The Coordinating Team of Yak Improvement Research of Northwest Sichuan grassland, sponsored by the Sichuan Provincial Land-Reclaiming Bureau, held their fifth annual conference in Chengdu on 18-25 December 1980. The conference summarized the work of the team in 1980 and made plans for scientific research in 1980. Leaders from the provincial government and Party Committee made speeches at the conference. Eighteen units from colleges, universities, and grassroots animal farms were present at the conference. The conference had 96 yak improvement stations were established with more than 400 workers, of which 100 were technicians and 12 were scientists with intermediate and senior titles. In 1976, yak improvement was started in Northwest Sichuan with frozen semen of ordinary cattle. By 1950, 5,719 filial-generation had been born through artificial insemination (there were only 2,490 cattle in 1980). In the 96 yak improvement stations, 8,615 female yaks were mated with frozen semen in 1980. One after another, frozen semen of eight breeds of cattle (Charolais, Limousin, Simmental, Hereford, Angus, Murray Grey, Shorthorn and Holstein-Friesian) were introduced for research and comparison.

Key Words: Yak, Improvement, Northwest Sichuan, Coordinating Team, Annual Conference

[Source: China Yak, first issue, 1981]

The Second Conference of the China Coordinating Team of Scientific Research on Yaks was held in Chengdu city, Sichuan on 24-29 November 1981. Those present were 96 representatives, experts, and professors of some coordinating units in Xinjiang, Tibet, Yunnan, Qinghai, Gansu and Sichuan Province. A leadership group was organized by leaders of these coordinating units in the six provinces/regions. The conference summarized the work of the Coordinating Team in the last two years, exchanged experiences and made plans for the year 1982-1985. In the last two years, 1,096 technicians in yak improvement were trained, 156 yak improvement stations were established, and 6,900 improved crossbreeds were obtained. Totally scientific research was conducted on 17 subjects and 37 projects, and good progress was made on 28 projects. More than 30 scientific essays were written. Sponsored by the Coordinating Team, China Yak has published seven issues of 145 articles of 600,000 words.

Key Words: China Yak, Scientific Coordinating Team, Minutes

[Source: China Yak, first issue, 1982]

Since the establishment in 1979, China Yak Coordinating Team of Scientific Research had conducted 17 scientific subjects and 37 research projects by 1981, with 28 research projects having made good progress. These research projects included a resource survey, combination test of yak crossbreeding improvement, frozen semen application on highland grassland, and artificial insemination. There was also research regarding the improvement of survival rate of interspecific crossbreeding, physiology of yak breeding, yak ecosystem, best slaughter age of yaks, mechanism of male sterility in interspecific crossbreeding, and test of milk, beef, draft, lactation and fast fattening performance of crossbred cattle. In the last two years, 1,096 yak improvement technicians have been trained, and 156 yak improvement stations have been established. Through improvement, 6,900 improved yaks were obtained. Crossbred cows began to milk at the age of three, one year earlier than yaks. The average milk yield is five kilos, which is one to three times that of female yaks. The initial weight of cattle is 70% more than that of yaks. Every crossbred cow produces 500 kg more milk than a female yak in a year, creating a total economic income of over one million yuan. Improved bulls produce 80 kg more beef than yaks. The price of an improved draft cattle is 150 yuan more than that of a male yak.

Key Words: China Yak, Coordinating Team of Scientific Research, Work Summary

[Source: China Yak, first issue, 1982]

