Vitamin E may be an alternative to antimicrobials in reducing turkey pathogens.

One way of keeping turkeys healthy on their way to market is to guard them against infection by L. monocytogenes. Food Safety Consortium scientists have found that vitamin E helps turkeys resist infection from this bacterium because it increases their white blood cell count.

Vitamin E is a dietary supplement that boosts turkeys' immune response. Previous research showed that vitamin E fed to turkeys prolonged the shelf life of turkey meat. Vitamin E in the bird increases the levels of immune cells known as T lymphocytes--lymphocytes that have a certain marker on them known as CD-4. These lymphocytes boost the immune response.

Birds treated with vitamin E also have lymphocytes labeled CD-8 that kill infected cells and help eliminate foodborne pathogens. Vitamin E also prevents the off-odors that occur after oxidation. Vitamin E tends to inhibit the deterioration of the meat so that its quality is protected.

It's too soon to determine if the vitamin should be a significant dietary supplement for turkeys. The use of antimicrobial drugs in turkey processing may eventually be phased out. Vitamin E, since it boosts the immune response, will lead to a healthier bird and therefore diminish the use of antimicrobials.

The researchers are testing both natural vitamin E and synthetic vitamin E to find out if either is more effective in boosting turkeys' immune responses. After researching the effects on L. monocytogenes, the scientists will begin investigating vitamin E's effects on Salmonella in turkeys. They'll try vitamin E with Salmonella to see if they can obtain the same kind of Salmonella inhibition they saw with Listeria. They are expecting to see a boost in the immune response and associate this with a diminution of carriage of foodborne pathogens.

Vitamin E is just one vehicle for potentially reducing foodborne pathogens in animals. Another is conjugated linoleic acid (CLA). The researchers' preliminary studies indicated that CLA in the diet changed the meat's fatty acid content and influenced the meat's storage stability. The use of vitamin E or CLA, separately or in combination, may improve the birds' immune response and reduce the colonization of potential foodborne pathogens in their intestines. Either dietary supplement can also lessen the changes in turkey meat caused by oxidation and allow the turkeys to keep the original color that consumers want to see in the market.

Further information. Irene Wesley, USDA-ARS National Animal Disease Center, 2300 Dayton Ave., Ames, IA 50010; phone: [phone]; fax: [phone]; email: [e-mail].