Explaining the principle of large stock units and its implications on grazing capacity

Author: M.C. Mokolobate, M.M. Scholtz & F.J. Calitz
Year: 2017
Issue: 1
Volume: 10
Page: 17 - 20

The difference between the grazing capacity of the veld and the stocking rate is that grazing capacity refers to the true number of animals that the vegetation can sustain; and stocking rate to the perceived number of animals that the vegetation can sustain. This sometimes differ by as much as 300% leading to the total degradation of the natural vegetation. The principle of Large Stock Units should be used to address this, in which beef cattle are categorized in different frame sizes and physiological phases. It should be noted that the feed requirements of animals of different frame and at different physiological stages are different, even if they have the same body weight. The reason for this is that there are differences in voluntary feed intake between such animals, which can be ascribed to differences in basal metabolism. The different breeds are categorized into different frame sizes. As an example, the Large Stock Unit equivalents for beef cattle of different frame sizes for heifers older than 12 months and cows with calves are presented. This should be used by farmers when planning their grazing strategies, or when deciding on the size of the cow herd. A livestock grazing capacity map of South Africa is also presented, which should be used as base line information only, since it can vary from farm to farm.

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