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Impact of Transportation of Feedlot Cattle to the Harvest Facility on the Prevalence of E. coli O157:H7 and Salmonella spp

Miller, Mark
Texas Tech University
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Past research has shown that handling and transportation of livestock can cause animals to become stressed, which can increase the shedding of fecal material and pathogens. The transportation trailer has been proposed as a possible source of the increased prevalence, but it is not known how cleaning and sanitizing trailers prior to animal transportation will affect contamination on beef hides entering the slaughter plant. In addition, animals on the lower deck of the trailer may have increased levels of contamination compared to those on the upper deck.

The objective of this project was 1) to determine the impact of transportation of beef animals to the harvest facilities on the prevalence of E. coli O157:H7 and Salmonella spp, 2) determine the impact of the animal location (upper versus lower level) during transportation on the prevalence of E. coli O157:H7 and Salmonella spp, and 3) determine the effectiveness of trailer washing as a means of minimizing hide contamination during transportation of beef animals on the prevalence of E. coli O157:H7 and Salmonella spp.

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Findings: Salmonella spp at the harvest facility had a higher number of positive samples than those collected at the feedyard for both animal midline and withers locations. Less than 2% of all E. coli O157:H7 samples were positive for animal and trailer samples taken, which shows that prevalence of this microorganism was random. Even with increased levels of Salmonella spp at the harvest facility, positive samples for both microorganisms found in trailers did not relate to the contamination found on animal hides. Neither the cleanliness of trailers nor level in which the animals were transported affected the contamination present on the animal at the harvest facility. Increased levels found on animal hides agrees with previous research, but is not caused by the trailer itself. Other sources of contamination include animal to animal contact, dirt/dust present in the loading area at the feedyard, holding areas at the feedyard just prior to loading, holding areas at the plant prior to slaughter and equipment/personnel found inside the plant during stunning and exsanguinations. Further research should be conducted to evaluate other possible contamination sources, so producers as well as packers can implement pre-harvest intervention steps to reduce the prevalence of food borne disease microorganisms.

For complete projects details, view the Project Summary.

Funding Source
Nat'l. Cattlemen's Beef Assoc.
Project number
Escherichia coli