Effect of winter nutritional levels on subsequent growth of beef heifers in the Highland Sourveld of Natal

Author: A. van Niekerk, R. Kernick and A.W. Lishman
Year: 1990
Issue: 2
Volume: 20
Page: 84 - 89

The effect of different levels of winter nutrition on the subsequent performance of Simmentaler weaner (seven-month-old) heifers on summer veld at different stocking rates was evaluated in the Highland Sourveld of Natal. The data from 300 heifers over a three-year period were analysed. During their second winter, the heifers were fed to achieve a target mating mass of 330 kg at 26 months of age. The feed cost to achieve a growth rate of 0,5 kg/ d during the first winter following weaning was 93% higher than the cost to achieve a growth rate of 0,25 kg/d. On summer veld, heifers run at a low stocking rate of 0,75 LSU /ha (for the grazing period) gained significantly (P < 0,01) more mass than heifers subjected to a high stocking rate of 1,25 LSU / ha, irrespective of the previous winter nutritional level. Within each stocking rate, the heifers at a low winter nutritional level gained significantly (P < 0,01) more mass on veld than those on the high winter plane of nutrition. Significantly (P < 0,01) more compensatory growth occurred during the first half (94 days) of the grazing season. The data suggest that the ability of a beef heifer to achieve compensatory growth on summer sourveld in Natal should be exploited, but that the degree of compensatory growth might be significantly modified by stocking rate. The difference of R73 (at current money value) per head between the lowest and highest feed costs up to the mating stage underlines the importance of selecting the correct rearing strategy for heifers in the sourveld.


Keywords: Compensatory growth, economics, heifers, winter nutrition
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