Thermal inactivation of African swine fever virus in feed ingredients

Abstract

Abstract African swine fever virus (ASFV) causes a fatal infectious disease affecting domestic pigs and wild boars. ASFV is highly stable and easily transmitted by consumption of contaminated swine feed and pork products. Heat treatment of feed ingredients is a means to minimize the risk of contamination through swine feed consumption. The objectives of this study were to determine the thermal inactivation of ASFV in non-animal and animal origin feed ingredients. The rate of thermal inactivation is represented by decimal reduction time (D T) or time required to reduce ASFV per 1 log at temperature T. The mean D 60, D 70, D 80 and D 85 of meat and bone meal (MBM), soybean meal (SBM), and maize grain (MZ) are in the ranges 5.11–6.78, 2.19–3.01, 0.99–2.02, and 0.16–0.99 min, respectively. D T is used to compare the heat resistance of ASFV in the feed ingredient matrices. The mean D T of ASFV in MBM, SBM and MZ was not statistically significant, and the heat resistance of ASFV in MBM, SBM, and MZ was not different at 60, 70, 80, or 85 °C. The multiple D T was used to develop a D T model to predict D T at various inactivation temperatures. The D T models for MBM, SBM, and MZ are log D T = − $$\left( {\frac{T}{32.08}} \right)$$ T 32.08 + 2.69, log D T = − $$\left( {\frac{T}{31.77}} \right)$$ T 31.77 + 2.55, and log D T = − $$\left( {\frac{T}{18.96}} \right)$$ T 18.96 + 4.01. To expand and ease the field applications, a spreadsheet predicting the D T and the inactivation time (with 95% confidence interval) from these D T models is available to download.