Effect of vitamin E and A on humoral immunity and phagocytosis in E. coli infected chicken.

Dietary supplementation of either vitamin E (300 mg./kg. diet) or vitamin A (60,000 I.U./kg. diet) significantly reduced E. coli caused mortality, but the combination of the two vitamins did not. Protection was attributed to increased antibody production and increased phagocytosis, although neither factor alone gave a significant correlation with mortality. Vitamin E level significantly increased especially in the spleen of supplemented chicks, but vitamin A suppressed this increase, partially explaining the lack of protection in vitamin E and A supplemented chicks.