Heightened attention is being placed on properly cleaning and disinfecting trucks to reduce the PRRS risk.
Replacement gilts and semen are arguably the chief concerns when it comes to transmission of the porcine reproductive and respiratory syndrome (PRRS) virus.
But the industry has completely missed what is probably the next biggest biosecurity risk: PRRS virus spread from transport, says R.B. “Butch” Baker, DVM, director of Health Assurance, Premium Standard Farms (PSF).
The swine industry spent years worrying that PRRS virus was an airborne virus for which nothing could be done, he states.
Instead, Baker suggests focusing on practical problems like trucking, which can make a real difference. “Transportation is a biosecurity nightmare, and the trucking staff needs to get behind transport biosecurity,” he declares.
A central focus of PSF's trucking biosecurity program is a heat treatment system put in place two years ago at their Missouri location for use with all non-slaughter tractors and trailers to prevent disease transmission between farms, Baker explains. Heat treatment is applied with a 4.5-million-btu.-capacity industrial, natural gas heater retrofitted into two bays of an existing truck maintenance building.
Explains Baker: “Our process is monitored by infrared temperature probes at eight locations on the trailer. Once the heater achieves 165° F at all locations, that temperature is maintained for 10 minutes. We can do about 24 tractor and trailer combinations in a 12-hour shift.”
The process provides quick killing of viruses without total drying and kills viruses even in concealed locations where drying can't reach. It costs about $15/trailer.
The heat treatment system, called the “Trailer Baker,” was developed in collaboration with Temp-Air, a Burnsville, MN, company, and is an extension of Baker's research while at PIC.
For PSF in Missouri, the heat treatment system has eliminated virus activity from PRRS and Transmissible gastroenteritis (TGE) in breeding and gestation and nursery facilities.
“The result of this and other biosecurity efforts has been no sow farm PRRS or TGE outbreaks the past two winters in this 100,000-sow system,” declares Baker.
The validity of the PSF heat treatment procedure was tested and proven effective by Scott Dee, DVM, University of Minnesota, in on-site, full-size trailers and in models at the University of Minnesota. A bioassay system using PRRS-negative pigs was injected with samples taken from “spiked” positive trailers after the heat process; none became infected with the PRRS virus.
At PSF, once trucks have gone through the truck wash, cleaning and baking processes, a red seal is placed on each vehicle, says Baker. If a truck arrives at a PSF farm without the red seal, farm staff is empowered not to load that truck, he emphasizes.
PSF staff is sharing what they have learned with the swine industry, and is collaborating with others to find ways to make the system more efficient, says Baker. He spoke at the Leman Swine Conference Sept. 20.