Supplementation during winter of two types of merino sheep on Cymbopogon-Themeda veld I. Influence on wool production.

An experiment was conducted to determine the influence of supplementary feeding during winter on wool production. The reduction in body weight in autumn and early winter was used as criterium for commencing supplementary feeding. Two types of Merino wethers, differing in wool production potential were used in a 2 x 5 factorial experiment. Supplementary feeding consisted of maize and lucerne in the ratio 1:4. This was fed to the animals ad lib. twice weekly. The results indicated that the greatest benefit from supplementary feeding was obtained when supplementation was commenced after·the sheep had lost 5% of their body weight. The beneficial effect of supplementary feeding is apparently influenced by compensatory wool growth during the summer months. No significant interaction was obtained between the type of sheep and treatments. Supplementary feeding improved the quality of the wool by decreasing normal fibre diameter reduction in winter. Although the increase in total wool production was in direct proportion to body weight and age it was inversely proportional when calculated per unit body weight. The total wool production and efficiency of food conversion to wool of the sheep with the moderately high production potential was consistently and significantly higher than those with the lower potential. It was concluded that supplementary feeding of wool producing sheep can only be justified economically if they have a relatively high wool production potential.