In ruminants, copper is absorbed in the first parts of the intestine. Mainly transported by ceruloplasmin, it concentrates in the liver; then it is eliminated by feces, bile, urine and milk. Copper intoxications are relatively rare. On the contrary, deficiencies are more frequent: they are due to a shortage of alimentary supply or to a competition with molybdenum and/or sulphate. These deficiencies induce the inhibition of copper-enzymes determining mainly troubles of hair pigmentation, reproduction and hematopoiesis. These troubles can be prevented or cured by the administration of copper salts.