Study reveals African Swine Fever virus can withstand feed processing

USA – A new study from the University of Minnesota suggests that the African swine fever (ASF) virus may survive soybean processing, raising concerns about feed-related transmission risks. 

In a controlled trial simulating commercial soybean processing, researchers introduced a virus related to ASF—one that is safe for use in research—into raw soybeans before running them through a pilot facility used by an industrial soybean processor. 

The virus withstood the heat and pressure of the process, remaining largely intact on soybean hulls and flakes, even after exposure to temperatures as high as 100°C (212°F).

However, the final products told a different story. The processed soybean meal showed a three-log reduction in virus levels, and the finished soybean oil tested virus-free. 

Declan Schroeder, professor of virology at the University’s College of Veterinary Medicine, believes a chemical solvent used during processing may have played a critical role in reducing the virus’s viability.

“This could help explain why ASF hasn’t managed to reach U.S. pig farms despite the ongoing import of potentially contaminated feed ingredients,” Schroeder said. “It suggests that chemical treatments used in feed processing may offer a layer of protection.”

Solvent application offers potential chemical-based strategy to curb spread

Solvent use in soybean processing is not universal, but it is common among major processors. Schroeder said the findings open the door to further exploring chemical mitigants as a practical defense against ASF, especially as past research has shown the virus is surprisingly resistant to extended holding times and heat.

While the solvent did not completely eradicate the virus from the soybean meal, Schroeder emphasised that the experiment used much higher virus concentrations than in real-world conditions. This was necessary to obtain measurable and reliable results, he said.

The results present a double-edged sword: on one hand, they highlight the potential of chemical solvents to weaken the virus; on the other, they underscore the resilience of ASF, especially on feed components that are less processed, like soybean hulls, flakes, or even corn.

“What this study clearly says is that temperature on its own is not enough,” Schroeder said. “ If heat isn’t the answer, let’s explore what else we can do.”

Schroeder is now pivoting his research to identify and test chemical additives that could be incorporated during feed processing to help neutralise the virus.

ASF, which affects pigs but poses no risk to human health, has devastated pig populations in parts of Asia, Europe, and Africa in recent years. Controlling its spread is a top priority for the global pork industry.

Sign up HERE to receive our email newsletters with the latest news updates and insights from Africa and the World, and follow us on our WhatsApp channel for updates.