Lycopene Supplementation Enhances Growth Performance, Antioxidant Enzymes, Heat Shock Protein 70, and Some Biochemical and Immune Parameters in Broiler Chickens Exposed to Heat Stress

Heat stress is one of the major physiological factors in poultry that causes oxidative stress, acid-base imbalance, impaired immune function, reduced feed efficiency, and increased mortality. Therefore, this study aimed to evaluate lycopene supplementation on performance, antioxidant enzyme activity, heat shock protein 70 (HSP70), and some biochemical and immune parameters in broiler chickens. A total of 300 one-day-old broiler chicks were randomly distributed into six groups with five replicates and 10 of each. The first group had a basal diet, while the other groups received a basal diet supplemented with lycopene at different levels: 200, 300, 400, 500, or 600 mg/kg. For 35 days, the birds received unlimited feed and water. The results revealed that supplementation of lycopene improved (P 0.01) the body weight, body weight gain, feed intake, and feed conversion ratio. The greatest improvement in performance was recorded with supplementation of lycopene at 500 mg/kg of diet during the starter period and 400 mg/kg of diet during the grower-finisher period. T3 and T4 levels increased (P 0.01) in the groups supplemented with lycopene at all levels of addition, while creatinine and uric acid levels were unchanged (P 0.05) compared to the control group. Adding lycopene improved (P 0.01) serum lipid levels, HSP70, and the gene expression of the antioxidant enzymes GPX1, SOD1, and CAT. Also, the serum levels of IL-1β, IFNγ, IL10, C3, and lysozyme activities were elevated (P 0.01) in the groups receiving lycopene supplementation. These findings indicated that the addition of lycopene at 400 or 500 mg/kg of diet can improve growth performance, antioxidant enzyme activity, lipid profile, HSP70, IL-1β, IFNγ, IL10, C3, and lysozyme activities in the serum of broilers.‎