This study was conducted to evaluate the effect of rosemary leaves on the growth performance, blood parameters, and immune response of broiler chickens by determination of the serum immunoglobulins (IgA, IgM, and IgG), interferon-γ (INF-γ) and interleukin-10 (IL-10). Also, malondialdehyde (MDA), total superoxide dismutase (T.SOD), glutathione S-transferase (GST), and glutathione reduced (GSH) levels in the thigh and breast muscles were determined to evaluate the effect of rosemary in the broiler chickens muscles. To achieve this aim, 120 Cobb of one-day-old chicks were allocated into four equal groups as a control group that supplemented by the basal diet, while the other three groups were fed basal diet supplemented with 0.5, 1.0, and 1.5% of rosemary. The data of growth performance indicated that supplementation of broiler with rosemary had no growth-promoting effects. Feeding diet with rosemary leaves meal significantly increased the serum total protein and globulin, while significantly decreased total cholesterol and triacylglycerol levels. Rosemary significantly increased the IgG, IgM, INF-γ, IL-10, and muscle GSH levels and T. SOD and GST activities. Whereas, muscle MDA levels were significantly decreased, so rosemary could be considered as a natural antioxidant in broiler diet. Concomitantly, provide a healthy broilers meat with less MDA that favorable to human consumption.
Key words: Broilers, Immunity, Antioxidant, Performance, Feed additives, Rosemary