A Mongolian rider herds goats and sheep across the Gobi Desert.
"The American wants to pull hair off your goats." The translator spoke in Mongolian, signaling toward Lincoln Rodgers. The Mongolian herders smiled and gave him funny looks, but agreed, knowing that it was somehow supposed to benefit their herds.
"The herders would tackle as many goats as we had time for," Rodgers explains, "and hold them down while I plucked a tuft of hair from each of them with a small pair of pliers." He would place each sample in a plastic bag along with a packet of silica gel, like you find in new shoes, to keep it dry and prevent rot.
"Yes, they thought it was kind of," he pauses, "odd, but they were happy to do it." The samples of hair that Rodgers carefully labeled and stored were a source of genetic material—and the reason he had traveled to the Gobi Desert. In a sense, anyone who goes to the Gobi Desert goes there for goat hair—in particular, for the one kind that's fine enough to be designated cashmere.
Cashmere is crucial to the Mongolian economy. As the nation's major agricultural export, it grosses nearly $80 million each year. When Rodgers arrived there in October 2000, a non-profit agricultural assistance agency called Agricultural Cooperative Development International/Volunteers in Oversees Cooperative Assistance, or ACDI/VOCA, was overseeing a cashmere-goat breeding project, begun in 1995. Rodgers, then an 18-year old honors student in Penn State's College of Agricultural Sciences, volunteered to sample DNA from herds that were selectively bred, as well as from herds not part of the breeding program, then use genetic markers to determine how much progress had been made.
The Altay mountain goats of Mongolia, like many other mammals, have an outer coat of guard hairs to protect them from the weather and an undercoat of fine hair to provide insulation. In the spring the herders harvest these fine hairs, by brushing the goats, and sort them. To be designated as cashmere a hair must be less than 17.5 microns in diameter (less than seven ten thousandths of an inch). Next to it, human hair, with an average diameter of 100 microns, seems coarse. Hairs that are thicker than the international standard for cashmere are classified "cashgora." Still downy, these fibers are worth only one fourth the market value of cashmere. They are used in look-alike cashmere goods, though they come from the same animals.
"Any goat can produce cashmere," says Rodgers. But some breeds produce very little. All goats produce a certain amount of cashgora as well, but by selective breeding the agricultural agency hoped to increase the ratio of the finest, most valuable hairs.
At milking time, the goats lined up and student Lincoln Rodgers weaved among them, pulling out tufts of hair. Later he would extract DNA to gage the breeding program.
Before the breakup of the Soviet Union in 1991, Mongolia had communal herds that were brought together for breeding. Breeding records were maintained in Russia, which also supplied about $400 per capita in annual aid. When the U.S.S.R. collapsed, the Mongolians lost this agricultural assistance and their major customer for cashmere. The goat herds were privatized and divided among the nomadic herders; breeding records lapsed. As the Mongolian herds became mixed, the quality of the cashmere began to decrease.
The new buyers came primarily from China, where cashmere is also produced. The Chinese traders profit from the Mongolian surplus because native traders cannot afford to pay the herders as much. Since prices were good, the herders saw no problem with their goats—after all, there is only 4.5 microns of difference between the cashmere and cashgora. If, when sorting the bundles of fibers after purchase, the traders found more cashgora than anticipated, they did not complain: They were already making a good profit.
Because of this pricing system, the herders had little incentive to improve the quality of the cashmere through breeding. Instead they preferred to breed larger goats to provide more meat and skins. Oddly, in cashmere goats, body size is negatively correlated with fiber diameter. Larger goats mean fewer profitable fibers.
By the year 2006, ACDI/VOCA predicted that the quality of Mongolian cashmere would drop below international standards, resulting in a loss of $25 million a year. To prevent this, the breeding scheme identifies the top ten percent of males and breeds them to the highest quality females.
When Rodgers first decided to go to Mongolia he didn't know what he'd be doing. "It was an idea that came from my interest in genetics and livestock," Rodgers says, "I thought, 'Mongolia must have some interesting genetics.'" He talked it over with his thesis adviser, Guy Barbato, a professor of poultry science,and together they formulated an idea. Rodgers learned from the U. S. Department of Agriculture that he could transport hair from Mongolia without the expensive permits that would be required for blood or tissue samples. So he decided to collect hair samples from some type of livestock and examine genetic differences.
