Studies on the supplementary feeding of sheep consuming mulga (Acacia aneura). 5. The effect of cobalt and cottonseed meal supplementation

Abstract

In the first experiment designed to identify the deficiencies in mulga leaves, four groups of sheep were fed mulga and offered one of the following supplements; cobalt, sulfur, cobalt plus sulfur, and molasses. A fifth group acted as a control. All sheep received a phosphorus supplement. The cobalt supplement had no beneficial effect on liveweight or clean wool production. In contrast, the sulfur and molasses supplements significantly improved liveweight gain, clean wool production and sulfur balance. The liveweight and wool growth responses were more than twice as large in the sheep receiving a molasses supplement as in those receiving sulfur. In a second experiment, three groups of sheep on a diet of mulga leaves were supplemented with molasses and phosphorus and, in addition, two groups received 50 g/head.d of either formaldehyde treated or untreated cottonseed meal. Both cottonseed meal supplements significantly improved liveweight gain, but formaldehyde treatment of the meal had no additional effect. Under the conditions of the experiment rumen ammonia was a major limiting nutrient.