Dynamics of absorption rates, endogenous excretion, tissue turnover, and homeostatic control mechanisms of zinc, cadmium, manganese, and nickel in ruminants
Miller, W.J.
Federation Proceedings 32(8): 1915-1920
1973
ISSN/ISBN: 0014-9446 PMID: 4718910 Document Number: 59798
Absorption, endogenous excretion, tissue turnover, milk secretion and homeostasis are compared for Zn, Mn, Cd and Ni. The % of dietary Zn found in milk is inversely related to that in diet; with 17 ppm Zn in the diet, 17.7% is found in milk and with 1279 ppm, 0.8% is in milk. Mn level in milk is also affected by diet. Normal levels of Cd and Ni in milk are low and not well defined, and only minute proportions of orally administered Cd and Ni are secreted into cows' milk. Transfer of Zn and Cd into milk after intravenous injection and removal from the udder after intramammary infusion are also mentioned.