMID:3081114

Feed rate affecting surface roughness and tool wear in dry hard turning of AISI 4140 steel automotive parts using TiN+AlCrN coated inserts

NASA Astrophysics Data System (ADS)

Paengchit, Phacharadit; Saikaew, Charnnarong

2018-02-01

This work aims to investigate the effects of feed rate on surface roughness (Ra) and tool wear (VB) and to obtain the optimal operating condition of the feed rate in dry hard turning of AISI 4140 chromium molybdenum steel for automotive industry applications using TiN+AlCrN coated inserts. AISI 4140 steel bars were employed in order to carry out the dry hard turning experiments by varying the feed rates of 0.06, 0.08 and 0.1 mm/rev based on experimental design technique that can be analyzed by analysis of variance (ANOVA). In addition, the cutting tool inserts were examined after machining experiments by SEM to evaluate the effect of turning operations on tool wear. The results showed that averages Ra and VB were significantly affected by the feed rate at the level of significance of 0.05. Averages Ra and VB values at the feed rate of 0.06 mm/rev were lowest compared to average values at the feed rates of 0.08 and 0.1 mm/rev, based on the main effect plot.

Influence of dietary supplementation of prebiotics (mannanoligosaccharide) on the performance of crossbred calves.

PubMed

Ghosh, Sudipta; Mehla, Ram Kumar

2012-03-01

Thirty-six Holstein cross calves 5 days of age in their preruminant stage were used to study the effect of feeding prebiotic (mannanoligosaccharide) on their performance up to the age of 2 months. Treatment and control groups consisted of 18 calves each. Treatment group was supplemented with 4 g prebiotic (mannanoligosaccharide)/calf/day. Performance was evaluated by measuring average body weight (BW) gain, feed intake [dry matter (DM), total digestible nutrient (TDN) and crude protein(CP)], feed conversion efficiency (DM, TDN, and CP), fecal score, fecal coliform count and feeding cost. Body weight measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analyzed weekly, fecal score monitored daily and fecal coliform count done weekly. There was a significant increase in average body weight gain, feed intake and feed conversion efficiency; and a significant decrease in severity of scours as measured by fecal score and fecal coliform count in the treatment group compared with control group (P < 0.01). Feed cost/kg BW gain was significantly lower in the treatment group compared to control group (P < 0.01). The results suggest that prebiotic (mannanoligosaccharide) can be supplemented to the calves for better performance.

Genetic markers that influence feed efficiency phenotypes also affect cattle temperament as measured by flight speed

USDA-ARS?s Scientific Manuscript database

The measure of flight speed for cattle has been shown to be a predictive indicator of temperament and has also been associated with feed efficiency phenotypes, thus, genetic markers associated with both traits may assist with the selection of animals with calmer disposition and economic value. Chrom...

Microbial community profiles of the jejunum from steers differing in feed efficiency

USDA-ARS?s Scientific Manuscript database

Research regarding the association between the microbiome and host feed efficiency in cattle has primarily focused on the rumen. However, the various microbial populations within the gastrointestinal tract as a whole are critical to the overall well-being of the host and need to be examined when de...

Endocannabinoid concentrations in plasma during the finishing period are associated with feed efficiency and carcass composition of beef cattle

USDA-ARS?s Scientific Manuscript database

We previously have shown that plasma concentrations of endocannabinoids (EC) are positively correlated with feed efficiency and leaner carcasses in finishing steers. However, whether the animal growth during the finishing period affects the concentration of EC is unknown. The objective of this study...

21 CFR 558.248 - Erythromycin thiocyanate.

Code of Federal Regulations, 2012 CFR

2012-04-01

... 18.5 Chickens; growth promotion and feed efficiency ,061623 (ii) 9.25 to 18.5 Turkeys; growth promotion and feed efficiency For turkeys not over 12 weeks of age ,061623 (iii) 9.25 to 64.75 Swine...; withdraw 24 h before slaughter 3. Turkeys; as an aid in the prevention of chronic respiratory disease...

21 CFR 558.248 - Erythromycin thiocyanate.

Code of Federal Regulations, 2013 CFR

2013-04-01

... 18.5 Chickens; growth promotion and feed efficiency ,061623 (ii) 9.25 to 18.5 Turkeys; growth promotion and feed efficiency For turkeys not over 12 weeks of age ,061623 (iii) 9.25 to 64.75 Swine...; withdraw 24 h before slaughter 3. Turkeys; as an aid in the prevention of chronic respiratory disease...

21 CFR 558.248 - Erythromycin.

Code of Federal Regulations, 2014 CFR

2014-04-01

...; growth promotion and feed efficiency ,061623 (ii) 9.25 to 18.5 Turkeys; growth promotion and feed efficiency For turkeys not over 12 weeks of age ,061623 (iii) 9.25 to 64.75 Swine; increase in weight gain... before slaughter 3. Turkeys; as an aid in the prevention of chronic respiratory disease during periods of...

Feeding methods and efficiencies of selected frugivorous birds

USGS Publications Warehouse

Foster, M.S.

1987-01-01

I report on handling methods and efficiencies of 26 species of Paraguayan birds freeding on fruits of Allophyllus edulis (Sapindaceae). A bird may swallow fruits whole (Type I: pluck and swallow feeders), hold a fruit and cut the pulp from the seed with the edge of the bill, swallowing the pulp but not the seed (Type II: cut or mash feeders), or take bites of pulp from a fruit that hangs from the tree or that is held and manipulated against a branch (Type III: push and bite feeders). In terms of absolute amount of pulp obtained from a fruit, and amount obtained per unit time. Type I species are far more efficient than Type II and III species. Bill morphology influences feeding methods but is not the only important factor. Diet breadth does not appear to be significant. Consideration of feeding efficiency relative to the needs of the birds indicates that these species need to spend relatively little time feeding to meet their estimated energetic needs, and that handling time has a relatively trivial effect on the time/energy budges of the bird species observed.

Effects of enzyme supplementation on the nutrient, amino acid, and energy utilization efficiency of citrus pulp and hawthorn pulp in Linwu ducks.

PubMed

Zhang, Xu; Li, Haobang; Jiang, Guitao; Wang, Xiangrong; Huang, Xuan; Li, Chuang; Wu, Duanqin; Dai, Qiuzhong

2018-04-11

The objective of this study was to evaluate the effects of enzyme supplementation on the nutrient, amino acid, and energy utilization efficiency of citrus pulp and hawthorn pulp as unusual feedstuffs in Linwu ducks. Forty ducks were assigned to each treatment group and fed diets with or without complex enzyme supplementation. All birds received the same quantity of raw material (60 g) via the force-feeding procedure. With the exception of leucine and phenylalanine, amino acid concentrations in hawthorn pulp were twice those in citrus pulp. Enzyme supplementation significantly increased apparent dry matter digestibility (ADM) of citrus pulp (P < 0.05), but had no significant effects (P > 0.05) on the apparent and true utilization rates of other nutrients, apparent metabolizable energy (AME), or true metabolizable energy (TME), from citrus pulp and hawthorn pulp by Linwu ducks. However, enzyme supplementation significantly increased (P < 0.05) apparent gross energy, true gross energy, AME, and TME of hawthorn pulp for Linwu ducks. There were no differences in the apparent and true utilization rates of amino acids from citrus pulp (P > 0.56) between the groups, with the exception of arginine (P < 0.05). There was an increasing trend in the apparent and true utilization rates of alanine (P = 0.06) and tyrosine (P = 0.074) from citrus pulp with enzyme supplementation. The apparent and true utilization rates of threonine in hawthorn pulp were increased significantly (P < 0.05) following enzyme supplementation. The addition of exogenous enzymes improved the forage quality of citrus pulp and hawthorn pulp, which represent potential feed resources for husbandry production.

New benchmarks for costs and cost-efficiency of school-based feeding programs in food-insecure areas.

PubMed

Gelli, Aulo; Cavallero, Andrea; Minervini, Licia; Mirabile, Mariana; Molinas, Luca; de la Mothe, Marc Regnault

2011-12-01

School feeding is a popular intervention that has been used to support the education, health and nutrition of school children. Although the benefits of school feeding are well documented, the evidence on the costs of such programs is remarkably thin. Address the need for systematic estimates of the cost of different school feeding modalities, and of the determinants of the considerable cost variation among countries. WFP project data, including expenditures and number of schoolchildren covered, were collected for 78 projects in 62 countries through project reports and validated through WFP Country Office records. Yearly project costs per schoolchild were standardized over a set number of feeding days and the amount of energy provided by the average ration. Output metrics, such as tonnage, calories, and micronutrient content, were used to assess the cost-efficiency of the different delivery mechanisms. The standardized yearly average school feeding cost per child, not including school-level costs, was US$48. The yearly costs per child were lowest at US$23 for biscuit programs reaching school-going children and highest at US$75 for take-home rations programs reaching families of schoolgoing children. The average cost of programs combining on-site meals with extra take-home rations for children from vulnerable households was US$61. Commodity costs were on average 58% of total costs and were highest for biscuit and take-home rations programs (71% and 68%, respectively). Fortified biscuits provided the most cost-efficient option in terms of micronutrient delivery, whereas take-home rations were more cost-efficient in terms of food quantities delivered. Both costs and effects should be considered carefully when designing school feeding interventions. The average costs of school feeding estimated here are higher than those found in earlier studies but fall within the range of costs previously reported. Because this analysis does not include school-level costs, these findings highlight the higher nontransfer costs for programs delivering cooked meals in schools than for other school feeding modalities. The benchmarks presented here reflect the centralized WFP implementation model, which is not always relevant in terms of government school feeding programs, particularly those procuring within national boundaries using "home-grown" approaches.

Evaluating digestion efficiency in full-scale anaerobic digesters by identifying active microbial populations through the lens of microbial activity

NASA Astrophysics Data System (ADS)

Mei, Ran; Narihiro, Takashi; Nobu, Masaru K.; Kuroda, Kyohei; Liu, Wen-Tso

2016-09-01

Anaerobic digestion is a common technology to biologically stabilize wasted solids produced in municipal wastewater treatment. Its efficiency is usually evaluated by calculating the reduction in volatile solids, which assumes no biomass growth associated with digestion. To determine whether this assumption is valid and further evaluate digestion efficiency, this study sampled 35 digester sludge from different reactors at multiple time points together with the feed biomass in a full-scale water reclamation plant at Chicago, Illinois. The microbial communities were characterized using Illumina sequencing technology based on 16S rRNA and 16S rRNA gene (rDNA). 74 core microbial populations were identified and represented 58.7% of the entire digester community. Among them, active populations were first identified using the ratio of 16S rRNA and 16S rDNA (rRNA/rDNA) for individual populations, but this approach failed to generate consistent results. Subsequently, a recently proposed mass balance model was applied to calculate the specific growth rate (μ), and this approach successfully identified active microbial populations in digester (positive μ) that could play important roles than those with negative μ. It was further estimated that 82% of microbial populations in the feed sludge were digested in comparison with less than 50% calculated using current equations.

Promotion of exclusive breast-feeding at scale within routine health services: impact of breast-feeding counselling training for community health workers in Recife, Brazil.

PubMed

Coutinho, Sonia B; Lira, Pedro Ic; Lima, Marilia C; Frias, Paulo G; Eickmann, Sophie H; Ashworth, Ann

2014-04-01

Breast-feeding counselling has been identified as the intervention with the greatest potential for reducing child deaths, but there is little experience in delivering breast-feeding counselling at scale within routine health systems. The study aim was to compare rates of exclusive breast-feeding associated with a breast-feeding counselling intervention in which community health agents (CHA) received 20 h of training directed at counselling and practical skills with rates pre-intervention when CHA received 4 h of didactic teaching. Cross-sectional surveys of breast-feeding practices were conducted pre- and post-intervention in random samples of 1266 and 1245 infants aged 0-5.9 months, respectively. Recife, Brazil, with a population of 2 million. CHA (n 1449) of Brazil's Family Health Programme were trained to provide breast-feeding counselling at home visits. Rates of exclusive breast-feeding improved when CHA were trained to provide breast-feeding counselling and were significantly higher by 10-13 percentage points at age 3-5.9 months when compared with pre-intervention rates (P < 0.05). Post-intervention point prevalence of exclusive breast-feeding for infants aged <4 months was 63% and for those aged <6 months was 50%. Multifunctional CHA were able to deliver breast-feeding counselling at scale within a routine health service and this was associated with a significant increase in rates of exclusive breast-feeding. The study reinforces the need to focus training on counselling and practical skills; a key component was an interactive style that utilized the knowledge and experience of CHA. The findings are relevant to the call by international organizations to scale up breast-feeding counselling.

Impact of Feed Efficiency and Diet on Adaptive Variations in the Bacterial Community in the Rumen Fluid of Cattle

PubMed Central

Hernandez-Sanabria, Emma; Goonewardene, Laksiri A.; Wang, Zhiquan; Durunna, Obioha N.; Moore, Stephen S.

2012-01-01

Limited knowledge of the structure and activities of the ruminal bacterial community prevents the understanding of the effect of population dynamics on functional bacterial groups and on host productivity. This study aimed to identify particular bacteria associated with host feed efficiency in steers with differing diets and residual feed intake (RFI) using culture-independent methods: PCR-denaturing gradient gel electrophoresis (DGGE) and quantitative real-time PCR analysis. PCR-DGGE profiles were generated from the ruminal fluid of 55 steers fed a low-energy-density diet and then switched to a high-energy-density diet. Bacterial profile comparisons by multivariate statistical analysis showed a trend only for RFI-related clusters on the high-energy diet. When steers (n = 19) belonging to the same RFI group under both diets were used to identify specific bacterial phylotypes related to feed efficiency traits, correlations were detected between dry matter intake, average daily gain, and copy numbers of the 16S rRNA gene of Succinivibrio sp. in low-RFI (efficient) steers, whereas correlations between Robinsoniella sp. and RFI (P < 0.05) were observed for high-RFI (inefficient) animals. Eubacterium sp. differed significantly (P < 0.05) between RFI groups that were only on the high-energy diet. Our work provides a comprehensive framework to understand how particular bacterial phylotypes contribute to differences in feed efficiency and ultimately influence host productivity, which may either depend on or be independent from diet factors. PMID:22156428

Short communication: Feed utilization and its associations with fertility and productive life in 11 commercial Pennsylvania tie-stall herds.

