The Effect of Chromium Supplementation on Metabolic Response to Exercise in Thoroughbred Horses

Chromium has been recognized as an essential nutrient in humans for many years (Mertz, 1992). Though chromium may well be involved in other physiological processes, at present its only known role is as a component of glucose tolerance factor (GTF) which potentiates the action of insulin. Therefore, it is involved in carbohydrate metabolism and other insulin dependent processes such as protein and lipid metabolism. A number of recent experiments have evaluated the effect of supplemental chromium in a wide range of species including humans, cattle, pigs, and turkeys. In these studies, chromium supplementation has increased lean muscle deposition (humans and swine), improved immune response (cattle), and reduced cortisol production caused by heat and transport stress (cattle and swine). No research, however, has been conducted with chromium in horses. Therefore, the following study was conducted to determine the effect that chromium supplementation has on metabolic response to exercise in trained Thoroughbred horses.