A library of livestock heritage
Small feral sheep with soft gray or brown fleece thrived for most of the 20th century on a small island off the Southern California coast.
More than 21,000 Santa Cruz sheep lived in Channel Islands National Park in 1981, according to a scientific article published in 1989 in the Journal of Wildlife Management. The animals, likely a mix of domesticated Merino and Rambouillet breeds, can survive on little forage and rarely have birthing problems, according to the American Livestock Breeds Conservancy.
But, few of the sheep survived eradication efforts intended to preserve their home island’s flora. About 37,000 were shot between 1981 and 1987, when some 40 remained, the 1989 article states. Their population is still estimated at fewer than 100.
In an effort to preserve the genetic heritage of the breed, the Swiss Village Farm Foundation in Newport, R.I., has collected and frozen about 350 embryos and 2,800 straws of semen from around 40 of the remaining Santa Cruz sheep, with the intention that the material could someday benefit livestock breeders and agriculturists, possibly by reviving the breed or enabling study of its attributes.
“We don’t know exactly what it is about those sheep that we might need in the future,” said Sarah C. Bowley, program and livestock manager for the foundation. Without such preservation, the world may lose the chance to find out how the sheep are able, for example, to withstand hot temperatures and resist parasites and hoof rot.
Swiss Village in Rhode Island
The privately funded foundation, created in 1999, is establishing a collection similar to a seed bank but for rare or legacy livestock breeds—currently limited to ruminants. The stored materials could be used either to restore an extinct breed or to study the genes that give a breed advantages with respect to, say, maternal ability, longevity, feed utilization, heat tolerance, or disease resistance.
Bowley said about 80 North American livestock breeds, including nonruminant breeds, are at risk of extinction, but the available technology precludes storing viable pig embryos or poultry eggs.
Preserving livestock breeds has become both a national and global concern.
The Food and Agriculture Organization of the United Nations, through its Commission on Genetic Resources for Food and Agriculture, reported in 2007 that the world has lost a mean of almost one breed a month during the preceding six years. This alarmingly quick loss of biodiversity, particularly genetic diversity, is eroding the potential to adapt agriculture to changing conditions such as human population expansion and climate change.
The FAO report, “The State of the World’s Animal Genetic Resources for Food and Agriculture,” stated that 20 percent of the world’s 7,600 reported livestock breeds were at risk of extinction.
Over about 11 years, the foundation has acquired samples from 24 ruminant breeds and complete collections—or at least 300 embryos and 3,000 straws of semen—from nine. The samples are collected, frozen, and maintained by a mix of employees of the foundation and the Tufts University Cummings School of Veterinary Medicine.
Dr. George Saperstein, chair of the Department of Environmental and Population Health in the Tufts veterinary school, said the foundation’s benefactor, Dorrance H. Hamilton, bought the farm property in 1998 and sought advice from Tufts on how it could be used to help reduce loss of genetic diversity in agriculture. The farm’s 45 acres would have room only for a small flock of swine or sheep, which Dr. Saperstein saw as a dead end for an unpopular breed.
“I said you can do that, or you can do something really different, which is create a livestock seed bank and save them all, so to speak,” he said. Such a germ plasm collection could, he added, become “a library of our nation’s livestock heritage.”
Advantages and survival
The Swiss Village farm typically houses about 125 borrowed or donated animals, the latter of which are later sent to breeders, Bowley said.
The animals have visible differences from their more popular counterparts, such as the corkscrew horns of a myotonic goat, splotched red-and-white hair of a Pineywoods cow, and thickets of straw-entwined fur of a Belted Galloway cow. Some of the sheep physiques led breeders to describe them as scrawny, jug-headed, or bowlegged.
But these heritage breeds have typically declined in popularity because of some production disadvantage. Many grow more slowly or produce smaller quantities of meat, milk, or wool than do animals from popular commercial breeds.
Genetic research over the past 70 years has helped U.S. livestock industries develop breeds along specific lines, resulting in superb protein production, Dr. Saperstein said. Commercially popular breeds also are increasingly protected by climate control, vaccines, improved nutrition, and stress reduction methods.
“We facilitated the process of selection for the traits that were important for human survival and productivity, so we became, in large part, the most effective agricultural producer in the world because of that process,” Dr. Saperstein said. “So I’m not here to say, ‘We’re saving these rare breeds because the new ones are bad.’”
But Dr. Saperstein cited the mid-1800s potato famine in Ireland as an example of the risks posed by limiting genetic diversity.