PubMed

Vallimont, J E; Dechow, C D; Daubert, J M; Dekleva, M W; Blum, J W; Liu, W; Varga, G A; Heinrichs, A J; Baumrucker, C R

2013-02-01

The objectives of this study were to quantify the relationships of various definitions of feed utilization with both fertility and productive life. Intake and body measurement data were collected monthly on 970 cows in 11 tie-stall herds for 6 consecutive months. Measures of feed utilization for this study were dry matter intake (DMI), dry matter intake efficiency (DME, defined as 305-d fat-corrected milk/305-d DMI), DME with intake adjusted for maintenance requirements (DMEM), crude protein efficiency (defined as 305-d protein yield/305-d crude protein intake), and 2 definitions of residual feed intake (RFI). The first, RFI(reg), was calculated by regressing daily DMI on daily milk, fat, and protein yields, body weight (BW), daily body condition score (BCS) gain or loss, the interaction between BW and BCS gain or loss, and days in milk. The second, RFI(NRC), was estimated by subtracting 305-d DMI predicted according to their fat-corrected milk and BW from actual 305-d DMI. Data were analyzed with 8-trait animal models and included one measure of feed utilization and milk, fat, and protein yields, BW, BCS, days open (DO), and productive life (PL). The genetic correlation between DME and DO was 0.53 (± 0.19) and that between DME and PL was 0.66 (± 0.10). These results show that cows who had higher feed efficiency had greater DO (undesirable) and greater PL (desirable). Results were similar for the genetic correlation between DO and crude protein efficiency (0.42). Productive life had genetic correlations of -0.22 with BW and -0.48 with BCS, suggesting that larger, fatter cows in this study had shorter PL. Correlations between estimated breeding values for feed utilization and official sire genetic evaluations for fertility were in agreement with the results from the multiple-trait models. Selection programs intended to enhance feed efficiency should factor relationships with functional traits to avoid unfavorable effects on cow fertility. Copyright © 2013 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of TiO2 NPs on Silkworm Growth and Feed Efficiency.

PubMed

Li, YangYang; Ni, Min; Li, FanChi; Zhang, Hua; Xu, KaiZun; Zhao, XiaoMing; Tian, JiangHai; Hu, JingSheng; Wang, BinBin; Shen, WeiDe; Li, Bing

2016-02-01

Silkworm (Bombyx mori) (B. mori) is an economically important insect and a model species for Lepidoptera. It has been reported that feeding of low concentrations of titanium dioxide nanoparticles (TiO2 NPs) can improve feed efficiency and increase cocoon mass, cocoon shell mass, and the ratio of cocoon shell. However, high concentrations of TiO2 NPs are toxic. In this study, we fed B. mori with different concentrations of TiO2 NPs (5, 10, 20, 40, 80, and 160 mg/L) and investigated B. mori growth, feed efficiency, and cocoon quality. We found that low concentrations of TiO2 NPs (5 and 10 mg/L) were more effective for weight gains, with significant weight gain being obtained at 72 h (P < 0.05). TiO2 NPs at 20 mg/L or higher had certain inhibitory effects, with significant inhibition to B. mori growth being observed at 48 h. The feed efficiency was significantly improved at low concentrations of 5 and 10 mg/L for 14.6 and 13.1 %, respectively (P < 0.05). All B. mori fed with TiO2 NPs showed increased cocoon mass and cocoon shell mass; at 5 and 10 mg/L TiO2 NPs, cocoon mass was significantly increased by 8.29 and 9.39 %, respectively (P < 0.05). We also found that low concentrations (5 and 10 mg/L) of TiO2 NPs promoted B. mori growth and development, improved feed efficiency, and increased cocoon production, while high concentrations (20 mg/L or higher) of TiO2 NPs showed inhibitory effect to the B. mori. Consecutive feeding of high concentrations of TiO2 NPs led to some degrees of adaptability. This study provides a reference for the research on TiO2 NPs toxicity and the basis for the development of TiO2 NPs as a feed additive for B. mori.

PROCESS FOR CONTROLLING ANIMAL GROWTH RATE

DOEpatents

Visek, W.J.

1962-04-10

A method of injecting growing animals with the enzyme urease subcutaneously in increasing dosages is described; this generates within the blood anti-urease which enters the intestinal tract and inhibits the enzymatic decomposition of urea by urease in that location. Ammonia, one of the decomposition products, is thereby kept from diffusing through the intestinal walls into the blood, and this greatly reduces the energy requirements of the liver for removing the ammonia, thereby increasing the feeding efficiency of the animals. (AEC)

Mechanics, Hydrodynamics and Energetics of Blue Whale Lunge Feeding: Efficiency Dependence on Krill Density

DTIC Science & Technology

2011-01-01

obtained these morphometric data from blue whale specimens reposited at the National Museum of Natural History in Washington, DC (USNM 124326), the Santa...mouth-closing stage. The basic distance scale for this force is set by the ratio Ac/whead, calculated from Eqn A4, and the morphometrics of the body...allometry of mammalian metabolic rate supports niether geometric nor quarter-power scaling. Evolution 63, 2658-2667. Williams, T. M. (1999). The

Genetic parameters and expected responses to selection for components of feed efficiency in a Duroc pig line.

PubMed

Sánchez, Juan P; Ragab, Mohamed; Quintanilla, Raquel; Rothschild, Max F; Piles, Miriam

2017-12-01

Improving feed efficiency ([Formula: see text]) is a key factor for any pig breeding company. Although this can be achieved by selection on an index of multi-trait best linear unbiased prediction of breeding values with optimal economic weights, considering deviations of feed intake from actual needs ([Formula: see text]) should be of value for further research on biological aspects of [Formula: see text]. Here, we present a random regression model that extends the classical definition of [Formula: see text] by including animal-specific needs in the model. Using this model, we explore the genetic determinism of several [Formula: see text] components: use of feed for growth ([Formula: see text]), use of feed for backfat deposition ([Formula: see text]), use of feed for maintenance ([Formula: see text]), and unspecific efficiency in the use of feed ([Formula: see text]). Expected response to alternative selection indexes involving different components is also studied. Based on goodness-of-fit to the available feed intake ([Formula: see text]) data, the model that assumes individual (genetic and permanent) variation in the use of feed for maintenance, [Formula: see text] and [Formula: see text] showed the best performance. Joint individual variation in feed allocation to maintenance, growth and backfat deposition comprised 37% of the individual variation of [Formula: see text]. The estimated heritabilities of [Formula: see text] using the model that accounts for animal-specific needs and the traditional [Formula: see text] model were 0.12 and 0.18, respectively. The estimated heritabilities for the regression coefficients were 0.44, 0.39 and 0.55 for [Formula: see text], [Formula: see text] and [Formula: see text], respectively. Estimates of genetic correlations of [Formula: see text] were positive with amount of feed used for [Formula: see text] and [Formula: see text] but negative for [Formula: see text]. Expected response in overall efficiency, reducing [Formula: see text] without altering performance, was 2.5% higher when the model assumed animal-specific needs than when the traditional definition of [Formula: see text] was considered. Expected response in overall efficiency, by reducing [Formula: see text] without altering performance, is slightly better with a model that assumes animal-specific needs instead of batch-specific needs to correct [Formula: see text]. The relatively small difference between the traditional [Formula: see text] model and our model is due to random intercepts (unspecific use of feed) accounting for the majority of variability in [Formula: see text]. Overall, a model that accounts for animal-specific needs for [Formula: see text], [Formula: see text] and [Formula: see text] is statistically superior and allows for the possibility to act differentially on [Formula: see text] components.

Sensitivity and feeding efficiency of the black garden ant Lasius niger to sugar resources.

PubMed

Detrain, Claire; Prieur, Jacques

2014-05-01

Carbohydrate sources such as plant exudates, nectar and honeydew represent the main source of energy for many ant species and contribute towards maintaining their mutualistic relationships with plants or aphid colonies. Here we characterise the sensitivity, feeding response curve and food intake efficiency of the aphid tending ant, Lasius niger for major sugars found in nectar, honeydew and insect haemolymph (i.e. fructose, glucose, sucrose, melezitose and trehalose). We found that sucrose concentrations - ranging from 0.1 to 2.5 M - triggered food acceptance by L.niger workers with their food intake efficiency being enhanced by sugar concentrations of 1M or higher at which points energy intake was maximised. The range of sucrose concentrations that elicit a feeding response by L. niger scouts thus overlaps with that of natural sugar resources. The response curves of feeding acceptance by scouts consistently increased with sugar concentration, except for trehalose which was disregarded by the ants. Ants are highly sensitive to sucrose and melezitose exhibiting low response thresholds. Sucrose, fructose and glucose share a same potential to act as phagostimulants as they had similar half feeding efficiency concentration values when expressed as the energetic content of sugar solution. Aphid-biosynthezised melezitose generated the highest sensitivity and phagostimulant potential. The feeding behavior of ants appears to be primarily regulated by the energy content of the food solution for the main sugars present in nectar and honeydew. However, feeding by scouts is also influenced by the informative value of individual sugars when it serves as a cue for the presence of aphid partners such as the aphid-biosynthesised melezitose. Copyright © 2014 Elsevier Ltd. All rights reserved.

Genetic parameters of feed efficiency traits and their relationships with egg quality traits in laying period of ducks.

PubMed

Zeng, T; Zhang, H; Liu, J; Chen, L; Tian, Y; Shen, J; Lu, L

2018-03-01

The objective of this study was to estimate genetic parameters for feed efficiency and relevant traits in 2 laying duck breeds, and to determine the relationship of residual feed intake (RFI) with feed efficiency and egg quality traits. Phenotypic records on 3,000 female laying ducks (1,500 Shaoxing ducks and 1,500 Jinyun ducks) from a random mating population were used to estimate genetic parameters for RFI, feed conversion ratio (FCR), feed intake (FI), BW, BW gain (BWG), and egg mass laid (EML) at 42 to 46 wk of age. The heritability estimates for EML, FCR, FI, and RFI were 0.22, 0.19, 0.22, and 0.27 in Shaoxing ducks and 0.14, 0.19, 0.24, and 0.24 for Jinyun ducks, respectively. RFI showed high and positive genetic correlations with FCR (0.47 in Shaoxing ducks and 0.63 in Jinyun ducks) and FI (0.79 in Shaoxing ducks and 0.86 in Jinyun ducks). No correlations were found in RFI with BW, BWG, or EML at either genetic or phenotypic level. FCR was strongly and negatively correlated with EML (-0.81 and -0.68) but inconsistently correlated with FI (0.02 and 0.17), suggesting that EML was the main influence on FCR. In addition, no significant differences were found between low RFI (LRFI) and high RFI (HRFI) ducks in egg shape index, shell thickness, shell strength, yolk color, albumen height, or Haugh unit (HU). The results indicate that selection for LRFI could improve feed efficiency and reduce FI without significant changes in EML or egg quality.

The Infant Feeding Genogram: a tool for exploring family infant feeding history and identifying support needs.

PubMed

Darwent, K L; McInnes, R J; Swanson, V

2016-10-19

Family culture and beliefs are passed through the generations within families and influence what constitutes appropriate infant care. This includes infant feeding decisions where a family history and support network congruent with women's infant feeding intentions has been shown to be important to women's breastfeeding experience. This is reflected in breastfeeding rates where women who were not breastfed themselves are less likely to initiate and continue with breastfeeding. Given the importance of family infant feeding history in the initiation and duration of breastfeeding, and the limited ability of some families to provide support; it is unclear why infant feeding family history and support networks are not explored during pregnancy. The Infant Feeding Genogram was adapted from a simple pictorial device that is widely used in psychotherapy and genetic counselling. This tool was developed as part of a study investigating the experience of women when they were the first to breastfeed in their family. Fourteen Scottish participants completed their Infant Feeding Genogram as part of a semi-structured interview. The tool was adapted alongside their narratives to give a visual representation of each participant's family infant feeding history. The utility of the genogram is illustrated through two contrasting case examples with very different family feeding histories. The genogram showed family structures, patterns of infant feeding over time, and supportive or conflicting relationships. In the research setting it assisted women to explore their infant feeding history, identify challenges and sources of support and build rapport with the interviewer. The infant feeding genogram is proposed as a time efficient tool that could assist health professionals and other breastfeeding workers to support women and their families and by stimulating discussion around breastfeeding, Bby identifying strengths or possible deficits in social support for each individual, the tool could inform tailored support and care interventions. The effectiveness and acceptability of the Infant Feeding Genogram requires testing in the clinical environment. However, its successful application in other clinical contexts, combined with the interest in genealogy in popular culture, mean this is likely to be an acceptable, family friendly way to develop more effective breastfeeding conversations.

VLBI2010 Feed Comparison

NASA Technical Reports Server (NTRS)

Petrachenko, Bill

2013-01-01

VLBI2010 requires a feed that simultaneously has high efficiency over the full 2.2-14 GHz frequency range. The simultaneity requirement implies that the feed must operate at high efficiency over the full frequency range without the need to adjust its focal position to account for frequency dependent phase centre variations. Two feeds meet this specification: The Eleven Feed developed at Chalmers University. (For more information, contact Miroslav Pantaleev, miroslav.pantaleev@chalmers.se. The Eleven Feed, integrated with LNA's in a cryogenic receiver, is available as a product from Omnisys Instruments, info@omnisys.se). The Quadruple Ridged Flared Horn (QRFH) developed at the California Institute of Technology. (For more information please contact Ahmed Akgiray, aakgiray@ieee.org or Sander Weinreb, sweinreb@caltech.edu) Although not VLBI2010 compliant, two triband S/X/Ka feeds are also being developed for the commissioning of VLBI2010 antennas, for S/X observations during the VLBI2010 transition period, and to support X/Ka CRF observations. The two feeds are: The Twin Telescopes Wettzell (TTW) triband feed developed by Mirad Microwave. (For more information please contact Gerhard Kronschnabl, Gerhard.Kronschnabl@bkg.bund.de) The RAEGE (Spain) triband feed developed at Yebes Observatory. (For more information please contact Jose Antonio Lopez Perez, ja.lopezperez@oan.es)

Plasma concentrations of acyl-ghrelin are associated with average daily gain and feeding behavior in grow-finish pigs

USDA-ARS?s Scientific Manuscript database

Feeding behavior is an important component of growth and feed efficiency in swine. Acyl-ghrelin is a peptide produced in the stomach that is orexigenic. The role of ghrelin in regulating feeding behavior in swine under commercial conditions is unknown. The objectives of this study were to determine ...

