Effect of supplemental dietary vitamin E on the serologic response of swine to an Escherichia coli bacterin.

Three groups of 10 pigs (6 to 8 weeks old) were fed a nutritionally complete ration (control ration, CR), CR plus 20,000 IU of vitamin E/ton (CR + recommended E), and CR plus 100,000 IU of vitamin E/ton (CR + high E), respectively. Each pig was given an intramuscular injection of an Escherichia coli bacterin at experimental days 0 and 35. Serums were collected 7 days prior to the first injection and at days 7, 14, 21, 35, 42, 49, and 56. Pigs fed the CR + high E ration developed anti-E coli serum antibody titers two- to threefold higher than those of the controls. Pigs fed the CR + recommended E ration developed serum antibody titers intermediate between those of pigs in the other 2 groups.