Validated-Qualified Swine Herds

Last Modified: April 07, 2024

To protect U.S. swine health, APHIS established the validated brucellosis-free and qualified pseudorabies-negative herd programs. Producers can choose to participate in one or both programs.

A combined validated-qualified (VQ) status gives assurance that the swine herd is free of brucellosis and pseudorabies. To gain VQ status for your herd, you must:

  • Test a certain amount of your herd for brucellosis and pseudorabies every year (with negative results),
  • Follow guidelines to prevent diseases from entering your herd when purchasing new animals, and
  • Renew your status annually.

To verify VQ status when buying animals, look for a document from the State department of agriculture showing the herd meets the VQ requirements and the last test date. This date should be within the past 12 months. If you have any questions, contact your State animal health official or the APHIS Veterinary Services district office in your State.

Want To Learn More? 

Read below for a summary of the programs. For more details, view the swine brucellosis uniform methods and rules and the pseudorabies eradication program standards.

Gaining VQ Status for Your Herd

Start by contacting your veterinarian or State animal health official. Depending on the State, you may need to complete an application form, or your veterinarian may simply indicate VQ status on laboratory submission forms as the reason for testing your herd. Your veterinarian will collect blood samples from your animals for testing.

For both statuses (validated brucellosis-free and qualified pseudorabies-negative), all breeding swine over 6 months of age must be tested. You must also test some 4- to 6-month-old pigs that were born on the farm to gain qualified pseudorabies-negative status; the number of these pigs tested must equal 20 percent of the breeding swine (for example, 10 pigs born on the farm for a herd with 50 breeding pigs). All tests must be negative to gain VQ status.

You may choose one of the three options below to reach the required testing numbers:

  1. Test annually—all animals once a year
  2. Test quarterly (every 80–105 days)—25 percent of breeding swine over 6 months of age and the number of 4- to 6-month-old offspring that equals 6 percent of the breeding herd
  3. Test monthly (every 25–35 days)—10 percent of breeding swine over 6 months of age and the number of 4- to 6-month-old offspring that equals 2 percent of the breeding herd

No individual animal can be tested twice in 10 months to meet the testing numbers. The herd cannot gain VQ status until all of its breeding swine and the required number of offspring test negative.

Keeping VQ Status

VQ status is good for 1 year. If all pigs were tested on the same date, the anniversary date is the day the blood was drawn. To maintain VQ status, a whole herd test can be done once a year, before the anniversary date. There is no grace period—the VQ status expires 1 year after the anniversary date.

Once your herd gains VQ status, you can maintain it by testing monthly or quarterly (at the same rate as to obtain VQ status over time). This helps prevent the herd’s status from expiring.

To keep VQ status when adding new animals to the herd, you should purchase them from other current VQ herds. Swine moved from one VQ herd to another VQ herd do not require additional testing. For artificial insemination, only use semen from boars in VQ herds as well.

Breeding swine moved from a non-VQ herd into a VQ herd must be:

  • Tested for brucellosis and pseudorabies in the herd of origin 30 days before movement;
  • Retested for brucellosis and pseudorabies 30-60 days after arrival; and
  • Kept isolated from other animals until you get negative results for the second test.

Benefits of Participation

Owning a VQ Herd

VQ status is helpful if you sell, trade, or share feeder pigs; show pigs; or breed pigs. Buyers look to VQ herds to ensure their new animals are free of brucellosis and pseudorabies. With a few simple steps, any herd with breeding animals can gain VQ status and be an important part of keeping U.S. swine healthy.

Your participation also goes beyond swine health. These diseases can affect other livestock, pets, and even people. For example, pseudorabies can infect cattle, sheep, and other animals, and it's usually fatal in animals other than swine. Brucellosis can affect both people and other animals. So, in gaining VQ status, you protect not only your herd, but U.S. animal and public health as whole.

Buying From a VQ Herd

The testing regimen and requirements for VQ herds mean you can feel confident in the health of your new additions. Buying animals from VQ herds greatly reduces the risk of introducing swine brucellosis or pseudorabies into your herd—even more so than testing an individual animal from a non-VQ herd.

Why? First, the accuracy of the test depends on the length of infection, the immune response, reactions to other disease agents, and the type of test used. Second, the tests are much better at identifying an infected herd (many tests being run on the herd) than detecting just one infected animal. Herds that test negative over time are more likely to be truly disease-free.