Frozen library

Animal archivists preserve rare breeds

If Noah were here today, gathering two of every livestock breed for the ark would be tough. That’s because of the 65,000 breeds of livestock in the world, about one a week goes extinct, according to the United Nations Food and Agriculture Organization. And about 80 North American breeds are in decline or facing extinction.

dr. george saperstein with cows

With the aid of a “frozen library,” Dr. George Saperstein is helping preserve heritage breeds of livestock threatened with extinction. © Andrew Cunningham

Researchers at the School of Veterinary Medicine are working to solve the problem. In conjunction with the nonprofit SVF Foundation of Newport, R.I., Tufts scientists implanted a frozen embryo from a rare Tennessee Myotonic goat into a common Nubian doe. The result: a healthy Myotonic baby goat named Chip that was born last spring.

“We proved that should there ever be a need for this germ plasm, it’s viable in a frozen state,” says Dr. George Saperstein, who holds the Amelia Peabody Chair in Agricultural Sciences and is the assistant dean of research at the veterinary school.

Chip was selected from a SVF Foundation library of 12,000 embryos, doses of semen, cells and blood samples gathered from rare breeds of food- and fiber-producing cows, sheep and goats. The SVF library was established in 2002 to protect genetic diversity and guard the nation’s food supply from catastrophic loss, including agroterrorism.

“Chip the goat represents the closure of the first chapter of this effort,” Saperstein says, “and that is the completion of the first breeding library in the frozen state. Now we’re moving on to other breeds.”

Frozen embryos are viable for more than 50 years and could some day help solve livestock disease or parasite problems. For example, a major challenge in the sheep industry is internal parasites. If the drugs to control the parasites stop working, Saperstein says, “we might decide to reawaken the Gulf Coast sheep breed, which is naturally resistant to such parasites.” A half-century from now, he says it might be possible to insert genetic blueprints from frozen cells into valuable commercial breeds to confer immunity to disease or improve their hardiness.

Saperstein notes this is not a commercial venture. “It’s really a historical project. The genetics we’re dealing with and preserving are the same as they were 100, 200, 300 years ago. If we’re preserving a breed that was present in Thomas Jefferson’s day, we’re preserving a part of Americana.”