A K-State veterinary researcher has demonstrated how additives help mitigate the risk of African swine fever transmission through feed.

Kansas State University says new research at the school is showing that the risk of spreading a deadly animal virus through feed can be effectively reduced through the use of different feed additives.

The University says its research team, headed by Megan Niederwerder an assistant professor of diagnostic medicine and pathobiology in the College of Veterinary Medicine, has published a new study, Mitigating the risk of African swine fever virus in feed with antiviral chemical additives, in the scientific journal Transboundary and Emerging Diseases. 

The school says this study provides the first evidence that feed additives may be effective tools against African swine fever.

“Over the last two years, ASF is estimated to be responsible for the death of at least 25% of the world’s pig population due to the emergence of the virus within China and subsequent spread to over 10 other Asian countries,” Niederwerder said. “In 2019, we published the first report of African swine fever virus, or ASFV, transmission through the natural consumption of plant-based feed. Our subsequent work has focused on the mitigation of ASFV in feed through the use of chemical feed additives and heat treatment.”

The researchers say although feed additives have historically been used to reduce the risk of bacterial contamination in feed, research so far has not reported efficacy for the inactivation of African swine fever virus in feed ingredients.

Niederwerder says there are currently no commercially available vaccines and no effective treatments that can be administered to pigs for ameliorating disease caused by the virus. This makes the control of African swine fever is focused on biosecurity measures to prevent the introduction of the virus into negative countries or negative farms and regions within a positive country.

Niederwerder says the other method of containment would involve large-scale culling of infected or high-risk animals to contain the spread of the virus.

“Our new research reports novel data evaluating the efficacy of feed additives on inactivating ASFV in an in vitro cell culture model and a feed ingredient transoceanic shipment model,” Niederwerder said. “This will provide valuable information to the swine industry with regards to mitigating the risk of potential routes for introduction and transmission of ASFV through feed and ingredients.”

Niederwerder says her team examined two different classes of liquid feed additives, including a medium-chain fatty acid-based additive and a formaldehyde-based additive for efficacy against African swine fever virus in cell culture and in feed ingredients.

She says in general, both chemical additives demonstrated evidence of reducing the virus infectivity, with data supporting dose-dependent efficacy.