Factors affecting the pre-weaning performance of Nguni and Angus x Nguni calves in an arid environment of South Africa

Author: M.M. Scholtz, A. Theunissen, M.C. Mokolobate, O. Ntwaeagae & M. Ferreira
Year: 2017
Issue: 1
Volume: 10
Page: 1 - 8

The importance of indigenous breeds that are adapted to the anticipated warmer climate, lower nutritional value of the grazing and harsher conditions will increase as a result of climate change. South Africa has indigenous beef cattle breeds such as the Nguni that are widely recognized for its adaptive attributes. Extensive livestock production is an important agricultural activity in the Northern Cape and many other parts of South Africa. Continuous deterioration in beef cattle production environments as well as alternative grass-fed production systems necessitates the reviewing and evaluation of current production and breeding strategies. Crossbreeding between British / European and indigenous breeds may become more important to increase beef production in the near future, where management is at relatively high levels, but where conditions are harsh. The aim of this study was to evaluate the Nguni in a terminal crossbreeding system. The research was conducted over a period of four years at the Vaalharts Research Station of the Northern Cape Department of Agricultural, Land Reform and Rural Development near Jan Kempdorp. A total of 238 weaning weight records was collected (167 Nguni and 81 Angus x Nguni). The 205-day weaning weight of the Angus x Nguni calves were 177 kg and that of the pure Nguni calves 145 kg. Although the adjusted weaning weight of the Angus x Nguni calves was 32 kg higher than that of pure Nguni calves, the difference was not significant. This can be attributed to the large variation in weaning weights, with that of the pure Nguni calves ranging from 56 kg to 230 kg and that of the Angus x Nguni calves from 105 kg to 303 kg. The 205-day weight also increased with an increase in the age of the cow until five years, where after it decreased. The cow weight at weaning did not seem to have an effect on the weaning weights of the calves. If cow efficiency is expressed as kilogram calf weaned per Large Stock Unit, the cow efficiency of cows with Angus x Nguni calves improves by 22%. The results showed that crossbreeding can increase the weaning weights of crossbred calves from Nguni cows. As a result of the very large variation in the 205-day weights, some non-genetic factors affecting this weight were evaluated. It was found that in addition to the sex of the calf, 205-day weight was also affected by age of the dam, the year of weaning, month of birth, year x genotype interaction and the herd of origin of the dam. The fact that herd of origin of the cow affects the weaning weights of her calves may indicate the presence of epigenetics or large differences in genetic merit between herds.

Keywords: non-genetic factors
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