146 Survey of residual feed intake in Katahdin and Texel lambs in a feedlot environment

Abstract Residual feed intake (RFI) is quickly becoming the preferred measurement of efficiency in many species due to its inherent independence of most other important production traits. Making meaningful improvement in feed efficiency of sheep will require a consistent methodology to accurately identify efficient individuals. Due to difficulty in measuring this trait efforts must be made to incorporate efficiency data in large-scale genetic evaluations. The aim of this study was to evaluate lambs in a feedlot with large-scale genetic evaluations for feed efficiency calculated by residual feed intake (RFI) utilizing a Growsafe™ system. RFI was calculated by subtracting expected intake from actual intake. Expected intake was determined by regressing metabolic body size of mid-test weight. Regression determined ADG on actual intake for individuals in the population. Texel (n = 58) and Katahdin (n = 118) lambs were placed in a feedlot and fed in separate feeding trials, a complete pellet ad libitum as the sole source of nutrition. In this environment Texel and Katahdin lambs had expected ADG values (0.27 kg/day, 0.32 kg/day respectively) and actual intake data (2154.17 g/day, 1909.33 g/day respectively. After a period of adaptation, Texel average intake was determined over a period of 27 consecutive days and used to calculate individual RFI within the test population. Observable ranges of RFI (-0.62 – +0.62) were seen in the Texel lambs. At the start of the Katahdin trial lambs were separated by sex and FEC treatment. After a period of adaptation, Katahdin average intake was determined over a period of 42 consecutive days and used to calculate individual RFI within the test population. Observable ranges of RFI (-0.53 – +0.50) were seen in the Katahdin lambs as well. In both feeding trials RFI appeared to be normally distributed. Use of this technology may be useful in identifying superior individuals for feed efficiency.

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RAPID COMMUNICATION: Residual feed intake in beef cattle is associated with differences in protein turnover and nutrient transporters in ruminal epithelium

Journal of Animal Science ◽

10.1093/jas/skz080 ◽

2019 ◽

Vol 97 (5) ◽

pp. 2181-2187

Author(s):

Ahmed A Elolimy ◽

Emad Abdel-Hamied ◽

Liangyu Hu ◽

Joshua C McCann ◽

Daniel W Shike ◽

...

Keyword(s):

Amino Acid ◽

Beef Cattle ◽

Protein Degradation ◽

Insulin Signaling ◽

Feed Intake ◽

Feed Efficiency ◽

Protein Turnover ◽

Residual Feed Intake ◽

Ubiquitin Proteasome ◽

Ruminal Epithelium

Abstract Residual feed intake (RFI) is a widely used measure of feed efficiency in cattle. Although the precise biologic mechanisms associated with improved feed efficiency are not well-known, most-efficient steers (i.e., with low RFI coefficient) downregulate abundance of proteins controlling protein degradation in skeletal muscle. Whether cellular mechanisms controlling protein turnover in ruminal tissue differ by RFI classification is unknown. The aim was to investigate associations between RFI and signaling through the mechanistic target of rapamycin (MTOR) and ubiquitin-proteasome pathways in ruminal epithelium. One hundred and forty-nine Red Angus cattle were allocated to 3 contemporary groups according to sex and herd origin. Animals were offered a finishing diet for 70 d to calculate the RFI coefficient for each. Within each group, the 2 most-efficient (n = 6) and least-efficient animals (n = 6) were selected. Compared with least-efficient animals, the most-efficient animals consumed less feed (P < 0.05; 18.36 vs. 23.39 kg/d DMI). At day 70, plasma samples were collected for insulin concentration analysis. Ruminal epithelium was collected immediately after slaughter to determine abundance and phosphorylation status of 29 proteins associated with MTOR, ubiquitin-proteasome, insulin signaling, and glucose and amino acid transport. Among the proteins involved in cellular protein synthesis, most-efficient animals had lower (P ≤ 0.05) abundance of MTOR, p-MTOR, RPS6KB1, EIF2A, EEF2K, AKT1, and RPS6KB1, whereas MAPK3 tended (P = 0.07) to be lower. In contrast, abundance of p-EEF2K, p-EEF2K:EEF2K, and p-EIF2A:EIF2A in most-efficient animals was greater (P ≤ 0.05). Among proteins catalyzing steps required for protein degradation, the abundance of UBA1, NEDD4, and STUB1 was lower (P ≤ 0.05) and MDM2 tended (P = 0.06) to be lower in most-efficient cattle. Plasma insulin and ruminal epithelium insulin signaling proteins did not differ (P > 0.05) between RFI groups. However, abundance of the insulin-responsive glucose transporter SLC2A4 and the amino acid transporters SLC1A3 and SLC1A5 also was lower (P ≤ 0.05) in most-efficient cattle. Overall, the data indicate that differences in signaling mechanisms controlling protein turnover and nutrient transport in ruminal epithelium are components of feed efficiency in beef cattle.

