Enhancement of productive performance, nutrient digestibility, and meat quality in broilers subjected to cyclic heat stress via different organic and inorganic chromium concentrations

Dietary chromium (Cr) supplementation of chickens may be a tool to reduce heat stress and its associated consequences. This study aims to investigate the effect of supplementation with various levels of inorganic and organic Cr on productive performance, nutrient digestibility, and meat quality in broiler chickens subjected to cyclic heat stress. A total of 245 as-hatched, 1 d old broiler chickens were randomly assigned to seven treatments, each with seven replicates of five birds. The control group received a basal diet without Cr supplementation. In the six other groups, chickens were fed a basal diet supplemented with 100, 200, and 400 ppb of organic and inorganic Cr. From days 25 to 42 d of age, the birds were subjected to heat stress for 3 consecutive days per week. Within chromium-supplemented treatments, the interaction between source and level of Cr influenced body weight gain (BWG) and feed conversion ratio (FCR) (P<0.01), with the best values obtained at 400 ppb of organic Cr and 100 ppb of inorganic Cr. Dietary supplementation with organic Cr resulted in higher apparent digestibility (AD) of organic matter (OM; P<0.05) and crude protein (CP; P<0.01), while Cr levels (P<0.01) affected AD of OM, CP, and ether extract (EE), with the best values observed at 200 and 400 ppb of Cr. Supplementation with 400 ppb of organic Cr or 100 ppb of inorganic Cr improved the growth performance and nutrient digestibility of broiler chickens raised under heat stress conditions. These findings align with the objective of the study and support the use of source-specific chromium supplementation strategies to mitigate cyclic heat stress in broilers.