Estimation of pre-weaning productive performance and genetic parameters in beef cattle (Bos taurus) and crosses, VIII Region of Chile

Abstract

The objective was to determine the productive performance in body weight change from birth until weaning, of calves sired by Angus, Hereford and Polled Hereford with Clavel, Hereford, Holstein, Polled Hereford, and Hybrid (different Holstein and Hereford combinations) cows in a beef cattle herd in the dry area of the Ñuble, province of the VIII Region in Chile. The sires and cows were classified according to their phenotypic characteristics. The productive performance was evaluated by analyzing 1,119 production records from year 1990 to 2000 for the variables: birth weight (PN, N=1,119), adjusted weaning weight (PD205, N=660) and preweaning daily gain (GDP; N=660) using the least squares method to determine the effects of breed group of the sire (GRT), breed group of the dam (GRV), and contemporary groups (GC), with age of dam (EDV) as a covariable, on PN, PD205 and GDP. Genetic and environmental parameters were estimated using an animal model with MTDFREML methodology, through univariable and bivariable analyses to estimate variance and covariance components. GRT and the GC had a significant effect (P<0.05) on PN and PD205 but did not affect GDP (P•0.05). Calves sired by Hereford bulls were 7.5, 12.5 y 14.0 % above the herd average for PN, PD205 and GDP, respectively. The GRV did not have an effect (P•0.05) on PN, PD205 and GDP. Heritabilities (h²) calculated were 0.49 for PN, 0.15 for PD205 and 0.35 for GDP. Genetic correlation between PN and PD205 was 0.23. Within the GRT the h2 for PN and PD205 were 0.69 and 0.21 for Angus and 0.47 and 0.23 for Polled Hereford, respectively.