Effect of dietary manganese on growth and manganese metabolism in sheep.

Three groups of five wethers were each fed ad libitum a practical type diet containing 22, 300, or 3000 ppm of manganese for 8 wk. The wethers then were fistulated and killed 13 h after intraruminal dosing with manganese-54. Several tissues were sampled. Average daily gains and feed/gain ratios of sheep fed diets containing 22 and 300 ppm manganese were similar, but gain was lower and the ratio higher for sheep fed the diet containing 3000 ppm manganese than for those fed other diets. Feed intake was approximately the same for all treatments. Increased dietary manganese increased its concentration in soft tissues and bile. There was also a decrease in the uptake and specific activity of manganese-54 in the liver with increasing dietary manganese. Concentration of copper increased and concentration of zinc decreased in liver of sheep with increasing dietary manganese.