Influence of copper supplementation in milk replacers on the copper concentration of calf livers

At present fattening of calves aims at more than 200 kg live weight. The feeding of milk replacers containig milkpowder of 15 mg copper/kg leads to copper levels of up to 490 mg copper per kg fresh weight of liver tissue. For purposes of consumer protection a provisional level of 300 mg copper/kg fresh weight of livers has been laid down. This level has been exceeded in 9 of 20 livers in our present study. Fattening results in groups fed milk replacers containing 5 mg copper/kg or 15 mg respectively did not show any significant differences. It is proposed to assess a legal limit of copper of 6 mg/kg milk replacers in the interest of consumer and animal protection.