Genetic parameters for ultrasound and carcass measures of yield and quality among replacement and slaughter beef cattle.

摘要: Real time ultrasound (RTU) measures of longissimus muscle area and fat depth were taken at 12 14 mo age on composite bulls (n = 404) heifers 514). Carcass depth, hot carcass weight, estimated percentage lean yield, marbling score, Warner-Bratzler shear force, 7-rib dissectable seam percentages measured steers 235). Additive genetic variances for 76 77% larger in than the corresponding estimates heifers. Heritability 0.61 0.52 0.49 0.47 mo, respectively. The correlations vs 0.84 Genetic steer carcasses 0.71 0.67 with areas 0.73 0.79 mo. 0.50 0.35 0.44 correlation was 0.65 slaughter 0.23 0.21, between 0.66 0.86, Live weights genetically equivalent (r(g) 0.98). live weight also high > 0.80). Longissimus using RTU positively correlated area, a section from steers. Measures backfat obtained carcasses. negative but low. These results indicate that may be under sufficiently different control to warrant being treated as separate traits evaluation models. Further, potential replacement considered