Trace Mineral Nutrition in Cattle

Abstract

Trace minerals are needed in only trace amounts, and are measured in either parts per million (ppm) or mg/kg. Fifteen of these mineral elements have been identified (arsenic, cobalt, copper, chromium, fluoride, iodine, iron, manganese, molybdenum, nickel, selenium, silicon, tin, vanadium, and zinc), but this discussion will concern only copper, cobalt, iodine, selenium, and zinc.¹ These minerals are required in specific biochemical reactions as part of metalloenzyme systems or as cofactors for enzymematic functions. Trace mineral deficiencies usually occur slowly over time. The clinician who is confronted with a problem where trace minerals are suspected should always obtain a detailed herd history, perform a complete physical examination on affected animals, evaluate the total diet, including pastures, and harvest tissues needed to evaluate the specific mineral concentrations in the body.¹

Salt is commonly used as a carrier to ensure trace mineral intake, as cattle have a clear cut drive for NaCl. If the clinician and rancher elect to use a salt containing mineral mixture to insure mineral intake it should be remembered individual animal intakes may vary drastically.¹ Further, improperly prepared salt mixtures, feed supplements or blocks, liquid feeds, or some types of contamination can alter nutrient absorption and produce conditional deficiencies.