Additives may help mitigate the risk of ASFV transmission through feed

Researchers at Kansas State University have found that chemical feed additives may potentially serve as mitigants for reducing the risk of introduction and transmission of African swine fever virus (ASFV) through feed. Their findings are published in Transboundary and Emerging Diseases.

The research team, headed by Megan Niederwerder, assistant professor of diagnostic medicine and pathobiology in the College of Veterinary Medicine, published a report on ASFV transmission through feed in 2019. Their subsequent work has focused on mitigation of ASFV in feed through the use of chemical feed additives and heat treatment.

Although feed additives have historically been used to reduce the risk of bacterial contamination in feed, research thus far has not reported efficacy for the inactivation of ASFV in feed ingredients. Niederwerder said there are currently no commercially available vaccines and no effective treatments that can be administered to pigs for ameliorating disease caused by the virus. Thus, 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. 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 and 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 ASFV in cell culture and in feed ingredients. In general, both chemical additives demonstrated evidence of reducing the virus infectivity, with data supporting dose-dependent efficacy.

While the results of the study are promising, Niederwerder emphasized the need for a multifaceted approach to reducing the risk of ASFV in feed, including sourcing ingredients from countries without the virus when possible, applying holding times to high-risk ingredients, and implementing consistent biosecurity protocols at the feed mill.

The study was funded by a grant from the Swine Health Information Center and the State of Kansas National Bio and Agro-defense Facility Fund.

Article: Niederwerder, M.C., Dee, S., Diel, D.G., Stoian, A. M. M., Constance, L. A., Olcha, M., Petrovan, V., Patterson, G., Cino‐Ozuna, A. G., Rowland, R. R. R. (2020). Mitigating the risk of African swine fever virus in feed with antiviral chemical additives. Transboundary and Emerging Diseases, Online ahead of print, 2 July 2020, doi: 10.1111/tbed.13699

[SOURCE: Kansas State University]

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