Effect of Different Levels of Turmeric and Rosemary Essential Oils on Performance and Oxidative Stability of Broiler Meat

The present study was conducted to investigate the effect of dietary supplementation of turmeric (TEO) and rosemary (REO) essential oils on growth performance and oxidative stability of broiler meat. Five hundred forty day-old chickens (Cobb 500) were randomly allotted to a 3 × 3 factorial arrangement with three levels of turmeric essential oil (T1=0, T2=75 and T3=150 mg/kg) and three levels of rosemary essential oil (R1=0, R2=100, and R3=200 mg/kg), with 4 replicates of 15 chickens. The combination of the essential oils, R2T3 and R3T3 improved (P<0.05) body weight gain compared to control group, during the first 3 wk of the trial. Control group had the lowest feed conversion ratio (P<0.05) compared to the other treatments with the ex-ception of R1T2, R2T3 and R3T1 groups during of grower period (22-42d) and total period (1-42d). The highest values of the relative weights of carcass and thigh muscle achieved by birds fed 75 and 150 mg TEO supplementation respectively. Adding TEO supplementation to the diets significantly reduced (P<0.05) pancreas, proventriculus, gizzard and crop relative weights. The highest value of relative weight of liver was achieved by birds fed control diet compared to the birds fed other diets. With the exception of R3T2 and R3T3 groups, all of the treatments had a significant different (P<0.05) in malondialdehyde (MDA) value compared to control group after days 30 of storage at -20 °C. The birds fed supplementation of R1T2, R2T2, R3T3 and R3T1 showed lower levels of MDA values (P<0.05) in the breast meat compared to control group after days 60 of preservation at -20 °C. It was concluded that adding REO and TEO to the feed did not improve the broiler chicken’s performance, whereas these feed additives had great potential to improve oxidative stability of breast meat and reduced the concentration of MDA after days 30 and 60 of preservation at -20 °C.