Effect of beta carotene on disease protection and humoral immunity in chickens.

The effect of beta carotene on disease protection and humoral immunity in chickens was investigated in comparison with the effect of other lipid-soluble antioxidant vitamins, vitamin E and A, which are both proven immunoenhancers and contributors to disease protection. Beta carotene alone was not as effective as either vitamin in protecting chickens from Escherichia coli infection, nor did it significantly enhance humoral immunity. In combination with vitamin E, however, beta carotene significantly increased disease protection and reduced hepatomegaly caused by E. coli infection.