Elucidating Genetic Mechanisms of Feed Efficiency in Beef Cattle by Gene Expression

Abstract

The objective of the experiments conducted for this thesis was to improve our understanding of the genetic mechanisms which underlie feed efficiency by measuring residual feed intake (RFI) in beef cattle. This thesis reports the results from three experiments studying RFI in cattle by gene expression using quantitative real-time PCR (qPCR) and deep sequencing. qPCR was used to study and validate the gene expression of eight candidate RFI-related genes in bovine liver of Angus production line cattle, and assess gene expression changes in response to hormonal growth promotant (HGP). Deep sequencing was used to profile microRNAs (miRNA) in liver tissue of Angus cattle that had been divergently selected for RFI.