Effect of spray-drying and ultraviolet C radiation as biosafety steps for CSFV and ASFV inactivation in porcine plasma

Spray-dried animal plasma (SDAP) is widely used in diets of domestic animals to improve health status and increase growth and feed efficiency. Individual steps in the SDAP manufacturing process, including spray-drying, have been validated to inactivate potential pathogens. Manufacturing standards have established a minimum exit temperature of 80 degrees C and a minimum post-drying storage period of 14 days at 20 degrees C for production of SDAP. Also, UV-C irradiation has been evaluated as another inactivation step that could be included in the manufacturing process. The aim of this study was to assess the inactivation effectiveness of spray-drying on Classical swine fever virus (CSFV) and African swine fever virus (ASFV) and the effect of UV-C inactivation on ASFV as redundant biosafety steps of the manufacturing process for producing spray-dried porcine plasma (SDPP). This study demonstrated that UV-C treatment of liquid porcine plasma can inactivate more than 4 Log(10) TCID50/mL of ASFV at 3000 J/L. Spray-drying effectively inactivated at least 4 Log(10) TCID50/mL of both CSFV and ASFV. Incorporating UV-C technology within the SDAP manufacturing process can add another biosafety step to further enhance product safety.