Today we are sharing a new publication from a collaboration with our colleagues at the School of Public Health and the College of Agricultural and Natural Resource Sciences at the University of Minnesota. In this study, Drs. Sampedro, Urriola, Van de Ligt, Schroeder, and Shurson estimated the maximal viral load of Porcine Epidemic Diarrhea and African Swine Fever that could be found in spray-dried porcine plasma to still achieve a virus-free batch (no infectious viral particle) for three different batch sizes (10, 15, and 20 tons). They also quantified the impact of different treatments such as spray-drying, UV and extended storage in decreasing viral loads to meet the thresholds.

Highlights

• The SDPP production process has been validated to inactivate PEDV and ASFV (8.4–11.1 mean log reduction).

• Under the current conditions, the model estimated that an inactivation level (log-kill) of 7.0, 7.2, and 7.3 log must be achieved to manufacture a 10-, 15-, and 20-tons batch size, respectively.

• Performance Objective compliance rates were >95% for the baseline SDPP production scenario and 100% for the baseline + UV processing scenario.

• Chemical and physical factors that contribute to the inactivation of various swine viruses in feed ingredients during storage need to be determined.

Abstract

Introduction: There are no microbiological regulatory limits for viruses in animal feed and feed ingredients.

Methods: A performance objective (PO) was proposed in this study to manufacture a spray-dried porcine plasma (SDPP) batch absent of any infectious viral particles. The PO levels of −7.0, −7.2, and −7.3 log TCID₅₀/g in SDPP were estimated for three batch sizes (10, 15, and 20 tons).

Results and discussion: A baseline survey on the presence of porcine epidemic diarrhea virus (PEDV) in raw porcine plasma revealed a concentration of −1.0 ± 0.6 log TCID₅₀/mL as calculated using a TCID₅₀-qPCR derived standard curve. The mean African swine fever virus (ASFV) concentration in raw plasma was estimated to be 0.6 log HAD₅₀/mL (0.1–1.4, 95% CI) during a pre-clinical scenario (collected from asymptomatic and undetected viremic pigs). Different processing scenarios (baseline: spray-drying + extended storage) and baseline + ultraviolet (UV) radiation were evaluated to meet the PO levels proposed in this study. The baseline and baseline + UV processing scenarios were >95 and 100% effective in achieving the PO for PEDV by using different batch sizes. For the ASFV in SDPP during a pre-clinical scenario, the PO compliance was 100% for all processing scenarios evaluated. Further research is needed to determine the underlying mechanisms of virus inactivation in feed storage to further advance the implementation of feed safety risk management efforts globally.