The recent increase in resistance to commonly used dewormers is a good example of why preserving rare breeds is so important, Dr. Saperstein said. Gulf Coast sheep, for example, are small and slow-growing, making them less than ideal for commercial purposes. But, they are able to survive heavy parasite loads without becoming anemic.
Dr. Kevin Lindell, an assistant professor with Tufts University who extracts cattle embryos for the foundation, also expressed concern over rising anthelmintic resistance.
“There are farms out there that have intestinal parasites in their sheep and goats that are now resistant to pretty much any type of medication that we have,” Dr. Lindell said. “And one of the best ways to combat resistance like that is to bring in animals that are genetically resistant to those parasites.”
Dr. David J. Matsas, assistant professor of environmental and population health at Tufts, said certain areas of modern agriculture are dominated by one or only a few breeds, such as the millions of Holstein cattle that produce most of the milk consumed in the U.S. He noted that Holsteins have high productivity, but that fertility of the breed is falling.
“We may not be looking to replace the Holstein dairy cows with one of our heritage breeds, but we might be able to go back and find the right genes to incorporate into those types of technologies that are becoming available and introduce the genes,” he said.
Dr. Matsas has overseen embryo and semen collection since the foundation began operating, and he hopes to capture an image of rare breeds that others can study, once more advanced technology is available.
“A future generation may look back at it and say, ‘Man, those guys really had the foresight to save this stuff,’” he said. “Or maybe nothing will be done with it.”
About 350 veterinary students, most of them fourth-year students at Tufts, have worked at the farm since 2005. Dr. Matsas said even students interested only in small animal medicine want the exposure to ruminant medicine and surgery, and they spread the word about the preservation mission.
Alex Robb, a veterinary student at Tufts, said his work at the farm earlier this year involved sheep embryo collection, which included experience using an endoscope and closing incisions.
“That’s very practical, relevant surgical experience for us, no matter what area of veterinary medicine we go into,” he said.
Robb, a fourth-year student, plans to focus on small animal medicine during his career, but more experience with farm animals will help him work with his maternal relatives’ dairy farm.
On the hoof and in banks
The Rhode Island foundation also works with animal owners to promote “on the hoof” conservation.
Kerry cattle, Santa Cruz sheep, San Clemente goats, Tamworth pigs, and a Milking Devon cow live on a combination of farmland and resort at the 15-acre East Hill Farm in Troy, N.H. Dave Adams, who ran the farm with his wife, Sally, until their children took over a few years ago, said he was fascinated by the idea of raising Kerry cattle, an Irish breed used to produce meat and milk. The farm has six.
Information from the breed conservancy indicates the cows typically thrive on meager forage, give birth with little difficulty, and produce milk into their teens. Yet, only about 75 of the cattle lived in the U.S. at the end of 2011, and even Ireland had only about 360 when the population was estimated the preceding year, according to the conservancy.
Adams acknowledged that Kerry cattle produce less milk than Holsteins but praised Kerrys’ rich milk as a component of excellent butter and cheese.
Adams has worked with Swiss Village to preserve samples from his livestock, and the foundation gave him his Santa Cruz sheep. He said he is fortunate to be able to help rare animals and explain to visitors the need to preserve the breeds and their attributes.
Eat them to save them
The foundation is on track to complete the collections detailed in its original 20-year mission, Dr. Saperstein said, although the goals shift with breed popularity. For example, the Belted Galloway was an endangered cattle breed at the project’s inception, but it was moved to the breed conservancy’s “recovering” list in recent years.
Bowley, the program manager, said surging interest in grass-fed beef may be helping that breed. Others, such as Milking Devon cattle, can provide a small local milk supply, and Canadienne cattle produce milk with fat content high enough to make distinct cheeses, butter, and ice cream.
People may be willing to pay more to eat products from niche or critically endangered breeds, Bowley said. The rarest animals have lost their jobs rather than their habitats, she said.
Dr. Saperstein expressed concern that intensive selection for production-related factors could lead to declines in properties that people enjoy, such as the taste of beef. He wants people to have a chance to develop breed-based preferences based on, say, taste, texture, shelf life, or color.
“That’s my dream, that someday you’ll go to the butcher shop and order Jacob lamb chops, and that’s what will save the breed,” he said.
Dr. Saperstein worked early in his career to eradicate genes responsible for diseases in livestock. He said that, with farms and production breeds becoming less diverse, veterinary medicine needs to help conserve the remaining diversity.
“As large animal veterinarians, we are dependent on the success of livestock producers,” Dr. Saperstein said. “I don’t get paid if the cow doesn’t make milk, so anything that we are involved in that makes our national herds and flocks more healthy for the long term benefits the livelihoods of future veterinarians and current veterinarians.”