In Mongolia he rented an apartment from a family of missionaries in the capital city of Ulann Bataar (pronounced OO-lan ba-TOOR). The English-speaking population in the city is small. Beginning with the U.S. embassy, he soon made connections with people involved in agriculture. "Once I started asking questions, it was easy to get in touch with the foreign aid community," Rodgers explains. His research plan, he learned, was perfect for assessing the progress of the ACDI/VOCA breeding scheme.
It was difficult to determine by looking at the goats and their fibers whether progress was being made. However, because goats mature at three years and three kids can be born to a doe in a two-year period, the agency thought that enough time had passed to show genetic distinctions between the herds. Yet data on goat DNA is not common, and neither are samples of hair from those breeds that wander the Gobi Desert. Rodgers became the agency's connection to a state-of-the-art genetics lab at Penn State, while being admitted to a place where luxury is produced by patience, thrift, and a constant struggle with the elements.
Nomadic Mongolians don't wear the cashmere they harvest from their goats. Used American clothes, traded en route, are much more popular.
In Mongolia no one wears cashmere. Mongolians tend to have only a few clothes, which they wear for a while and then sell or trade. They have the opportunity to buy new clothes (new to them) when they live near towns, which is only for a small part of the year. The rest of the year, these nomads are following the goats to rough pastures. Just as the goats provide a use for the otherwise coarse landscape (they thrive on a much wider variety of vegetation than cattle or other livestock), they also provide almost everything that their herders need to survive in the Gobi Desert. Along with horse, sheep, and yak, a herder may have hundreds of goats. "They think of their animals as a walking bank account," Rodgers explains. The sheep provide wool and the horses are used for transportation, but all the animals, including the goats, provide dairy products, meat, skins, hair, and even dung.
Mongolia is land-locked; most of the rain has dropped on Europe and west Asia before reaching the higher elevations of Mongolia, making the Gobi a barren land with none of the tempering effects of water. The winds are high in the absence of trees, and wood is too scarce to be burned. The Mongolians make use of dung, which has no more clearly desirable use than as a fuel.
Their goats are constantly producing it where they pasture, and the herders rake it up into large baskets which they carry on their backs. They then lay it out to dry in the sun. During his 17 days of travel through the Gobi, Rodgers became skilled at building a dung fire. "It doesn't smell bad like you'd think it would," he says. "I guess I began to associate the smell with being warm, so I liked it." While he was there the temperature rarely rose above freezing.
In the winter these dung fires are constantly burned inside each family's ger. A ger (the Russian word is yurt) is a dome-like wooden structure that can be up to 20 feet in diameter. Its edges are 4-foot high walls made of lattice that can be folded and easily transported. The top is designed like a wagon wheel, rising to about 8 feet at the center, from out of which spews the smoke of the dung fires. The gers are completely portable down to the removeable floors of wood or tile. The ger is insulated with layers of wool and canvas tucked under the floor to protect its inhabitants from the weather, giving the effect of a large white dome. Against the sepia landscape a ger stands out among miles of otherwise empty, rocky terrain.
"If the Gobi Desert were in the United States," Rodgers says, "we would make it a national park and stay out of it." The Mongolians, however, use it to its fullest extent. For generations their lives have been dictated by the demands of the goat. Many families have seasonal camps that they return to year after year, but they still must carry all of their possessions with them. Rodgers got used to this lifestyle, carrying a pack of only 20 pounds on his back. The herders move by the seasons, traveling only as fast as their goats and stopping where the goats find food. There they set up their gers. "Two people who know what they're doing can put one up in a couple of hours," says Rodgers. Inside, the wood is ornately painted and holds ceremonial meaning. The edges, where the ceiling is lowest, are lined with cots so that each one looks directly toward the stove which sits in the center between two upright supports. Leaning on these supports is taboo; that's just one of the customs that must be considered when meeting with the herders, but a fairly important one considering that the stability of their homes depends on it.
These customs also dictate where one may sit upon entering a ger: men to the left, women to the right, with the most senior person furthest from the door and the others moving down toward it by rank. "You have to be aware of their customs," Rodgers says, "but they're an easygoing people. If you did something wrong, one of the members of the group would correct you, but the people wouldn't get deeply offended.
"They would always offer vodka," Rodgers says, as well as pass around a hospitality dish of candy or biscuits. These social gatherings would go on before any business was attended to. "Nothing happens quickly in Mongolia."