Using biochar in animal farming to recycle nutrients and reduce greenhouse gas emissions

NASA Astrophysics Data System (ADS)

Schmidt, Hans-Peter; Wilson, Kelpie; Kammann, Claudia

2017-04-01

Charcoal has been used to treat digestive disorder in animals since several thousand years. But only since about 2010 biochar has increasingly been used as regular feed additive in animal farming usually mixed with standard feed at approximately 1% of the daily feed intake. The use of biochar as feed additive has the potential to improve animal health, feed efficiency and the animal-stable environment; to reduce nutrient losses and GHG emissions; and to increase soil organic mater and thus soil fertility. The evaluation of more than 150 scientific papers on feeding (activated) biochar showed in most of the studies and for all investigated livestock species positive effects on parameters like toxin adsorption, digestion, blood values, feed use efficiency and livestock weight gain, meat quality and GHG emissions. The facilitation of direct electron transfers between different species of bacteria or microbial consortia via the biochar mediator in the animal digestion tract is hypothesized to be the main reason for a more energy efficient digestion and thus higher feed efficiency, for its selective probiotic effect, for reduced N-losses and eventually for less GHG emissions. While chicken, pigs, fish and other omnivore animals provoke GHG-emissions (mainly NH3, CH4, N2O) when their liquid and solid excretions decompose anaerobically, ruminants cause direct methane emissions through flatulence and burps (eructation). Preliminary studies demonstrated that feeding high temperature biochars might reduce ruminant CH4 emissions though more systematic research is needed. It is likely that microbial decomposition of manure containing digested biochar produces less ammonia, less methane and thus retain more nitrogen, as seen when manure was composted with and without biochar or when biochar is used as bedding or manure treatment additive. Laboratory adsorption trials estimated that using biochar for liquid manure treatment could safe 57,000 t NH4 and 4,600 t P2O5 fertilizer per year in California alone. It was further shown that feeding 0.3 to 1% biochar could replace antibiotic treatment in chicken and ducks, respectively. Feeding biochar could thus have an indirect effect on GHG emissions when it is able to replace regular antibiotic "feeding" that produces high indirect GHG emissions after soil application of antibiotic contaminated manure. Moreover, it was demonstrated that feeding biochar to grazing cows had positive secondary effects on soil fertility and fertilizer efficiency reducing mineral N-fertilizing requirements which could be another indirect biochar GHG mitigation effect. Considering an average C-content of fed biochar of 80% and produced at recommended temperatures above 500°C resulting in H/Corg ratios below 0.4, at least 56% of the dry weight of the fed and manure-applied biochar would persist as stable carbon in soil for at least 100 years. If the global livestock would receive 1% of their feed in form of such a biochar, a total of about 400 Mt of CO2eq or 1.2 % of the global CO2 emissions could be compensated. The apparent potential for improving animal health and nutrient efficiency, for reducing enteric methane emissions as well as GHG emissions from manure management and for sequestering carbon with soil fertility improvements makes it compelling to increase the scientific effort to investigate, measure and optimize the GHG reduction potential of biochar use in animal farming systems. The main results from literature and own experiments will be presented to illustrate and calculate this potential.

Effect of housing conditions (clean vs. dirty) on growth performance and feeding behavior in growing pigs in a tropical climate.

PubMed

Renaudeau, D

2009-04-01

The effect of bad sanitary conditions on growth performance and feeding behaviour were studied on a total of 48 Large White pigs between 95 and 130 d of age. This experiment carried out during the hot season in a tropical humid climate. Two groups of 12 pigs each were housed in a clean environment in which the pens were disinfected thoroughly prior to stocking and maintained in a clean state by daily washing the pens and by weekly emptying the manure stored beneath the partial concrete floor. The dirty environment was achieved by not cleaning the pens prior to stocking or throughout the experiment and by storing the manure beneath the floor slats throughout the experimental period. The microbial pressure was increased by introducing 5 additional non experimental pigs near each experimental dirty pen. Feeding behaviour parameters were measured using automatic feed dispensers. Pigs housed in a clean environment consumed more feed (2.283 vs. 1.953 kg/d; P < 0.001) and grew faster (871 vs. 780 g/d; P < 0.05) than those housed in the dirty environment. No significant effect on treatment was reported for the feed conversion efficiency (2.70 kg/kg on average). The reduced average daily feed intake in dirty pens was associated with a reduction of the meal size (334 vs. 282 g/meal; P = 0.10) whereas the meal frequency was not affected by treatment (7.5 meals/d on average). The rate of feed intake was significantly higher in the clean than in the dirty environment (34.0 vs. 29.9 g/min; P < 0.05).

Breast-feeding and Vitamin D Supplementation Rates in the Ochsner Health System

PubMed Central

Ponnapakkam, Tulasi; Ravichandran, Anisha; Bradford, Elease; Tobin, Gregory; Gensure, Robert

2008-01-01

Breast-feeding imparts many benefits to both mothers and infants. Because of these numerous recognized benefits, there has been an effort to increase breast-feeding rates nationwide; increasing breast-feeding rates was one of the goals of the U.S. Department of Health and Human Services' Healthy People 2010 initiative. This study examined the breast-feeding rate at the Ochsner Clinic Foundation by conducting a retrospective chart review of patients aged 0–12 months who visited any branch of the Ochsner hospital system. Our results indicate that the rate of initiation of breast-feeding for children followed at the Ochsner Clinic Foundation is 66.3%. However, as breast-feeding rates rise, there is concern that there may be a resurgence of rickets, a disease caused by the deficiency of vitamin D. Currently the American Academy of Pediatrics recommends that exclusively breast-fed infants receive vitamin D supplementation starting within the first 2 months of life. We have therefore initiated a clinical trial to determine whether vitamin D supplementation is required to prevent rickets in breast-fed children. In the course of conducting this study, we have gathered additional data regarding the patterns of breast-feeding and of vitamin D supplementation for babies born at Ochsner. PMID:21603467

Breast-feeding and Vitamin D Supplementation Rates in the Ochsner Health System.

PubMed

Ponnapakkam, Tulasi; Ravichandran, Anisha; Bradford, Elease; Tobin, Gregory; Gensure, Robert

2008-01-01

Breast-feeding imparts many benefits to both mothers and infants. Because of these numerous recognized benefits, there has been an effort to increase breast-feeding rates nationwide; increasing breast-feeding rates was one of the goals of the U.S. Department of Health and Human Services' Healthy People 2010 initiative. This study examined the breast-feeding rate at the Ochsner Clinic Foundation by conducting a retrospective chart review of patients aged 0-12 months who visited any branch of the Ochsner hospital system. Our results indicate that the rate of initiation of breast-feeding for children followed at the Ochsner Clinic Foundation is 66.3%. However, as breast-feeding rates rise, there is concern that there may be a resurgence of rickets, a disease caused by the deficiency of vitamin D. Currently the American Academy of Pediatrics recommends that exclusively breast-fed infants receive vitamin D supplementation starting within the first 2 months of life. We have therefore initiated a clinical trial to determine whether vitamin D supplementation is required to prevent rickets in breast-fed children. In the course of conducting this study, we have gathered additional data regarding the patterns of breast-feeding and of vitamin D supplementation for babies born at Ochsner.

A model of clearance rate regulation in mussels

NASA Astrophysics Data System (ADS)

Fréchette, Marcel

2012-10-01

Clearance rate regulation has been modelled as an instantaneous response to food availability, independent of the internal state of the animals. This view is incompatible with latent effects during ontogeny and phenotypic flexibility in clearance rate. Internal-state regulation of clearance rate is required to account for these patterns. Here I develop a model of internal-state based regulation of clearance rate. External factors such as suspended sediments are included in the model. To assess the relative merits of instantaneous regulation and internal-state regulation, I modelled blue mussel clearance rate and growth using a DEB model. In the usual standard feeding module, feeding is governed by a Holling's Type II response to food concentration. In the internal-state feeding module, gill ciliary activity and thus clearance rate are driven by internal reserve level. Factors such as suspended sediments were not included in the simulations. The two feeding modules were compared on the basis of their ability to capture the impact of latent effects, of environmental heterogeneity in food abundance and of physiological flexibility on clearance rate and individual growth. The Holling feeding module was unable to capture the effect of any of these sources of variability. In contrast, the internal-state feeding module did so without any modification or ad hoc calibration. Latent effects, however, appeared transient. With simple annual variability in temperature and food concentration, the relationship between clearance rate and food availability predicted by the internal-state feeding module was quite similar to that observed in Norwegian fjords. I conclude that in contrast with the usual Holling feeding module, internal-state regulation of clearance rate is consistent with well-documented growth and clearance rate patterns.

Breast-feeding patterns in Central Israel.

PubMed

Berger-Achituv, Sivan; Shohat, Tamar; Garty, Ben-Zion

2005-08-01

The rate of breast-feeding in Israel has increased over the last two decades but is still lower than rates in other developed countries that have taken an active role in promoting breast-feeding. To determine breast-feeding patterns and the association between sociodemographic characteristics and breast-feeding in the Tel Aviv district. The mothers of infants aged 2, 4, 6 and 12 months, attending 59 well-baby clinics in the Tel Aviv district, were interviewed by telephone. Singleton infants who weighed less than 2,000 g and multiple-gestation infants were excluded from the study. The questions covered background data, sociodemographic characteristics of the family, and breast-feeding practices. Stepwise logistic regression was used to analyze the association between breast-feeding and various sociodemographic characteristics. Altogether, 78.5% of the mothers (1,307/1,665) initiated breast-feeding. The rate of breast-feeding at 2, 4, 6 and 12 months was 55.8, 36.8, 29.9 and 11.8%, respectively. Only 35.8% of the infants at 2 months and 11.2% at 6 months were exclusively breast-fed. The mean duration of breast-feeding was 5.2 +/- 0.2 months. Grand multiparas (> or = 5 children) had a significantly higher rate of breast-feeding than women with one to four children (P < 0.001). More likely to breast-feed for 2 weeks or longer were women married to Yeshiva students (odds ratio = 5.3), women with > or = 13 years education (OR = 2.1), and women on maternity leave (OR = 1.6). The predictors for breast-feeding for 6 months or longer were similar. Although the rate of breast-feeding initiation in central Israel was 78.5%, only 29.9% of the mothers continue to breast-feed for 6 months. Already at a young age, an appreciable number of breast-fed infants receive infant formula. Breast-feeding promotion should focus on less educated women, homemakers, and families with one to four children.

Costs of Promoting Exclusive Breastfeeding at Community Level in Three Sites in South Africa

PubMed Central

Nkonki, Lungiswa Leonora; Daviaud, Emmanuelle; Jackson, Debra; Chola, Lumbwe; Doherty, Tanya; Chopra, Mickey; Robberstad, Bjarne

2014-01-01

Background Community-based peer support has been shown to be effective in improving exclusive breastfeeding rates in a variety of settings. Methods We conducted a cost analysis of a community cluster randomised-controlled trial (Promise-EBF), aimed at promoting exclusive infant feeding in three sites in South Africa. The costs were considered from the perspective of health service providers. Peer supporters in this trial visited women to support exclusive infant feeding, once antenatally and four times postpartum. Results The total economic cost of the Promise-EBF intervention was US$393 656, with average costs per woman and per visit of US$228 and US$52, respectively. The average costs per woman and visit in an operational ‘non research’ scenario were US$137 and US$32 per woman and visit, respectively. Investing in the promotion of exclusive infant feeding requires substantial financial commitment from policy makers. Extending the tasks of multi-skilled community health workers (CHWs) to include promoting exclusive infant feeding is a potential option for reducing these costs. In order to avoid efficiency losses, we recommend that the time requirements for delivering the promotion of exclusive infant feeding are considered when integrating it within the existing activities of CHWs. Discussion This paper focuses on interventions for exclusive infant feeding, but its findings more generally illustrate the importance of documenting and quantifying factors that affect the feasibility and sustainability of community-based interventions, which are receiving increased focus in low income settings. PMID:24427264

Session 1: Public health nutrition. Breast-feeding practices in Ireland.

PubMed

Tarrant, Roslyn C; Kearney, John M

2008-11-01

Breast-feeding is the superior infant feeding method from birth, with research consistently demonstrating its numerous short- and long-term health benefits for both mother and infant. As a global recommendation the WHO advises that mothers should exclusively breast-feed for the first 6-months of life, thus delaying the introduction of solids during this time. Historically, Irish breast-feeding initiation rates have remained strikingly low in comparison with international data and there has been little improvement in breast-feeding duration rates. There is wide geographical variation in terms of breast-feeding initiation both internationally and in Ireland. Some of these differences in breast-feeding rates may be associated with differing socio-economic characteristics. A recent cross-sectional prospective study of 561 pregnant women attending a Dublin hospital and followed from the antenatal period to 6 months post partum has found that 47% of the Irish-national mothers initiated breast-feeding, while only 24% were still offering 'any' breast milk to their infants at 6 weeks. Mothers' positive antenatal feeding intention to breast-feed is indicated as one of the most important independent determinants of initiation and 'any' breast-feeding at 6 weeks, suggesting that the antenatal period should be targeted as an effective time to influence and affect mothers' attitudes and beliefs pertaining to breast-feeding. These results suggest that the 'cultural' barrier towards breast-feeding appears to still prevail in Ireland and consequently an environment that enables women to breast-feed is far from being achieved. Undoubtedly, a shift towards a more positive and accepting breast-feeding culture is required if national breast-feeding rates are to improve.

The relation between child feeding problems as measured by parental report and mealtime behavior observation: A pilot study.

PubMed

van Dijk, Marijn; Bruinsma, Eke; Hauser, M Paulina

2016-04-01

Because feeding problems have clear negative consequences for both child and caretakers, early diagnosis and intervention are important. Parent-report questionnaires can contribute to early identification, because they are efficient and typically offer a 'holistic' perspective of the child's eating in different contexts. In this pilot study, we aim to explore the concurrent validity of a short screening instrument (the SEP, which is the Dutch MCH-FS) in one of its target populations (a group of premature children) by comparing the total score with the observed behavior of the child and caretaker during a regular home meal. 28 toddlers (aged 9-18 months) and their caretakers participated in the study. Video-observations of the meals were coded for categories of eating behavior and parent-child interaction. The results show that the total SEP-score correlates with food refusal, feeding efficiency, and self-feeding, but not with negative affect and parental instructions. This confirms that the SEP has a certain degree of concurrent validity in the sense that its total score is associated with specific 'benchmark' feeding behaviors: food refusal, feeding efficiency and autonomy. Future studies with larger samples are needed to generalize the findings from this pilot to a broader context. Copyright © 2016 Elsevier Ltd. All rights reserved.

Digestion, growth and reproductive performance of the zoophytophagous rove beetle Philonthus quisquiliarius (Coleoptera: Staphylinidae) fed on animal and plant based diets.

PubMed

García, Matías; Farinós, Gema P; Castañera, Pedro; Ortego, Félix

2012-10-01

The zoophytophagous feeding habits of larvae and adults of the rove beetle, Philonthus quisquiliarius (Gyllenhal) (Coleoptera: Staphylinidae), are reported for the first time. This study evaluates the effects of different feeding regimes on its growth and reproductive performance (i.e., larval growth, adult weight gain, consumption, fecundity and fertility) and digestive physiology. Larvae presented similar growth rates when fed on living animal or on green plant material for 48 h. However, higher consumption rates and lower efficiencies of conversion of digested matter to body mass were obtained when leaves were consumed. Adults presented also positive weight gains regardless of the food consumed (plant or animal material). Interestingly, the highest weight gain rate and efficiency of digestion resulted when adults fed on a rearing diet containing nutrients from both animals and plants. Moreover, we have found negative effects upon P. quisquiliarius fecundity and fertility when supplemental plant nutrients were removed from the optimum rearing diet. Physiological adaptations to allow trophic switching between predation and phytophagy have been found, such as the higher ratio of α-amylase activity to protease activity to deal with the inverted protein-carbohydrate ratio of plant versus animal tissues. Furthermore, this species has an arsenal of digestive proteases whose activity is affected by the type of diet ingested. All together, our results suggest that P. quisquiliarius needs certain nutrients, which are obtained only from plant material. This knowledge will help to understand the complex trophic interactions that occur in agroecosystems. Copyright © 2012 Elsevier Ltd. All rights reserved.

