Breed and crossbreeding effects in a crossing experiment between dutch friesian and holstein friesian cattle

In the second generation of a crossbreeding experiment with Holstein Friesian bulls and Dutch Friesian cows the difference in additive genetic merits between Holstein Friesian and Dutch Friesian bulls (a), the heterotic effects (d) and the maternal effects (m) were calculated from the mean values of the four subpopulations with 0%, 25%, 50% and 75% Holstein Friesian genes. Significant a effects were found for milk yield, fat percentage, fat yield, protein yield, fleshiness (beef bulls and veal calves), fat covering (beef bulls), dressing percentage (veal calves), birth weight, percentage of calving difficulties and gestation period. A significant d effect was found for fat covering (beef bulls). For dressing percentage (veal calves), for the percentage of calving difficulties and of retained placenta, significant m effects were calculated.