Zinc Toxicity in Ruminants. I. Effect of High Levels of Dietary Zinc on Gains, Feed Consumption and Feed Efficiency of Lambs

Abstract

Four experiments were conducted with lambs to determine the levels of dietary zinc which could be tolerated without affecting performance. Zinc consumption above 1.5 gm. per kg. of diet caused depressed feed consumption, while 1.0 gm. of zinc per kg. of diet caused reduced gains, decreased feed efficiency and increased mineral consumption. Decreased feed consumption was shown to be in part a palatability effect. Water consumption was also suppressed by force feeding 4.0 to 6.0 gm. of zinc daily. No other external symptoms of the toxicity were observed, but prolonged consumption of high levels of zinc caused death.