The effect of chromium on ruminant health

Chromium (Cr) is a micronutrient that occurs in the natural environment in different oxidation states. Natural compounds contain chromium in the +3 oxidation state, whereas chromic(VI) acid derivatives are industrial products with strong toxicity. Hexavalent chromium compounds can adversely affect the respiratory system and the gastrointestinal tract, cause skin changes, and exert carcinogenic, mutagenic, embryotoxic as well as teratogenic effects. Research indicates that both organic and inorganic trivalent chromium compounds improve carbohydrate, lipid, and protein metabolism. These compounds are found in many enzymes, and they influence antioxidant processes, regulation of immune responses, and the secretion of hormones and selected vitamins in the body. In animals, Cr has been found to increase fat-free body mass, improve reproductive parameters, enhance growth, increase feed conversion efficiency, boost immunity, and decrease mortality. It has been suggested that Cr supplements can intensify the effects of insulin, decrease the plasma levels of non-esterified fatty acids (NEFAs), decrease triglyceride concentrations in the liver, and improve glucose tolerance, thus improving the performance and productivity of cattle in the perinatal period. Symptoms of chromium deficiency, including decreased feed intake, lower weight gains, reproductive disorders, and higher lipid levels, are observed in cattle fed diets that are low in this nutrient, and in animals that are exposed to considerable and prolonged stress. In ruminants, chromium supplementation is recommended during thermal stress, in the perinatal period, and during infections.