Ultraviolet treated liquid plasma PCR+ for PEDV spray dried and fed to naïve pigs was not infective and performed equal to pigs fed untreated plasma

Spray dried plasma (SDP) is a specialty protein source used in pig diets due to its beneficial effects on post-weaning performance and survival. Processing of SDP produces a safe product; however, further evaluation of redundant safety steps may be investigated. The objectives were to determine the effect of commercially produced ultraviolet light (UV) treated liquid porcine plasma containing PEDV genome with a special UV system developed for turbid liquids and then spray dried (UV-SDPP) and used in a diet for PEDV naïve weaned pigs on performance and PEDV transmission compared to pigs fed a diet without SDP or with spray dried bovine plasma (SDBP).

Eighty pigs (21 d of age) were randomized to three treatments (trt) and balanced by BW and gender to provide 4-6 replications per trt (4 pigs/pen). Dietary trt were: 1) control: soy protein concentrate; 2) UV-SDPP: 5% UV treated (2836 J/L) commercial SDPP positive for PEDV genome (qrtPCR Ct = 32); and 3) SDBP: 5% commercial SDBP. All pigs were housed in the same room and air space. All diets contained 20% SBM and 20.6% dried whey, were non-pelleted, non-medicated and formulated to contain 3.4 Mcal ME/kg and 1.45% SID lysine, and fed for 14 d post-weaning. Individual pig BW was recorded at 0, 7, and 14 d post-weaning and average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (F:G) was calculated for these periods. Pigs were evaluated daily for symptoms of diarrhea, respiratory, and body condition. Rectal fecal swabs for each pig were collected at d 0, 3, 7, and 14 and submitted for PEDV qrt-PCR. Pigs were necropsied on d 14 and gross evaluation of tissues noted. Intestinal contents were collected at termination and submitted for PEDV qrt-PCR and tissue samples were subjected to immunohistochemistry (IHC). Terminal blood samples were submitted for PEDV antibodies. Analysis of variance included effect of diet and the covariance of initial BW.

Pigs fed UV-SDPP or SDBP had greater (P< 0.05) ADG and ADFI compared to the control diet. No significant differences (P> 0.05) were noted for F:G, diarrhea, or respiratory symptom days, or physical condition. Analysis of fecal swabs for D 0, 3, 7, and 14 were all negative for PEDV by qrt-PCR for all trt. IHC of intestine samples and PEDV serum antibodies on d 14 were also all negative for all trt.

Feeding pigs diets containing UV-SDPP positive for PEDV genome did not transmit PEDV to naïve pigs through 14 d post-weaning based on fecal qrt-PCR, IHC, and lack of seroconversion. Performance was similar for pigs fed diet with UV-SDPP compared to SDBP diet and better than control diet.

Disclosure of Interest: J. Campbell Conflict with: Employee, J. Crenshaw Conflict with: Employee, J. Polo Conflict with: Employee, R. Saltzman: None Declared, L. Kesl: None Declared.