Motherly love

Yan, who has spent 35 years on the plateau studying yak breeding, is like a mother to the Ashidan yak. She also finds the animal pretty. "When the yaks walk, their long furs sway in the wind like a skirt," Yan said.

When Yan entered the Lanzhou institute in 1984, she was assigned to the yak research team. Since then, her first research subject has become her lifelong career.

At the Qinghai breeding farm, Yan saw yaks for the first time. Conditions on the farm were hard during the 1980s, with no electricity or running water.

Yan would spend more than half a year at a time on the farm, domesticating wild yaks, and making observations and measurements.

She stayed with herding families, and recorded the yaks' growth. She often trekked with the yaks for hours at altitudes of 3,000 to 5,000 meters.

She has lost count of the number of times the yaks had injured her, but she has never given up.

Over the past 35 years, Yan has left her footprints all over grazing areas in the Tibet autonomous region and the provinces of Qinghai, Sichuan, Yunnan and Gansu.

Yan has also taught herders new techniques in building barns and replacing stud yaks, and explained the risks of overgrazing and overmilking.

In 2005, Yan led her team to cultivate the Datong yak breed, which has the genes of wild yaks.

"Yaks lived on the Qinghai-Tibet Plateau before humans did, and Tibetans domesticated yaks 8,000 years ago. Yaks are the means of production and the totem of people on the plateau," Yan said.

"I study and love yaks because of their toughness, bravery and hard work, which are precious qualities. Yak breeding on the Qinghai-Tibet Plateau is a long cycle of time-and energy-consuming research. We need the spirit of the yak to respond to the difficulties and challenges in our research."