There’s insurance to cover most everything these days, so it’s no surprise that there’s a policy to preserve genetic diversity in the U.S. ag sector.
The National Animal Germplasm Program is conducting a project to do exactly that for swine, beef cattle, dairy cattle, sheep, goats, poultry and aquaculture. The swine committee has already started collecting samples from the Yorkshire, Berkshire and Hereford breeds.
“All biological systems require genetic diversity to remain stable,” says Don Bixby, technological program director for the American Livestock Breeds Conservancy. “Once the gene pool becomes too constricted, the industry loses options to make changes in the future.”
“We’re not saying that producers are going in the wrong direction,” says Terry Stewart, Purdue University animal scientist and NAGP’s swine committee coordinator. “Producers are trying to raise homogeneous products, which encourages breeders to minimize genetic variation. But there’s merit in preserving genetic material, in case it has some future value.”
The fact is, markets change. Stewart points to Berkshires as an example of a breed that was dwindling until its meat-quality traits were identified.
Potential disease outbreaks are additional reasons to preserve rare genetics. “If the United States would have an outbreak like foot-and-mouth disease, repopulation could be a lot easier with NAGP germplasm,” says Harvey Blackburn, NAGP coordinator.
Inbreeding is another potential danger of a narrow gene pool. For swine, inbreeding can cause production losses, a decline in piglet vigor and loss of genetic diversity, says Tim Safranski, University of Missouri animal scientist.
The gene pool is not as narrow as it could be, but more uniform genetics will continue to be the rule. The American Livestock Breeds Conservancy lists seven swine breeds as “critical,” two as “rare.” There is one breed each on the “watch,” “study” and “recovering” lists. (See sidebar.)
The laws of supply and demand have dictated the U.S. swine herd’s genetic direction. “Commercial producers are capitalists. Packers pay producers to provide traits that consumers demand, and seedstock companies respond,” says Safranski. “With fewer and larger production systems and the rise of artificial insemination, the industry can use only 20 percent of the boars needed for natural service.”
Stewart says today’s pork industry is “one-size-fits all,” with similar diets and environments, which allows for similar genetics.
To help guard against genetic homogenization, a 1990 congressional act formed NAGP. A similar crop/seed industry program has been underway since the 1970s.
NAGP’s goal is to collect all U.S. swine breeds – and 100 boars of each breed. Donations from commercial genetic companies and boar studs have expedited the Yorkshire collection. The Hereford’s collection has proven more difficult. Because genetics companies or boar studs don’t offer rare breeds, a technician has to collect the boar semen at the farm, extend it, pack it in a cooler and overnight it to NAGP’s lab in Fort Collins, Colo., where it’s cryopreserved.
Although NAGP is the genetic repository, it works closely with the National Swine Registry, National Pork Board and animal scientists from various universities. Cooperation with genetic companies and boar studs has played an important role, and Blackburn expects that to continue.
For more information about NAGP, contact Stewart at (765) 494-0138 or Blackburn at (970) 495-3268, or visit the Web site at www.ars-grin.gov/nag. Look under “Updates” for semi-annual updates. To learn more about the American Livestock Breed Conservancy visit its Web site at www.albc-usa.org
What is a Rare Breed?
The American Livestock Breeds Conservancy monitors livestock breeds whose numbers are dwindling and are in danger of disappearing. Here’s the criteria for swine:
Critical: Fewer than 200 annual North American registrations, and fewer than 2,000 globally. Swine breeds: Gloucestshire Old Spots, Guineau Hog, Large Black, Mulefoot, Ossabaw Island, Saddleback and Red Wattle.
Rare: Fewer than 1,000 annual North American registrations, and fewer than 5,000 globally. Swine breeds: Hereford and Tamworth.
Watch: Fewer than 2,500 annual North American registrations, and fewer than 10,000 globally. Swine breed: Choctaw.
Study: Breeds that are of genetic interest, but lack documentation or definition. Swine breed: Choctaw.
Recovering: Breeds that once fell into one of the other categories; have exceeded the numbers in the “watch” category but still need monitoring. Swine breed: Berkshire.