Sheep are seen in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

For shepherds, summer is the milking season for ewes in the Tibetan pasturing area.

LHASA, Aug. 7, 2019 (Xinhua) -- Herdsmen here chain up ewes one by one while milking them with buckets in order, a traditional milking way followed by local herdsmen for almost 1,000 years.

Sheep milk is highly nutritious, and can be frozen and stored, which will not affect the quality of the milk. Since sheep usually produces less milk than goats and cows, sheep milk sells for a relatively higher price.

As an important livestock breeding area in Tibet, Ngari prefecture provides butter, yogurt, beef and mutton to other parts of Tibet.

Herdsmen milk sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

A herdswoman milks sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

A herdswoman milks sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

A herdswoman milks sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

Sheep are seen in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)

A herdswoman milks sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019.(Xinhua/Jigme Dorje)

Herdsmen milk sheep in Rutog County of Ngari Prefecture, southwest China's Tibet Autonomous Region, Aug. 4, 2019. (Xinhua/Jigme Dorje)