Genetic evaluation of carcass traits in Simmental-sired cattle at different slaughter end points.

摘要: Our objectives were to estimate genetic parameters for carcass traits and evaluate the influence of slaughter end point on estimated breeding values (BV). Data provided by American Simmental Association divided into three sets: 1) 9,604 records hot weight (CW) percentage retail cuts (PRC), 2) 6,429 CW, PRC, marbling score (MS), 3) 1,780 MS, fat thickness (FT), longissimus muscle area (LMA). Weaning weights (WW) from animals with data their weaning contemporaries used. analyzed a multiple-trait animal model REML procedures BV an age-, CW-, MS-, or FT-constant basis. The included fixed contemporary group covariates breed, heterozygosity, random additive direct residual effects. was preadjusted founder effects, maternal heterosis, age dam, calf. WW genetic, permanent environment, Heritabilities set 1 0.34 CW 0.25 PRC age-constant basis point. 2 0.35, 0.24, 0.36 respectively, heritabilities MS CW-constant 0.33 at constant 3 as follows: 0.32; 0.09; 0.12; FT, 0.10; LMA, 0.26. Heritability estimates similar those 0.12 0.14 0.22 LMA basis; 0.30 0.09 0.10 0.28 point; 0.33, 0.17, 0.13, 0.29 Genetic correlations among varied across groups points but suggested that it should be possible select improved lean yield without sacrificing quality grade. Correlations calculated computed different points. Adjustment various resulted in some changes reranking sires, especially PRC; however, number available had larger than