[The incidence of copper poisoning in sheep and the role of concentrates as a causative factor. Report of an inquiry (author's transl)].

An inquiry among Animal Health Services supplied data on the causes and incidence of copper poisoning in sheep in the Netherlands as well as on the copper levels of concentrates for sheep in random samples and concentrates causing copper poisoning. Approximately one hunderd sheep die from copper poisoning annually, at least 30 per cent of these deaths being due to high copper levels in concentrates for sheep. Provided other factors promoting accumulation of copper are absent, 15 ppm of copper in concentrate DM appear to be a safe limit, whereas levels over 20 ppm involve a definitie hazard.