Judging by its impact on sow operations over the past several months, it looks like the Porcine Reproductive and Respiratory Syndrome (PRRS) virus has followed the pattern of virus evolution. What veterinarians and producers thought they had under good control with solid biosecurity practices has evolved to new levels of virulence.

Need Protection All Year

What usually was considered an October to March virus when environmental conditions were right for spreading from animal to animal and operation to operation has evolved to something that can be spread regardless of the time of year. It’s effects have been felt hardest in southern Minnesota and northern Iowa, with many impacted sow operations depopulating whole herds.

Strict adherence to biosecurity practices were important before these new PRRS strains but are even more important now as these new viruses make their way from farm to farm. Biosecurity protocols should be revisited to ensure they exclude, contain and manage virus interactions. But one important yet often overlooked aspect of biosecurity involves managing virus transfer on feed ingredients.

“Feed is really a Trojan Horse when it comes to virus transmission,” says Dr. Scott Dee, director of research for Pipestone Applied Research. “Research shows viruses live in feed. Certain viruses live in certain feed ingredients, within certain feed combinations, and soybean meal appears to be our leader.” Dr. Dee conducted an experiment that showed how three significant viral pathogens, including PRRS, can survive in feed under actual conditions of long-distance transport across the U.S.

Make Feed Part of Biosecurity

While it’s not at the top of the list of threat opportunities when it comes to virus protection, preventing viruses from entering your herd on feed ingredients should be a part of your biosecurity protocols. In recent years the use of feed mitigants to control virus spread on feed has been identified as an effective way to prevent disease spread through feed. But not all feed mitigants are created equal, and it’s important that pig farmers choose the right ingredient as an effective biosecurity solution.

“If pigs are on a diet that contains feed mitigated products, they perform significantly better than pigs on a non-mitigated diet,” says Dr. Dee. “Using feed additives for virus control is a very good thing to do. The more cases I hear about PRRS 1-4-4 moving around the U.S. in far reaching places and spreading rapidly like PED did, I’m wondering about feed playing a role in that. I’d put pigs, trucks, air, then feed in terms of risk factors for PRRS transmission.”

In the past, formaldehyde has been a popular ingredient used to control viruses and other pathogens that could be carried on feed. It’s cheap and relatively effective at controlling diseases. However, working with or around formaldehyde on the farm or in the feed mill can be a challenge, and even dangerous to anyone handling the ingredient. The use of formaldehyde as a feed ingredient for a food product that eventually reaches consumer dinner tables has negative connotations as well. All of these factors have caused the industry to find alternative feed additives that are effective at virus and pathogen control.

Use a Safe, Natural Product

One feed mitigant used by pork producers to avoid PRRS is pHorce from Anpario. pHorce is a natural, effective feed additive that can control the spread of viruses without the use of formaldehyde and without sacrificing performance. In the research conducted by Dr. Dee, in pigs fed pHorce there was no evidence of PRRS infection, no clinical signs of disease with lower mortality and significantly higher average daily gain.

Regardless of your situation, a strong biosecurity program is your best defense against PRRS or any other virus. While risk of contamination from feed is lower than other potential sources such as vehicles, pigs and people, research shows that feed can carry viruses like PRRS making use of a feed mitigant—including pHorce—an important part of a biosecurity program.