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Genetic parameters and breed differences for feed efficiency, growth, and body composition traits of young beef bulls

Canadian Journal of Animal Science ◽

10.4141/a03-085 ◽

2004 ◽

Vol 84 (2) ◽

pp. 177-185 ◽

Cited By ~ 124

Author(s):

F. S. Schenkel ◽

S. P. Miller ◽

J. W. Wilton

Keyword(s):

Body Composition ◽

Genetic Correlation ◽

Feed Intake ◽

Feed Efficiency ◽

Fixed Effects ◽

Residual Feed Intake ◽

Backfat Thickness ◽

Daily Weight Gain ◽

Feed Conversion ◽

Beef Bulls

Genetic associations between feed efficiency, growth, and live ultrasound measured body composition traits were studied in purebred beef bulls of six breeds in Ontario bull test stations from 1991 to 2000. Feed traits included average daily feed intake (FI), feed conversion ratio (FCR), and residual feed intake [feed intake adjusted for production alone (RFIp) or production and backfat thickness (RFIb)]. Growth traits were average daily weight gain (ADG), mid-test metabolic weight (MW), hip height (HH), and scrotal circumference (SC). Body composition traits included ultrasound backfat thickness (BF), longissimus muscle area (LMA), and predicted percentage of intramuscular fat (IFAT). Bulls were measured every 28 d for weight and individual feed intake, and at the end of test for ultrasound body composition traits. Number of records per trait ranged from 2284 (FI) to 13 319 (ADG). Fixed effects of test group, breed and end of test age (within breed), and random effects of animal and herd of origin were modeled using REML bivariate analyses for all traits. Heritability estimates were moderate for all traits (0.30 to 0.55), except for IFAT (0.14). The genetic correlation between RFIp and RFIb was high (0.99) within breeds, but breeds ranked differently with respect to RFIp and RFIb. Genetic correlations of RFIb with ADG and backfat thickness were essentially zero, which indicate that selection on residual feed intake could be implemented to reduce feed intake and improve feed conversion without compromising growth or changing levels of subcutaneous fat. Key words: Central test, genetic correlation, heritability, residual feed intake

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Claw health and feed efficiency as new selection criteria in the Czech Holstein cattle Krupová Z., Wolfová M., Krupa E., Přibyl J., Zavadilová L.

Czech Journal of Animal Science ◽

10.17221/44/2018-cjas ◽

2018 ◽

Vol 63 (No. 10) ◽

pp. 408-418 ◽

Cited By ~ 1

Author(s):

Z. Krupová ◽

M. Wolfová ◽

E. Krupa ◽

J. Přibyl ◽

L. Zavadilová

Keyword(s):

