The Copper Content of Milk

The presence of copper in cow’s milk has been reported by several investigators (l-5). The most extensive investigation was that of Supplee and Bellis (2) who determined the copper content of freshly drawn milk of a large number of cows fed on different rations. They found that the copper content per liter varied from 0.2 to 0.8 mg., with no apparent correlation between copper content and ration. The variation in results obtained by investigators in widely different localities suggests the possibility of the influence of the copper content of native feed products. The analyses in this laboratory of milk collected from four states would indicate, however, that we can expect quite constant copper content of raw cow’s milk. The copper content of milk of the sheep and of the goat was found to be about the same as that for the cow. The copper content of goat milk was low in all cases but always easily detectable notwithstanding the report to the contrary by Titze and Wedemann (6).