Effect of Dietary Green Tea Powder and Vitamin E on Performance and Meat Oxidative Stability of Broiler Chickens in Different Storage Times

This experiment was conducted to evaluate the effects of 7 experimental diets (2 diets containing 100 and 200 mg vitamin E (VE)/kg and 5 diets containing 0, 0.5, 1, 1.5 and 2% green tea powder (GTP) ) on performance and breast and thigh meat oxidative stability of broiler chicks during different storage times. A total of 364 male broiler chicks were divided to 28 groups of 13 chicks each. Then every 4 groups were randomly allocated to one of experimental diets. During the experimental period (7-42 days of age) feed intake, weight gain and feed conversion of the experimental groups were measured. On day 42, 2 birds from each replicate (8 chicks per treatment) were weighed, slaughtered and their muscles of breast and thigh were minced and stored at 4ºC. Meat oxidative stability of the samples was determined on days 0, 6 and 9 of storage time using thiobarbituric acid test (TBA test). The results showed that addition of the VE and GTP to diets tended to significantly (P<0.05) reduce live body weight, weight gain, feed intake and abdominal fat accumulation and increase feed conversion ratio and pancreas size compared to control group. Increasing storage time from 0 to 6 and 9 d significantly (P< 0.05) increased TBA number. Lipid peroxidation and TBA values in thigh muscle were significantly (P<0.05) higher than breast muscle (1.46 vs. 0.359 mg Malonaldehyde/kg meat). Different dietary levels of GTP in diets did not have any significant effect on prevention of meat lipid peroxidation. In addition, the values of TBA in meat of the groups fed diets containing high levels of GTP significantly (P<0.05) increased in comparison to control group and those fed VE supplemented diets.