Previous Page Table of Contents Next Page

Part 2 Yak in other countries with a long tradition of yak keeping

Bhutan by Tashi Dorji, Walter Roder and Lham Tshering[6]

The kingdom of Bhutan is located in the eastern Himalayas. It borders the Indian states of Sikkim in the west and Arunachal Pradesh in the east, both of which are home to small populations of yak (see section on India). West Bengal and Assam border on the south of Bhutan and on the northern and northwestern border lies the Tibetan Autonomous Region of China.

Bhutan is a small country - the maximum north-south distance being 170 km and the longest east-west distance 300 km. Its topography is completely mountainous with elevations ranging from a few hundred meters in the south to peaks over 7 000 m along the northern boundary. The climate is dominated by the monsoon with dry periods in the winter and wet summers. Permanent snow cover is found at elevations above 5 000 m. Precipitation varies widely; while south-facing slopes may receive up to 4 000 mm, high-altitude valleys, sheltered behind ridges, may receive less than 700 mm.

Importance of yak at the national and regional level

Yak rearing is the main source of livelihood for the Bhutanese population living at high altitudes. According to the 1997 livestock census, there were 37 700 yak in nine districts of Bhutan and about 10 percent of the country's population depended on yak production (Gyamthso, 1996). Consequently, the yak production system has considerable national importance, unlike in many other yak-rearing countries. Milk and meat are the most important products, but yak are also used as riding and pack animals and they provide fibre, fuel and fertilizer (use of manure or ash after burning manure).

Yak play an important role in the religious and cultural life, especially for the pastoralists but also for the Bhutanese population in general. Some of the yak-herding communities have their own distinct culture and dress habits. Geographical and social isolation is a major problem faced by yak herders. It is not uncommon for winter camps to be reached only by walking for one to three days from the nearest road point. Summer camps are even more remote and access to school and medical services present great difficulties for the yak-erding communities.

Genetic and physical characterization of yak populations

The genetic diversity within Bhutanese yak populations has been assessed using genetic distance, which is used as a measure of genetic similarity. Genetic distance was estimated from allele frequencies using eight microsatellite markers. From these distances, representations of the relationships were obtained between three yak populations, one yak hybrid (yak crossed with cattle) and four cattle populations (which are involved in hybridizing with yak) (Figure 11.2.1). The branch length of the tree is an indication of the genetic distance and populations that are closely related would be placed in the same clade. Higher "bootstrap" values, which are the figures at the nodes (and represent the percentage occurrence in 1 000 replications of the resampled loci), indicate strong support of the relationships among populations. From this study, substantial differences between yak populations from eastern Bhutan and those from other parts (central and west) of the country were apparent. Dorji et al., (2002), therefore proposed that Bhutanese yak populations could be categorized into two breeds, namely Merakpa yak of eastern Bhutan and Haapa yak of western and central Bhutan. Yak from the eastern region of the country are distinctly smaller in size and body weight compared to those of western Bhutan (Table 11.2.1)

Figure 11.2.1. Unrooted neighbour-joining phylogenetic tree representing the genetic relationships among the yak and cattle populations (Goleng = local Bos taurus, Brown Swiss cross = Brown Swiss crossed with local cattle, Mithun cross = Bos frontalis crossed with local cattle, Nublang = local Bos indicus). The numbers at the nodes are the percentage of support for each cluster in a bootstrap re-sampling of 1 000 trees with replacement.

About 73 percent of yak in eastern Bhutan, 65 percent in central and 60 percent in western Bhutan are black in colour. Other common colours include a mixture of black and white and brown. Absolute white or albino animals constitute less than 5 percent. The proportion of polled animals were 17 percent in east Bhutan yak while it was less than 10 percent in central and western Bhutan population. Long, hairy forehead type yak are also common among eastern Bhutan yak.

Table 11.2.1 Body measurements (mean ± s.e.) of adult yak in three regions of Bhutan


Western Region

Central Region

Eastern Region







Height at withers (cm)

136.0 ± 1.2

117.0 ± 0.8

129.0 ± 1.9

110.0 ± 5.8

128.0 ± 2.0

113.0 ± 1.6

Body length (cm)

159.0 ± 1.7

137.0 ± 1.2

152.0 ± 4

133.0 ± 1.2

148.0 ± 1.7

133.0 ± 2.3

Chest girth (cm)

194.0 ± 1.7

165.0 ± 0.9

185.0 ± 3.5

165.0 ± 1.3

177.0 ± 2.8

160.0 ± 1.6

Body weight (kg)*

419.0 ± 11.0

264.0 ± 4.0

369.0 ± 22.0

252.0 ± 4.5

323.0 ±12.0

239.0 ± 8

Height at hips (cm)

107.0 ± 0.9

97.0 ± 2.2

101.0 ± 1.8

91.0 ± 0.9

101.0 ± 1.2

93.0 ± 1.7

Cannon circumference (cm)