Effects of dietary cholesterol supplementation on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal or rapeseed meal.

PubMed

Deng, Junming; Zhang, Xi; Long, Xiaowen; Tao, Linli; Wang, Zhen; Niu, Guoyi; Kang, Bin

2014-12-01

This study was conducted to evaluate the effects of cholesterol on growth and cholesterol metabolism of rainbow trout (Oncorhynchus mykiss) fed diets with cottonseed meal (CSM) or rapeseed meal (RSM). Four experimental diets were formulated to contain 550 g kg(-1) CSM or 450 g kg(-1) RSM with or without 9 g kg(-1) supplemental cholesterol. Growth rate and feed utilization efficiency of fish fed diets with 450 g kg(-1) RSM were inferior to fish fed diets with 550 g kg(-1) CSM regardless of cholesterol level. Dietary cholesterol supplementation increased the growth rate of fish fed diets with RSM, and growth rate and feed utilization efficiency of fish fed diets with CSM. Similarly, dietary cholesterol supplementation increased the plasma total cholesterol (TC), high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, and triiodothyronine levels, but decreased the plasma triglycerides and cortisol levels of fish fed diets with RSM or CSM. In addition, supplemental cholesterol increased the free cholesterol and TC levels in intestinal contents, but decreased the hepatic 3-hydroxy-3-methyl-glutaryl-CoA reductase activity of fish fed diets with RSM or CSM. These results indicate that 9 g kg(-1) cholesterol supplementation seems to improve the growth of rainbow trout fed diets with CSM or RSM, and the growth-promoting action may be related to the alleviation of the negative effects caused by antinutritional factors and/or make up for the deficiency of endogenous cholesterol in rainbow trout.

Contrary seasonal changes of rates of nutrient uptake, organ mass, and voluntary food intake in red deer (Cervus elaphus)

PubMed Central

Beiglböck, Christoph; Burmester, Marion; Guschlbauer, Maria; Lengauer, Astrid; Schröder, Bernd; Wilkens, Mirja; Breves, Gerhard

2015-01-01

Northern ungulates acclimatize to winter conditions with restricted food supply and unfavorable weather conditions by reducing energy expenditure and voluntary food intake. We investigated in a study on red deer whether rates of peptide and glucose transport in the small intestines are also reduced during winter as part of the thrifty phenotype of winter-acclimatized animals, or whether transport rates are increased during winter in order to exploit poor forage more efficiently. Our results support the latter hypothesis. We found in a feeding experiment that total energy intake was considerably lower during winter despite ad libitum feeding. Together with reduced food intake, mass of visceral organs was significantly lower and body fat reserves were used as metabolic fuel in addition to food. However, efficacy of nutrient absorption seemed to be increased simultaneously. Extraction of crude protein from forage was higher in winter animals, at any level of crude protein intake, as indicated by the lower concentration of crude protein in feces. In line with these in vivo results, Ussing chamber experiments revealed greater electrogenic responses to both peptides and glucose in the small intestines of winter-acclimatized animals, and peptide uptake into jejunal brush-border membrane vesicles was increased. We conclude that reduced appetite of red deer during winter avoids energy expenditure for unproductive search of scarcely available food and further renders the energetically costly maintenance of a large gut and visceral organs unnecessary. Nevertheless, extraction of nutrients from forage is more efficient in the winter to attenuate an inevitably negative energy balance. PMID:26017492

Digesta passage rates in the Florida manatee (Trichechus manatus latirostris).

PubMed

Larkin, Iskande L V; Fowler, Vivienne F; Reep, Roger L

2007-11-01

The Florida manatee, Trichechus manatus latirostris (Sirenia: Trichechidae), is an herbivorous marine mammal found within coastal areas throughout the state of Florida, which feeds on both fresh and salt water sea grasses. Manatees, like other Sirenians, are a tropical species with little tolerance for water temperatures below 20 degrees C, rely on a relatively poor nutritional food source, and have a low metabolic rate. Although manatees are hindgut fermenting herbivores, they are very efficient at extracting nutrients from the plants on which they feed. Slow passage rates of digesta have been suggested to be a factor in this increased efficiency. Two studies monitored the digesta passage times and mixing of particulate digesta within the manatee digestive tract using MicroGrits colored corncob grit as a fecal marker. Fecal samples were collected subsequently from four manatees in Study 1 and 3 manatees in Study 2, grit pieces removed, counted, and measured. The digesta passage times ranged from 6 and 10 days in Study 1, and 4.3 and 8.3 days in Study 2, supporting data presented in previous studies. When two different colored markers were administered on sequential days, minimal to no mixing was seen in recovered feces, suggesting that the digesta from a given day traveled through the tract as a bolus. Less than 1% of the marker fed was recovered and we hypothesize that perpendicular folds of the large intestine may be the major contributing factor, with pieces being retained and eventually digested. Zoo Biol 26:503-515, 2007. (c) 2007 Wiley-Liss, Inc.

Sulfide catalysts for reducing SO2 to elemental sulfur

DOEpatents

Jin, Yun; Yu, Qiquan; Chang, Shih-Ger

2001-01-01

A highly efficient sulfide catalyst for reducing sulfur dioxide to elemental sulfur, which maximizes the selectivity of elemental sulfur over byproducts and has a high conversion efficiency. Various feed stream contaminants, such as water vapor are well tolerated. Additionally, hydrogen, carbon monoxide, or hydrogen sulfides can be employed as the reducing gases while maintaining high conversion efficiency. This allows a much wider range of uses and higher level of feed stream contaminants than prior art catalysts.

Effects of milk flow on the physiological and behavioural responses to feeding in an infant with hypoplastic left heart syndrome.

PubMed

Pados, Britt F; Thoyre, Suzanne M; Estrem, Hayley H; Park, Jinhee; Knafl, George J; Nix, Brant

2017-01-01

Infants with hypoplastic left heart syndrome often experience difficulty with oral feeding, which contributes to growth failure, morbidity, and mortality. In response to feeding difficulty, clinicians often change the bottle nipple, and thus milk flow rate. Slow-flow nipples have been found to reduce the stress of feeding in other fragile infants, but no research has evaluated the responses of infants with hypoplastic left heart syndrome to alterations in milk flow. The purpose of this study was to evaluate the physiological and behavioural responses of an infant with hypoplastic left heart syndrome to bottle feeding with either a slow-flow (Dr. Brown's Preemie) or a standard-flow (Dr. Brown's Level 2) nipple. A single infant was studied for three feedings: two slow-flow and one standard-flow. Oral feeding, whether with a slow-flow or a standard-flow nipple, was distressing for this infant. During slow-flow feeding, she experienced more coughing events, whereas during standard-flow she experienced more gagging. Disengagement and compelling disorganisation were most common during feeding 3, that is slow-flow, which occurred 2 days after surgical placement of a gastrostomy tube. Clinically significant changes in heart rate, oxygen saturation, and respiratory rate were seen during all feedings. Heart rate was higher during standard-flow and respiratory rate was higher during slow-flow. Further research is needed to examine the responses of infants with hypoplastic left heart syndrome to oral feeding and to identify strategies that will support these fragile infants as they learn to feed. Future research should evaluate an even slower-flow nipple along with additional supportive feeding strategies.

40 CFR 63.453 - Monitoring requirements.

Code of Federal Regulations, 2014 CFR

2014-07-01

... process wastewater feed rate; (2) The steam feed rate; and (3) The process wastewater column feed...: (A) Composite daily sample of outlet soluble BOD5 concentration to monitor for maximum daily and...

40 CFR 63.453 - Monitoring requirements.

Code of Federal Regulations, 2012 CFR

2012-07-01

... process wastewater feed rate; (2) The steam feed rate; and (3) The process wastewater column feed...: (A) Composite daily sample of outlet soluble BOD5 concentration to monitor for maximum daily and...

40 CFR 63.453 - Monitoring requirements.

Code of Federal Regulations, 2013 CFR

2013-07-01

... process wastewater feed rate; (2) The steam feed rate; and (3) The process wastewater column feed...: (A) Composite daily sample of outlet soluble BOD5 concentration to monitor for maximum daily and...

The effect of dietary garlic supplementation on body weight gain, feed intake, feed conversion efficiency, faecal score, faecal coliform count and feeding cost in crossbred dairy calves.

PubMed

Ghosh, Sudipta; Mehla, Ram K; Sirohi, S K; Roy, Biswajit

2010-06-01

Thirty-six crossbred calves (Holstein cross) of 5 days of age were used to study the effect of garlic extract feeding on their performance up to the age of 2 months (pre-ruminant stage). They were randomly allotted into treatment and control groups (18 numbers in each group). Performance was evaluated by measuring average body weight (BW) gain, feed intake (dry matter (DM), total digestible nutrient (TDN) and crude protein (CP)), feed conversion efficiency (FCE; DM, TDN and CP), faecal score, faecal coliform count and feeding cost. Diets were the same for the both groups. In addition, treatment group received garlic extract supplementation at 250 mg/kg BW per day per calf. Body weight measured weekly, feed intake measured twice daily, proximate analysis of feeds and fodders analysed weekly, faecal scores monitored daily and faecal coliform count done weekly. There was significant increase in average body weight gain, feed intake and FCE and significant decrease in severity of scours as measured by faecal score and faecal coliform count in the treatment group compared to the control group (P < 0.01). Feed cost per kilogramme BW gain was significantly lower in the treatment group compared to control group (P < 0.01). The results suggest that garlic extract can be supplemented to the calves for better performance.

In-vitro analysis of forces in conventional and ultrasonically assisted drilling of bone.

PubMed

Alam, K; Hassan, Edris; Imran, Syed Husain; Khan, Mushtaq

2016-05-12

Drilling of bone is widely performed in orthopaedics for repair and reconstruction of bone. Current paper is focused on the efforts to minimize force generation during the drilling process. Ultrasonically Assisted Drilling (UAD) is a possible option to replace Conventional Drilling (CD) in bone surgical procedures. The purpose of this study was to investigate and analyze the effect of drilling parameters and ultrasonic parameters on the level of drilling thrust force in the presence of water irrigation. Drilling tests were performed on young bovine femoral bone using different parameters such as spindle speeds, feed rates, coolant flow rates, frequency and amplitudes of vibrations. The drilling force was significantly dropped with increase in drill rotation speed in both types of drilling. Increase in feed rate was more influential in raising the drilling force in CD compared to UAD. The force was significantly dropped when ultrasonic vibrations up to 10 kHz were imposed on the drill. The drill force was found to be unaffected by the range of amplitudes and the amount of water supplied to the drilling region in UAD. Low frequency vibrations with irrigation can be successfully used for safe and efficient drilling in bone.

Part height control of laser metal additive manufacturing process

NASA Astrophysics Data System (ADS)

Pan, Yu-Herng

Laser Metal Deposition (LMD) has been used to not only make but also repair damaged parts in a layer-by-layer fashion. Parts made in this manner may produce less waste than those made through conventional machining processes. However, a common issue of LMD involves controlling the deposition's layer thickness. Accuracy is important, and as it increases, both the time required to produce the part and the material wasted during the material removal process (e.g., milling, lathe) decrease. The deposition rate is affected by multiple parameters, such as the powder feed rate, laser input power, axis feed rate, material type, and part design, the values of each of which may change during the LMD process. Using a mathematical model to build a generic equation that predicts the deposition's layer thickness is difficult due to these complex parameters. In this thesis, we propose a simple method that utilizes a single device. This device uses a pyrometer to monitor the current build height, thereby allowing the layer thickness to be controlled during the LMD process. This method also helps the LMD system to build parts even with complex parameters and to increase material efficiency.

Intra-plant differences in seaweed nutritional quality and chemical defenses: Importance for the feeding behavior of the intertidal amphipod Orchestoidea tuberculata

NASA Astrophysics Data System (ADS)

Duarte, Cristian; Acuña, Karin; Navarro, Jorge M.; Gómez, Iván

2011-10-01

As a result of their morphological complexity, large macroalgae show intra-thallus variations in their nutritional composition and secondary metabolite content, which influences the trophic ecology of herbivorous invertebrates, and ultimately their fitness. In this study, we evaluated for the first time the variability in nutritional quality (protein content, carbohydrates, lipids, and total organic matter), secondary metabolites (phlorotannins), and structure (shape and toughness) between blades and stipes of the macroalgae Durvillaea Antarctica. Specifically, we looked at their effect on feeding preference, rate of consumption, absorption efficiency, and growth rate of the amphipod Orchestoidea tuberculata, one of the most abundant organisms on Chilean sandy beaches. Proteins, carbohydrates, total organic matter and phlorotannin contents were significantly higher in blades than in stipes. Preference experiments revealed that the amphipods preferred blades when fresh pieces of blades and stipes were offered at the same time. Similar results were found when artificial food (in which structures of both parts of the alga were standardized) was offered, suggesting that shape and toughness of the two different parts of the alga did not influence preference patterns of O. tuberculata. Absorption efficiency of O. tuberculata was higher on blades compared to stipes. When the amphipods were kept with each of the algal parts separately (i.e. no choice), they consumed a significantly higher amount of stipe, which suggests that O. tuberculata used food quantity to compensate for the lower nutritional quality of stipes. The higher nutritional values of blades compared to stipes appears to explain observed preference patterns by O. tuberculata. Phlorotannin content did not appear to inhibit blade consumption, suggesting that the nutritional quality of the food could be more important than chemical defense in determining food choice in O. tuberculata. Growth did not differ between the amphipods maintained with either blades or stipes (i.e. no choice), which is consistent with the hypothesis of compensatory feeding. To conclude, O. tuberculata can actively select specific parts of an alga and this selection appears to be based on nutritional quality. The capacity for using different feeding strategies allow O. tuberculata, in some cases, to successfully exploit food types with different nutritional qualities.

Growth performance and feed conversion efficiency of three edible mealworm species (Coleoptera: Tenebrionidae) on diets composed of organic by-products.

