The Swine Health Information Center (SHIC) funded a pilot study to determine if a fluorescent powder could be used to study the transfer of contamination from livestock trailers to barns during marketing events.
Conducted by staff from Iowa State University in collaboration with Iowa Select Farms, the study addresses concerns that livestock trailers are frequently contaminated with porcine reproductive and respiratory syndrome virus, porcine epidemic diarrhea virus and other pathogens at U.S. swine slaughter plants, SHIC executive director Dr. Paul Sundberg said in a May 15 post on the American Association of Swine Veterinarians website.
Results of this pilot study demonstrated that fluorescent powder can be used to track contamination between livestock trailers and barns, offering a needed tool for evaluation and subsequent improvement in transport biosecurity, Sundberg said. Complete study results are available on the SHIC website.
Since swine barns in the U.S. are typically marketed over several weeks, livestock trailers present an opportunity for pathogens from the marketplace to travel back to a farm, Sundberg said, noting that contaminated trailers may also become carrying agents to other farms and that drivers might carry pathogens on their clothing or boots.
During the study, dry woodchips on the floor of the chute appeared to inhibit the transfer of the fluorescent powder -- a marker for pathogen contamination -- on the boots of the loadout crew; however, as feces and urine began to accumulate in the chute, the inhibition quickly dissipated, Sundberg reported.
He added that with a fluorescent light, investigators were able to document that the fluorescent powder was transferred from the trailer to the loadout chute during the loading procedure at all three study sites. Transfer was confirmed by the detection of the fluorescent powder on the bottom of workers' boots, on cutting boards for sorting, in the chute, in the loadout alleyway, in the center alleyway of the barn and in the first three pens adjacent to the loadout alleyway on both sides, Sundberg said.
He noted that the pilot study revealed several other issues relating to transportation biosecurity. For example, once pigs were on the trailer, they occasionally lost their footing while lunging forward off their back legs, which propelled significant amounts of woodchips from the livestock trailer onto the chute.
Additionally, Sundberg said the line of separation between the livestock trailer and chute was often violated by both the driver and the farm worker.
He said further studies are planned to use fluorescent powder to evaluate multi-zone loading -- where members of the loading crew are restricted to specific zones in the barn, chute and loadout area -- as an alternative loading strategy, with the intent of reducing the likelihood of transferring pathogens from livestock trailers to the center alleyway and pens inside the barn.
While this pilot study was conducted on market pigs, the concept can apply to all sizes of pigs and all stages of production, Sundberg said.
SHIC is funded by America's pork producers to protect and enhance the health of the U.S. swine herd and focuses its efforts on prevention, preparedness and response. As a conduit of information and research, SHIC encourages sharing of its publications and research for the benefit of swine health.