Copper deficiency, which causes metabolic problems in ruminants, is of serious concern to livestock producers. This bulletin presents information on the factors that influence copper deficiency diseases, the symptoms & lesions associated with these diseases in sheep & cattle, the causes of copper deficiency in animals, the critical levels of copper in various parts of animals, and the prevention & treatment of copper deficiency in sheep & cattle.

Excess minerals in the diet and water of animals can have an adverse effect on animal health, consumers, and the environment. Preventing unsafe mineral exposure is a fundamental part of animal nutrition and management. At the request of the Food and Drug Administration, the National Academies convened a committee to make recommendations on animal tolerances and toxic dietary levels, updating a 1980 report on mineral tolerance in domestic animals. Based on a review of current scientific data and information, the report sets a "maximum tolerable level" (MTL) for each mineral as it applies to the diets of farm animals, poultry, and fish. The report includes an analysis of the effects of toxic levels in animal diets, and it identifies elements that pose potential human health concerns. The report recommends research that includes a better characterization of animal exposure to minerals through feedstuffs; a better understanding of the relationship between mineral concentrations in feed and water and the levels in consumer products such as meat, milk, and eggs; and more research on the maximum tolerable level of minerals for aquatic and companion animals.

Rapid copper depletion without clinical symptoms of copper deficiency was found in cattle under natural Klamath basin conditions. Copper metabolism was influenced by grass species fed to the animals. Tall fescue, Festuca arundinacea Schreb. 'Altar and 'Fawn', reduced liver copper stores and decreased blood plasma copper and ceruloplasmin activity to a deficiency level in less than four months. Cattle fed during the same time period with quackgrass, Agropyron repens (L.) Beauv., maintained normal blood copper and ceruloplasmin activity levels and increased liver copper stores. Quackgrass was lower than fescue in copper content (4.6 ppm and 6.6 ppm respectively). The average copper/ molybdenum ratio was lower in fescue (2.80) than in quackgrass (3.82). Cattle fed quackgrass grew faster than cattle fed fescue (P