MELLO, Sílvio de Paula.; ALENCAR, Maurício Mello de.; TORAL, Fabio Luiz Buranelo.; BARBOSA, Pedro Franklin.; SILVA, Ana Mary da.
Résumé:
The objective of this study was to estimate genetic correlations between age at first calving (AFC) and
parameters A (asymptotic weight) and k (maturation rate) of Von Bertalanffy’s model and mature weight (MW) of
females of the Canchim beef cattle breed. (Co)variance components were estimated by the restricted maximum
likelihood method, in two-trait analyses of AFC with A, k and MW, using an animal model with additive direct and
residual random effects and the fixed effects of year and season of birth for AFC, A and k, and year and season
of calving for MW. The heritability estimates were 0.27 (A), 0.37 (k), 0.48 (MW) and 0.03 (FAC). The genetic
correlations between AFC and A (0.16), k (-0.75) and MW (0.25) show that selection for higher maturation rate
and small asymptotic weight would decrease AFC and, then, improve productivity of Canchim herds.