Yaks, cattle, and some sheep graze in the lowland forests and, during the summer, in the uplands and high valleys. In 1999 there were an estimated 435,000 head of cattle, 75,000 hogs, 59,000 sheep, and 42,000 goats. Draft animals that year included 30,000 horses, 18,000 donkeys, and 10,000 mules. Meat production in 1999 was estimated at 8,000 tons, 75% of it beef. Wool has been in short supply since its importation from Tibet was stopped by the government in 1960; sheep breeding is therefore encouraged. In 1999, one ton of hides was produced.