Estimates of crossbreeding parameters in a multibreed beef cattle crossbreeding project

Data from purebred and crossbred cattle, consisting of the Afrikaner (A), Simmentaler (S) and Hereford (H) breeds managed in a relatively intensive but high stocking rate environment, were analysed to estimate breed direct effects, individual heterotic effects, breed maternal and maternal heterotic effects for birth weight (BW) and weaning weight (WW). Simmentaler breed direct effects, expressed as deviation from the general mean, were positive (P 0.05) for WW. Individual heterotic effects for BW were significant (P 0.05) for both BW and WW. (South African Journal of Animal Science, 2000, 30(3): 193-203