Dietary curcumin influences broiler immunity under high temperature

This study examines the efficacy of curcumin, a bioactive component found in turmeric, in mitigating the negative impacts of heat stress on broiler chicks. 120 unsexed Ross 308 chicks were allocated into four groups: a control group receiving a basal diet and three experimental groups receiving basal diets supplemented with 100, 200, and 400 mg/kg of curcumin, respectively. The trial included 35 days, during which all birds experienced 6 hours of daily heat stress at 35±1°C. The results demonstrated that curcumin administration markedly enhanced live body weight (LBW) at 35 days of age with respect to the control. Moreover, white blood cell (WBC) counts, lymphocyte and monocyte levels, and the heterophil/lymphocyte (H/L) ratio were markedly elevated in the curcumin-treated groups. Total serum protein and globulin concentrations were raised, although albumin levels remained unchanged. Curcumin supplementation significantly enhanced immunoglobulin levels (IgG, IgA, IgM) and several immunological measures, including lysosomal activity, bactericidal activity, lymphocyte transformation tests, phagocytic index, and phagocyte activity. Moreover, the groups treated with curcumin demonstrated heightened serum interleukin-2 (IL-2) concentrations, increased blood glucose levels, and diminished corticosterone levels. The bacterial count, encompassing E. coli and Proteus, was markedly reduced in curcumin-treated groups. In conclusion, dietary curcumin supplementation effectively enhances the immune response and mitigates the adverse effects of heat stress in broiler chickens, suggesting its potential as a natural antioxidant in poultry diets.