Abstract
This chapter focused on the significant effect of copper in the diets of ruminant livestock. Emphasis of the chapter are on the functions, clinical signs of copper deprivation in ruminants, copper value in feeds, outcome of copper-molybdenum-sulfur interactions in forage, sources of copper and its antagonists, copper requirements of ruminants and non-ruminants, metabolism of copper, occurrence and diagnosis of copper deprivation in ruminant and non-ruminants, and copper poisoning.