Manure pumping and land application are operational necessities, but research confirms they represent one of the most critical disease transmission windows for swine herds. Pumping and application activities are significantly associated with an increased risk of porcine reproductive and respiratory syndrome virus (PRRSV) and porcine epidemic diarrhea virus (PEDV) outbreaks, according to research led by Dr. Ana Paula Silva, a research scientist at Iowa State University.
Starting in 2022, Dr. Silva evaluated the link between manure handling events and herd disease outbreaks. Her findings demonstrate that the risk is not just theoretical—it is measurable, acute and highest within a five-week window following pumping and application.
The study revealed that manure pumping was associated with 3.38 times greater odds of PRRSV outbreaks within five weeks following a pumping event. While pumping alone does not cause an outbreak, it creates a convergence of biosecurity vulnerabilities, significantly increasing the opportunity for pathogen spread between sites.
“We saw that the odds of a PRRSV outbreak increase if the application field is within 1-3 miles of a pig site,” Silva explains. “We also found that risk increases when younger pigs are present in the barn. Nursery pigs were identified as the population at greatest risk following manure pumping events.”
How Can You Protect Your Pigs?
Dr. Brent Pepin, swine health director at the National Pork Board, outlines key strategies producers should implement to mitigate risk through scheduling, physical separation and rigorous sanitation:
1. Pump low-risk farms first.
Pepin encourages producers to pump farms that are known to be PRRSV and PEDV negative first before pumping farms that have a known disease challenge.
2. Avoid pumping during the first four weeks of pig placement.
“We know those pigs are higher risk and more susceptible to disease,” he says. “So, whenever possible, try to avoid pumping during those first four weeks after pigs have been placed into a barn.”
3. Keep contractors outside the line of separation.
Require that all contractors stay outside of the building and animal spaces. Pepin says keeping that line of separation and keeping those people that are not regular farm staff outside of those spaces can prevent them potentially dragging something into your barn.
4. Clean, disinfect and dry equipment between farms.
“If your equipment’s leaving a farm that has a known disease, especially PRRSV or PEDV, be sure to thoroughly clean and disinfect every piece of equipment before moving it to another farm,” Pepin says. “And don’t forget the drying step.”
5. Monitor herd health after pumping.
If you do have a disease break after pumping, keeping a close eye on your pigs during this time will allow you to respond to it quickly to minimize loss, he adds. It also gives pork producers a chance to validate the biosecurity process that took place during that pumping event.
Preparing for Operations and Managing Breaches
Pepin urges producers to view manure pumping as a high-risk biosecurity event with strict physical and logistical boundaries.
“Treat it as a planned biosecurity event, just so everybody is aware of what could go wrong,” he says. “Then, if something does not go as planned, they can address it quickly to help protect the pigs.”
He says having a meeting with your farm team is a good idea so they can understand expectations. Assign a designated person to oversee that manure event.
“If you do have a contamination break, secure the affected area, apply appropriate disinfectant or cleaning to that area, or keep that area isolated,” Pepin advises. “If it’s a manure spill, contain it and reach out to your veterinarian.”
Post-Pumping Surveillance
Biosecurity does not end when the pump is shut off. Test and inspect pigs closely for 5 weeks post-pumping. Open communication with neighbors is also vital.
“Be sure to communicate with your neighbors before you pump, but also communicate about when they will be pumping,” Silva says. “That collaboration with neighbors and peers in the field is a key takeaway from the new guide.”
The National Pork Board’s comprehensive guide, “PRRSV and PEDV: Reducing Disease Spread During Manure Pumping and Land Application,” is available for download here.
