Estimates of heritabilities and correlations of traits associated with pelvic area in beef cattle.

摘要: Pelvic measurements, cow weights and ages were obtained on 703 Angus- Hereford-sired cows from five Louisiana Agricultural Experiment Station herds. Cows either purebred or crossbred, ranging in age 1 to 14 yr, sired by 52 Angus 63 Hereford bulls. All pelvic measurements via the rectum same technician. Paternal half-sib heritability estimates genetic (rG) phenotypic (rP) correlations computed for height (PH), width (PW), area (PA-I; product of PH X PW), ratio PW weight (CW). was also calculated as an ellipse using formula PA-II = pi (PH/2)(PW/2). Mean PA-I 298.5 cm2 while averaged 234.4 cm2. The pooled estimate .68 +/- .34, indicating that is a highly heritable trait should respond selection. similar (.66 .34). higher than PA-I. CW .57 .34 positively correlated (rG2 .47 rP .40) with Direct selection estimated yield response 12.2 one generation 12.5 kg. If change held at zero restricted index, about 90% much increase compared ignoring index. Therefore, increased can be accomplished without causing large increases size. This aid reducing calving difficulty.