Therapeutic efficacy and pharmacological safety of parenteral supplementation of different concentrations of copper in cows

Abstract. The objective of the present study was to determine the parenteral dosage of the trace mineral copper (Cu) which re-establishes serum and hepatic levels in hypocupperhemic animals without causing intoxication in the liver or residuals in milk. The experiment was carried out in two phases; in the first phase, 20 hypocupperhemic animals were used. Those were divided into 4 groups of 5 cows each: 3 groups which received 25, 50 and 100 mg of Cu respectively and 1 control group without supplementation, but with induced copraemia 5 days before and after the treatment. The milk of the cows treated with 100 mg Cu was examined for residuals of this element for one month. In the second phase, 25 animals were selected and divided into 5 groups of 5 cows each: 1 control group and 4 groups which received 25, 50, 100 and 200 mg of Cu respectively. The impact of this Cu dosages on liver reserves of this element, on hepatic enzymes (alanine-amine-transaminase, aspartate-amine-transferase, alkaline phosphatase and glutamate dehydrogenase) and on bilirubin was analyzed. The groups treated with 50 and 100 mg Cu showed increased levels in blood serum and hepatic tissues (P<0.05) in comparison to the control group and the one treated with 25 mg, obtaining the physiological level considered normal in cows during 60 days without an effect to the level of Cu in milk or to the liver’s enzymatic activity. We conclude that treatment with this dosage results in a restoration of the Cu concentration in blood serum and hepatic tissues without toxic effects or residuals.