Impact of Transportation of Feedlot Cattle to the Harvest Facility on the Prevalence of Escherichia coli O157:H7, Salmonella, and Total Aerobic Microorganisms on Hides

Abstract

Prevalences of Escherichia coli O157:H7, Salmonella, and total aerobic microorganisms were determined on the hides of beef feedlot cattle before and after transport from the feedyard to the harvest facility in clean and dirty trailers. Swab samples were taken from the midline and withers of 40 animals on each of 8 days before and after shipping. After samples were collected, animals were loaded in groups of 10 on upper and lower levels of clean and dirty trailers. Animals were unloaded at the harvest facility and kept in treatment groups for sample collection after exsanguination. Salmonella was found more often on hide swabs collected from the midline than on than samples collected from the withers from animals transported in both clean and dirty trailers. Salmonella was found on significantly more hide swabs collected at harvest from both sampling locations than on those collected at the feedyard, with no differences attributed to the type of trailer. At the feedyard, clean trucks had a lower percentage of Salmonella-positive samples than did dirty trucks before animals were loaded. However, after transport, both clean and dirty trucks had a similar prevalence of Salmonella. There were no differences in Salmonella prevalence on hides collected from animals transported on the top and bottom levels of clean and dirty trucks. E. coli O157:H7 was detected on less than 2% of the samples; therefore, no practical conclusions about prevalence could be drawn. Hides sampled at harvest had higher concentrations of aerobic microorganisms than did hides sampled at the feedyard, and concentrations were higher on the midline than on the withers. Although the prevalences of Salmonella and total aerobic microorganisms increased on hides after transport from the feedyardto the plant, this increase was not related to the cleanliness of the trailers or the location of the cattle in the trailers.

Effects of Long- or Short-Haul Transportation of Slaughter Heifers and Cattle Liner Microclimate on Hide Contamination with Escherichia coli O157

“…Trailer cleanliness has not consistently influenced contamination of cattle with E. coli O157, and trailer cleaning might be less critical when the incidence of the organism is low (12,23). Accordingly, in the present study, prevalence of E. coli O157 did not increase (P .…”

Diversity of Multidrug-Resistant Salmonella enterica Strains Associated with Cattle at Harvest in the United States

“…Previous analysis of the aerobic bacterial load (aerobic plate count [APC]) of hide and preevisceration carcass samples collected in this study (n ϭ 3,040 for each sample site) showed that on average ϳ1.7% (95% CI, 0.96 to 3.13%) of hide contamination was observed to be transferred to carcasses during the dressing process (15). Also, numerous studies have shown that cattle hide hygiene is significantly affected by transportation and lairage prior to slaughter (5,24,49,63). Accordingly, measurements of hide pathogen prevalence at harvest are an essential aspect of both understanding the magnitude of risk and determining what control measures may be necessary to mitigate those risks.…”

Source Tracking of Escherichia coli O157:H7 and Salmonella Contamination in the Lairage Environment at Commercial U.S. Beef Processing Plants and Identification of an Effective Intervention

“…It was not determined in either of these studies if these isolates were found on the hides of cattle after transport, or if they were ever transferred to the carcasses. Reicks et al reported that Salmonella prevalence on the hides of animals increased after transport, but could not attribute the change to the cleanliness of the trailers (21). In previous work, Arthur et al found 7 of 8 tractor trailers to harbor E. coli O157:H7 prior to loading cattle (1).…”