Manganese Metabolism with Oral and Intravenous 54Mn in Young Calves as Influenced by Supplemental Manganese1

Abstract

Twelve young (average age — 4 days) male Holstein calves fed either whole milk or whole milk supplemented with 15 ppm manganese (Mn) were given either an oral or intravenous (iv) tracer ⁵⁴Mn dose. Manganese-supplemented calves excreted more (P< .01) ⁵⁴Mn in the feces than controls. Feeding supplemental Mn reduced ⁵⁴Mn retention, as measured directly, by 73% (60.1 vs. 16.3%) in iv-dosed animals and by 88% (18.2 vs. 2.2%) in orally-dosed animals. Liver and small intestinal ⁵⁴Mn were most affected by dietary Mn intake. Supplemental Mn reduced liver ⁵⁴ Mn from over half of the total body content to less than one-tenth. The added Mn caused a twofold increase in liver Mn (11.5 vs. 22.1 ppm) and gall bladder (5.8 vs. 11.6 ppm), a 30-fold increase in bile (1.3 vs. 39.4 ppm), but no significant increase in other tissues. Manganese absorption by controls was far greater than generally reported in any species. The data indicate that both variable excretion and absorption play important roles in Mn homeostasis, and that iv-administered Mn is metabolized quite differently from that absorbed. Copyright © 1974. American Society of Animal Science . Copyright 1974 by American Society of Animal Science.