Effects of dietary protein concentration on lipid metabolism gene expression and fatty acid composition in 18–23‐month‐old hanwoo steers

Abstract

The present study evaluated the influence of dietary protein level on growth performance, fatty acid composition, and the expression of lipid metabolic genes in intramuscular adipose tissues from 18‐ to 23‐month‐old Hanwoo steers, representing the switching point of the lean‐to‐fat ratio. Forty steers with an initial live weight of 486 ± 37 kg were assigned to one of two treatment groups fed either a concentrate diet with 14.5% CP and or with 17% CP for 6 months. Biopsy samples of intramuscular tissue were collected to analyze the fatty acid composition and gene expression at 23 months of age. Throughout the entire experimental period, all steers were restrained twice daily to allow individual feeding. Growth performance, blood metabolites, and carcass traits, according to ultrasonic measurements, were not affected by the experimental diets. The high‐protein diet significantly increased the expression of intramuscular PPARα (p < 0.1) and LPL (p < 0.05) but did.