Chromium propionate in broilers: human food and broiler safety

Chromium propionate (Cr Prop) is approved by the U.S. Food and Drug Administration Center for Veterinary Medicine for supplementation to broiler diets up to 0.20 mg Cr/kg diet. A 49-D study was conducted to: 1) determine the safety of Cr Prop when supplemented at 2 and 10 times (×) the approved feeding level over the normal life span of broilers, and 2) determine the effects of supplementing Cr Prop on Cr concentrations of tissues consumed by humans. On day zero, 216 Ross 708 broilers were stratified by weight within sex and randomly assigned to treatments. Dietary treatments were 0 (control), 0.40, and 2.0 mg supplemental Cr/kg diet from Cr Prop. There were 6 replicate cages each of male and female broilers per treatment. At the end of the study blood was collected for determination of plasma biochemical measurements and tissue samples were collected for Cr analysis. Supplementing 0.40 mg Cr/kg diet (2×) did not adversely affect broiler performance, mortality, plasma biochemical measurements or Cr concentrations in breast muscle, skin with adhering fat, or liver. Chromium propionate supplemented at 2.0 mg Cr/kg (10×) did not affect Cr concentrations in breast muscle or skin with adhering fat, but increased (P < 0.05) liver Cr concentrations. Supplementing Cr Prop at 10× the approved feeding level decreased feed intake and gain in male but not female broilers from days 21 to 49. Results of this study support the safety of Cr Prop in broiler diets, and indicate that Cr Prop supplementation to broiler diets at 2 or 10× the approved feeding level does not present a human health concern.