The Effect of Different Levels of Vitamin E on Humoral Immunity, and performance in broiler chicks

Vitamin E is known for its antioxidant properties and has been shown to modulate immune system in various species.An experiment with 240 one-day old Ross 308 male broilers was coducted to investigate the effects of 4 different levels of vitamin E (0,10,20 and 40 mg/kg) on performance and response of humoral immunity. Chicks at age of 15, 30 and 45 days were injected I.M. with 0.2ml of a 5% saline suspension of sheep red blood cell (SRBC). Blood samples were collected from each bird at 7 and 14 days of the second and third challenge.Afterwards, the 2-mercaptoethanol sensitive (2MES, presumably IgM) and 2-mercaptoethanol resistant (2MER, presumably IgG), Anti-SRBC antibody titers were determined using a microheamagglutination technique. Then chicks were slaughtered and their bursa of fabricius and spleens were weighted.The results of this study suggested that vitamin E has no significant effect on performance of broiler chicks such as body weight, feed intake and feed efficiency. There was a significant difference on total anti-SRBC-titter, 2-mercaptoethanol sensitive antibody titer (2-ME sensitive), anti-New Castle disease virus titter (NDV) in group which was given 40 mg/kg supplemented vitamin E compared to the control group(p<0.05). 2-mercaptoethanol resistant antibody titter (2-ME resistant) and lymphatic organs (bursa of fabricius and spleen) weight were not under the effect of diet. Furthermore significant difference wasn`t observed between treatments.These results indicated that supplementation of vitamin E increases humoral immune responses.