2023
Evaluation of inactivation of EhV (surrogate for African swine fever virus) in corn- and soybean-based feed ingredients and diets during storage and in vitro digestion processes
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Contributor/Checkoff:
United Soybean Board
Category:
Feed
Keywords:
Animal healthDiseaseForeign animal diseasesSoy mealSwine
Parent Project:
This is the first year of this project.
Lead Principal Investigator:
Gerald Shurson, University of Minnesota
Co-Principal Investigators:
Project Code:
23-107-D-E-1-A
Contributing Organization (Checkoff):
United Soybean Board
$137,574
Institution Funded:
University of Minnesota
$137,574
Brief Project Summary:
No studies have been conducted to determine the fate of ASFV contaminated feed in the gastrointestinal tract of pigs. Results from our previous USB project showed that the majority of the surrogate virus remains bound to SBM when inoculated. The timing of this project is urgent because ASFV is a major threat to the U.S. pork industry (recent outbreak in Dominican Republic) and SBM use needs to increase because of increased crush capacity to meet oil demand for renewable diesel production. Results from this study will provide industry guidance on the value of storage time and temperature on ASFV inactivation in corn- and soybean-based ingredients and diets, and the extent of degradation of our surrogate virus (Emiliania huxylei;EhV) in these ingredients and diets during the digestion process in pigs using our RISNA assay (developed and used in previous USB projects).
Information And Results
Project Summary

Project Objectives

Project Deliverables

Progress Of Work

Final Project Results

Results from the current study indicate that storing corn- and soybean-based feed ingredients and completed feed inoculated with EhV at 4, 24, or 34 °C for up to 120 days did not result in the inactivation of EhV in any of the ingredients or complete feed. Because EhV is similar to ASFV, these results showed that EhV and ASFV can maintain viability in various feed matrices during long-term storage and suggest that extending storage time alone may not be an effective mitigation practice against African swine fever virus. We also determined that between 2- to 5-log (99% to 99.999%) reductions in EhV in various feed matrices occur during the entire digestion and fermentation process, but these estimates need to be validated once we refine the fermentation protocol to address the cross-contamination issue to obtain accurate data from this portion of the in vitro assay.

Benefit To Soybean Farmers

Global soybean meal (SBM) demand and consumption have been reduced due to the outbreak of African Swine Fever virus (ASFV) that has spread globally except for North America. Studies have shown that if SBM is contaminated with ASFV, it can survive for many months during storage and may cause disease when consumed by pigs. Therefore, SBM is an ingredient of potential concern for transmission of ASFV and mitigation solutions are needed. However, access to ASFV is highly restricted, limited, and requires adhering to strict biosecurity protocols in government approved high biosecurity research facilities (BSL-3). Therefore, we developed a surrogate virus assay (RISNA) using Emiliania huxylei virus (EhV) to safely and accurately conduct research to understand ASFV survival and mitigation in feed ingredients. There are no data on ASFV survival in corn- and soybeans-based ingredients at different temperatures during storage. There are conflicting findings on the infectivity of ASFV in feed, which may be related to the extent that ASFV is degraded in the pig’s digestive system after it is consumed. No studies have been conducted to determine the fate of ASFV contaminated feed in the gastrointestinal tract of pigs. Results from our previous USB project showed that the majority of the surrogate virus (Emiliania huxylei; EhV) remains bound to SBM when inoculated.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.