Date Full Report Received

10/28/2014

Date Abstract Report Received

10/28/2014

Investigation

Institution: ,
Primary Investigator:

This project was designed to test manure from deep pits in 30 barns across southern Minnesota and Northern Iowa for the presence of viable PEDV in an effort to understand the risk of transmitting this virus during pit pumping season of 2014. Of the pits we tested, we found that 2 still had infectious virus 4 months after PEDV positive pigs were on the site. This continues to emphasize the need for proper biosecurity measures and planning during the pit pumping season of 2014.

In this study, we sampled 30 manure pits from barns in southern Minnesota and northern Iowa. At each site, manure was sampled through pump outs, using a 10 foot section of PVC piping angled into the pit as far under the animal space as the collection personnel could reach. At each site, a minimum of 3 pump out were sampled. The manure was pooled, and tested for PEDV at the University of Minnesota Veterinary Diagnostic lab by polymerase chain reaction (PCR). Positive samples were then tested by swine bio-assay for presence of live virus. Additionally, samples were sent to Minnesota Valley Testing Laboratory (New Ulm, MN) for complete nutrient profile.

We found that on average, pits had a PCR cycle time value of about 30, indicating a relatively high amount of viral genetic material. When tested by swine bio assay, 2 barns 4 months after having PEDV positive pigs were positive. In the swine bio-assay, 20 mL of manure from one site was administered via a stomach tube to a single pig and was observed for 3.5 days. At the end of the study the pig was taken to the diagnostic laboratory and infection was confirmed by the diagnosticians there.
When we compared the nutrient analysis between sites that had live PEDV and those that did not have live PEDV, we found that those with live PEDV had lower pH (around 7.4 versus greater than 8.0), and higher levels of copper (around 50mg/kg versus less than 40 mg/kg). While it is not clear yet how these two factors influence whether or not a pit has live PEDV, ongoing studies will attempt to describe this.

touIt is important to note, that it is possible for to us have missed live PEDV in some of the pits. This is because we sampled a small amount of manure from the perimeter of the pit through pump outs.

In conclusion, it appears that some barns will still have live PEDV in them during the pit pumping season of 2014. It is recommended to be very careful about sequencing of equipment when possible and practice good bio security measures. It is hopeful that careful planning and good communication may help minimize the spread of PEDV during this time. Additional studies will be conducted to better understand the risk of manure coming from sow barns where the infection patterns are likely to be very different.