21.0 ± 0.2

17.0 ± 0.2

20.0 ± 0.3

16.0 ± 0.2

19.0 ± 0.2

16.0 ± 0.2

M = male; F = female; n = Number of animals;
* Body weight (kg) estimated from (Chest girth, m)2 × (Body length, m) × 70;


Mating of yak with cattle for better milk or draft production is practised on a modest scale, especially in central and eastern Bhutan. The most common approach involves mating yak cows with bulls of a small Tibetan breed (Goleng, Bos taurus). Occasionally Bos indicus bulls on yak cows or yak bulls on B. taurus or B. indicus cows are also used to produce hybrids. Female offspring are backcrossed to yak or cattle for more than five generations. A modest number of yak hybrids from Brown Swiss crossbred bulls (Brown Swiss crossed with local cattle) with yak cows and their reciprocal crosses are also available, but due to difficulties in implementing a recording scheme, it was not possible to generate reliable performance data. Recent genetic studies indicated limited gene flow from cattle to yak (Dorji et al., 2002, Figure 11.2.1). Most herders retain only the F1 generation in the herd due to reduced productivity and quality of subsequent backcrosses. It is mostly the herders with few animals that practise repeated backcrossing beyond the F1 stage.

This restricted practice of backcrossing may in turn have limited introgression of cattle genes in the yak population. Another reason could be positive selection against cattle alleles in later backcrossed generations.

Production parameters

The normal breeding season is from June to September. Most Bhutanese yak have their first calf when they are around four to five years of age. Two calves in every three years is the norm and less than 20 percent of cows calve annually (Dorji, 2000; Gyamtsho, 1996). Bulls are first put into service when they are three or four years old.

Gyamtsho (1996) recorded a daily milk production of 1.2 kg in July and 0.90 kg in October from yak in western Bhutan. Highest yields were obtained from animals of seven to ten years age and in their third and fourth lactation. During a survey carried out in November 1999, Dorji (2000) measured morning milk yields of 0.74, 0.58, and 1.4 l for yak in Western Bhutan, yak in Central Bhutan and Zom (F1 of yak crossed with cattle) in central Bhutan, respectively.

When a yak cow conceives again she may refuse access to the calf and it is usually at this time that the calves are weaned.

Harvesting of yak hair takes place in May and June. The outer hair is cut using scissors or a knife. Only castrates and females are sheared while the breeding bull is never sheared to retain its superior appearance in front of the other bulls. An average hair yield of 1 kg and 0.3 kg were measured from shearing 8 males and 22 females, respectively (Gyamtsho, 1996). Dorji (2000) reported hair yields of 0.8 - 1.0 kg per animal. The staple length of the hair varies from 20 to 40 cm (Gyamtsho, 1996). The inner soft wool tends to loosen during early summer and is plucked by hand. The average wool yield from castrated yak varies from 0.2 to 0.4 kg per year (Dorji, 2000; Gyamtsho, 1996).

Production systems

The animals are herded in a transhumance pattern, depending on the state of the grazing. The alpine summer pastures, at around 5 000 m, are grazed until late September or early October. Thereafter the herds begin to descend to winter pastures on lower ground at an altitude of around 2 500 m - 3500 m.

All yak-herding families have permanent homes near their winter pastures. Wooden fences or stone walls to provide some protection may surround winter and summer camps. Temporary shelters are provided for the calves.

Winter pastures at elevations ranging from 3 000 m to 3 800 m are generally used from November to April. During the summer, the herders move with their animals to pastures ranging from 3 500 m to 5 000 m. Usually herders also carry out some cultivation near their permanent settlements. Species commonly cultivated include barley, wheat, mustard, potato, buckwheat, radish and turnip.

The average herd size per household was 85 animals in western and 42 animals in central Bhutan (Dorji, 2000). Yak herding families may also own cattle, sheep and horses. A few monasteries and wealthy families have large herds of yak and sheep, tended by herders under well-defined tenure agreements (Dorji, 2000). The proportion of yak owned by absentee owners ranges from 34 percent in western Bhutan to less than 10 percent in the eastern area.

In general, yak cows are not milked for the first three to four weeks after calving. After that, milking is done in the morning only by keeping the calf separate during the night. Calves are allowed to suckle for a brief moment to initiate milk flow. When milking, one to two teats are left for the calf without being milked. Milk is processed into butter and cheese by individual herders using traditional methods.

Meat and milk products are sold and/or used to barter for rice, chillies, salt, tea, etc. Yak meat receives a premium price, about 60 - 100 percent higher than the beef of other cattle.

There is no special group of animals raised for meat. Unproductive females and male castrates are generally slaughtered during October and November when they are in prime condition. Yak herders in central Bhutan do not slaughter animals because of religious sentiments. Meat from animals that die of natural causes or accidents is, however, consumed or sold.

To reduce inbreeding and improve the population, yak semen was imported from China and used from 1990 to 1997. A total of 82 inseminations were made and 45 progeny recorded (Tshering et al., 2002). Detailed information on the productivity of the A.I. progeny is not yet available. The trial demonstrated difficulties in using artificial insemination because of logistical (accessibility) and management problems (heat detection, exclusion of breeding bulls).

