SOON after porcine epidemic diarrhea virus (PEDV) emerged in the U.S., the ability of the virus to live in manure became a topic of concern.
In 2014, research conducted by Dr. Steve Tousignant at the University of Minnesota Swine Disease Eradication Center confirmed that the virus could remain viable in manure pits for up to four months after pigs were removed.
Gerald May, senior extension educator with Michigan State University Extension, said knowing this created discussion about what happens when swine producers start filling manure tanks with virus-contaminated manure, whether aerosol particles could be present and, if they are present, whether the particles could potentially re-infect pigs in the barn where the manure was being removed.
May said ongoing research seeks to answer whether aerosol particles are present at the point where the manure discharges into the manure spreader.
The Michigan Pork Producers Assn. (MPPA) initially funded a project that tested one farm, but after positive results, MPPA and the Michigan Alliance for Animal Agriculture provided further funding to test 10 additional farms.
May pointed out that the hog industry has done such a good job of handling PEDV that the researchers have been limited in the number of qualifying farms.
"Our concern is bio-aerosol spread of the virus," May said. "If you think of (crop) sprayer drift, that's what we're looking for — that size particle that will carry the virus to farther distances."
May said while the research is rather limited in scope, there is currently some discussion about conducting additional research projects to look at all phases of the manure spreading process.
Dr. Melissa Millerick-May with Michigan State University's department of occupational and environmental medicine leads the research project.
Four farms have already been tested this year, and the other six farms will be tested throughout the summer, May said, adding that the summarized report will be available in the fall.