One breed of livestock vanishes from the planet every month. Why that’s not a good thing for any of us, and what Tufts is doing about it
The 15 shaggy Arapawa goats from Alan and Joan Caldwell’s farm in Rehoboth, Mass., are in a fight for their breed’s life. Whalers and British colonists first brought these goats’ ancestors to Arapawa Island, off the coast of New Zealand, where the hardy breed lived in isolation, largely unchanged for more than 200 years.
Then, about 30 years ago, the New Zealand Forest Service decided the goats had outstayed their welcome—trampling and grazing through large swaths of the native forest—and so began to cull them from the island. Today, only a few hundred Arapawa goats remain in the world, scattered in small herds throughout the United States, New Zealand and the United Kingdom.
If the Arapawa breed disappears, so too goes our last link to the original hardy “Old English” goat that the Pilgrims ferried to Massachusetts aboard the Mayflower for milk and meat. To make sure the Arapawa don’t vanish from the planet, the Caldwells dispatched their entire herd of rare goats to a most unlikely destination: a place called Swiss Village Farm in tony Newport, R.I.
The setting appears straight out of a fairy tale, but the plot is plucked straight from science fiction. Built in the early 20th century as a “gentleman’s folly” hobby farm, the property looks just like what its name implies: an extravagant re-creation of a Swiss village. More than a dozen tile-roofed stone cottages with hand-hewn wooden beams dot verdant pastures surrounded by the sprawling Newport mansions and, just beyond, a stunning coastline.
Inside these quaint buildings are high-tech surgical suites and laboratories, where Tufts University veterinarians will harvest sperm and embryos from the Arapawa goats and then bathe the genetic material in liquid nitrogen to cryogenically preserve it at temperatures so bitterly cold that the cells are essentially frozen in time. Should the Arapawa become extinct, this precious DNA could be thawed and used to reawaken the breed.
The procedure has been repeated many times over the past decade as Tufts and the Swiss Village Farm Foundation, also known as SVF Foundation, race against the clock to conserve 40 of the rarest breeds of cattle, sheep and goats in North America.
The U.N. Food and Agriculture Organization reports the planet is losing one breed of livestock every month. Now halfway into its 20-year conservation campaign, SVF has collected more than 60,000 samples of genetic material from 21 of the target breeds.
So why should you care about saving a handful of odd-looking goats or heat-loving Pineywoods cows or the multihorned sheep named for Jacob in the Old Testament?
For starters, SVF’s “seed bank” of frozen material protects the world’s food supply by maintaining its diversity. Preserving an array of livestock breeds that can thrive in hot, humid climates or more arid regions of the world means people have access to food, no matter where they live. Beyond the dinner table, though, this cache of frozen germplasm could one day be instrumental in developing treatments for human diseases, such as Tay-Sachs and some neuromuscular disorders.
Bigger Isn’t Always Better
Barnyard critters don’t typically figure into our mental picture of endangered species, what with a handful of super-producing breeds meeting nearly all our food needs.
Consider the dairy industry. Although Guernsey cows produce creamier products than those made with milk from Holstein cows, they can’t touch the ubiquitous black-and-white breed for sheer volume of milk production. A top-producing Holstein churns out 25,000 pounds of milk each year—several thousand more pounds than any other major dairy breed. Today, nine of every 10 U.S. dairies milk Holsteins.
Our reliance on monocultures—growing one type of high-yield plant or raising one animal species in overwhelmingly large numbers—has benefited U.S. consumers through the widespread availability of uniform, affordable food products.
However, this bigger-is-better approach comes with significant risks, warns George Saperstein, an expert in preserving endangered livestock and the Amelia Peabody Professor of Agricultural Sciences at the Cummings School of Veterinary Medicine. “Genetic diversity in livestock is as important as it is in plants,” says Saperstein, a scientific advisor to SVF.
