[Photo by Jiang Wenyao/provided to China Daily]

The shepherds anxiously watch their flock by night, with dozens of lambs expected to be delivered overnight. Without timely care, the new arrivals will die soon after birth.

Dilai and Qimti are on night watch and have to spend it in an open enclosure without heating and nothing but a small torch for light. For a month, they have to spend their nights in the enclosure, keeping an eye on the pregnant sheep, preventing them from running away or giving birth elsewhere. Dilai's eyes are bloodshot after little sleep.

"The family's income depends on the new lambs, so taking good care of them is crucial, even if it means we don't eat or sleep," he said.

Wrapped in a quilt, he huddles up beside the enclosure, waiting, listening.

Dilai's wife, Tuya, prepares supper at 11 pm. It is the family's only chance to get together after a hard day's work.