This study was conducted to evaluate the effects of chromium (Cr) levels and dilution rates in broiler diets under heat stress (HS) on performance, digestibility, immunity, carcass characteristics, and mineral retention. One-hundred and twenty-eight 1-day-old Arbor Acres broiler chickens (initial body weight of 37.98 ± 0.22 g) were used in this experiment for d 35. They were assigned to four treatment groups (eight replications, four birds each per cage): PC, birds fed a basal diet under thermoneutral temperature; NC, birds fed a basal diet and were exposed to cyclic HS at d 14 of age; CP2, PC with supplementing Cr 200 μg/kg as chromium propionate (Cr-Pro); CP4, PC with supplementing Cr 400 μg/kg as Cr-Pro. In this study, the NC exhibited decreased (p p p p p p p p p < 0.05) in serum cortisol and H:L ratio compared to the NC. In conclusion, Cr-Pro is an additive that can mitigate the effects of HS, supplementation with 400 µg/kg Cr is suggested as a more effective alternative than 200 µg/kg.
Kim et al. (Wed,) studied this question.