Data of 1810 milk and fat records of 109 sires and their pedigree in 48 herds calving from 1985 to 1991 were used to estimate genetic parameters for the animal model. The estimates of the heritabilities for milk and fat yields by multivariate REML pro...
Data of 1810 milk and fat records of 109 sires and their pedigree in 48 herds calving from 1985 to 1991 were used to estimate genetic parameters for the animal model. The estimates of the heritabilities for milk and fat yields by multivariate REML procedure were 0.32(0.10) and 0.29(0.10), respectively. Estimated genetic and phenotypic correlations were 0.70(0.13) and 0.72(0.01). respectively. The additive genetic relationship between milk yield and fat yield appeared to be quadratic rather than the linear based on the PTA from the animal model. Relative magnitudes of variance components for error. permanent environment, and herd-sire interaction did not have significant effects on the PTA and their ranks, iteration time, and iteration number to meet convergence in the animal model. But there were considerable differences(420) in the number of iteration to meet convergence when some different variance component ratios of error to additive genetic effect(1 to 5) were used in the animal model.