PubMed

van Broekhoven, Sarah; Oonincx, Dennis G A B; van Huis, Arnold; van Loon, Joop J A

2015-02-01

Insects receive increasing attention as an alternative protein-rich food source for humans. Producing edible insects on diets composed of organic by-products could increase sustainability. In addition, insect growth rate and body composition, and hence nutritional quality, can be altered by diet. Three edible mealworm species Tenebrio molitor L., Zophobas atratus Fab. and Alphitobius diaperinus Panzer were grown on diets composed of organic by-products originating from beer brewing, bread/cookie baking, potato processing and bioethanol production. Experimental diets differed with respect to protein and starch content. Larval growth and survival was monitored. Moreover, effects of dietary composition on feed conversion efficiency and mealworm crude protein and fatty acid profile were assessed. Diet affected mealworm development and feed conversion efficiency such that diets high in yeast-derived protein appear favourable, compared to diets used by commercial breeders, with respect to shortening larval development time, reducing mortality and increasing weight gain. Diet also affected the chemical composition of mealworms. Larval protein content was stable on diets that differed 2-3-fold in protein content, whereas dietary fat did have an effect on larval fat content and fatty acid profile. However, larval fatty acid profile did not necessarily follow the same trend as dietary fatty acid composition. Diets that allowed for fast larval growth and low mortality in this study led to a comparable or less favourable n6/n3 fatty acid ratio compared to control diets used by commercial breeders. In conclusion, the mealworm species used in this study can be grown successfully on diets composed of organic by-products. Diet composition did not influence larval protein content, but did alter larval fat composition to a certain extent. Copyright © 2015 Elsevier Ltd. All rights reserved.

The effect of qat chewing and other factors on breast-feeding and child survival in a Yemeni society

PubMed Central

Mansoub, Mohammed Al; Omer, Rahab; Omer, Rasha; Shadli, Muna; Williams, Rachael

2011-01-01

In a survey conducted in Dammar, Republic of Yemen, 755 mothers were interviewed to investigate the patterns and factors affecting childhood feeding practices. It was found that full breast-feeding rate (41.8%) and timely introduction of complementary feeding rate (57.4%) were low, bottle-feeding rate (25.1%) was high and timely first suckling rate was zero. It was also found that the more educated and older mothers tended to wean their children earlier than illiterate and younger mothers. A significant association between regular frequent qat chewing and history of child death was observed. The implications of these findings were discussed. PMID:27493314

The effect of qat chewing and other factors on breast-feeding and child survival in a Yemeni society.

PubMed

Ibrahim Ali Omer, Mohammed; Mansoub, Mohammed Al; Omer, Rahab; Omer, Rasha; Shadli, Muna; Williams, Rachael

2011-01-01

In a survey conducted in Dammar, Republic of Yemen, 755 mothers were interviewed to investigate the patterns and factors affecting childhood feeding practices. It was found that full breast-feeding rate (41.8%) and timely introduction of complementary feeding rate (57.4%) were low, bottle-feeding rate (25.1%) was high and timely first suckling rate was zero. It was also found that the more educated and older mothers tended to wean their children earlier than illiterate and younger mothers. A significant association between regular frequent qat chewing and history of child death was observed. The implications of these findings were discussed.

Differential expression of feeding-related hypothalamic neuropeptides in the first generation of quails divergently selected for low or high feed efficiency.

PubMed

Blankenship, Kaley; Gilley, Alex; Piekarski, Alissa; Orlowski, Sara; Greene, Elizabeth; Bottje, Walter; Anthony, Nicholas; Dridi, Sami

2016-08-01

Livestock and poultry sectors are facing a combination of challenges, including a substantial increase in global demand for high quality animal protein, general droughts and steady rise in animal feed cost. Thus feed efficiency (FE), which defines the animal's ability to convert feed into body weight, is a vital economic and agricultural trait. Genetic selection for FE has been largely used in chickens and has been applied without knowledge of the underlying molecular mechanisms. Although it has made tremendous progress (breast yield, growth rate, egg production), there have been a number of undesirable changes such as metabolic disorders. In the present study we divergently selected male and female quail for high and low FE and we aimed to characterize the molecular basis of these differences at the central level, with the long-term goal of maximizing FE and avoiding the unfavorable consequences. The FE phenotype in first generation quails seemed to be achieved by reduced feed intake in female and increased body weight gain in males. At the molecular level, we found that the expression of feeding-related hypothalamic genes is gender- and line-dependent. Indeed, the expression of NPY, POMC, CART, CRH, melanocortin system (MC1R, MC2R, MC4R, MC5R), ORX, mTOR and ACCα was significantly decreased, however ORXR1/2, AMPKα1, S6K1 and STAT1, 5 and 6 were increased in high compared to low FE males (P<0.05). These genes did not differ between the two female lines. ADPN gene expression was higher and its receptor Adip-R1 was lower in LFE compared to HFE females (P<0.05). In male however, although there was no difference in ADPN gene expression between the genotypes, Adip-R1 and Adip-R2 mRNA abundances were higher in the LFE compared to HFE line (P<0.05). This study identified several key central feeding-related genes that are differentially expressed between low and high FE male and female quails which might explain the differences in feed intake/body weight gain observed between the two lines. Of particular interest, we provided novel insights into central AMPK-mTOR-ACC transcriptional differences between low and high FE quail which may open new research avenues on their roles in the regulation of energy balance and FE in poultry and livestock species. Copyright © 2015 Elsevier Ltd. All rights reserved.

Association of residual feed intake with abundance of ruminal bacteria and biopolymer hydrolyzing enzyme activities during the peripartal period and early lactation in Holstein dairy cows.

PubMed

Elolimy, Ahmed A; Arroyo, José M; Batistel, Fernanda; Iakiviak, Michael A; Loor, Juan J

2018-01-01

Residual feed intake (RFI) in dairy cattle typically calculated at peak lactation is a measure of feed efficiency independent of milk production level. The objective of this study was to evaluate differences in ruminal bacteria, biopolymer hydrolyzing enzyme activities, and overall performance between the most- and the least-efficient dairy cows during the peripartal period. Twenty multiparous Holstein dairy cows with daily ad libitum access to a total mixed ration from d - 10 to d 60 relative to the calving date were used. Cows were classified into most-efficient (i.e. with low RFI, n  = 10) and least-efficient (i.e. with high RFI, n  = 10) based on a linear regression model involving dry matter intake (DMI), fat-corrected milk (FCM), changes in body weight (BW), and metabolic BW. The most-efficient cows had ~ 2.6 kg/d lower DMI at wk 4, 6, 7, and 8 compared with the least-efficient cows. In addition, the most-efficient cows had greater relative abundance of total ruminal bacterial community during the peripartal period. Compared with the least-efficient cows, the most-efficient cows had 4-fold greater relative abundance of Succinivibrio dextrinosolvens at d - 10 and d 10 around parturition and tended to have greater abundance of Fibrobacter succinogenes and Megaspheara elsdenii . In contrast, the relative abundance of Butyrivibrio proteoclasticus and Streptococcus bovis was lower and Succinimonas amylolytica and Prevotella bryantii tended to be lower in the most-efficient cows around calving. During the peripartal period, the most-efficient cows had lower enzymatic activities of cellulase, amylase, and protease compared with the least-efficient cows. The results suggest that shifts in ruminal bacteria and digestive enzyme activities during the peripartal period could, at least in part, be part of the mechanism associated with better feed efficiency in dairy cows.

Breast-feeding patterns and factors determining exclusive breast-feeding.

PubMed

Koosha, A; Hashemifesharaki, R; Mousavinasab, N

2008-12-01

Breast-feeding is a major determinant of infants' health and survival. The aim of this study was to examine breast-feeding patterns and the role of some factors on exclusive breast-feeding. The study was done at the Health Centre of Community Oriented Medical Education of Zanjan City, Iran. Mothers of 650 infants younger than one year of age were interviewed directly by healthcare providers. The necessary information was recorded on pre-structured questionnaires, and the feeding patterns of all infants were determined. The rate of breast-feeding was greater than 92 percent during the first year of life. Exclusive breast-feeding rate in the first five days of life was 82 percent, but it declined to 44 percent at the first month. The chance of exclusive breast-feeding was higher in infants who were on demand feeding (odds ratio [OR] 2.6), breastfed more than eight times per day (OR 2.23), and their birth weight ranged from 2.5 to 4 kg (OR 2.16). This chance was less among infants exposed to pacifiers (OR 2.62) and with the numbers of deliveries equal to or more than three (OR 2.25). The rates of breast-feeding initiation and its duration at six and 12 months were higher than the national goal. The rate of exclusive breast-feeding was nearly 44 percent. It seems necessary to elucidate the role of other factors, such as socioeconomic status, on exclusive breast-feeding.

Successful selection of rainbow trout (Oncorhynchus mykiss) on their ability to grow with a diet completely devoid of fishmeal and fish oil, and correlated changes in nutritional traits.

PubMed

Callet, Thérèse; Médale, Françoise; Larroquet, Laurence; Surget, Anne; Aguirre, Pierre; Kerneis, Thierry; Labbé, Laurent; Quillet, Edwige; Geurden, Inge; Skiba-Cassy, Sandrine; Dupont-Nivet, Mathilde

2017-01-01

In the context of limited marine resources, the exponential growth of aquaculture requires the substitution of fish oil and fishmeal, the traditional components of fish feeds by terrestrial plant ingredients. High levels of such substitution are known to negatively impact fish performance such as growth and survival in rainbow trout (Oncorhynchus mykiss) as in other salmonids. In this respect, genetic selection is a key enabler for improving those performances and hence for the further sustainable development of aquaculture. We selected a rainbow trout line over three generations for its ability to survive and grow on a 100% plant-based diet devoid of both fish oil and fishmeal (V diet) from the very first meal. In the present study, we compared the control line and the selected line after 3 generations of selection, both fed either the V diet or a marine resources-based diet (M diet). The objective of the study was to assess the efficiency of selection and the consequences on various correlated nutritional traits: feed intake, feed efficiency, digestibility, composition of whole fish, nutrient retention and fatty acid (FA) profile. We demonstrated that the genetic variability present in our rainbow trout population can be selected to improve survival and growth. The major result of the study is that after only three generations of selection, selected fish fed the V diet grew at the same rate as the control line fed the M diet, whilst the relative reduction of body weight was 36.8% before the selection. This enhanced performance on the V diet seems to be mostly linked to a higher feed intake for the selected fish.

Successful selection of rainbow trout (Oncorhynchus mykiss) on their ability to grow with a diet completely devoid of fishmeal and fish oil, and correlated changes in nutritional traits

PubMed Central

Médale, Françoise; Larroquet, Laurence; Surget, Anne; Aguirre, Pierre; Kerneis, Thierry; Labbé, Laurent; Quillet, Edwige; Geurden, Inge; Skiba-Cassy, Sandrine; Dupont-Nivet, Mathilde

2017-01-01

In the context of limited marine resources, the exponential growth of aquaculture requires the substitution of fish oil and fishmeal, the traditional components of fish feeds by terrestrial plant ingredients. High levels of such substitution are known to negatively impact fish performance such as growth and survival in rainbow trout (Oncorhynchus mykiss) as in other salmonids. In this respect, genetic selection is a key enabler for improving those performances and hence for the further sustainable development of aquaculture. We selected a rainbow trout line over three generations for its ability to survive and grow on a 100% plant-based diet devoid of both fish oil and fishmeal (V diet) from the very first meal. In the present study, we compared the control line and the selected line after 3 generations of selection, both fed either the V diet or a marine resources-based diet (M diet). The objective of the study was to assess the efficiency of selection and the consequences on various correlated nutritional traits: feed intake, feed efficiency, digestibility, composition of whole fish, nutrient retention and fatty acid (FA) profile. We demonstrated that the genetic variability present in our rainbow trout population can be selected to improve survival and growth. The major result of the study is that after only three generations of selection, selected fish fed the V diet grew at the same rate as the control line fed the M diet, whilst the relative reduction of body weight was 36.8% before the selection. This enhanced performance on the V diet seems to be mostly linked to a higher feed intake for the selected fish. PMID:29059226

Effect of milk replacer and concentrate intake on growth rate, feeding behaviour and systemic metabolite concentrations of pre-weaned bull calves of two dairy breeds.

PubMed

Byrne, C J; Fair, S; English, A M; Johnston, D; Lonergan, P; Kenny, D A

2017-09-01

Early-life nutrition affects calf development and thus subsequent performance. The aim of this study was to examine the effect plane of nutrition on growth, feeding behaviour and systemic metabolite concentrations of artificially reared dairy bull calves. Holstein-Friesian (F; n=42) and Jersey (J; n=25) bull calves with a mean±SD age (14±4.7 v. 27±7.2 days) and BW (47±5.5 v. 33±4.7 kg) were offered a high, medium or low plane of nutrition for 8 weeks using an electronic feeding system which recorded a range of feed-related events. Calves were weighed weekly and plasma samples were collected via jugular venipuncture on weeks 1, 4 and 7 relative to the start of the trial period. The calves offered a high plane of nutrition had the greatest growth rate. However, the increased consumption of milk replacer led to a reduction in feed efficiency. Holstein-Friesian calves offered a low plane of nutrition had the greatest number of daily unrewarded visits to the feeder (P<0.001). β-hydroxybutyrate (BHB) concentrations were greater in F calves on a low plane of nutrition (P<0.001). Although there was no effect of plane of nutrition, BHB concentrations in F calves increased before weaning, concomitant with an increase in concentrate consumption. Urea concentrations were unaffected by plane of nutrition within either breed. Jersey calves on a low plane of nutrition tended to have lower triglycerides than those on a high plane (P=0.08), but greater than those on a medium plane (P=0.08). Holstein-Friesian calves offered a high plane of nutrition tended to have greater triglyceride concentrations than those on a medium plane (P=0.08). Triglycerides increased from the start to the end of the feeding period (P<0.05), across both breeds. A medium plane of nutrition resulted in a growth, feeding behaviour and metabolic response comparable with a high plane of nutrition in pre-weaned bull calves of both F and J breeds.

The value of creep feeding during the last 84, 56, or 28 days prior to weaning on growth performance of nursing calves grazing endophyte-infected tall fescue.

PubMed

Tarr, S L; Faulkner, D B; Buskirk, D D; Ireland, F A; Parrett, D F; Berger, L L

1994-05-01

To evaluate limiting the number of days that calves are creep fed, 84 crossbred cows (frame score 4) nursing steer calves were randomly assigned to three replicates over 2 yr to receive one of four lengths of creep feeding (0, 28, 56, or 84 d) for cows and calves grazing endophyte-infected tall fescue. There were no differences in cow performance due to treatments. Calf daily gain increased (P < .001) as the length of time exposed to creep increased. In yr 1, creep intake increased (P < .05) as the length to time exposed to creep increased. In yr 2, there was no difference in intake by period among 28-, 56-, and 84-d treatments. Supplemental feed efficiency was best for 56 and 84 d, and the 28-d treatment was extremely poor. During the feedlot phase, there were differences in performance between the 2 yr and there were no differences in carcass composition due to length of time receiving creep feed. Overall, creep feeding calves for 56 or 84 d improved performance, and the 56-d calves had the most efficient gain. Creep feeding calves for 28 d showed no advantage during the creep feeding period or in the feedlot. Four ruminally fistulated nursing steer calves were used in a 4 x 4 Latin square design to receive treatments of forage alone or .68 kg, 1.13 kg, or 2.27 kg/d of creep plus high-quality, freshly harvested forage available on an ad libitum basis. Forage OM intake and NDF digestibility tended (P = .11) to decrease as intake of creep feed increased. The pH decreased (P < .001), molar proportion of propionate tended to increase (P = .06), and acetate tended to decrease (P = .07) as the level of creep feed intake increased. Higher levels of creep feed tended to cause a decrease in ruminal fiber digestibility and forage intake. Creep feeding calves for 56 or 84 d improved gain; 56 d had the most efficient supplemental gain. Creep feeding calves for 28 d showed no advantage during the creep feeding period or in the feedlot.