On 20 July to 22 August 1981, the Coordinating Team of Scientific Research on Yaks of Northwest Sichuan made a survey on the benefits of six yak improvement stations in Aba and Ganzi prefectures through interspecific crossing. According to statistical analysis, crossbred cattle with frozen semen created obvious economic benefits. First, the milk production of crossbred cattle is three times that of yaks. The milk production value of crossbred cattle is 329.36% times that of yaks. A crossbred cattle still produces a value of 67.6% more than a yak does. For a black Dzo, it is 43.15%. Secondly, an improved female Dzo milks at the age of three, one year earlier than a yak. The income from a yak covers its own cost after it milks for five years, while it only takes one year for an improved cattle to cover the cost and still produces income. The cost of an improved male dzo is 80.31 yuan if slaughtered at the age of three. The cost of a male yak is 87.66 yuan if slaughtered at the age of five. Therefore, not only the cost of dzo is lower than that of yak, but the cost can be returned much faster. Thirdly, milk and beef production per unit area of grassland is very high. At the grassland of the same area, an improved cattle produces as much as two to three yaks.

Key Words: Yak, Interspecific Crossing, Improvement

[Source: China Yak, first issue, 1982]

Twenty female yaks and 20 new-born calves were randomly selected from Pengbo Farm, Tibetan Autonomous Region in 1980-81. They were weighed on a regular basis every month to study the seasonal dynamics of yak body weight. It is cold during the period of October through April (212 days), and during this time of the year the yaks weigh 44 kg less on average (body weight ranged from 39.5 - 48.5 kg), with a daily loss of 207.5 grams. In September, the yaks lose 24.4% of their body weight. It is warm from May to September (153 days) at Pengbo Farm. The weight gain of a female yak is 48.4kg on average, with a relative weight gain of 27.4%. Deducting the weight loss in cold seasons, the annual net gain of a female yak aged five and up is 4.4 kg on average. Yak calves lose 5.4 kg on average during the cold season, but it is very easy for them to gain weight in the warm season. In May and June, a yak calve weighs 11.1 kg more than in April, with a relative weight gain of 32.4%. An adult yak weighs the most in September - 180.1 kg, and the least in April - 136.1 kg.

Key Words: Weight Gain, Warm Season, Cold Season, Seasonal Dynamics

[Source: China Yak, first issue, 1982]

Since 1979, Xinjiang Land-Reclaiming Institute conducted a test of crossbreeding yak with beef cattle. The crossbreeds showed better performance in initial weight, environment adaptability, beef production, and income generation than yaks. A 14-month crossbred weighed 263.6 kg, while a yak of the same age weighed only 139.4 kg. The body weight of a crossbred is 123 kg more than that of a yak, increasing by 88.6% over a yak. The crossbreeds all survived during the first winter. In late May, the crossbred began to fatten very fast, with a daily weight gain of 800 grams. A 7-month crossbred weighed 90.6 kg more than a one-year yak, its carcass weight was 49.7 kg more, and the dressing percentage was 1.5% more. A crossbred was slaughtered at the age of 18 months, producing as much as two yaks of the same age, creating an income of 101.4 yuan. Deducting the six yuan for mating, there is a total income of 96.5 yuan.

Key Words: Yak, Beef Cattle, Interspecific Crossing

[Source: China Yak, first issue, 1982]

The effects of crossbreeding yak with the frozen semen of ordinary cattle are obvious. The improvement was slow, though, because of low conception rates and reproductive and survival rates. From May 1980 to August 1981, the Aba Research Institute of Animal Science conducted research on improving the reproductive and survival rate of interspecific crossing of yaks. The test, which was assigned by the Sichuan Provincial Coordinating Team of Yak Improvement, was to use frozen semen of ordinary cattle to crossbreed yaks. Researchers strengthened feeding and management, disease control, artificial insemination, and calves protection which improved the reproductive and survival rate by more than 40%. Therefore it is possible to maintain the mortality rate of adult yaks and cattle at 40%. This is an improvement over the reproductive and survival rate of 12-18% reported in 1976-1979 in Aba prefecture.

