105 Chromium propionate improves insulin sensitivity in horses following oral concentrate consumption

Forty-eight Quarter Horse geldings (3–8 yr of age) were used to determine the effects of dietary chromium (Cr), in the form of Cr propionate (Cr Prop), on insulin sensitivity. Horses were blocked by age, body condition score, and glucose response to concentrate feeding on d 0, and randomly assigned to treatments. Treatments consisted of 0, 2, 4, or 8 mg Cr/d from Cr Prop. Horses were fed daily a concentrate mix at a rate of 0.2 kg/100 kg BW and grass hay at 1.75 to 2.0 kg/100 kg BW. After an overnight fast, jugular blood samples were obtained at 0, 2, and 4 h after concentrate feeding on d 0 and 28 for determination of glucose and insulin. Plasma glucose on d 28 was affected (P < 0.05) by treatment, time, and treatment x time. Horses fed 4 mg Cr/d had lesser (P < 0.05) plasma glucose concentrations than those in the other treatments at 0 h. At 2 h post feeding glucose concentrations were greater (P < 0.05) in control horses than in those given 4 mg Cr. Horses fed 2 mg Cr/d had lesser (P < 0.05) plasma glucose at 4 h post feeding compared to controls. Plasma glucose did not differ among horses receiving 2 or 4 mg Cr/d at 2 or 4 h. Insulin concentrations were greater (P < 0.05) in horses fed 0 or 2 mg Cr/d than in those given 4 or 8 mg Cr at 0 h. At 4 h post feeding insulin concentrations were greater (P < 0.05) in control horses than in those fed 2 or 4 mg Cr/d. Results of this study indicate that 2 or 4 mg Cr/d from Cr Prop increased insulin sensitivity in adult horses following oral carbohydrate consumption.