COPPER-OXIDE POWDER AS A COPPER SUPPLEMENT FOR SHEEP

The ability of oral doses of copper oxide powder to raise liver and bl ood copper concentration was examined in penned sheep given a pelleted diet containing 4 mg of copper per kg dry matter. Merino sheep of sim ilar live weight and liver copper concentration were allocated at rand om to one of six treatment groups of four sheep each. Treatment groups received nil, 2.5 g, 5 g, 10 g, 20 g and 40 g of cupric oxide powder. The cupric oxide powder of sieve size 250-350 microns was effective i n raising the liver copper concentration for a least 12 weeks. The lar ge particles of oxide powder were retained in the gut for at least 13 days after closing. Sheep given 10-40 g doses of cupric oxide powder w ere at risk of copper toxicity, as indicated by elevated plasma enzyme activities, liver copper concentrations and reduced liveweight gains. It was concluded that a 2.5 g dose of cupric oxide powder could be us ed to prevent short periods of copper deficiency in sheep at pasture w ithout risk of copper toxicity.