The performance of Brahman-Shorthorn and Sahiwal-shorthorn beef cattle in the dry tropics of northern Queensland, 3. Birth weights and growth to weaning
1993
Fordyce, G. | James, T.A. | Holroyd, R.G. | Beaman, N.J. (Queensland Dept. of Primary Industries, Ayr (Australia)) | Mayer, R.J. (Queensland Dept. of Primary Industries, Townsville (Australia)) | O'Rourke, P.K. (Queensland Dept. of Primary Industries, Brisbane (Australia))
In general, for 4 inter se mated herd groups, Brahman crosses were heavier at birth and grew faster to weaning than Sahiwal crosses, with consequent advantages in weaning weights of 11 and 6 kg in first backcross and late generation crosses, respectively. There was a birth weight advantage of half crosses over three quarter crosses, which was eroded by the time of weaning. Superior growth rates of three quarter crosses were primarily expressed in years with greater nutritional stress and appeared to be due to better adaptation to environmental stresses by the calf. Males exhibited an 8 percent average advantage over females for all weight and growth traits in late generation calves. Calves with mature dams were 1.8 kg heavier at birth. This, along with their higher preweaning growth rate (19-49 g per day), resulted in calves with mature dams being 4-10 kg heavier at weaning than calves of young cows. Differences between years in birth weights and preweaning growth rates were 25 percent or less. Birth weight was affected by nutrition of the dam in late pregnancy, and growth of calves was higher in years when the pasture growing season commenced earlier.
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