Correlação genética do peso e do perímetro escrotal de machos aos 12 meses de idade e característica de crescimento de fêmeas, na raça Canchim.

Abstract

The objective of this work was to estimate heritability of body weight at 12 (FBW12) and 18 (FBW18) months of age, and absolute (ABWG) and relative (RBWG) body weight gains from 12 to 18 months of age of females, and the genetic correlations of these trais with body weight (MBW12) and scrotal circumference (MSC12) of males at 12 months of age, in Canchim cattle. The variance and covariance components, used to obtain the genetic parameters, were estimated by the restricted maximum likelihood method, using one-trait analyses for the female traits only and two-trait analyses for a male trait with a female trait. The model included fixed effects (contemporary group and, or, the covariable age of the animal at 12 months) and random additive direct effects. The heritability estimates were: 0.30 (FBW12), 0.34 (FBW18), 0.07 (ABWG) and 0.04 (RBWG). The genetic correlations of MBW12 with FBW12, FBW18, ABWG and RBWG were equal to 1.00, 0.99, 0.66 and -0.18, respectively. The genetic correlations of MSC12 with FBW12, FBW18, ABWG and RBWG were equal to 0.27, 0.24, 0.66 and 0.60, respectively. The results show that selection to increase MBW12 should result in higher FBW12, FBW18 and ABWG of females; and selection to increase MSC12 should result in increased ABWG and RBWG of females.