Key Words: Interspecific Crossing, Reproductive and survival rate

[Source: China Yak, first issue, 1982]

Waqie Farm of Hongyuan county observed the milk performance of the crossbred F₁ 71 cattle in 1980. During lactation, the four-year dzo of Holstein-Friesian x yak had the best performance in both total milk production and daily milk yield. After converted to the standard milk containing 4% fat, the milk produced by the Holstein-Friesian x yak dzo is 2.84 times that of a yak. A three-year dzo of Holstein-Friesian x yak and of Simmental x yak produces milk of 2.45 and 2.37 times as much as a yak. During lactation period, the fat content in the milk of a three-year and four-year dzos of Holstein-Friesian x yak has 2.53 and 2.22 times as much fat as yak milk. A dzo of Holstein-Friesian x yak produces 151.58 yuan more than a yak during the summer, which is an increase in income of 260%. The crossbred dzo began to mate and milk earlier than the yak, and it produced milk for one more year than the yak.

Key Words: Frozen Semen, Crossbred F₁ , Female Dzo, Lactation Performance

[Source: China Yak, first issue, 1982]

There used to be only a small number of white yaks in Tianzhu. Through constant selections, they have multiplied into today? population. The main characteristics of Tianzhu white yaks are that adult males have a body height of 120.8 cm and their live weight is 264.1 kg. An adult female has a body height of 108.1 cm and its live weight is 189.7 kg. These are average levels for China yaks. Tianzhu white yaks are considered mature at four years of age. A test was conducted on three males and three females of slaughtered Tianzhu white yaks. The dressing percentage of the yaks was 52%, and the meat percentage was 36.28% and 39.59% for the male and female, respectively. Four adult yak steers were slaughtered, with an average dressing percentage of 54.57%, and meat percentage of 41.39%. Adult male yak produced 3.62 kg of wool on average, with the highest amount produced weighing six kg. The down production was 0.4 kg, and the switch of tail was 0.62 kg. For adult female Tianzhu white yaks, these indexes for wool production, down production, and switch of tail were 1.18, 0.75, and 0.35; for a yak steer, they were 1.69, 0.48, and 0.30. A Tianzhu white yak produces 400 kg milk annually. Tianzhu white yak adapts well to high mountain and grassland. In summary, the Tianzhu white yak produces fine quality wool, beef and milk.

Key Words: Tianzhu, White Yak

[Source: China Yak, first issue, 1982]

Zhongdian yaks live mainly in the highland areas of Gezan, Niru, Large Zhongdian, Small Zhongdian, Dongwang, Deqing and Weixi county. According to statistics in 1980, there were 19,234 yaks in Zhongdian, and 2,441 yaks in Deqing and Weixi county. There were 964 female yaks that were ready for breeding, accounting for 39.5% of the yak population in Zhongdian, Deqing county, and Weixi county. A male adult Zhongdian yak has the following physiological indexes. Its body is 119.05 cm tall, 126.87 cm long, and 234.55 kg. For a female adult Zhongdian yak, the body height is 105.23 cm, body length is 117.06 cm, and body weight is 192.47 kg.

A yak steer is 119.58 cm tall, 139.58 cm long, and weighs 294.92 kg. Every female yak produces 302.4-324 kg milk, with an average milk fat percentage of 6.17%. The live weight of a male Zhongdian yak before slaughter averages 228.4 kg. The carcass weight averages 103.2 kg, the dressing percentage averages 45.18%, the meat weight averages 77.9 kg, and the meat percentage is 34.11%. For a female yak on average, live weight is 202.7 kg, carcass weight is 92.25 kg, dressing percentage is 45.51%, meat weight is 66.5 kg, and meat percentage is 32.31%. For a yak steer, the following information was found. On average, the live weight is 273.9 kg, carcass weight is 150.8 kg, dressing percentage is 55.06%, meat weight is 132.6 kg, and meat percentage is 48.41%. The annual wool production of Zhongdian yaks is 3.55 kg for a male and 1.32 kg for a male. Zhongdian yaks show estrus late. A female Zhongdian yak will not show estrus until it is three years of age. It can be mated at the age of four, however the best mating period is when the yak is between five and eleven years of age.

Key Words: Zhongdian Yak, Survey Report