479 Determining Effects of Residual Feed Intake on Economically Important Production Traits in Crossbreed Beef Cattle.

2018 ◽  
Vol 96 (suppl_2) ◽  
pp. 256-257
Author(s):  
S A Hershorin ◽  
R Manjarin ◽  
A M Emond ◽  
S Id-Lahoucine ◽  
P Fonseca ◽  
...  
2019 ◽  
Vol 97 (5) ◽  
pp. 2181-2187
Author(s):  
Ahmed A Elolimy ◽  
Emad Abdel-Hamied ◽  
Liangyu Hu ◽  
Joshua C McCann ◽  
Daniel W Shike ◽  
...  

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.


2013 ◽  
Vol 85 (4) ◽  
pp. 374-387 ◽  
Author(s):  
Brian Karisa ◽  
Stephen Moore ◽  
Graham Plastow

2020 ◽  
Vol 98 (Supplement_2) ◽  
pp. 75-76
Author(s):  
Camren l Maierle ◽  
Andrew R Weaver ◽  
Eugene Felton ◽  
Scott P Greiner ◽  
Scott A Bowdridge

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.


2013 ◽  
Vol 91 (6) ◽  
pp. 2542-2554 ◽  
Author(s):  
R. Saintilan ◽  
I. Mérour ◽  
L. Brossard ◽  
T. Tribout ◽  
J. Y. Dourmad ◽  
...  

2016 ◽  
Vol 95 (9) ◽  
pp. 1999-2010 ◽  
Author(s):  
L. Drouilhet ◽  
R. Monteville ◽  
C. Molette ◽  
M. Lague ◽  
A. Cornuez ◽  
...  

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