Biosecurity measures have been standard operating procedure for custom manure applicators for a long time, but the presence of porcine epidemic diarrhea virus (PEDV) has forced them to revisit or step up their practices.
“I don’t want to create paranoia, because I’m not aware of any cases of manure applicators spreading PEDV, but we still need to be vigilant,” says John Carney, executive director of the Manitoba Livestock Manure Management Initiative. “We can’t eliminate the risk, but we can manage it through communication and strong biosecurity.”
A lot has been learned since PEDV was first confirmed in the United States in 2013, but there is still a lot that is unknown.
Lisa Becton, a veterinarian and director of swine health information and research for the National Pork Board (NPB), says what we have learned is that large amounts of the virus are shed by pigs during the early infection, and it takes a small amount of the virus to cause infection in other pigs. “PEDV is spread through contact with contaminated manure,” Becton says, “so anything that comes in contact with manure can be a potential source of infection.”
Researchers have found that the virus is not shed in the respiratory tract and is not aerosolized, but there is evidence that the virus can be moved in the wind on dust particles and even moisture; thus, “it brings up a concern about the proximity of farms,” she says.
With that in mind, custom manure applicators need to maintain that vigilance to prevent the spread of PEDV and other diseases. Key to this vigilance is maintaining a strict “line of separation,” defined as the division between the area that is to be used by the manure haulers and the area to be used by all daily farm traffic and personnel.
Since he has operated his own custom manure application business, Andrew Henson has strived to maintain the line of separation. “We treat every operation as if they have something,” says Henson, owner of Arm’d Custom Pumping at Sac City, IA. He grew up working in hog operations, and for years saw the wrong ways of doing things. He has implemented the right way to do things in his operation, which that consists of two drag-line units purchased in 2012.
He worked on his parents’ 900-sow farrowing unit as early as age 8, later working for a 3,300-sow unit and a 6,300-sow unit throughout high school and college. After graduating, he went on to grad school in Utah. After the company expanded, he moved back to the Midwest.
Though hog producers are his main clients, he also hauls and applies manure for dairy operations as well. Arm’d Custom Pumping works with clients in Iowa, Minnesota, Missouri and South Dakota.
When Arm’d Custom Pumping pulls onto a site, there is limited exposure. “The only equipment that we bring onto a site is the semi lead pump and a pickup,” he says. “There is always a field driveway that we can use as access, so most of our equipment will stay out in the field.” For example, agitators will be brought in through the field, only brought onto the site from the back side, and placed in a fan opening for agitating purposes.
Before the Arm’d crew comes to a site, Henson has done his homework, looking for the roads less traveled. “We’ve been taking screenshots of the area and look at a 10-mile radius of the farms, and highlight the highways and the busy intersections,” Henson says. “Those are the ways we won’t go. We’ll take a back route to the place.”
Maintaining the line of separation does little good if equipment is not cleaned and disinfected properly. Henson’s crews clean all — and he means all — equipment before they arrive on a new job, and before they leave a farm site. “We disinfect anything that can come in contact with manure,” he says. “And that means interiors of pickups and tractors, floor mats, tools, inside of pumps.” Henson recommends the use of a foaming disinfectant “so you can see where you’ve applied.” The Henson crews power-wash, disinfect and then allow for a drying period. “We like to leave our equipment on the farm to dry for 24 hours,” because, Henson says, the drying period is often skimped on. “You have to realize that equipment needs to be 100% dry after disinfecting.”
Communication and clear expectations understood by all parties are also necessary components in the process. For more information on the NPB protocol, visit www.pork.org/filelibrary/PEDV Biosecure Manure Fact Sheet.pdf.
Carney’s organization and Kevin Erb of the University of Wisconsin Extension collaborated to conduct a survey of custom manure applicators, the results of which were announced at the North American Manure Expo held in early July in Springfield, MO. More information about that study can be found at nationalhogfarmer.com/business/managing-risk-custom-manure-application-and-pedv-spread.