Effects of the Disposal of Copper-Rich Slurry on the Health of Grazing Animals

Abstract

The effects of the disposal of pig slurry of high copper content on the development of copper toxicosis in sheep are reviewed. Special consideration is given to the increases in pasture copper content which can arise from surface contamination of plants with slurry residues. Studies on the absorption and hepatic accumulation of slurry-bound copper by sheep indicate that this copper is relatively available to animals. However, no cases of copper toxicosis or any major increases in liver copper content have been reported when sheep were allowed to graze severely contaminated pasture for up to 3 years. Provided reasonable precautions are taken as to the rates and times of slurry application, there appears to be no immediate hazard to grazing sheep from slurry disposal.