M. Zhengchao, L. Jiye, H. Kai and Zh. Longquan
Qinghai Datong Yak Farm, Datong 810102, Qinghai, P.R. China
Qinghai Datong Yak Farm is a state-owned yak farm, which was established in 1952. There are 51 ha usable pasture and 20 thousand yak and other livestock. Yak production is the main source of income for the farm. However, the growth and development of yak have been slow due to traditional extensive management and poor, degenerated, vegetation caused by overgrazing, which has been going on for a long time. To change this situation, and after consulting the scientists of Lanzhou Research Institute of Animal Science of Chinese Academy of Agricultural Sciences and Qinghai Academy of Animal and Veterinary Sciences, the farm began to carry out the seasonal animal husbandry with slaughtering male yak calves at six months of age for veal production.
Over 43 thousand male calves have been slaughtered during the last 13 years (up to 1997), with an average of 3980 male calves each year. The slaughter rate was up 57% during this period. The output value of the slaughtered calves accounted for 20% of the total income of the farm. The results suggest that this measure, not only enhanced the development of yak husbandry, but also formed a new opportunity for the economy in the pastoral area. It will play an important role in the development of animal husbandry in the future.
The nutritive composition of the yak veal in the Datong Yak Farm was analysed (Table 1). The results showed that the yak veal is nutritive meat. It is fresher and tender, has lower fat, higher protein and is richer in minerals compared with the yak beef.
Table 1. Comparison of nutrients between the yak veal and beef (%).
Item |
Dry |
Crud |
Crud |
Crude |
Calcium |
Phosphorus |
Calorific |
Veal |
30.5 ± 0.3 |
24.1 ± 0.1 |
5.1 ± 0.1 |
1.4 ± 0.02 |
0.04 ± 0.01 |
0.11 ± 0.01 |
5987.0 |
Beef |
35.4 ± 0.5 |
27.6 ± 0.1 |
6.2 ± 0.3 |
1.6 ± 0.02 |
0.06 ± 0.01 |
0.12 ± 0.01 |
7157.0 |
The yak calves live in the cold and high alpine pasture at an elevation of over 3000 metres above sea level where there is no pollution and contaminants from pesticides, fertilisers and other chemical pollutants. Yak veal is ideal for roasting and stew because it tastes fresh and is tender. It is a product, which can do well in both local and international markets.
Normally, the yak cow only gives birth from March to May every two years, mostly due to the poor body condition of the nursing cow since the yak calf is only weaned the following summer. According to a survey, proportion of cows calving every year in yak herds was less than 20% under traditional system before 1984. It has been shown that, if the calf is weaned in early autumn, the cow may get oestrus 5 to 10 days after the lactation ends (after the calf is slaughtered). This substantially increases the reproductive rate of the herds. In the study farm, the conception rate reached 62% and the proportion of cows calving every year increased by 38% after the veal production had been implemented starting in 1985.
Using a strategy of slaughtering the male calves at 6 months of age and poorly-developed female calves, and culling cows with poor reproductive performance and reducing the number of animals in the 9 to 24 month age range, increased the percentage of reproductive females and, in turn, improved the reproduction at herd level. For example, the reproductive cows took only 49% in 1983, but it was up to 54.7% in 1995 in the Datong Yak Farm.
The study has shown that the body weight gain of calves nursed by unmilked cows was highest by the age of 8 months. So, veal production taking full advantage of all the cow's milk, which is translated into high calf growth rates, substantially enhances the marketing rate and economic income. Results of analysis of calf live weights in the farm showed that the percentage of six-month-old yak calves with carcasses weighing 35–45 kg, 40–45 kg and over 45 kg were 40–43%, 30–35% and 22%, respectively.
The yak calves get all of their nutrition and energy needs for growth and development from their mothers. But in harsh winter and spring seasons on the Qinghai-Tibetan Plateau, the yak cow can only support itself with the nutrition from natural pasture and provide very little for her calf. Under these circumstances, the starving calf resorts to nibbling the forage by itself from an early age, resulting in reduced physique, extreme weakness and lowered resistance to all kinds of diseases and natural disasters. This results into increased calf mortality. According to statistics from Qinghai Datong Yak Farm in 1984, calf mortality was over 13%, representing up to 74% of the overall mortality of yak in the herd. Therefore, slaughtering the yak calves can reduce this kind of loss under the harsh conditions in spring and winter.
Generally, calving season of the yak cow begins in March. If the calves born in the year are not slaughtered, the requirement for forage increases, especially during winter and the following spring when the grass withers. The veal production is an alternative to solve this problem. Moreover, this measure can also reduce labour costs and the investments on basic infrastructure by about 100 RMB Yuan (US$ 1 = 8.2 Yuan during this study) per calf slaughtered.
Qinghai Datong Yak Farm has made an important contribution in the development of veal and its related by-products. The project, titled 'Technique of increasing output from developing the yak veal' has been confirmed as one of the extended projects of 'harvest scheme of national agriculture, animal husbandry and fishery' by the Ministry of Agriculture and is receiving great attention from the Animal Husbandry Department of Qinghai Province and other related departments.