Along with some other agency employees, including a translator and a driver, Rodgers traveled with Zagdsuren Yondon, a Mongolian native who has long been active in efforts to coordinate the cashmere industry. After the formalities, he would examine the goats and update the herders on the project while Rodgers would collect hair samples. If he was lucky he would arrive at milking time. The goats are so familiar with the process that when they are herded together they begin to line themselves up, neck to neck, in order to be tied. At these times he could get a large number of samples efficiently. Otherwise he got the herders to grab nearby goats and took a hair sample from each.
During his three weeks traveling by jeep through the Gobi Desert Rodgers was able to collect over 200 samples from five herds in the breeding project and one that was not.
High winds, little rain, and bitterly cold temperatures characterize Mongolia's harsh climate. Herders traveling in the winter burn goat dung to keep warm.
After he returned to Penn State, Rodgers began the lab portion of his research project in a genetics lab in the department of poultry sciences. There, graduate student Michelle Block coached him in micro-genetics techniques. DNA extraction is typically considered "standard protocol in a genetics lab," Block says. "Yet the assay is more difficult when the tissue source is a hair follicle. The primary source of DNA from Lincoln's plucked goat hairs were the epidermal cells of the follicle. These cells are few in number and are encased in a particularly sturdy keratinized sheath. In attempting to get to the DNA through the sheath, it was easy to damage the DNA. Overcoming this obstacle requires a great deal of time, effort, and goat hair."
During the spring semester of 2001, Rodgers met with Barbato daily to consult on the project, and spent 30 to 40 hours a week working in the lab devising a procedure to get at the DNA and deciding what to look for once he had it. DNA to a geneticist is something like a word jumble to a native speaker: the desired information is there, but it is complicated by a lot of unintelligible gibberish.
Drawing on previous studies of the goat genome, Rodgers selected ten DNA markers, specific sequences located at a known place in the genome. The ten occurred on different chromosomes, limiting the influences one trait would have on another. He looked for these markers by running the goat DNA samples through a Polymerase Chain Reaction, or PCR machine. This machine uses small synthesized pieces of DNA called primers to find a specific DNA sequence. If these sequences (in this case, the markers) are present, they will be copied thousands of times. All the copies are then separated by size in a gel which has an electric current running through it. Large pieces of DNA pass through the gel more slowly, while small pieces more faster. Pieces of the same length flow through the gel at the same speed and so form a visible band. By comparing the band patterns, Rodgers could, in theory, tell how closely related two goats were and see how much progress had been made in establishing a distinct high quality herd.
However, the PCR tests showed only faint bands; and these were inconsistent even for the control markers—markers that should be present in any goat. This result meant that the DNA itself was damaged. The PCR primers either could not initiate—or could not complete—the copying or it could not be completed.
Rodgers's methods for extracting the DNA had included microwaving as well as chemical treatments. Some of these methods, he believes, may have agitated the DNA too much. After a semester of work in the genetics lab, he was only able to send preliminary information back to ACDI/VOCA.
"As goat hair is not an abundant source of genomic DNA, Lincoln eventually came to a point where he simply did not have enough DNA to test all of the primer sets," Block says. "It really was more than an honors project, " she adds. His attempts to establish a breeding record based on genetic data for herds of animals which have been little studied would have been more suited for a master's degree. "Lincoln really did a lot of groundwork research on the breeding," she says. "His work will benefit future studies."
With a family's ger, or yurt, and goat herds in the background, Mongolian men discuss the future of their cash crop, cashmere.
The project begun by ACDI/VOCA established three central herds of high quality goats, spread across 78 herder households and including over 6,000 animals, and led to the establishment of the Superior Goat Breeders "Millennium Quality" Association. With Rodgers's Mongolian traveling companion, Zagdsuren, as its president, this group is currently working independently to expand into other provinces, and into more herds. ACDI/VOCA completed their work on the project in September of 2001.
According to Zagdsuren, the average cashmere diameter has improved by 0.6 microns on goats bred as a result of the ACDI/VOCA project. The Millennium Quality association also links the herders to each other as well as to international contacts, and gives them access to market information. Finally, the association links the nomadic herders with agricultural developments, such as genetic research like Rodgers's into the code that makes goat hair into cashmere.
Lincoln Rodgers received a B.S. in agricultural sciences in December 2001, with honors in agricultural sciences and a minor in international agriculture, from the College of Agricultural Sciences and the Schreyer Honors College. His adviser was Guy Barbato, Ph.D., associate professor of poultry science, 201 Henning Bldg., University Park, PA 16802; 814-865-4481; firstname.lastname@example.org. Michelle Block is a graduate student in the intercollege graduate degree program in genetics. Rodgers's travel expenses were funded by the Schreyer Honors College.