In this newly published paper from the Torremorell lab, the authors followed 63 wean-to-finish farms in the Midwest and recorded wild-type PRRSV introduction, describing the biggest factors.
Methods
- 63 wean-to-finish sites in the Midwest
- 10 swine production companies
- Receiving pigs from PRRS negative or PRRS stable sow farms
- Monthly oral fluid samples tested for PRRSV by PCR
- Participants were surveyed to understand management practices
Results
- The enrolled sites had a median of 4,560 pigs in two barns of 2,400 heads each.
- The majority was fully slated, with mechanical ventilation and double stocked at arrival.
- Half of the farms sourcing the pigs were PRRSV negative but 90% of the enrolled sites had MLV-vaccinated pigs.
- 80% of the sites shared daily personnel with other sites; 94% used an external crew to unload pigs.
- 60% had a visitor log book; 62% had showering SOPs and 55% required downtime
- 73% of sites used rendering and 71% of sites used shared manure pumping equipment.
- Third-party rendering and the entry of maintenance crews in the barn increased the risk of wild-type PRRSV introduction (OR 7.08 and 7.14, respectively)
Abstract
Porcine reproductive and respiratory syndrome virus (PRRSV) infections in growing pigs are common and costly. We evaluated risk factors related to production practices and herd characteristics associated to wild-type PRRSV (WT-PRRSV) introduction into 63 wean-to-finish (WTF) herds through the implementation of surveys, active recording of activities and monthly oral fluid sampling during the growing phase. Herds were located in the Midwest region of the USA and observed prospectively. Logistic regression analysis of risk factors indicated that WTF herds that outsourced trucks for mortality removal (OR 7.08, p = 0.03) and herds with external maintenance crews (OR 7.14, p = 0.03) had higher risk of WT-PRRSV infections. These findings highlight the importance of mechanical transmission of PRRSV and the need to develop stricter biosecurity protocols in growing pigs. Overall, this study describes most common production management practices and characteristics of WTF sites, and potential risk factors that if addressed, can help improve biosecurity, control and elimination of PRRSV in growing pigs.