Minnesota's Rice County was the first county in the country to attempt a regional control project for porcine reproductive and respiratory syndrome (PRRS). While progress was achieved through the years since its launch in 2002, the effort stalled and was abandoned a year ago, according to project coordinator Bob Morrison, DVM, University of Minnesota.
“We had good people, but the veterinarians and the producers were not unified and we had too many PRRS-positive pigs entering the region,” he says in a talk at the Leman Swine Conference in late September in St. Paul, MN.
Some herds eliminated the virus while others did not, thus compromising the whole project in the county, located a stone's throw south of the Twin Cities.
In 2004, Morrison spearheaded a new regional control project in Stevens County in western Minnesota. It turned out to be a fortunate choice. Stevens County is the only county in the area that is a high pig-dense county that is surrounded by low pig-dense counties. There are 89 hog sites, 19 sow sites and a number of seedstock farm sites.
That ideal location in west central Minnesota gives Morrison encouragement that as the Stevens project progresses, it will be fairly easy to expand the control zone to all of the surrounding counties.
The Stevens County project proceeded initially without any external funding. In 2007, the U.S. Department of Agriculture provided funding. It was renewed a year ago and expires in December.
Much progress has been made, Morrison states. He stresses because the program is voluntary, it's not possible to know for sure the PRRS status of all farms. But as far as it is known, there are two PRRS-positive sites remaining out of the 89 hog farm sites identified initially.
A finishing site purchased pigs that were thought to be negative, but then broke with PRRS when the pigs arrived at the producer's farm.
The second site involves a farrow-to-finish producer who has been positive for PRRS ever since the regional control project in Stevens County started. “But we continue to work with this producer and are optimistic that we will find a way to eliminate the virus from his farm,” he says, noting the county could be nearing PRRS-free status.
Morrison is confident that the surrounding low-pig-dense counties won't take long to clean up, provided local producer and veterinary cooperation is secured.
That raises the question of where to turn to next. There has been discussion among veterinary and producer leaders to create a northern PRRS-free zone. Work is ongoing to identify production sites in that vast region.
“The thinking is that a large portion of these northern sites are negative and we don't know yet, but we haven't identified any positive herds so far,” he says.
Morrison's hope is that the level of cooperation and success with PRRS could lead in the long run to more voluntary regional disease control programs for swine influenza virus, Mycoplasmal pneumonia or other infectious agents.
Eventually, the project will need to address PRRS infections in southern hog-dense counties, which will challenge the need for motivated leaders and stringent biosecurity practices.
Exhibition pigs must also be involved as they can also be a source of virus, Morrison says.
