Table of Contents
International Scholarly Research Notices
Volume 2015, Article ID 194014, 5 pages
Research Article

Relationship between Liver Mitochondrial Respiration and Proton Leak in Low and High RFI Steers from Two Lineages of RFI Angus Bulls

1School of Veterinary Medicine, University of California, Tulare, CA 93271, USA
2Zoetis Inc., Kalamazoo, MI 49001, USA
3School of Veterinary Medicine, University of California, Davis, CA 95616, USA

Received 23 October 2014; Revised 3 April 2015; Accepted 6 April 2015

Academic Editor: Rui Curi

Copyright © 2015 G. Acetoze et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.


The objective of this research is to evaluate liver mitochondrial oxygen consumption and proton leak kinetics in progeny from two lineages of Angus bulls with high and low residual feed intake (RFI). Two Angus bulls were selected based on results from a genetic test for RFI and were used as sires. Eight offspring at 10-11 months of age from each sire were housed in individual pens for 70–105 days following a diet adaptation period of 14 days. Progeny of the low RFI sire had 0.57 kg/d () lower average RFI than progeny of the high RFI sire. There was no difference in dry matter intake between low and high RFI steers, but low RFI steers gained more body weight () and tended to have higher average daily gains (). State 3 and State 4 respiration, RCR, and proton leak did not differ between high and low RFI steers (, , , and , resp.). Therefore, the increase in bodyweight gain which distinguished the low RFI steers from the high RFI steers may be associated with other metabolic mechanisms that are not associated with liver mitochondrial respiration and proton leak kinetics.