Vitamin E May
Be Key to Listeria-Free Turkeys
By Luis Pons
January 16, 2004 Adding Vitamin E to the diets of
turkeys may further reduce the likelihood of consumers contracting a serious
foodborne illness from the popular holiday and sandwich fowl.
That's what Agricultural Research Service scientists and their colleagues
found when studying ways to control Listeria monocytogenes, a major
human bacterial foodborne pathogen found in poultry.
ARS is the chief scientific research
agency of the U.S. Department of Agriculture (USDA).
Microbiologist Irene Wesley of the ARS National Animal Disease Center (NADC) in Ames, Iowa, found that
supplementing turkeys' diets with the vitamin stimulates their immune
responses, helping them clear the gut of the microorganism that causes the
disease. This can in turn lead to reduced contamination of carcasses at
slaughter and during processing. Wesley is part of NADC's
Pre-Harvest Food
Safety and Enteric Diseases Research Unit.
Listeria monocytogenes causes listeriosis, a disease that affects
mainly pregnant women, newborns, and adults with weakened immune systems. It
accounts for 2,500 total cases annually of human meningitis, encephalitis,
sepsis, fetal death and premature births. In a 1998 USDA study, L.
monocytogenes was found in nearly 6 percent of turkey carcass rinses and in
31 percent of the ground turkey meat examined.
These studies, conducted in collaboration with the
University of Arkansas and
Iowa State University, found that vitamin
E boosts turkeys' white blood cells, which go into action when disease-causing
organisms are detected.
Turkeys require vitamin E for normal development and function of the immune
system. Wesley used alpha-tocopherol--the most active form of vitamin E in
humans, and a powerful biological antioxidant--because it is readily available
from commercial sources and can be used in animal feed preparations.
Earlier tests conducted at Iowa State showed that dietary vitamin E also
enhances poultry meat's quality and shelf life.
Plans are in the works for testing vitamin E against Salmonella and
Campylobacter, two other important foodborne pathogens.
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