Zinc Toxicity in the Weanling Pig

Abstract

Ninety-two weanling pigs were used to determine zinc tolerance and the characteristics of zinc toxicosis. Levels of zinc supplementation, as reagent grade zinc carbonate, up to 0.8% of the diet were fed for 42 days. Corn-soy-bean oil meal diets were used. The addition of 0.1% zinc to the diet was the maximum level tolerated. Higher levels produced symptoms of zinc toxicosis. Toxic symptoms were characterized by depressed rate of gain, feed intake and efficiency of gain. In addition, arthritis, extensive hemorrhage in the axillary spaces, gastritis, catarrhal enteritis, congestion of the mesentery, and hemorrhages in the ventricles of the brain, lymph nodes and spleen were observed. Feeding high levels of zinc frequently caused death within 21 days on treatment. Hemoglobin values determined on the 21st day of the experiment were unaffected by the levels of zinc fed. Calcium added at 1% of the diet as dicalcium phosphate had no effect upon the level of zinc tolerance or upon the toxic reactions. Copyright © . .