In plant agriculture, the scariest tale about a monoculture is the Irish Potato Famine. Between 1845 and 1849, more than 1 million people starved to death when Ireland’s genetically identical “lumpers” potatoes rotted in the fields, destroyed by a new fungus. The plant disease, which is difficult to control even today, ran rampant because lumpers had no natural resistance to the blight. (Fungicides wouldn’t become available for another 40 years.)
In the case of food animals, the delicate balance between genetic diversity and high-volume production may already be coming undone.
Artificial insemination, which was perfected in cattle in the late 1940s, now accounts for 85 percent of Holstein births. One Holstein bull can sire as many as 50,000 daughters—and half the genes in America’s 8.6 million Holstein cows come from fewer than 20 prize bulls, according to a New York Times report. This kind of intensive inbreeding promotes undesirable traits, and Holstein breeders recently have had to contend with a raft of new health issues in their herds, including fertility problems, compromised immunity and congenital defects.
Meanwhile, the growing “global reliance on Holsteins, which need lots of water and [expensive] grain to make milk, is risky in a world where desertification is spreading and economies are not growing,” says Jennifer Kendall of the American Livestock Breeds Conservancy.
“Developing countries want our Holsteins because we’ve taken that cow to the next level of increased efficiency,” agrees Saperstein. “However, many countries that import Holsteins to tropical climates watch them die, because they’ll never do as well in heat and humidity as their indigenous breeds.”
Although SVF chose to focus on grass-grazing farm animals native to North America, it was a cattle scourge in England that launched the foundation’s campaign to rescue these heritage breeds.
Dorrance Hill Hamilton, a Philadelphia philanthropist who spent her girlhood summers in Newport, was flying home from Europe in 1998 when she read a newspaper article about the mass slaughter of cattle following the outbreak of mad cow disease. In Great Britain alone, 180,000 cattle were infected with bovine spongiform encephalopathy, a fatal neurodegenerative disease that humans could get by eating meat from infected cows. Ultimately, Britain slaughtered 3.7 million cows, a third of its bovine population, to contain the outbreak.
Hamilton had recently purchased Swiss Village—once the opulent country home of railroad baron Arthur Curtiss James and his prize herd of Guernsey cattle—to preserve the rolling, green farmland that she remembered from her childhood. “I read that when rare livestock was slaughtered, it might be hard to bring them back,” recalls Hamilton. “I thought maybe I could help by raising some of those breeds.”
Back in Rhode Island, Hamilton shared her idea with a city councilwoman whose dog had been a patient at the Foster Hospital at the Cummings School. She encouraged Hamilton to approach Tufts, where she met Saperstein, professor and chair of environmental and population health, and talked about her vision for her 45-acre farm.
Saperstein told Hamilton that she had only enough land for a small herd of one breed. Then he asked the money question: “But have you thought about cryopreservation?”
Hamilton was sold. In 2002, she established the nonprofit SVF Foundation and signed a contract with Tufts to begin the work. The goal of the Tufts/SVF collaboration is to collect and cryopreserve at least 200 embryos and 3,000 samples of semen for each of the rare North American livestock breeds on SVF’s conservation priority list—a modern-day Noah’s ark, if you will.
Typically, the heritage breeds are loaned or donated to SVF. At first, breeders needed quite a bit of convincing to participate, says Peter Borden, SVF’s executive director. “On the one hand, they knew they had the last remaining bloodlines of their breed, so they’d recognize our plan as, ‘What a great opportunity to preserve what I have here for all time.’ But quite a few breeders also had anxiety about what we were going to do with those genetics—kind of like a poodle breeder worrying, ‘Are you going to be making Labradoodles with my genes?’ ”
To date, nearly 700 head of livestock have passed through the program. SVF staff pick up and return all the animals in a 28-foot antiseptic trailer to make sure no diseases infect their precious cargo en route to Swiss Village.
They have driven more than 80,000 miles, to every corner of the country, in pursuit of the weird and wonderful—from one animal to an entire herd. Although the trips may sound blissful—winding through the Rocky Mountains or passing former Pony Express stations on the Great Plains—mostly it’s grinding work. The herd staff drive 14 hours at a time. They stay only at motels where their rooms overlook the trailer, and they can hitch hoses to a kitchen faucet so the animals always have water.
