Association of single nucleotide polymorphisms in the leptin gene with carcass and meat quality traits of beef cattle1

作者：Flávio Schramm Schenkel, Stephen Paul Miller, X. Ye, S. S. Moore, J. D. Nkrumah, C. Li, Yu Jiang, I. B. Mandell, James W. Wilton, John Lewis Williams · 发表于：Journal of Animal Science · 年份：2005 · DOI：10.2527/2005.8392009x · 被引用次数：317 · 研究领域：Meat and Animal Product Quality、Regulation of Appetite and Obesity、Biochemical Analysis and Sensing Techniques

Calpastatin (CAST) is a naturally occurring protein that inhibits the normal tenderization of meat as it ages postmortem. A SNP was identified in the CAST gene (a G to C substitution) and genotyped on crossbred commercially fed heifers (n = 163), steers (n = 226), and bulls (n = 61) from beef feedlots, and steers (n = 178) from a University of Guelph feeding trial. The association of the CAST SNP with carcass and meat quality traits was studied. Carcass traits included fat, lean, and bone yield; grade fat; LM area; and HCW. Meat quality traits included marbling grade; i.m. fat content of LM; tenderness evaluation of LM (Warner-Bratzler shear force) at 2, 7, 14, and 21 d of postmortem aging; and tenderness evaluation of semitendinosus muscle at 7 d of postmortem aging. The mixed model used in the analyses included fixed effects of CAST genotype, sex, slaughter group, and breed composition (linear covariate); sire was a random effect. For the analysis of shear force, i.m. fat content of LM was also included in the model as a linear covariate. Shear force measures were analyzed within days of postmortem aging and by repeated measures analysis. The CAST SNP allele C was more frequent (63%) in the crossbred population than allele G. The CAST SNP was associated with shear force across days of postmortem aging (P = 0.005); genotype CC yielded beef that was more tender than GG (-0.32 kg +/- 0.13), and CG had intermediate tenderness. The corresponding average allele substitution effec...