Effect of quantity and route of administration of manganese monoxide on feed intake and serum manganese in ruminants.

The experiment investigated effects of high quantities of manganese and route of administration (diet versus capsule-dosed) on feed intake and blood characteristics in sheep. Twenty-four Florida native or Florida native by St. Croix crossbred wethers, 47 kg initially, were assigned randomly to eight treatments including basal diet supplemented with 0, 3000, 6000, or 9000 ppm manganese as a reagent grade manganese monoxide or basal diet plus gelatin capsules containing the equivalent of 0, 3000, 6000, or 9000 ppm manganese based on intake of the previous day. Three sheep per treatment were provided feed and tap water for ad libitum intake. Sheep were fed basal diet for 7 days followed by a 21-day experimental period, then placed back on the basal diet for 7 days. Average daily feed intake was reduced by increasing supplemental manganese, regardless of route. Animals dosed by capsule consumed less feed than those administered manganese in the diet. Serum manganese increased as manganese supplementation increased, but route of administration had no effect.