Correlated responses in calf body weight and size to divergent selection for yearling growth rate in Angus cattle

摘要: Correlated responses in calf weight and size traits resulting from 17 years (1974–1991) of divergent selection for yearling growth rate an Angus beef cattle experiment were evaluated. Deviations two lines (High line Low line) unselected Control line, as well trends estimated breeding values (EBVs) the examined. per year birth weight, weaning height, girth, length, pelvic area scrotal circumference at age 0.18, 1.53, 2.23 kg, 0.35, 0.47, 0.29 cm, 1.06 cm2 0.12 respectively, High −0.24, −1.71, −2.41 −0.29, −0.41 −0.83 −0.05 line. The changes EBVs after 1.52, 18.36 30.70 0.40, 1.35 2.88 −2.85, −15.40 −27.07 These correlated responses, which large enough to allow 90% correct discrimination between based on body size, occurred without any shape animals. Realised genetic correlations these with gain all positive ranged 0.24 0.97. results indicate that was effective changing potential up age.