Effects of chromium methionine supplementation on performance, carcass traits, and the Ca and P metabolism of broiler chickens under heat-stress conditions

We investigated the effects of different levels of chromium methionine (CrMet) on the performance, carcass traits, and Ca and P metabolism of broiler chickens under conditions of heat stress. A total of 288 male broiler chickens (Ross 308) were allocated to 4 treatment groups (supplementation with 0, 200, 400, or 800 ppb of Cr in the form of CrMet) in a completely randomized design. The experiments were conducted under heat-stress conditions, but all birds were kept below 33 +/- 2 degrees C. The BW and feed intake of the broilers supplemented with Cr increased at 800-ppb concentrations of Cr (P < 0.05). The feed conversion was not affected by different levels of supplemental Cr in the broilers (P > 0.05). Chromium supplementation did, however, increase carcass yield and decrease the abdominal fat contents. The serum Ca and P levels of the broilers were unaffected (P > 0.05) by different level of CrMet supplementation, but the alkaline phosphatase activity significantly (P < 0.05) decreased by these treatments. Therefore, supplemental CrMet at the level of 800 ppb can improve both performance and carcass traits in broiler chickens reared under heat-stress conditions.