Liveweight gain and wool growth in sheep fed rations containing virginiamycin

• Published in: Australian journal of experimental agriculture Vol. 32; no. 8
• Main Authors: Murray, P.J, Rowe, J.B, Aitchison, E.M, Winslow, S.G. (Western Australian Dept. of Agriculture, South Perth. Div. of Animal Industries)
• Format: Journal Article
• Language: English
• Published: 1992
• Subjects: ADDITIF AUX ALIMENTS DES ANIMAUX; ADITIVOS DE PIENSOS; GAIN DE POIDS; GANANCIA DE PESO; LAINE; LANA; OVIN; OVINOS; VIRGINIAMICINA; VIRGINIAMYCINE
• ISSN: 0816-1089; 1446-5574
• DOI: 10.1071/EA9921037

In an experiment with Merino wethers fed a pelleted diet based on lucerne chaff, lupin and barley grain, virginiamycin was found to reduce feed intake during the first 4-5 weeks when included at levels at or above 20 g per kg. There was a dose-related reduction in liveweight gain. There was a dose-related reduction in liveweight gain. There was no significant effect of virginiamycin on wool growth. In a second experiment, weaners and adults from 2 locations in Western Australia were fed a pelleted diet at rates equivalent to 3.5 and 3.1 percent, respectively, of liveweight. The pelleted ration was based on wheat and lucerne chaff, lupin grain, and fishmeal. Virginiamycin was included at 20 mg per 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 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.