Use of Bayesian analysis of growth functions to estimate crossbreeding parameters in Iberian pigs

Bayesian techniques allow to analyze performance data from growth functions taking into account all the information recorded from each animal, its relatives and the individuals whose data are located in the same systematic effects. This procedure was used to estimate crossbreeding parameters for growth performance up to 95 kg using two data sets from a complete diallel cross among four strains of Iberian pigs (i) 14 037 weight records from 1274 pigs with restricted feeding; and (ii) 3280 records from 450 pigs hand-fed to appetite. The intercept (a) and the slope (b) of the linear growth function were analyzed with a bivariate animal model including as covariables the crossbreeding parameters. The means of posterior distributions of heritabilities and genetic correlation were ha2 = 0.48 and 0.58, hb2 = 0.32 and 0.55, rG =0.81 and 0.99, for the two data sets, respectively. Expressed as percentage of parental strains, the values of the mean heterosis were 14.1 and 12.1 for the intercept and 14.6 and 10.9 for the slope. © 2002 Elsevier Science B.V. All rights reserved.