Genetic parameter estimates of live animal ultrasonic measures of retail yield indicators in yearling breeding cattle.

摘要: Ultrasonic measures of backfat thickness (BFT) and longissimus muscle area (LMA) taken on Angus bulls (n = 805) heifers 877) ranging in age from approximately 8 to 20 mo a production setting western Nebraska were used estimate genetic (co)variances. Further information the analyses, including weaning weight (WWT), postweaning ADG, scrotal circumference (SC), was obtained American Association, St. Joseph, MO, for these individuals animals same herd contemporary groups. Data analyzed using single-trait, sire model, restricted maximum likelihood (REML) procedures starting variances later two-trait analyses. These analyses done variance components WWT coupled with BFT, LMA, SC, also REML procedures, but sire-maternal grandsire model other trait(s). Heritabilities direct, maternal, ADG .56, .11, .19, .24, .51, respectively. Genetic correlations between direct maternal BFT -.57, .42, .01, -.69, parameters this study calculate possible change typical selection scenario, it shown that among WWT, could be affected most by selection, relative its mean.