Feed Intake ◽

Feed Efficiency ◽

Disease Incidence ◽

Selection Index ◽

Residual Feed Intake ◽

Selection Response ◽

Holstein Cattle ◽

Breeding Objective ◽

Economic Weights ◽

The Impact

The objective of this study was to calculate economic weights for ten current breeding objective traits and for four new traits characterising claw health and feed efficiency in Czech Holstein cattle and to investigate the impact of different selection indices on the genetic responses for these traits. Economic weights were estimated using a bio-economic model, while applying actual (2017) and predicted (2025) production and economic circumstances. For the actual situation, the economic weights of claw disease incidence were –100.1 € per case, and those of daily residual feed intake in cows, breeding heifers, and fattened animals were –79.37, –37.16, and –6.33 €/kg dry matter intake per day, respectively. In the predicted situation, the marginal economic weights for claw disease and feed efficiency traits increased on average by 38% and 20%, respectively. The new traits, claw disease incidence and daily residual feed intake, were gradually added to the 17 current Holstein selection index traits to improve the new traits. Constructing a comprehensive index with 21 traits and applying the general principles of the selection index theory, a favourable annual genetic selection response was obtained for the new traits (–0.008 cases of claw disease incidence and –0.006 kg of daily residual feed intake across all cattle categories), keeping the annual selection response of the most important current breeding objective traits at a satisfactory level (e.g., 73 kg of milk yield per lactation, 0.016% of milk fat). Claw health and feed efficiency should be defined as new breeding objectives and new selection index traits of local dairy population.

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Genetic variation in net feed efficiency in Hereford cattle and its association with other production traits

Proceedings of the British Society of Animal Science ◽

10.1017/s1752756200002027 ◽

1999 ◽

Vol 1999 ◽

pp. 47-47

Author(s):

R.M. Herd ◽

S.C. Bishop

Keyword(s):

Growth Rate ◽

Genetic Variation ◽

Feed Intake ◽

Feed Efficiency ◽

Genetic Correlations ◽

Feed Consumption ◽

Production Traits ◽

Performance Measurements ◽

Hereford Cattle ◽

Rate Selection

Net feed efficiency refers to variation in feed consumption between animals net of requirements for maintenance and production, and may be measured as residual feed intake (RFI). Because RFI is independent of liveweight (LW) and growth rate, selection for improved net feed efficiency is likely to reduce feed intake with little change in growth. The purpose of this study was to establish whether there exists genetic variation in RFI in young British Hereford bulls, and to determine the phenotypic and genetic correlations of RFI with key production traits.The data consisted of performance measurements on 540 bull progeny of 154 British Hereford sires, collected over ten 200-day postweaning performance tests conducted between 1979 and 1988. The traits analysed were food intake (FI), 200 to 400-day daily gain (ADG), 400-day weight (W400), predicted carcass lean content (LEAN), lean growth rate (LGR), food conversion ratio (FI/ADG) and lean FCR (LFCR; FI/(ADG x LEAN), described by Bishop (1992).

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Genetics of residual feed intake in growing pigs: Relationships with production traits, and nitrogen and phosphorus excretion traits1

Journal of Animal Science ◽

10.2527/jas.2012-5687 ◽

2013 ◽

Vol 91 (6) ◽

pp. 2542-2554 ◽

Cited By ~ 49

Author(s):

R. Saintilan ◽

I. Mérour ◽

L. Brossard ◽

T. Tribout ◽

J. Y. Dourmad ◽

...

Keyword(s):

Feed Intake ◽

Residual Feed Intake ◽

Growing Pigs ◽

Production Traits ◽

Nitrogen And Phosphorus ◽

Phosphorus Excretion

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Spectral analysis of feeding patterns of steers divergent in residual feed intake

Australian Journal of Experimental Agriculture ◽

10.1071/ea08021 ◽

2008 ◽

Vol 48 (7) ◽

pp. 843 ◽

Cited By ~ 8

Author(s):

Robin Dobos ◽

Robert Herd

Keyword(s):

Spectral Analysis ◽

Feed Intake ◽

Feed Efficiency ◽

Feeding Behaviour ◽

Feeding Rate ◽

Residual Feed Intake ◽

Selection Line ◽

Feeding Patterns ◽

Time Spent Feeding ◽

Efficient Selection

Spectral analysis was used to quantify differences in feeding patterns of Angus steers genetically divergent in residual feed intake (RFI). Forty-two low RFI (more efficient) and 28 high RFI (less efficient) selection line steers were fed a feedlot diet through electronic feeders for 72 days. Mean (±s.e.) daily feed intake was 11.9 ± 0.076 and 12.7 ± 0.095 kg dry matter/day over the 72-day feeding period for low and high RFI steers, respectively. The high RFI steers exhibited different temporal cycles to the low RFI steers in daily feed intake and time spent feeding. However, patterns of number of eating sessions, feeding rate, the time spent eating and the number of eating sessions were similar. Further analysis of daily (24 h) feeding behaviour is required to help improve our understanding of the association between feeding behaviour and feed efficiency.

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