Evaluation of Bonsmara and Belmont Red cattle breeds in South Africa, 2, Genetic parameters for growth and fertility

Genetic parameters were estimated for growth and fertility indicator traits in a South African beef cattle population. Measurements on 5601 pedigreed progeny of 96 Bonsmara sires, 18 Belmont Red sires and 20 Bonsmara x Belmont Red cross sires were recorded over 19 years in 4 diverse climate regions of South Africa. Growth traits were measured on growing stock from birth to 18 months at pasture. Cow weights were measured at calving and weaning. Age at first calving, and repeated measurement of calving interval were recorded on 1993 breading females as indicators of reproductive performance. The traits were analysed using univariate and bivariate animal models with maternal effects fitted.