Effects of liming and various forms of oral copper supplementation on the copper status of grazing sheep.

Abstract

AbstractSheep grazing limed pasture for periods extending to 14 months had consistently lower mean blood copper concentrations than similar sheep on comparable untreated pasture. Liver copper concentrations and total liver copper contents were also significantly lower for the sheep on the limed herbage. Liming did not affect the herbage copper concentration. Herbage copper concentrations of 8‐9 ppm appeared to be insufficient to maintain the blood and liver copper status of sheep grazing limed pasture at adequate levels.Prolonged oral supplementation providing 70 mg Cu per week as the sulphate, glycinate or EDTA salt increased blood and liver copper concentrations to similar degrees and with no apparent risk of toxicity.