Studies on the supplementary feeding of sheep consuming mulga (Acacia aneura). 1. The provision of phosphorus and molasses supplements under grazing conditions

Abstract

An examination was made of the effects of molasses and phosphorus supplements, either singly or combined, on the liveweight, wool growth, and reproductive performance of ewes grazing mulga, (Acacia aneura) a leguminous shrub, in the field near Charleviile, Queensland. Unsupplemented ewes lost 4.4 kg liveweight on average during the 14-month experiment, and bone analyses indicated that their dietary intake was insufficient to maintain the initial degree of skeletal mineralization. The provision of supplementary molasses increased liveweight and wool growth, and enhanced reproductive performance, but phosphorus supplements increased liveweight and wool growth only when fed in conjunction with molasses. Skeletal mineralization was not increased by a supplement of phosphorus except when molasses was also given.