[Effect of copper status on reproductive performance and milk yield of female cattle in two copper deficient habitats. Effect of supplemental copper feeding on copper status].

The influence of a nutrition poor in Cu on the copper status of dairy cows was investigated with and without Cu-supplementation through the mineral mixture typical of the territory and enriched with Cu. The roughage produced in the territory investigated contained less than 8.0 mg Cu/kg and did not guarantee a Cu supply of the dairy cows meeting their needs. Feeding the mineral mixture rich in Cu improved the Cu-status of the dairy cows, did, however, in one of the territories not result in a Cu-incorporation in the liver that meets the needs. Possibly the reason for this divergent behaviour is an oversufficient S- and Fe-supply. In contrast to this, the Cu-content of the cerebrum of the cows in both territories showed the effect of the Cu in the mineral mixture.