ESTIMATION OF DIRECT AND MATERNAL GENETIC-PARAMETERS FOR PREWEANING TRAITS IN THE ASTURIANA DE LOS VALLES BEEF-CATTLE BREED THROUGH ANIMAL AND SIRE MODELS

Estimates of variance components for birth weight, weaning weight and average daily gain were obtained comparing different animal and sire u nivariate models for an important local beef cattle breed. Problems en countered with models involving maternal effects were discussed. Direc t and maternal heritabilities were respectively 0.32 and 0.13 for birt h weight, 0.60 and 0.30 for weaning weight and 0.49 and 0.37 for avera ge daily gain. The correlation between direct and maternal genetic eff ects was not important for birth weight, but high and negative for wea ning weight (-0.73), and average daily gain (-0.87), in close agreemen t with the most recent estimates in other breeds.