COPPER BALANCE IN MINIATURE HORSES FED VARYING AMOUNTS OF ZINC

Copper balance was examined in Miniature Horse geldings fed diets cont aining 12 ppm copper and either 73, 170, 400 or 580 ppm zinc in a 4x4 Latin square experiment. Horses were fed each diet for 14 days and wer e maintained in wood metabolism stalls during the last four days of ea ch treatment period for total collections of feces and urine. Copper a bsorption ranged from 42.2% to 50.7% of intake, and copper retention a s a percentage of copper absorption ranged from 89% to 94% across diet treatments. There was no alteration in copper absorption with increas ing intake of zinc.