A NOTE ON THE EARLY CALVING OF BEEF HEIFERS

The Nguni, the smallest beef breed in South Africa, was used to investigate the advantages of mating beef heifers early. A group of 43 heifers was mated at 13 - 15 months of age, in contrast to the normal practice of mating heifers at 25-27 months of age. No significant differences were found in calving percentage, fecundity percentage or mature cow mass between the two groups. However, there were significant differences in birth mass (24,8 versus 26,0) and weaning mass (156,3 versus 174,4) of the progeny produced by the two groups during the entire experiment. The main reason for the differences in weaning mass seems to be a lower milk production in the early calving group due to reduced udder development. The results suggested that without additional inputs early mating may not be a feasible proposition.