Dietary Inclusion of Chromium to Improve Growth Performance and Immune-Competence of Broilers Under Heat Stress

Abstract

This study was conducted to investigate the effects of dietary supplementation with chromium chloride, CrCl3.6H2O (2mg kg–1 basal diet) on the performance and immune response of broiler chickens under heat stress condition (25-43°C). A total of 80 one-day-old broiler chicks (Ross-308) were assigned to two treatment groups according to a completely randomized design. Each treatment consisted of four equal replicates, each contained ten chicks. Chicks were fed on basal diets supplemented with different concentrations of chromium (0 and 2 mg kg–1 CrCl3) from 1 to 35 days of age. Chromium supplementation as feed additives resulted in a slightly lower rectal temperature, and significantly (P<0.05) lower respiration rate for the broiler chickens received diet supplemented with chromium compared to the control (0 mg kg–1 CrCl3). Dietary chromium supplementation increased final body weight (BW) at the end of the production period (5 weeks). Average weight gain was significantly (P<0.05) higher in chickens fed on chromium supplemented diet. Feed intake was not influenced by dietary chromium supplementation, however, the efficiency of feed conversion was improved (P<0.05) in chromium supplemented chickens. Furthermore, dressing percentage was significantly (P<0.05) higher in Cr-treated chickens compared to control chickens. Chromium supplementation significantly (P<0.05) improved the immune response to Newcastle Disease Virus vaccine (NDV). The present results suggest that dietary chromium supplementation provides a good nutritional management approach to ameliorate heat stress induced depression in production performance and immune response of broiler chickens.