Life on the road can, on occasion, get hairy. Once, on a night run down to Virginia to pick up Ancient White Park cows, the SVF truck nearly jackknifed as it swerved around a car inexplicably parked, with its lights off, across the middle lanes of the highway. “We were so happy to make it to the hotel alive,” says SVF program manager Sarah Bowley, who recruits breeders into the conservation fold.
On another trip, just after SVF staff had gotten back on the road after dropping off six Dutch belted cattle in West Virginia, the trailer got stuck in traffic as temperatures soared above 100 degrees. If they had been transporting animals, “we would have had to call 911 to get the fire department to hose them down inside the trailer or pull into the breakdown lane, let the livestock loose and try to move them somewhere shady,” Bowley says.
SVF staffers have gone to Louisiana to collect two Pineywoods heifers, a breed descended from cattle the first Spanish settlers brought to the Southeast in the 1500s. In California, SVF rounded up some of the last remaining Santa Cruz sheep, a meat and wool breed that had grazed on Santa Cruz Island since the mid-1800s. Twelve Canadienne cattle, an ancient French Canadian breed that can dine on all manner of scrawny shrubs and weeds and still produce tasty milk ideal for making cheese, came from a farm in New York.
“Before any animal is brought into the program, it is tested for a battery of viral and bacterial diseases,” says David Matsas, an assistant professor of environmental and population health at the Cummings School. “All new arrivals are placed in a quarantine pasture for a minimum of 30 days and given a thorough physical exam. We look for any signs of infectious or contagious diseases, such as pink eye, sore mouth, foot rot, parasites and respiratory or gastrointestinal disease.”
Sheep and goats are also checked for swollen lymph nodes or abscesses that might signal caseous lymphadenitis, a highly contagious bacterial disease known as “the curse” of these livestock.
“If we are going to preserve germplasm for all time, we don’t want to preserve any viruses along with it,” notes Saperstein.
Brave—and Cold—New World
The animals spend anywhere from nine months to two years roaming SVF’s pastures, under the watchful gaze of the farm’s three guard llamas, as they go through a breeding cycle and germplasm collection. Sheep and goats are bred naturally, during the typical breeding season from September to March. Matsas collects the embryos in SVF’s high-tech surgical suite, where fourth-year Tufts veterinary students assist in the laparoscopic procedure. Cattle are bred year-round by artificial insemination. Tufts population health veterinarians Kevin Lindell and Gene White and their students collect the bovine embryos.
After embryos are flushed from an animal’s womb, they are handed over in a Petri dish to the SVF lab director, Dorothy Roof, who has the all-important assignment of pronouncing them fit enough to freeze. She evaluates the quality of the embryos, nearly invisible to the naked eye, with a microscope that flashes images onto a large flat-screen monitor.
“It’s sort of like playing ‘Where’s Waldo?’ ” says Roof as she swirls the contents of one Petri dish and squints into the microscope before relaying her verdict via speakerphone to the Tufts veterinarians and SVF staff.
Embryos that make the cut are siphoned into plastic straws and put into a metal box full of liquid nitrogen, where they slowly chill to minus 35 degrees Celsius—just five degrees shy of the temperature at which human skin freezes instantly. The embryos are then stored in one of four 100-gallon tanks of liquid nitrogen, where they’ll remain, at a very arctic minus 196 degrees Celsius, until needed—and the hope is that will be never.
Although the technology at SVF is on par with that in human fertility clinics, Saperstein says you can’t beat fresh genetic material for reproductive success. “The process of freezing has to do some minor damage to cells,” says Saperstein, who notes that the conception rate for transferring a fresh embryo into a surrogate is slightly better than for a frozen one. “And everybody wants to know how can you tell if the collection is alive and usable.”
