Abstract
Earlier studies with ruminants point to a depressant effect of dietary iron on the copper status. To verify this we determined hepatic copper concentrations in dry, non-pregnant goats subjected to a 56×56-days cross-over trial with adequate copper rations containing either 269 or 2380 mg iron/kg dry matter. High iron intake reduced the group mean plasma copper (by 18%) and caerulo-plasmin activity (by 13%) and produced a significant decrease (27%) in hepatic copper concentrations. Hepatic iron concentrations were raised (by 56%) after feeding the high iron ration. It is concluded that high dietary levels of iron, within the range of their fluctuation in silage and forage, can impair the copper status of ruminants, especially when concurrent intakes of copper are low.