Every year more than 76 million Americans become ill from the consumption of food contaminated
with pathogenic bacteria. The bovine gastrointestinal tract is a well recognized reservoir for bacterial
pathogens like Escherichia coli O157:H7, Salmonella and Campylobacter. In the United States these
bacterial pathogens are responsible for more than 3.5 million human infections annually at an
estimated annual cost of more than $3.5 billion a year. As many as 66% of the cull dairy cow
markets have detectable amounts of Salmonella shedding and these cull cow markets contribute
substantially to the ground beef available for consumption. Thus, pre-harvest intervention strategies
that reduce the shedding of food-borne pathogens in cull dairy cattle are essential to reducing the
amount of pathogenic bacteria entering slaughter facilities and potentially contributing to
contamination of food products and human infections.
Sodium chlorate supplementation has been investigated as a pre-harvest food safety strategy to
reduce Salmonella and E. coli O157:H7 in vitro and in food producing animals. Research has also
shown that the addition of short chained nitro compounds like nitroethane can enhance the ability
of sodium chlorate to reduce if not kill Salmonella and E. coli as much as ten-fold in vitro and in vivo.
Based on the research done to date, sodium chlorate technology shows great promise for reducing
Salmonella and E. coli O157:H7 pre-harvest. The objective of the current research was to determine
if feeding sodium chlorate, with and without nitroethane, is effective in reducing populations of
Salmonella, E. coli O157:H7 and generic E. coli in cull dairy cattle on a commercial dairy prior to
Findings: Results demonstrated that all animals were negative for E. coli O157:H7 and sodium chlorate and sodium chlorate + nitroethane reduced the concentration of Salmonella in cull dairy cows, especially in the high shedding animals, to levels that can be effectively controlled by modern processing intervention strategies at the slaughter plant.