CONDITIONS UNDER WHICH FLAVOMYCIN INCREASES WOOL GROWTH AND LIVEWEIGHT GAIN IN SHEEP

Flavomycin, a glycolipid feed additive, was evaluated for its potential to improve wool growth and liveweight gain in sheep of two ages and from two different sources. Sheep came from two locations in the Mediterranean climatic region of Western Australia's agricultural area-Mount Barker, with a relatively high rainfall and Wongan Hills with a relatively low rainfall and shorter pasture growing period. Forty weaner sheep, from each source, initially eight months of age and with a mean liveweight of 29 kg (s.e. +/- 0.3) were studied. There were also 40 adult sheep, from each source, initially 20 months of age with mean liveweights (Wongan Hills) 42 kg (s.e. +/- 0.5) and (Mount Barker) 51 kg (s.e. +/- 0.7). All animals were housed individually in the one shed and fed a pelleted ration at a level equivalent to 3.1% (weaner) and 3.5% (adult) of each animal's liveweight. The pelleted ration was based on wheat and lucerne chaff, lupin grain and fishmeal. Flavomycin was included at 20 mg/kg pellets and there were 16 sheep of each age and source fed this medicated diet. Twenty-four sheep were fed the unmedicated diet. Wool growth was increased by flavomycin by 14.5% (P < 0.05) but only in adult sheep from Mount Barker. Inclusion of flavomycin in the diet increased liveweight gain in sheep of both ages and from both sources. There was no significant effect of flavomycin on fibre diameter of wool in sheep from the different age groups and sources.