Section of Science and Technology, Linzhou County, Lhasa, Tibetan Autonomous Region, P.R. China
Linzhou County is the second largest county in the Lhasa City, Tibet. Animal husbandry plays an important role in the total agricultural revenue, accounting for 25% in 1999. The population in the county is about 51,384 people, belonging to 8573 families resident in 102 villages of 10 townships. The total area is 450,866 hectare, of which 12 thousand hectare is arable land and 326,473 hectare natural highland pastures.
The main crops are Tibetan barley, wheat, peas and oilseed with a total annual yield of 50 thousand tonnes. The total livestock is 316 thousand head producing 3384 tonnes of meat and 2549 tonnes of milk in 1999. The yak is one of the main livestock species in the county and was estimated at 75,300 head in 1999, constituting 23.7% of the total large ruminants. The meat and milk production from the yak was 72% and 66%, respectively, of the total output in the county in 1999.
Due to the remoteness, severe environment, and poor social and economic infrastructure, yak production is predominantly under extensive management system with very poor feeding, poor health care, and generally low technical input. One of the consequences of this has been serious inbreeding in the herds which has resulted in the degeneration of yak productivity manifested in smaller body size, lower meat and milk yields and poor resistance to the harsh environmental and disease challenges.
To restore and improve the yak productivity, the county set up a state-owned yak farm in 1985 based on 3666 hectare fenced natural pastures and 120 hectare artificial pasture with support from both the Tibetan Commission of Science and Technology and the Tibetan Bureau of Agriculture and Animal Husbandry. The aim was to select breeding animals at the farm and then to distribute the superior stock to the local farmers in and out of the county. By introducing the top breeding bulls of the Pali yak in Chigatse and Sibu yak in Mozhugongka, two crossbreeding schemes were followed: either using Pali yak or Sibu yak bulls on the local yak cows.
The farm now has 605 breeding animals in the two nucleus herds. The reproductive females constitute 57.2% of the total female herd.
By 1999 the farm had supplied 580 top yak bulls to the Linzhou County itself and other counties in four Prefectures in Tibet. In Linzhou there were 32,260 head of improved yak, which accounted for 42.8% of the total yak population in the county. From live weight records, animals aged 0.5, 1, 3, 6 and 8 years weighed 66, 106, 183, 282 and 344 kg, respectively. These weights are higher than those of local yak of equivalent ages by 56%, 56%, 45%, 88% and 51%, respectively. The milk yield of the improved yak during the July to October period was 205 kg. In contrast, the local yak only produce 152.5 kg of milk in this period. From these results, it is obvious that the selection and breeding at this farm has produced remarkable achievements in terms of yak production in the area.