Effects of Wheat Naturally Contaminated with Fusarium Mycotoxins on Growth Performance and Selected Health Indices of Red Tilapia (Oreochromis niloticus × O. mossambicus)

PubMed Central

Tola, Siriporn; Bureau, Dominique P.; Hooft, Jamie M.; Beamish, Frederick W. H.; Sulyok, Michael; Krska, Rudolf; Encarnação, Pedro; Petkam, Rakpong

2015-01-01

An 8-week feeding trial was conducted to examine effects of wheat naturally contaminated with Fusarium mycotoxins (deoxynivalenol, DON 41 mg·kg−1) on growth performance and selected health indices of red tilapia (Oreochromis niloticus × O. mossambicus; initial weight = 4.3 g/fish). Five experimental diets were formulated by replacement of clean wheat with naturally contaminated wheat resulting in graded levels of DON and zearalenone (ZEN) (Diet 1 0.07/0.01, Diet 2 0.31/0.09, Diet 3 0.50/0.21, Diet 4 0.92/0.37 and Diet 5 1.15/0.98 mg·kg−1). Groups of 50 fish were randomly allocated into each of 20 aquaria and fed to near-satiety for eight weeks. Growth rate, feed intake and feed efficiency of fish fed the experimental diets decreased linearly with increasing levels of Fusarium mycotoxins (p < 0.05). Although growth depression was associated with feeding diets naturally contaminated with Fusarium mycotoxins, especially DON, no biochemical and histopathological parameters measured in blood and liver appeared affected by Fusarium mycotoxin concentrations of diets (p > 0.05). Though there was no clear evidence of overt DON toxicity to red tilapia, it is recommended that feed ingredients should be screened for Fusarium mycotoxin contamination to ensure optimal growth performance. PMID:26035489

Serial hepatic gene expression profiling in Angus steers during feed restriction and realimentation

USDA-ARS?s Scientific Manuscript database

Growing ruminants maintained under dietary restriction for extended periods will exhibit compensatory growth when reverted to ad libitum feeding. This period of compensatory growth is associated with increased feed efficiency, lower basal energy requirements, and changes in circulating concentration...

21 CFR 558.55 - Amprolium.

Code of Federal Regulations, 2013 CFR

2013-04-01

... obsignata) Feed according to subtable in item (i) Penicillin 2.4 to 50 Replacement chickens; development of active immunity to coccidiosis; growth promotion and feed efficiency As procaine penicillin. Feed... to subtable in item (i) Penicillin 2.4 to 50 Broiler chickens; prevention of coccidiosis caused by E...

21 CFR 558.55 - Amprolium.

Code of Federal Regulations, 2011 CFR

2011-04-01

... obsignata) Feed according to subtable in item (i) Penicillin 2.4 to 50 Replacement chickens; development of active immunity to coccidiosis; growth promotion and feed efficiency As procaine penicillin. Feed... to subtable in item (i) Penicillin 2.4 to 50 Broiler chickens; prevention of coccidiosis caused by E...

21 CFR 558.55 - Amprolium.

Code of Federal Regulations, 2012 CFR

2012-04-01

... obsignata) Feed according to subtable in item (i) Penicillin 2.4 to 50 Replacement chickens; development of active immunity to coccidiosis; growth promotion and feed efficiency As procaine penicillin. Feed... to subtable in item (i) Penicillin 2.4 to 50 Broiler chickens; prevention of coccidiosis caused by E...

The effect of feed rate and recycle rate variable on leaching process of Na2Zro3 with HCl in continuous stirred tank reactor (CSTR) series

NASA Astrophysics Data System (ADS)

Palupi, Bekti; Supranto, Sediawan, Wahyudi Budi; Setyadji, Moch.

2017-05-01

This time, the natural resources of zircon sand is processed into several zirconium products which is utilized for various industries, such as ceramics, glass industry, metal industry and nuclear industry. The process of zircon sand into zirconium products through several stages, one of them is leaching process of Na2ZrO3 with HCl. In this research, several variations of recycle-rate/feed-rate had been done to determine the effect on leaching process. The leaching was processed at temperature of 90°C, ratio of Na2ZrO3:HCl = 1g:30mL, and 142 rotary per minute of stirring speed for 30 minutes with variation of recycle-rate/feed-rate such as 0.478, 0.299, 0.218, 0.171 and 0.141. The diameter size of Na2ZrO3 powder that used are 0.088 to 0.149 mm. This process was carried out in Continuous Stirred Tank Reactor (CSTR) series with recycle. Based on this research, the greater of the recycle-rate/feed-rate variable, the obtained Zr recovery decreased. The correlation between recycle-rate/feed-rate and Zr recovery is shown by the equation y = -146.91x + 103.51, where y is the Zr recovery and x is the recycle-rate/feed-rate. The highest Zr recovery was 90.52% obtained at recycle-rate/feed-rate 0.141. The mathematical modeling involving the probability model P(r) = 2β2r2 exp(-βr2) can be applied to this leaching process with Sum of Squared Errors (SSE) values in the range of 6×10-7 - 7×10-6.

Dairy cow breed interacts with stocking rate in temperate pasture-based dairy production systems.

PubMed

Spaans, O K; Macdonald, K A; Lancaster, J A S; Bryant, A M; Roche, J R

2018-05-01

Economic optimum stocking rates for grazing dairy systems have been defined by accounting for the pasture production potential of the farm [t of dry matter (DM)/ha], the amount of feed imported from outside the farm (t of DM/ha), and the size of the cow (kg). These variables were combined into the comparative stocking rate [CSR; kg of body weight (BW)/t of feed DM available] measure. However, CSR assumes no effect of cow genetics beyond BW, and there is increasing evidence of within-breed differences in residual feed intake and between-breed differences in the gross efficiency with which cows use metabolizable energy for milk production. A multiyear production system experiment was established to determine whether Jersey (J) and Holstein-Friesian (HF) breeds performed similarly at the same CSR. Fifty-nine J cows and 51 HF cows were randomly allocated to 1 of 2 CSR in a 2 × 2 factorial arrangement; systems were designed to have a CSR of either 80 or 100 kg of BW/t of feed DM (J-CSR80, J-CSR100, HF-CSR80, and HF-CSR100 treatment groups). Data were analyzed for consistency of farmlet response over years using ANOVA procedures, with year and farmlet as fixed effects and the interaction of farmlet with year as a random effect. The collated biological data and financial data extracted from a national economic database were used to model the financial performance for the different breed and CSR treatments. On average, annual and individual season pasture DM production was greater for the J farmlets and was less in the CSR100 treatment; however, the effect of CSR was primarily driven by a large decline in pasture DM production in the HF-CSR100 treatment (breed × CSR interaction). This interaction in feed availability resulted in a breed × CSR interaction for the per-cow and per-hectare milk production variables, with HF cows producing more milk and milk components per cow in the CSR80 treatment but the same amount as the J cows in the CSR100 treatment. On a per-hectare basis, HF cows produced the same amount of 4% fat-corrected milk and lactose as J cows in the CSR80 treatment, but less fat; at CSR100, J cows produced more 4% fat-corrected milk, fat, and protein per hectare than HF cows. Our results support a greater gross efficiency for use of metabolizable energy by the J cow; 11% less total metabolizable energy was required to produce 1 kg of fat and protein at a system level. Economic modeling indicated that profitability of both breeds was less at CSR100, but the decline in profitability with increasing stocking rate was much greater in the HF breed. Holstein-Friesian cows were more profitable at CSR80 but were less profitable at CSR100. Copyright © 2018 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of concentrate supplementation during the dry period on colostrum quality and effect of colostrum feeding regimen on passive transfer of immunity, calf health, and performance.

PubMed

Dunn, A; Ashfield, A; Earley, B; Welsh, M; Gordon, A; McGee, M; Morrison, S J

2017-01-01

The objectives were to evaluate the effect of (1) supplementing concentrates to multiparous Holstein cows during the dry period on colostral and milk immunoglobulin G (IgG) concentration; and (2) feeding calves colostrum at either 5 or 10% of their body weight (BW) on passive transfer of immunity, health, and performance. Holstein multiparous cows (n=37) were assigned to 1 of 2 nutritional treatments during an 8-wk dry period: (1) offered ad libitum grass silage only (GS) or (2) offered ad libitum access to the same grass silage plus concentrate [total mixed ration in a 75:25 dry matter (DM) ratio], providing a mean concentrate DM intake of 3.0kg/cow per day (GSC). Both treatment groups were offered identical levels of mineral and vitamin supplementation. Calves from these cows were weighed immediately after birth and fed either 5% (5BW) or 10% (10BW) of their BW in colostrum from their own dams within 2.5h of birth. Calves in the 10BW group received their second feed of colostrum from first-milking colostrum. Concentrate supplementation during the dry period had no effect on colostral IgG concentration, first-milking IgG yield, or fat, protein, and lactose contents. However, cows in GSC produced a greater mean milk yield over the first 8 milkings compared with cows in the GS group. Concentrate supplementation had no effect on calf BW or BW gain, serum IgG, or apparent efficiency of absorption (AEA) at 24h after birth. However, offspring from the GSC group had fewer cases of enteritis during the first 56d of life compared with offspring from the GS group. Calves in the 10BW group had greater mean serum IgG concentration for the first 3d following birth; however, at 24h after birth, we observed no treatment effect on AEA. The rate of enteritis was greater for calves in the 5BW treatment compared with 10BW. The colostrum-feeding regimen had no effect on BW gain or on the incidence of pneumonia among calf treatment groups. In conclusion, concentrate supplementation regimens offered during the dry period had a positive effect on colostrum yield, and offspring from the GSC group had a reduced rate of enteritis. Feeding 10% of BW of colostrum versus 5% of BW resulted in a greater serum IgG concentration for the first 3d postpartum, and 10BW calves had a reduced rate of enteritis. Overall, to achieve successful passive transfer, decrease the rate of enteritis, and increase efficiency in the dairy calf, we recommend that dairy calves be fed 10% of their BW in colostrum as soon as possible after birth. Copyright © 2017 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effect of lower-energy, higher-fiber diets on pigs divergently selected for residual feed intake when fed higher-energy, lower-fiber diets

USDA-ARS?s Scientific Manuscript database

Residual feed intake (RFI) is the amount by which the observed and predicted feed intakes differ, given growth and maintenance requirements of an individual animal. In purebred Yorkshire pigs, divergent selection for increased (Low RFI) and decreased (High RFI) feed efficiency was carried out over 1...

Rumen papillae morphology of beef steers relative to gain and feed intake and the association of volatile fatty acids with kallikrein gene expression

USDA-ARS?s Scientific Manuscript database

Feed costs are the most expensive input in beef production. Improvement in the feed efficiency of beef cattle would lower feed inputs and reduce the cost of production. The rumen epithelium is responsible for absorption and metabolism of nutrients and microbial by-products, and may play a significan...

Transmission efficiency of the plague pathogen (Y. pestis) by the flea, Xenopsylla skrjabini, to mice and great gerbils.

PubMed

Zhang, Yujiang; Dai, Xiang; Wang, Qiguo; Chen, Hongjian; Meng, Weiwei; Wu, Kemei; Luo, Tao; Wang, Xinhui; Rehemu, Azhati; Guo, Rong; Yu, Xiaotao; Yang, Ruifu; Cao, Hanli; Song, Yajun

2015-05-01

Plague, a zoonotic disease caused by Yersinia pestis, is characterized by its ability to persist in the plague natural foci. Junggar Basin plague focus was recently identified in China, with Rhombomys opimus (great gerbils) and Xenopsylla skrjabini as the main reservoir and vector for plague. No transmission efficiency data of X. skrjabini for Y. pestis is available till now. In this study, we estimated the median infectious dose (ID50) and the blockage rates of X. skrjabini with Y. pestis, by using artificial feeders. We then evaluated the flea transmission ability of Y. pestis to the mice and great gerbils via artificial bloodmeal feeding. Finally, we investigated the transmission of Y. pestis to mice with fleas fed by infected great gerbils. ID50 of Y. pestis to X. skrjabini was estimated as 2.04 × 10(5) CFU (95% CI, 1.45 × 10(5) - 3.18 × 10(5) CFU), around 40 times higher than that of X. cheopis. Although fleas fed by higher bacteremia bloodmeal had higher infection rates for Y. pestis, they lived significantly shorter than their counterparts. X. skrjabini could get fully blocked as early as day 3 post of infection (7.1%, 3/42 fleas), and the overall blockage rate of X. cheopis was estimated as 14.9% (82/550 fleas) during the 14 days of investigation. For the fleas infected by artificial feeders, they seemed to transmit plague more efficiently to great gerbils than mice. Our single flea transmission experiments also revealed that, the transmission capacity of naturally infected fleas (fed by infected great gerbils) was significantly higher than that of artificially infected ones (fed by artificial feeders). Our results indicated that ID50 of Y. pestis to X. skrjabini was higher than other fleas like X. cheopis, and its transmission efficiency to mice might be lower than other flea vectors in the artificial feeding modes. We also found different transmission potentials in the artificially infected fleas and the naturally infected ones. Further studies are needed to figure out the role of X. skrjabini in the plague epidemiological cycles in Junggar Basin plague focus.

Breast feeding initiation rate across Western countries: does religion matter? An ecological study

PubMed Central

Cohen, Emmanuel; Kramer, Michael S

2016-01-01

Background Breast feeding initiation rates remain below 80% in some Western countries. Many individual-level determinants are known; however, less is known regarding cultural and societal determinants, such as religion, that could explain population-level variations. We examined the correlations of the proportions of Catholics and Protestants with the breast feeding initiation rates across and within Western countries. Methods Using publicly available data, we carried out an ecological study comparing the proportions of Catholics and Protestants with the rates of breast feeding initiation. We correlated data at the country level, and additionally explored within-country data in five Western countries: France (Departments), Ireland (counties), the UK (countries), Canada (provinces) and the USA (states). Our analyses accounted for human development index, gross domestic product and population density. Results We observed a negative correlation (r=−0.30) between the proportion of Catholics and the rate of breast feeding initiation in Western countries. This correlation was consistent when using within-country data in France (r=−0.27), Ireland (r=−0.23), the UK (r=−0.79) and Canada (r=−0.62). In the USA, the positive correlation (r=0.26) between a state's proportion of Catholics and its breast feeding initiation rate was confounded by race, education and socioeconomic status (SES). After controlling for education and SES, the state proportion of non-Hispanic white Catholics was negatively correlated (r=−0.29) with the rate of breast feeding initiation. Conclusions In this ecological study, we found consistent negative correlations between Catholicism and breast feeding initiation rates. Qualitative and quantitative studies at the individual level are needed to confirm and explain our findings. Our results suggest that women living in a country or region where Catholicism has historically dominated are less likely to initiate breast feeding, and that breast feeding promotion policies should be adapted to better fit populations' cultural and religious norms. PMID:28588983

Breast feeding initiation rate across Western countries: does religion matter? An ecological study.

