Editor's note: The following article was originally featured on the Pipestone Veterinary Services webiste. 

As the weather cools, the pork industry increases its vigilance against Porcine Reproductive & Respiratory Syndrome (PRRS). Over the past 20 years, PRRS has emerged as the most economically important disease for U.S. pork producers.

Dennis Wiebbecke has been on the front line of the fight against PRRS for the past three years.  As the Filter Compliance Technician at Pipestone System’s Grassland sow barn near LaPorte City in eastern Iowa, Dennis is responsible for monitoring ventilation and filtration systems at the barn.

Filters like those at Grassland have become an important part in preventing PRRS infections across the Pipestone System since the first sow barn was filtered in 2008.

“We suspected that diseases were spreading from farm to farm through the air.  No matter what other biosecurity measures we had in place, we couldn’t stop certain diseases, especially PRRS,” said Dr. Joel Nerem, Director of Health at Pipestone Veterinary Services. 

With a potential financial impact of up to $1 million per barn per outbreak, Pipestone System looked to adding filter systems to barns that would make all outside air go through filters to prevent virus particles from entering the building. 

“Since installing the first filters, we’ve learned more about the technology and other biosecurity practices and have been able to dramatically reduce the number of new PRRS infections in barns that had historically had one or more infections per year,” said Dr. Nerem. 

Filters were installed in the Grassland barn in 2012.  Prior to the installation, the barn was experiencing a new PRRS infection each year. Since the installation, they have had no new infections. 

However, installing the filters is just the first step.  Success depends on a commitment from employees to biosecurity.

Each day, Dennis checks all the fan chutes, exit doors and other possible areas where leaks could occur.  The filter banks are monitored daily to make sure there are no cracks or gaps where outside air can come into the barn. When fans aren’t running, there are interventions to make sure that there isn’t a backdraft of unfiltered air into the barn.  During winter, he is responsible for checking fan covers to make sure they aren’t frozen.

“Dennis is a big part of the success that Grassland has seen as a filtered farm,” said Dr. Nerem.  “He brings great attention to detail and a lot of ownership in making sure that the biosecurity and filtration technology is working the way it is supposed to every day.” 

Dennis has primary responsibility for the filtration systems, but he relies on all the farm’s employees to watch for potential biosecurity issues.

“Biosecurity should be a team effort at every farm,” he said.  “It makes a world of difference that everyone at Grassland is aware of their surroundings and will notify me if something is wrong so I can address is right away.”

Pipestone also provides support to Filter Compliance Technicians through training and audits by health technicians.

Health technicians from Pipestone Veterinary Services make an unannounced visit to each filtered barn each month.

“The monthly audits provide a second or third set of eyes to make sure everything is going well and all the protocols are being followed,” said Dr. Nerem.  “We also include an employee meeting at each visit to give farm staff an opportunity to bring up questions about animal health and biosecurity at the farm.”

FCTs from all the filtered barns meet in person for annual training each fall ahead of the traditional PRRS outbreak season.

“It is a good idea for everyone to get together to share ideas as we prepare for the new season,” said Dennis.  “It raises the alert level and makes sure we are all focused.”

There are currently 31 sow barns in the Pipestone System that are filtered. The success rate is in preventing PRRS infections is measured by the number of infections from July 1 to June 30.  Last year, there were only four new PRRS infections in the filtered barns.  According to Dr. Nerem, well over 50 to 75 percent of those barns would have had a new infection prior to filtration.

“From a shareholder perspective, installing filters at a farm can be very expensive, but we are convinced that the investment has been a good one,” said Dr. Nerem.  “When we look at the historical record of farms that are filtered and the reduction in new infections, there is a definite payoff.”

Dennis also sees the benefits that the systems have brought to pigs and the employees who care for them. 

“The extra effort it takes is worth it for the pigs and the employees,” said Dennis.  “When the pigs are healthier, the employees are happier.”

For some biosecurity tips, read Dr. Joel Nerem's article on Preparing Your Barn for PRRSv and PEDv Season.