Effect of vitamin E supplementation on growth performance, meat quality, and immune response of male broiler chickens: A meta-analysis

The effect of vitamin E supplementation on the growth performance, carcass traits, meat quality, and immune response of male broiler chickens was studied using a meta-analysis. The database was consisted of 51 scientific pats published in peer-reviewed journals. The dependent variables for meta-analysis included final body weight, average daily gain, daily feed intake, feed conversion ratio, vitamin E concentration in the muscle, tissue polyunsaturated fatty acid concentration, lipid peroxidation value, post mortem pH, heterophil to lymphocyte ratio, and total immunoglobulins. Linear mixed models were used to analyze the data. Vitamin E supplementation did not influence growth performance, as the estimated slopes were not different from zero, with P-values equal to 0.92 for final body weight, 0.81 for average daily gain, 0.31 for daily feed intake, and 0.83 for feed conversion ratio. Dietary vitamin E supplementation increased the vitamin E content in the muscle (P = 0.001), did not change the polyunsaturated fatty acid concentration, and decreased the lipid peroxidation (P = 0.01). The immune response was improved, the heterophil to lymphocyte ratio was constant, and the total immunoglobulins were increased (P = 0.037) by dietary vitamin E supplementation. With regard to broiler chicken performance, there seemed to be no relationship between dietary vitamin E supplementation and growth performance. There is ample indication that meat quality and immune response could be improved by dietary vitamin E supplementation.