Some very determined swine farmers and their veterinarians are working toward eliminating a devastating disease from herds in southern Minnesota.
Porcine reproductive and respiratory syndrome virus has been diagnosed in hog farms across the state since the early 1990s. Veterinarian Paul Ruen, Fairmont Vet Clinic, says some of his clients’ herds were among the first to be inflicted with deadly reproductive problems and respiratory illnesses. “It’s been a very disastrous disease, financially and emotionally, to producers,” Ruen says.
• Air infiltration plays a major role in eliminating PRRS in barns.
• The investment runs about $200 per sow — the same as the cost of the disease.
• Employees learn new ways to practice biosecurity on sow farms.
That’s why Ruen and veterinarians at his clinic and in Pipestone and St. Peter are involved with a University of Minnesota project led by veterinarian Scott Dee that focuses on barn air filtration and biosecurity to reduce and eliminate swine exposure to the disease. This is no small task, considering that U-M research has helped prove that PRRS easily travels up to six miles via the air. It moves more in cool, damp weather and thrives in low-sunlight/high-humidity conditions. With PRRS you have to consider how to control disease in the whole neighborhood, not just on one farm.
Veterinarian Jeff Kurt, Fairmont, has been working with a boar stud that had consistent disease outbreaks prior to 2005. That year, the owner decided to evaluate the effectiveness of air infiltration and installed attic ventilation units. From 2005 through 2008, the units circulated air during prime PRRS seasons, from September through May.
The investment paid off. PRRS has remained at bay, even with increased PRRS activity in Fairmont during the summer of 2008. That year, for additional protection, the stud owner decided to filter barn air year-round. He fitted filters to cooling units, added more filters and fans to create positive air pressure to increase air flow, tightened up exterior openings, and filled cracks and crevices.
Into sow barns
Word spread around Fairmont about the success at the boar stud. For the past year, two sow farms — one with 2,500 head and one with 1,500 head — have been operating with building updates and air infiltration. Three more farms are making renovations this fall. “The technology fits any size of farm,” Kurt says.
The cost to filter barns ranges from $100 to $250 per sow, depending on the amount of remodeling and new construction that takes place. The thoroughness of “buttoning up” the facilities and providing continuous filtered airflow is similar to bio-secure laboratories on the U-M St. Paul campus.
At Make Line Ridge near Fairmont, a 2,500-sow herd owned by Kevin Hugoson and managed by Kaj Jensen, all employees and visitors enter through a new double-door foyer. An 18-inch wall fan, triggered on when the exterior door opens, creates positive air pressure in the entry, preventing outside air from coming in. After walking through the second foyer door, a glass board-covered bench forces people to stop, sit and change footwear.
All other doors have been sealed, except one for supply delivery and pickup in the furnace room. This controls everyone’s entrance into the barn and eliminates the chance of disease coming in.
Another door, on the west end, is dedicated to loading out dead sows. A cement drop area was added outside the door for ease of animal removal. No one steps outside anymore to dispose of animals.
To filter incoming air, Hugoson hired a contractor to build filtration boxes over all ceiling barn inlets in the attic. Each box contains two types of filters.The top one, which is a regular furnace filter, costs about $3 and will have to be changed one to two times a year. The inside filter, with a rating of MERV 14, costs about $100 to $110, depending on size. Hugoson hopes this filter lasts three years.
Other exterior air inlets are covered with flaps or fabric socks. These socks or curtains collapse or close with negative air pressure, blocking the entry of the airborne virus. Plus, all obvious cracks along fans and pump-out areas were caulked or sealed in some manner.
Hugoson also invested in building a four-bin dead animal compost barn, which sits on the south side of the sow barns. It takes about two months to compost animal remains. The compost is then spread on fields.
With all the updates, Hugoson figures he’s invested about $200 per sow to eliminate PRRS, which is about equal to the cost of one PRRS break on the farm.
New habits for all
Employees continue to learn new ways of completing chores. The farm has a new herd biosecurity manual that is reviewed and updated.Veterinarians Ruen and Kurt provided one-page protocol sheets that describe how to do tasks.
With six full-time employees at Make Line, the process is a continual give-and-take of ideas and concerns. The most important fact, however, is that everyone is on board with the end result — no more PRRS.
That’s the same goal over at Welcam Farm, another operation owned by Hugoson.
“We’ve seen PRRS’ effects on sows, and we want to work on this [to eliminate the disease] as much as the owners do,” says manager Rick Benson. Farm employees went through several training sessions with Kurt that reviewed biosecurity practices, such loading pigs and disinfecting areas.
To minimize disease risk with transportation, a load-out room was added. That cost an additional $20,000 — an investment that most other farmers wouldn’t have to make.
“To do it right, you might have to make some investment,” Kurt says. “Here, we made the cull sow room big enough so you can load the trailer in one shot. We try to plan and focus on the details to minimize the risk.”