
%0 Journal Article
%A Murray, PJ 
%A Rowe, JB 
%A Aitchison, EM 
%A Winslow, SG 
%T Liveweight gain and wool growth in sheep fed rations containing virginiamycin
%J Australian Journal of Experimental Agriculture
%D 1992/12/01
%V 32
%N 8
%P 1037-1043
%K 
%R https://doi.org/10.1071/EA9921037
%U https://www.publish.csiro.au/paper/EA9921037 
%X The feed additive virginiamycin was evaluated for its potential to improve wool growth and liveweight gain in Merino sheep in 2 experiments. In the first experiment 84 wethers (about 10 months old) were housed individually and fed ad libitum a pelleted diet based on lucerne chaff, lupin, and barley grain. Control sheep (28) were fed an unmedicated diet, and 14 in each of 4 groups were given diets containing 10, 20, 40, or 60 mg virginiamycin/kg pellets. Virginiamycin was found to reduce feed intake during the first 4-5 weeks of the experiment when included at levels 220 g/t. There was a dose-related reduction in liveweight gain. There was no significant effect of virginiamycin on wool growth. In the second experiment, weaners and adults from 2 locations in Western Australia, Mount Barker (relatively high rainfall) and Wongan Hills (relatively low rainfall and shorter pasture-growing period), were housed individually in a shed and fed a pelleted diet at rates equivalent to 3.5 and 3.1%, respectively, of liveweight for weaners and adults. The pelleted ration was based on wheat and lucerne chaff, lupin grain, and fishmeal. Virginiamycin was included at 20 mg/kg pellets for 16 of 40 sheep of each age and location. The remaining sheep were fed the unmedicated diet. Feed conversion and liveweight gain improved (P<0.05) in response to the inclusion of virginiamycin during the first 4 weeks of the trial, but wool growth was reduced over the same period. Virginiamycin had no effect on fibre diameter in sheep in either experiment. 