PubMed

Bernard, Jonathan Y; Cohen, Emmanuel; Kramer, Michael S

2016-01-01

Breast feeding initiation rates remain below 80% in some Western countries. Many individual-level determinants are known; however, less is known regarding cultural and societal determinants, such as religion, that could explain population-level variations. We examined the correlations of the proportions of Catholics and Protestants with the breast feeding initiation rates across and within Western countries. Using publicly available data, we carried out an ecological study comparing the proportions of Catholics and Protestants with the rates of breast feeding initiation. We correlated data at the country level, and additionally explored within-country data in five Western countries: France (Departments), Ireland (counties), the UK (countries), Canada (provinces) and the USA (states). Our analyses accounted for human development index, gross domestic product and population density. We observed a negative correlation (r=-0.30) between the proportion of Catholics and the rate of breast feeding initiation in Western countries. This correlation was consistent when using within-country data in France (r=-0.27), Ireland (r=-0.23), the UK (r=-0.79) and Canada (r=-0.62). In the USA, the positive correlation (r=0.26) between a state's proportion of Catholics and its breast feeding initiation rate was confounded by race, education and socioeconomic status (SES). After controlling for education and SES, the state proportion of non-Hispanic white Catholics was negatively correlated (r=-0.29) with the rate of breast feeding initiation. In this ecological study, we found consistent negative correlations between Catholicism and breast feeding initiation rates. Qualitative and quantitative studies at the individual level are needed to confirm and explain our findings. Our results suggest that women living in a country or region where Catholicism has historically dominated are less likely to initiate breast feeding, and that breast feeding promotion policies should be adapted to better fit populations' cultural and religious norms.

Evolution of increased larval competitive ability in Drosophila melanogaster without increased larval feeding rate.

PubMed

Sarangi, Manaswini; Nagarajan, Archana; Dey, Snigdhadip; Bose, Joy; Joshi, Amitabh

2016-09-01

Multiple experimental evolution studies on Drosophila melanogaster in the 1980s and 1990s indicated that enhanced competitive ability evolved primarily through increased larval tolerance to nitrogenous wastes and increased larval feeding and foraging rate, at the cost of efficiency of food conversion to biomass, and this became the widely accepted view of how adaptation to larval crowding evolves in fruitflies.We recently showed that populations of D. ananassae and D. n. nasuta subjected to extreme larval crowding evolved greater competitive ability without evolving higher feeding rates, primarily through a combination of reduced larval duration, faster attainment of minimum critical size for pupation, greater efficiency of food conversion to biomass, increased pupation height and, perhaps, greater urea/ammonia tolerance. This was a very different suite of traits than that seen to evolve under similar selection in D. melanogaster and was closer to the expectations from the theory of K-selection. At that time, we suggested two possible reasons for the differences in the phenotypic correlates of greater competitive ability seen in the studies with D. melanogaster and the other two species. First, that D. ananassae and D. n. nasuta had a very different genetic architecture of traits affecting competitive ability compared to the long-term laboratory populations of D. melanogaster used in the earlier studies, either because the populations of the former two species were relatively recently wild-caught, or by virtue of being different species. Second, that the different evolutionary trajectories in D. ananassae and D. n. nasuta versus D. melanogaster were a reflection of differences in the manner in which larval crowding was imposed in the two sets of selection experiments. The D. melanogaster studies used a higher absolute density of eggs per unit volume of food, and a substantially larger total volume of food, than the studies on D. ananassae and D. n. nasuta. Here, we show that long-term laboratory populations of D. melanogaster, descended from some of the populations used in the earlier studies, evolve essentially the same set of traits as the D. ananassae and D. n. nasuta crowding-adapted populations when subjected to a similar larval density at low absolute volumes of food. As in the case of D. ananassae and D. n. nasuta, and in stark contrast to earlier studies with D. melanogaster, these crowding-adapted populations of D. melanogaster did not evolve greater larval feeding rates as a correlate of increased competitive ability. The present results clearly suggest that the suite of phenotypes through which the evolution of greater competitive ability is achieved in fruitflies depends critically not just on larval density per unit volume of food, but also on the total amount of food available in the culture vials. We discuss these results in the context of an hypothesis about how larval density and the height of the food column in culture vials might interact to alter the fitness costs and benefits of increased larval feeding rates, thus resulting in different routes to the evolution of greater competitive ability, depending on the details of exactly how the larval crowding was implemented.

Single-hidden-layer feed-forward quantum neural network based on Grover learning.

PubMed

Liu, Cheng-Yi; Chen, Chein; Chang, Ching-Ter; Shih, Lun-Min

2013-09-01

In this paper, a novel single-hidden-layer feed-forward quantum neural network model is proposed based on some concepts and principles in the quantum theory. By combining the quantum mechanism with the feed-forward neural network, we defined quantum hidden neurons and connected quantum weights, and used them as the fundamental information processing unit in a single-hidden-layer feed-forward neural network. The quantum neurons make a wide range of nonlinear functions serve as the activation functions in the hidden layer of the network, and the Grover searching algorithm outstands the optimal parameter setting iteratively and thus makes very efficient neural network learning possible. The quantum neuron and weights, along with a Grover searching algorithm based learning, result in a novel and efficient neural network characteristic of reduced network, high efficient training and prospect application in future. Some simulations are taken to investigate the performance of the proposed quantum network and the result show that it can achieve accurate learning. Copyright © 2013 Elsevier Ltd. All rights reserved.

Feeding of wheat bran and sugar beet pulp as sole supplements in high-forage diets emphasizes the potential of dairy cattle for human food supply.

PubMed

Ertl, P; Zebeli, Q; Zollitsch, W; Knaus, W

2016-02-01

Besides the widely discussed negative environmental effects of dairy production, such as greenhouse gas emissions, the feeding of large amounts of potentially human-edible feedstuffs to dairy cows is another important sustainability concern. The aim of this study was therefore to investigate the effects of a complete substitution of common cereal grains and pulses with a mixture of wheat bran and sugar beet pulp in a high-forage diet on cow performance, production efficiency, feed intake, and ruminating behavior, as well as on net food production potential. Thirteen multiparous and 7 primiparous mid-lactation Holstein dairy cows were randomly assigned to 1 of 2 treatments in a change-over design with 7-wk periods. Cows were fed a high-forage diet (grass silage and hay accounted for 75% of the dry matter intake), supplemented with either a cereal grain-based concentrate mixture (CON), or a mixture of wheat bran and dried sugar beet pulp (WBBP). Human-edible inputs were calculated for 2 different scenarios based on minimum and maximum potential recovery rates of human-edible energy and protein from the respective feedstuffs. Dietary starch and neutral detergent fiber contents were 3.0 and 44.1% for WBBP, compared with 10.8 and 38.2% in CON, respectively. Dietary treatment did not affect milk production, milk composition, feed intake, or total chewing activity. However, chewing index expressed in minutes per kilogram of neutral detergent fiber ingested was 12% lower in WBBP compared with CON. In comparison to CON, the human-edible feed conversion efficiencies for energy and protein, defined as human-edible output per human-edible input, were 6.8 and 5.3 times higher, respectively, in WBBP under the maximum scenario. For the maximum scenario, the daily net food production (human-edible output minus human-edible input) increased from 5.4 MJ and 250 g of crude protein per cow in CON to 61.5 MJ and 630 g of crude protein in the WBBP diet. In conclusion, our data suggest that in forage-based dairy production systems, wheat bran and sugar beet pulp could replace common cereal grains in mid-lactation dairy cows without impairing performance, while strongly increasing human-edible feed conversion efficiency and net food production index. Copyright © 2016 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

[Effects of breast-feeding education and support services on breast-feeding rates and infant's growth].

PubMed

Jang, Gun-Ja; Kim, Sun-Hee

2010-04-01

This study was done to investigate the effects of breast-feeding education and support services on rate of breast-feeding three and six months after birth, and the effect on infant's growth (weight, height, body mass index [BMI]). The experimental group which had both education and support services was compared with the control group which had only breast-feeding education. This study was a quasi-experimental study with a time-series design. The participants were 39 mothers who were hospitalized for childbirth. Twenty mother were assigned to the experimental group and 19 mothers, to the control group. The breast feeding education was done during hospitalization, and support services were provided once a week after discharge for a month (a total 4 times) by a maternity ward nurse. Data regarding breastfeeding rate at one month after childbirth was collected by phone call; the breast-feeding rates at three and six months after childbirth were collected in a visit to the families. The child's weight and height were also measured during the visit. The experimental group had a statistically significant higher rate for frequency of breast-feeding at one, three and six months after childbirth than the control group. However, there was no meaningful difference between the two groups for infant growth. The results of this study suggest that breast-feeding education is helpful for a start, but support services are also necessary to sustain breast-feeding.

Carbon flux to growth or polyhydroxyalkanoate synthesis under microaerophilic conditions is affected by fatty acid chain-length in Pseudomonas putida LS46.

PubMed

Blunt, Warren; Dartiailh, Christopher; Sparling, Richard; Gapes, Daniel; Levin, David B; Cicek, Nazim

2018-05-24

Economical production of medium-chain length polyhydroxyalkanoates (mcl-PHA) is dependent on efficient cultivation processes. This work describes growth and mcl-PHA synthesis characteristics of Pseudomonas putida LS46 when grown on medium-chain length fatty acids (octanoic acid) and lower-cost long-chain fatty acids (LCFAs, derived from hydrolyzed canola oil) in microaerophilic environments. Growth on octanoic acid ceased when the oxygen uptake rate was limited by the oxygen transfer rate, and mcl-PHA accumulated to 61.9% of the cell dry mass. From LCFAs, production of non-PHA cell mass continued at a rate of 0.36 g L -1  h -1 under oxygen-limited conditions, while mcl-PHA accumulated simultaneously to 31% of the cell dry mass. The titer of non-PHA cell mass from LCFAs at 14 h post-inoculation was double that obtained from octanoic acid in bioreactors operated with identical feeding and aeration conditions. While the productivity for octanoic acid was higher by 14 h, prolonged cultivation on LCFAs achieved similar productivity but with twice the PHA titer. Simultaneous co-feeding of each substrate demonstrated the continued cell growth under microaerophilic conditions characteristic of LCFAs, and the resulting polymer was dominant in C8 monomers. Furthermore, co-feeding resulted in improved PHA titer and volumetric productivity compared to either substrate individually. These results suggest that LCFAs improve growth of P. putida in oxygen-limited environments and could reduce production costs since more non-PHA cell mass, the cellular factories required to produce mcl-PHA and the most oxygen-intensive cellular process, can be produced for a given oxygen transfer rate.

[Removal of toluene from waste gas by honeycomb adsorption rotor with modified 13X molecular sieves].

PubMed

Wang, Jia-De; Zheng, Liang-Wei; Zhu, Run-Ye; Yu, Yun-Feng

2013-12-01

The removal of toluene from waste gas by Honeycomb Adsorption Rotor with modified 13X molecular sieves was systematically investigated. The effects of the rotor operating parameters and the feed gas parameters on the adsorption efficiency were clarified. The experimental results indicated that the honeycomb adsorption rotor had a good humidity resistance. The removal efficiency of honeycomb adsorption rotor achieved the maximal value with optimal rotor speed and optimal generation air temperature. Moreover, for an appropriate flow rate ratio the removal efficiency and energy consumption should be taken into account. When the recommended operating parameters were regeneration air temperature of 180 degrees C, rotor speed of 2.8-5 r x h(-1), flow rate ratio of 8-12, the removal efficiency kept over 90% for the toluene gas with concentration of 100 mg x m(-3) and inlet velocity of 2 m x s(-1). The research provided design experience and operating parameters for industrial application of honeycomb adsorption rotor. It showed that lower empty bed velocity, faster rotor speed and higher temperature were necessary to purify organic waste gases of higher concentrations.

Realizable feed-element patterns and optimum aperture efficiency in multibeam antenna systems

NASA Technical Reports Server (NTRS)

Yngvesson, K. S.; Rahmat-Samii, Y.; Johansson, J. F.; Kim, Y. S.

1988-01-01

The results of an earlier paper by Rahmat-Samii et al. (1981), regarding realizable patterns from feed elements that are part of an array that feeds a reflector antenna, are extended. The earlier paper used a cos exp q theta model for the element radiation pattern, whereas here a parametric study is performed, using a model that assumes a central beam of cos exp q theta shape, with a constant sidelobe level outside the central beam. Realizable q-values are constrained by the maximum directivity based on feed element area. The optimum aperture efficiency (excluding array feed network losses) in an array-reflector system is evaluated as a function of element spacing using this model as well as the model of the earlier paper. Experimental data for tapered slot antenna (TSA) arrays are in agreement with the conclusions based on the model.

Analysis of copy number variations in Holstein cows identify potential mechanisms contributing to differences in residual feed intake.

PubMed

Hou, Yali; Bickhart, Derek M; Chung, Hoyoung; Hutchison, Jana L; Norman, H Duane; Connor, Erin E; Liu, George E

2012-11-01

Genomic structural variation is an important and abundant source of genetic and phenotypic variation. In this study, we performed an initial analysis of copy number variations (CNVs) using BovineHD SNP genotyping data from 147 Holstein cows identified as having high or low feed efficiency as estimated by residual feed intake (RFI). We detected 443 candidate CNV regions (CNVRs) that represent 18.4 Mb (0.6 %) of the genome. To investigate the functional impacts of CNVs, we created two groups of 30 individual animals with extremely low or high estimated breeding values (EBVs) for RFI, and referred to these groups as low intake (LI; more efficient) or high intake (HI; less efficient), respectively. We identified 240 (~9.0 Mb) and 274 (~10.2 Mb) CNVRs from LI and HI groups, respectively. Approximately 30-40 % of the CNVRs were specific to the LI group or HI group of animals. The 240 LI CNVRs overlapped with 137 Ensembl genes. Network analyses indicated that the LI-specific genes were predominantly enriched for those functioning in the inflammatory response and immunity. By contrast, the 274 HI CNVRs contained 177 Ensembl genes. Network analyses indicated that the HI-specific genes were particularly involved in the cell cycle, and organ and bone development. These results relate CNVs to two key variables, namely immune response and organ and bone development. The data indicate that greater feed efficiency relates more closely to immune response, whereas cattle with reduced feed efficiency may have a greater capacity for organ and bone development.

