PSII-15 Evaluation of a blend of phytochemicals and carboxylic acid on complete feed when inoculated with porcine epidemic diarrhea virus, porcine reproductive and respiratory syndrome virus, and SVA virus 1

Abstract

Chemical mitigants have been found to decrease virus concentrations in swine feed. Continued research is needed to identify the appropriate inclusion levels and application time for different viruses in this matrix. The objective was to evaluate different inclusion levels of a synergistic blend of phytochemicals and carboxylic acid (PCA) when applied either before virus inoculation (pre-inoculation) or after inoculation (post-inoculation) of porcine epidemic diarrhea virus (PEDV), porcine reproductive and respiratory syndrome virus (PRRSV) and Seneca Valley virus 1 (SVV1) to complete feed. The experiment was designed in a 2×2 factorial with a PCA-based product, (Finio, Anitox Corp. Lawrenceville, GA) applied pre- or post-inoculation at either 1.75 or 2.75 kg/MT. On d0, samples of the respective matrices were weighed in 50 g aliquots and added to 500 mL bottles. The PCA blend was applied to the pre-inoculation samples at their respective inclusion levels and 50 µL of each virus were added to the post-inoculation samples. All bottles were incubated at room temperature for 24 hours. On d1, virus was added to the pre-inoculation samples and chemical mitigants were added to the post-inoculation bottles. Half of the samples were immediately processed (0 h) and the other half were incubated at room temperature for an additional 24 hours. Samples were processed and aliquots were analyzed via a triplex RT-PCR at Kansas State University Veterinary Diagnostic Laboratory. Cycle threshold and proportion of PCR positive were analyzed using SAS GLIMMIX v 9.4 (SAS, Inc., Cary, NC) with each virus analyzed individually. An application time × inclusion level interaction was observed for PRRSV at 0 h, where less RNA was detected (P < 0.05) in the post-inoculation samples at either 1.75 or 2.75 kg/MT as compared to the pre-inoculation or control samples. For other viruses at 0 h, the post-inoculation samples had less detectable PEDV or SVV1 RNA (P < 0.05) than the pre-inoculation samples. As time continued (24 h), both pre- and post-inoculation samples had less detectable PEDV RNA (P < 0.05) than the controls in feed. Inclusion of the PCA blend at either inclusion level decreased the quantity of detectable PEDV and PRRSV RNA at 24 h (P < 0.05), but no differences were observed between the 1.75 and 2.75 kg/MT inclusion samples (P > 0.05). The use of a PCA-based product reduced viral concentrations in feed. More research is needed to understand the contact time required for viral reduction and the infectivity of these samples at defined contact times.