Effect of high but nontoxic dietary intake of copper and selenium on metabolism in calves.

Sixteen male Holstein calves in a 2 X 2 factorial design with four animals per treatment were fed 0 and 100 ppm supplemental copper from copper carbonate and 0 and 1 ppm added selenium from sodium selenite for 15 days in a practical diet containing .1 ppm selenium and 15 ppm copper. On day 13, calves received an oral dose of selenium-75 and were sacrificed 48 h later. Feed consumption, serum glutamic oxaloacetic transaminase, creatine phosphokinase, and stable copper in blood and urine were unaffected by diets. Stable copper in pancreas, spleen, kidney, muscle, and spinal cord along with selenium-75 in lung, pancreas, liver, heart, and muscle also were unaffected. In calves fed high selenium, selenium-75 was lower in blood, kidney, and spinal cord, and more was excreted in the urine, indicating less retention. Urine was the major excretory pathway of excess selenium-75. Liverstable copper was greater for high copper diets. Stable copper in the lung was higher in calves fed high selenium-high copper than in either control or calves fed high copper. Stable copper was greater in heart tissue in both groups fed high selenium than in controls and slightly higher than the group fed high copper.