Commercial spray-dried porcine plasma does not transmit porcine circovirus type 2 in weaned pigs challenged with porcine reproductive and respiratory syndrome virus

The objective of this study was to evaluate if spray dried porcine plasma (SDPP) containing porcine circovirus type 2 (PCV2) genome supplemented in feed could transmit PCV2 to pigs challenged with porcine reproductive and respiratory syndrome virus (PRRSV). Twenty-three PRRSV-free pigs, non-viraemic for PCV2, were housed in bio-safety level 3 facilities and assigned to four groups in a 2 × 2 factorial design consisting of PRRSV challenge and a negative control. The diet contained 0 or 8 kg SDPP per 100 kg of feed. PRRSV challenge groups were inoculated intranasally with 2 mL of a suspension containing 106 TCID50/mL PRRSV. The SDPP used in the study contained 7.56 × 105 PCV2 genome copies per gram. Dietary treatments were fed from 4 days prior to PRRSV inoculation until 28 days post-inoculation (PI).All challenged pigs developed PRRSV viraemia by day 3 PI and PRRSV antibodies were detected in sera by day 14 PI, with no difference between diet treatments. Neither PRRSV viraemia nor seroconversion was observed in non-challenged pigs. PCV2 was not detected in the serum of any pigs throughout the experimental period. SDPP containing the PCV2 genome supplemented in feed did not result in PCV2 transmission to either healthy or PRRSV-infected pigs under these experimental conditions.