Comparison of Thermal and Non Thermal Processing of Swine Feed and the Use of Selected Feed Additives on Inactivation of Porcine Epidemic Diarrhea Virus (PEDV)
Infection with porcine epidemic diarrhea virus (PEDV) causes diarrhea, vomiting, and high mortality in suckling pigs. Contaminated feed has been suggested as a vehicle of transmission for PEDV. The objective of this study was to compare thermal and electron beam processing, and the inclusion of feed additives on the inactivation of PEDV in feed. Feed samples were spiked with PEDV and then heated to 120 145degC for up to 30 min or irradiated at 0 50 kGy. Another set of feed samples spiked with PEDV and mixed with Ultracid P (Nutriad) Activate DA (Novus International) KEM GEST (Kemin Agrifood) Acid Booster (Agri Nutrition) sugar or salt was incubated at room temperature ~25degC) for up to 21 days. At the end of incubation, the virus titers were determined by inoculation of Vero 81 cells and the virus inactivation kinetics were modeled using the Weibull distribution model. The Weibull kinetic parameter delta represented the time or eBeam dose required to reduce virus concentration by 1 log. For thermal processing, delta values ranged from 16.52 min at 120degC to 1.30 min at 145degC. For eBeam processing, a target dose of 50 kGy reduced PEDV concentration by 3 log. All additives tested were effective in reducing the survival of PEDV when compared with the control sample (delta 17.23 days) Activate DA (0.81) and KEM GEST (3.28) produced the fastest inactivation. In conclusion, heating swine feed at temperatures over 130degC or eBeam processing of feed with a dose over 50 kGy are effective processing steps to reduce PEDV survival. Additionally, the inclusion of selected additives can decrease PEDV survivability.
PloS one