Live feed enrichment with probiotics: current methods and future perspectives on increasing finfish larviculture success

USDA-ARS?s Scientific Manuscript database

Probiotics - active or inactive microorganisms incorporated to animal feeds - are considered a potential alternative to other treatments intended to enhance immune response, growth, or feed efficiency in animal rearing systems. While probiotics are extensively used in livestock practices, their use ...

Intermediate mass black holes in AGN discs - I. Production and growth

NASA Astrophysics Data System (ADS)

McKernan, B.; Ford, K. E. S.; Lyra, W.; Perets, H. B.

2012-09-01

Here we propose a mechanism for efficiently growing intermediate mass black holes (IMBH) in discs around supermassive black holes. Stellar mass objects can efficiently agglomerate when facilitated by the gas disc. Stars, compact objects and binaries can migrate, accrete and merge within discs around supermassive black holes. While dynamical heating by cusp stars excites the velocity dispersion of nuclear cluster objects (NCOs) in the disc, gas in the disc damps NCO orbits. If gas damping dominates, NCOs remain in the disc with circularized orbits and large collision cross-sections. IMBH seeds can grow extremely rapidly by collisions with disc NCOs at low relative velocities, allowing for super-Eddington growth rates. Once an IMBH seed has cleared out its feeding zone of disc NCOs, growth of IMBH seeds can become dominated by gas accretion from the active galactic nucleus (AGN) disc. However, the IMBH can migrate in the disc and expand its feeding zone, permitting a super-Eddington accretion rate to continue. Growth of IMBH seeds via NCO collisions is enhanced by a pile-up of migrators. We highlight the remarkable parallel between the growth of IMBH in AGN discs with models of giant planet growth in protoplanetary discs. If an IMBH becomes massive enough it can open a gap in the AGN disc. IMBH migration in AGN discs may stall, allowing them to survive the end of the AGN phase and remain in galactic nuclei. Our proposed mechanisms should be more efficient at growing IMBH in AGN discs than the standard model of IMBH growth in stellar clusters. Dynamical heating of disc NCOs by cusp stars is transferred to the gas in an AGN disc helping to maintain the outer disc against gravitational instability. Model predictions, observational constraints and implications are discussed in a companion paper (Paper II).

Ingestion Rates and Absorption Efficiencies of Abra ovata(Mollusca: Bivalvia) Fed on Macrophytobenthic Detritus

NASA Astrophysics Data System (ADS)

Charles, F.; Grémare, A.; Amouroux, J. M.

1996-01-01

Ingestion and absorption were investigated in the deposit-feeding bivalve Abra ovatafed on 14C-formaldehyde-labelled detritus derived from 11 macrophytes: Posidonia oceanica, Cystoseira compressa, Padina pavonica, Stypocaulon scoparium, Colpomenia sinuosa, Cystoseira mediterranea, Dilophus spiralis, Rissoella verruculosa, Ulva rigida, Corallina elongata andCodium vermilara . Labelling efficiency ranged from 3·2 (R. verruculosa ) to 53·0% (C. sinuosa) depending on the detritus. The stability of the labelling also varied among detritus types, and was negatively correlated with labelling efficiency. For all types of detritus, the exchanges of radioactivity between compartments were dominated by the transfer between particulate organic matter (POM) and bivalves. These transfers resulted from the interactions between the processes of ingestion, defaecation, and recycling of faeces. The coexistence of these processes together with the occasional lack of stability of the label complicated the actual determination of ingestion rates and absorption efficiencies, which necessitated the use of mathematical modelling. The model was initially composed of five compartments: Detritus, Bivalves, Dissolved organic matter (DOM), CO 2, and Faeces. Two first-order time delays were introduced to account for the production of faeces and CO 2by the bivalves. These delays resulted in the subdivision of the Bivalves compartment into three subcompartments: bivIng, bivDig, and bivAbs. The model also accounts for differences in utilization rates of detritus and faeces by the bivalves. It simulates the exchange of radioactivity between compartments and allows the quantification of ingestion and absorption efficiencies. Our results show large differences in both ingestion rates and absorption efficiencies of A. ovatafed on different types of detritus. Ingestion rates ranged between 0·16 ( C. mediterraneaand D. spiralis) and 8·65 μgOM mgDW -1 h -1( U. rigida). Absorption efficiencies ranged between 0·5 ( C. sinuosa) and 11·4% ( C. elongata). These results were related to the main characteristics of the detritus by using a principal component analysis. Results show a negative effect of both protein and phenolic contents on ingestion rates, and a negative effect of phenolic contents on absorption efficiencies, in good agreement with the existing literature.

Adaptation to hot climate and strategies to alleviate heat stress in livestock production.

PubMed

Renaudeau, D; Collin, A; Yahav, S; de Basilio, V; Gourdine, J L; Collier, R J

2012-05-01

Despite many challenges faced by animal producers, including environmental problems, diseases, economic pressure, and feed availability, it is still predicted that animal production in developing countries will continue to sustain the future growth of the world's meat production. In these areas, livestock performance is generally lower than those obtained in Western Europe and North America. Although many factors can be involved, climatic factors are among the first and crucial limiting factors of the development of animal production in warm regions. In addition, global warming will further accentuate heat stress-related problems. The objective of this paper was to review the effective strategies to alleviate heat stress in the context of tropical livestock production systems. These strategies can be classified into three groups: those increasing feed intake or decreasing metabolic heat production, those enhancing heat-loss capacities, and those involving genetic selection for heat tolerance. Under heat stress, improved production should be possible through modifications of diet composition that either promotes a higher intake or compensates the low feed consumption. In addition, altering feeding management such as a change in feeding time and/or frequency, are efficient tools to avoid excessive heat load and improve survival rate, especially in poultry. Methods to enhance heat exchange between the environment and the animal and those changing the environment to prevent or limit heat stress can be used to improve performance under hot climatic conditions. Although differences in thermal tolerance exist between livestock species (ruminants > monogastrics), there are also large differences between breeds of a species and within each breed. Consequently, the opportunity may exist to improve thermal tolerance of the animals using genetic tools. However, further research is required to quantify the genetic antagonism between adaptation and production traits to evaluate the potential selection response. With the development of molecular biotechnologies, new opportunities are available to characterize gene expression and identify key cellular responses to heat stress. These new tools will enable scientists to improve the accuracy and the efficiency of selection for heat tolerance. Epigenetic regulation of gene expression and thermal imprinting of the genome could also be an efficient method to improve thermal tolerance. Such techniques (e.g. perinatal heat acclimation) are currently being experimented in chicken.

Exclusive and any breast-feeding rates of Pacific infants in Auckland: data from the Pacific Islands Families First Two Years of Life Study.

PubMed

Schluter, Philip J; Carter, Sarnia; Percival, Teuila

2006-09-01

To present current breast-feeding rates for Pacific infants resident in New Zealand. Reasons for the introduction of complementary liquid foods were also explored. A longitudinal study using hospital discharge summary records and maternal home interviews undertaken at 6 weeks, 12 and 24 months postpartum. Turnbull's non-parametric survival analysis was used to model exclusive breast-feeding rates. Auckland, New Zealand. The cohort comprised 1376 infants at 6 weeks, 1223 infants at 12 months and 1142 infants at 24 months. Exclusive breast-feeding rates at hospital discharge, 6 weeks, 3 and 6 months postpartum were 84% (95% confidence interval (CI): 80-88%), 49% (95% CI: 43-55%), 37% (95% CI: 32-42%) and 9% (95% CI: 7-11%), respectively. Significant ethnic difference existed, with Samoan mothers having higher exclusive breast-feeding rates than Tongan mothers (P = 0.002). The percentage of infants receiving any breast milk at hospital discharge, 6 weeks, 12 and 24 months was 96% (95% CI: 94-97%), 95% (95% CI: 94-96%), 31% (95% CI: 28-34%) and 15% (95% CI: 13-17%), respectively. Again ethnic differences emerged. Common reasons cited for discontinuation of exclusive breast-feeding included uncertainty of breast milk supply (56%), problems with breasts (30%) and difficulties breast-feeding in work or educational environments (26%). However, 691 (50%) mothers sought no advice about their breast-feeding concerns within the first six weeks of life. Exclusive breast-feeding rates for Pacific infants are ethnically heterogeneous, have declined since the 1990s and fall short of the World Health Organization recommendations. The principal reasons cited for exclusive breast-feeding discontinuation echo those reported over a decade ago.

Using quality improvement to promote breast-feeding in a local health department.

PubMed

Wright, Sarah S; Lea, C Suzanne; Holloman, Roxanne; Cornett, Amanda; Harrison, Lisa Macon; Randolph, Greg D

2012-01-01

In 2008, breast-feeding initiation and continuation rates in Beaufort County, North Carolina, were lower than statewide rates. A quality improvement (QI) project was initiated to increase breast-feeding rates by enhancing the overall environment that supports breast-feeding at the Beaufort County Health Department. This case study describes one of the first QI initiatives implemented through the North Carolina Center for Public Health Quality QI training program, conducted in 2009. The aim of this project was to improve the health and wellness of mothers and infants in Beaufort County by promoting breast-feeding among Beaufort County Health Department Women, Infants and Children (WIC) clients. Using QI tools, 4 new approaches to breast-feeding promotion were tested and implemented: creating a nurturing location to breast-feed while at the health department, actively telephoning new mothers to provide breast-feeding support, incentivizing adoption of educational messages by providing a breast-feeding tote bag, and promoting new WIC food packages. These enhancements involved staff in QI planning and implementation and correlated with improved breast-feeding initiation for WIC clients during the year following project completion.

The effect of the baby-friendly hospital initiative on long-term breast feeding.

PubMed

Duyan Camurdan, A; Ozkan, S; Yüksel, D; Pasli, F; Sahin, F; Beyazova, U

2007-08-01

The aim of this study was to evaluate the effects of 'baby-friendly hospital initiative' (BFHI) on breast feeding. In the four consecutive months after BFHI in Gazi University Hospital (November 2002-February 2003), breast feeding status until the second year of life in 297 babies, born in the same hospital was compared with the values of 258 babies born before BFHI (November 2001-February 2002). The exclusive breast feeding rate in the first 6 months was higher in the babies born after BFHI. Cox regression analysis revealed that BFHI increases the duration of breast feeding 1.5 times. At the end of the second year, cumulative rate of breast feeding was higher in the group after-BFHI (p=0.0036). The rate of breast feeding was increased by BFHI implementation.

Effect of acute low body temperature on predatory behavior and prey-capture efficiency in a plethodontid salamander.

PubMed

Marvin, Glenn A; Davis, Kayla; Dawson, Jacob

2016-05-01

The low-temperature limit for feeding in some salamander species (Desmognathus, Plethodontidae) has been inferred from field studies of seasonal variation in salamander activity and gut contents, which could not determine whether feeding is more dependent on environmental conditions influencing salamander foraging behavior or prey availability and movement. We performed two controlled laboratory experiments to examine the effect of short-term (acute) low body temperature on predatory behavior and prey-capture efficiency in a semiaquatic plethodontid salamander (Desmognathus conanti). In the first experiment, we quantified variation in the feeding responses of cold salamanders (at 1, 3, 5 and 7°C) to a video recording of a walking, warm (15°C) cricket to determine the lower thermal limit for predatory behavior, independent of any temperature effect on movement of prey. Experimental-group salamanders exhibited vigorous feeding responses at 5 and 7°C, large variation in feeding responses both among and within individuals (over time) at 3°C, and little to no feeding response at 1°C. Feeding responses at both 1 and 3°C were significantly less than at each higher temperature, whereas responses of control-group individuals at 15°C did not vary over time. In the second experiment, we quantified feeding by cold salamanders (at 3, 5, 7 and 11°C) on live, warm crickets to examine thermal effects on prey-capture ability. The mean feeding response to live crickets was significantly less at 3°C than at higher temperatures; however, 50% of salamanders captured and ingested prey with high efficiency at this temperature. We conclude that many individuals stalk and capture prey at very low temperatures (down to 3°C). Our results support a growing body of data that indicate many plethodontid salamanders feed at temperatures only a few degrees above freezing. Copyright © 2016 Elsevier Inc. All rights reserved.

21 CFR 558.274 - Hygromycin B.

Code of Federal Regulations, 2014 CFR

2014-04-01

... whipworms (Trichuris suis) Withdraw 15 days before slaughter 000986012286 017790 054771 (ii) 12 Tylosin 10... (Oesophagostomum dentatum), and whipworms (Trichuris suis); growth promotion and feed efficiency Feed continuously...

Economic values of production and functional traits, including residual feed intake, in Finnish milk production.

PubMed

Hietala, P; Wolfová, M; Wolf, J; Kantanen, J; Juga, J

2014-02-01

Improving the feed efficiency of dairy cattle has a substantial effect on the economic efficiency and on the reduction of harmful environmental effects of dairy production through lower feeding costs and emissions from dairy farming. To assess the economic importance of feed efficiency in the breeding goal for dairy cattle, the economic values for the current breeding goal traits and the additional feed efficiency traits for Finnish Ayrshire cattle under production circumstances in 2011 were determined. The derivation of economic values was based on a bioeconomic model in which the profit of the production system was calculated, using the generated steady state herd structure. Considering beef production from dairy farms, 2 marketing strategies for surplus calves were investigated: (A) surplus calves were sold at a young age and (B) surplus calves were fattened on dairy farms. Both marketing strategies were unprofitable when subsidies were not included in the revenues. When subsidies were taken into account, a positive profitability was observed in both marketing strategies. The marginal economic values for residual feed intake (RFI) of breeding heifers and cows were -25.5 and -55.8 €/kg of dry matter per day per cow and year, respectively. The marginal economic value for RFI of animals in fattening was -29.5 €/kg of dry matter per day per cow and year. To compare the economic importance among traits, the standardized economic weight of each trait was calculated as the product of the marginal economic value and the genetic standard deviation; the standardized economic weight expressed as a percentage of the sum of all standardized economic weights was called relative economic weight. When not accounting for subsidies, the highest relative economic weight was found for 305-d milk yield (34% in strategy A and 29% in strategy B), which was followed by protein percentage (13% in strategy A and 11% in strategy B). The third most important traits were calving interval (9%) and mature weight of cows (11%) in strategy A and B, respectively. The sums of the relative economic weights over categories for RFI were 6 and 7% in strategy A and B, respectively. Under production conditions in 2011, the relative economic weights for the studied feed efficiency traits were low. However, it is possible that the relative importance of feed efficiency traits in the breeding goal will increase in the future due to increasing requirements to mitigate the environmental impact of milk production. Copyright © 2014 American Dairy Science Association. Published by Elsevier Inc. All rights reserved.

Effects of sire breed, gender, and postnatal litter size on plasma concentrations of acyl ghrelin and its relationship with growth traits and feeding behavior in swine

USDA-ARS?s Scientific Manuscript database

Feeding behavior is an important component of growth and feed efficiency in swine. Acyl ghrelin is a peptide produced in the stomach that is orexigenic. The role of ghrelin in regulating feeding behavior in swine under commercial conditions is unknown. The objective of this study was to determine th...