Fortunately, the Tufts veterinarians can easily assess the viability of semen by thawing a few of each breed’s thousands of samples and examining them under a microscope with the aid of computerized analysis. “You compare the data with what we saw when the semen was fresh,” says Saperstein. “That way, if you see the sperm was at 70 percent motility when it was fresh, and now it’s at 68 percent when it’s thawed out, you know you’re doing a good job. And you can check that every year if you want to.”
Embryos present a greater challenge. “We are collecting only 200 embryos per breed, and they are much more valuable,” notes Saperstein. To assess an embryo’s viability, there is just one option: thaw one out and transplant it into a surrogate mother from another breed and hope she gives birth to the rare breed.
Embryo transplant is successful about half the time, as is the case in the best breeding operations. At Swiss Village, common livestock have birthed nine endangered animals: Arapawa kids; American milking Devon, Dutch belted and Canadienne calves; and Cotswold, Gulf Coast, Santa Cruz and Tunis lambs. The first successful embryonic transfer was SVF’s mascot, Chip, a Tennessee fainting goat (yes, they do fall down, but only when startled) born to a common Nubian doe in 2005.
Back to the Future
At the end of the day, though, “it doesn’t do much good to have a population in isolation in a liquid-nitrogen tank,” observes Saperstein. “Over time, people would forget what the animals looked like or why we even had them. So we really need breeders to promote the conservation of the live animals.” To that end, SVF also acts as matchmaker, putting owners of heritage livestock in touch with each other so their rare animals can be bred on the hoof, as they say.
And while you’d never dream of serving endangered tigers for supper as a way to keep them around for another few centuries, the same can’t be said for rare cattle, goats or sheep. “That more than anything will benefit biodiversity,” says Saperstein. “We have to put these animals back to work if we are to really save them.”
That’s why SVF encourages small farmers nationwide to take advantage of consumer demand for artisan, local and sustainably grown foods by developing heritage-breed products. Many heritage livestock are far better suited to eating grass and living outdoors on small farms than the high-maintenance breeds raised on large commercial farms.
Though SVF is determined to save the rarest North American ruminants, regardless of whether there is an overt imperative for any particular breed, Saperstein notes that many breeds have special traits because they evolved in geographic isolation—and that has applications for human and veterinary medicine.
Consider, for example, the endangered Gulf Coast sheep, another breed the Spanish brought to the New World. “Sheep farming’s biggest problem [around the globe] is a widespread resistance to dewormers. It’s very similar to antibiotic resistance in people,” says Saperstein. “But the Gulf Coast breed evolved tolerating parasites. If we can figure out how that genetic resistance works, we may be able to impart that immunity to commercial breeds through cross-breeding, gene therapy or the development of a drug.”
He notes that other breeds “have unique genetic characteristics that may not seem particularly desirable, but those faulty genes might make the animal a good model for developing new treatments for human diseases.”
The genetic mutation that causes the fatal neurodegenerative disorder Tay-Sachs in children, for example, also exists in Jacob sheep. Research done at New York University School of Medicine not only has helped keep this defect from accelerating the disappearance of the rare sheep breed, but has led to the first animal model for studying gene therapies for Tay-Sachs, which typically kills children before their fifth birthday.
And Saperstein notes that Tennessee fainting goats—which fall over when startled because of a genetic disorder that triggers all their skeletal muscles to contract at once—could someday help people with congenital myotonia, a neuromuscular disorder that affects muscles used in such activities as walking, holding onto something, chewing and swallowing.
Saperstein says that while these are great, tangible reasons for preserving endangered livestock, it’s just as important to save them for reasons we’ve yet to imagine. If not, he says, it would be like a society in which all the libraries have been obliterated.
“What if we only kept what was written every year and threw the rest of our books away? Well, that’s what happens when we discard breeds cultivated over centuries to focus only on the animals currently deemed utilitarian,” he says. “Once these animals are gone, they’re gone. And then we’ll never be able to visit that genetic library to select a breed that’s right for that world we’re living in, whether we want animals with resistance to a certain disease or those better suited to meeting a consumer demand for grass-fed beef.”
This article first appeared in the Spring 2012 issue of Tufts Veterinary Medicine magazine.