HUMORAL IMMUNE-RESPONSE IMPAIRMENT FOLLOWING EXCESS VITAMIN-E NUTRITION IN THE CHICK AND TURKEY

The effect of high dietary intakes of vitamin E on antibody production was investigated in chicks and turkeys. Chicks were fed four diets wi th 0, 10, 30, and 150 mg/kg added vitamin E and turkeys were fed three diets with 0, 50, and 150 mg/kg added vitamin E. Antibodies produced in response to naturally occurring Escherichia coli and to Newcastle d isease virus and turkey pox vaccines were determined. In chicks, antib ody production in response to E. roll and Newcastle disease was affect ed by vitamin E nutrition: significantly higher responses were measure d in chicks that received 0 and 10 mg/kg added vitamin E, whereas in c hicks receiving 30 and 150 mg/kg, antibody production was significantl y lower. In turkeys, concentrations of circulating antibodies to Newca stle disease virus and to turkey pox were also influenced by dietary v itamin E: antibody titers to Newcastle disease and turkey pox vaccines were highest in groups receiving 0 mg/kg added vitamin E, whereas tit er in groups receiving 150 mg/kg were significantly lower. Responses o f groups receiving 50 mg/kg added vitamin E were slightly lower than g roups receiving 0 mg/kg, though not significantly so in most cases. Th ese results indicate that humoral immune responses are directly effect ed by vitamin E, and that excessive vitamin E intake has a detrimental effect on antibody production in chickens and turkeys.