The presence of the porcine epidemic diarrhea virus (PEDV) requires producers, manure haulers and land owners to cooperatively work together to reduce the risk of disease spread during the manure application season, explained Erin Cortus, assistant professor and extension environmental quality engineer at South Dakota State University.
"Biosecurity measures during the manure hauling season are not new to pork producers, but it never hurts to take a fresh look at procedures on your operation, especially in light of new and ongoing research," Cortus said. "Heat and time combinations can deactivate the virus, and limiting exposure can help reduce the risk of spreading this virus."
According to Cortus, ongoing research by Dr. S. Goyal at the University of Minnesota titled "Environmental Stability of PEDV" (http://www.pork.org/filelibrary/Goyal%2013-215%201-21-14.pdf) has shown PEDV can survive in slurry for 14 days at room temperature (77°F). At storage temperatures of -4°F and 39°F, the virus was still alive after 28 days.
Fresh fecal material stored at temperatures of 104-140°F and relative humidity between 30% and 70% survived for up to seven days. A deactivation period of seven days at room temperature was also measured by Iowa State University researchers, Cortus added.
Another separate study titled "Evaluation of Time & Temperature Sufficient to Kill PEDV in Swine Feces on Metal Surfaces" (http://www.pork.org/filelibrary/Holtkamp%2013-227%2012-20-13.pdf), provides more research data to work with.
"Although this report focused on addressing concerns about livestock trailers, the research has some application to manure application equipment as well," Cortus said. "The author of the research suggests the virus can be deactivated by heating livestock trailers to 160°F for 10 minutes, but this temperature and time combination does not replace the standard recommended practice of thoroughly washing, disinfecting and drying trailers."
Cortus said understanding the survival of the virus in manure may warrant a revisit of cleaning protocols for manure hauling equipment and personnel between sites or farms. Some key principles for cleaning to keep in mind are:
* Remove organic material prior to washing;
* After washing, allow the equipment to dry before applying any disinfectant because excess water can dilute disinfectant, and
* Follow label instructions for any disinfectant.
In addition, Cortus said producers should review for themselves, with their staff and contracted manure haulers, the line of separation.
"This is the physical or imaginary boundary that exists to keep the farm or biosecure side separate from the manure hauling side. They need to ask themselves, 'what existing or new procedures do you want followed for crossing over this line?'" Cortus said.