Injectable copper and tissue composition of cattle.

Copper in blood plasma and liver and tissue reactions were compared for cattle injected with various amounts of copper salts of glycine or edetate. In young Holstein calves, initial concentrations of copper in blood plasma were normal (89 micrograms/dl). At 1 h postinjection, concentrations in plasma and the change were higher for the edetate group than for the glycinate group. Thereafter no differences of plasma copper occurred between forms of copper. Differences between concentrations of copper in plasma, especially for higher injections, occurred during the first 24 h but only occasionally thereafter. Hemolysis was severe during the 1st wk when 240 mg of copper edetate was administered but without mortality. Copper edetate caused less tissue irritation than equivalent copper from glycinate. Calves apparently mobilize injected copper rapidly from the subcutaneous site of injection, especially copper edetate, but concentrations in plasma are only increased temporarily. Copper is stored rapidly in the liver postinjection and probably serves to minimize toxic hemoconcentrations of copper.