Influence of Dietary Copper and Ethylenediaminetetraacetate on Copper Concentration and Oxidative Stability of Milk

Effects of supplemental copper sulfate, copper ethylenediaminetetraacetate (ED-TA), and sodium EDTA at levels of 5.0, 8.0, and 7.6 g, respectively, per cow daily on the concentrations of copper and tocopherol and on the oxidative stability of milk were tested in a Latin-square changeover feeding trial with four treatments and four threeweek periods. The treatments did not influence the concentration of copper in the cow's blood, but milk copper was increased significantly by supplements of copper sulfate (P < 0.05) and copper EDTA (P < 0.01). All three supplements caused a small but statistically significant (P < 0.01) decrease in milk toeopherol. Differences in oxidative stability of the milk were not significant, possibly because of a relatively high resistance of the milk to copper-induced oxidized flavor.