The 100-boar Genetipork boar stud at Morris, MN, is one of a few that is negative for PRRS (porcine reproductive and respiratory syndrome).

Keeping it that way requires a constant vigil, says Scott Dee, DVM, Swine Health Center at Morris. The veterinary clinic partners with Genetipork USA to raise and sell the company's breeding stock.

The stud was originally stocked in 1995 with PRRS-negative boars and Dee along with AI director Tom Spaeth figured using the PCR technology would be a good way to monitor that status.

PCR (polymerase chain reaction) is a molecular method for detection of the virus protein.

"In the past, it has been basically impossible to isolate the PRRS virus from semen," Dee says. "But with PCR, you are not undertaking virus isolation; you are detecting for the viral protein in the semen. It is a very sensitive assay that will allow you to detect very, very small quantities of the virus.

"Our thinking was if we monitor this herd on a monthly basis, using serology only, we might miss something that happens in between our testing periods," says Dee. "But if we conduct PCR testing on a weekly basis, then we've got a lot better chance of catching the virus."

Monday is heavy collection day at the stud, Spaeth says. A sample of each boar's semen is collected and the raw ejaculate is pooled to reduce cost (three collections each) and sent to the University of Minnesota for PCR analysis. Results are usually back in a day or so. (Each PCR test for PRRS costs $30.) "This way we can find out within 1-2 days should infection have taken place," points out Dee.

Tom Spaeth's wife, Joan, enters the testing results in a database for the veterinarians of potential customers to review. The stud has never found a semen sample PRRS positive.

Only two locations perform the PCR tests, the diagnostic laboratory at Minnesota (612-625-8787) and the South Dakota diagnostic laboratory (605-688-5171).

The National Pork Producers Council (NPPC) is organizing a group to look at the science behind general farm biosecurity practices, to see what additional research needs to be done.

Dave Pyburn, DVM, NPPC director of Veterinary Science, says the first order of business is to form an industrywide group. At their first meeting, they will discuss a literature review of current knowledge.

Second will be to determine the reasoning behind biosecurity practices.

>From that the group will develop and distribute educational and informational pieces about on-farm and transportational biosecurity.

Pyburn suggests the group will also look at the biosecurity of the national swine herd to determine what protocols are needed to keep foreign animal diseases out of the U.S.