Yak health

The Government provides free veterinary health care. But because of the remoteness and the migratory system of husbandry, access to the services provided is limited, especially during the summer months. Gid disease (Multiceps multiceps) remains the single most important disease causing high mortality rates in some regions (Table 11.2.2).

Systematic gild control programmes initiated in the 1960s resulted in a dramatic reduction of mortality rates. In the past decade the problem has, however, come back with a vengeance.

Poisoning by plants or stagnant water (locally termed as baduk and chuduk) is another major cause of mortality, especially in the central region where no culling is practised (see Chapter 9).

Table 11.2.2 Causes of mortality in yak during 1997-1998. Results from a survey of 22 herds (1 353 animals) in western and 32 herds (1 879 animals) in central Bhutan [Source: Dorji, 2000]

Cause of mortality

Animals lost (%)

West Bhutan

Central Bhutan




Diarrhoea & weakness



Plant and water poisoning



Liver fluke






Fallen from cliff









Grassland resources and their management

Yak production depends largely on grassland resources at elevations ranging from 3 000 m to 5 000 m. The dominant species in alpine grazing lands belong to the genus: Carex, Juncus, Agrostis, Festuca, Kobresia, Poa, Rododendron, Potentilla, Primula and Danthonia (Roder, 2002). The major components of the vegetation consist of broadleaf species (Table 11.2.3). With an increase in altitude, grass species are gradually replaced by sedges.

The dry matter production varies widely, influenced by soil conditions, rainfall, elevation, exposure, and management. Dry matter yield estimates have been published in the range from 0.7 to 3.0 t ha-1 for temperate grasslands at elevations below 3 000 m and from 0.3 to 3.5 t ha-1 for alpine grasslands at an elevation above 3 000 m.

Herders generally use sound management systems with rotational grazing. Households with small herds often pool their animals together. The grazing land belongs to the Government, and most herders have grazing rights for one or more pastures either individually or on a community basis. In some regions absentee landlords own large areas of grazing land. Grazing areas in the vicinity of permanent settlements at mid-elevations (2 000 - 3 000 m) are often used by cattle for summer grazing and by yak for winter grazing. Overgrazing is frequently mentioned as the main cause of low and/or deteriorating grassland yields.

Table 11.2. 3 Vegetation cover and composition for selected regions1)

1) Methods used were: Region 1-4, visual estimates from plots of 0.1 m2; Region 5 and 6, point method along line transects (Roder, 2002).




Broad leaf



Bare ground2)


3 800 - 4 000 m


44 (41-47)3)

16 (12-23)

15 (9-22)

26 (17-35)


4 100 - 4 200 m


46 (20-70)

8 (1-19)

25 (15-35)

21 (6-38)


4 100 - 4 800 m


41 (4-83)

15 (1-46)

30 (0-91)

15 (1-30)


4 400 - 4 600 m


42 (12-72)

9 (7-12)

16 (6-30)

33 (5-75)


4 110 - 4 300 m


61 (49-67)

8 (3-15)

29 (21-35)

1 (0-3)


3 210 - 3 360 m


45 (36-53)

25 (11-41)

14 (8-17)

4 (3.3-5.4)

2) Including moss
3) Values in bracket indicate range observed across sites for a particular region.

The grassland resources are shared with a wide variety of wild animals of which the takin (Budorcus taxicolor), the blue sheep (Pseudovis nayaur), the sambar (Cervus unicolor) and the musk deer (Moschus chrysogaster) are the most important. In recent years, some of these species, especially the blue sheep, have increased in number, supposedly due to a decline in the population of its predators.

The traditional use of fire to control unwanted shrubby species is illegal currently, but possible changes in the law allowing for controlled burning are under discussion. Increasing production appears feasible as combined effects of white clover introduction and P-application have been shown to result in 8.2-, 3.2- and 0.6-fold increases in dry-matter yield at elevations of 2 700 m, 3 300 m and 4 020 m, respectively (Roder, 2002).

Fodder production is distinctly seasonal. Growth in the winter pasture area starts in May only, with the onset of the rainy season. Again, plant growth ceases towards the end of October when moisture and temperature become limiting. The gradual decline in fodder quality and quantity over the winter months leads to substantial live weight losses. The scarcity of fodder during the winter months can become quite serious in parts of Western Bhutan, with relative high concentrations of animals around the winter camps.

Hay, straw from barley and buckwheat and turnip are the most common winter fodder preserved in small quantities (generally less than 100 kg per animal) to supplement grazing and to provide emergency fodder during periods when the pastures are snow covered. Most authors agree that increasing winter fodder availability and quality should be given priority. For this, lucerne, white clover, tall fescue, cocksfoot and oat are the most promising species.

Future of yak

The resources used in the yak production system are very marginal, and thus, the opportunities for increasing the production are limited. Problems associated with geographical and social isolation are likely to further constrain future developments. In spite of this, yak will continue to be an important component of the Bhutanese landscape and society and will become an important attraction for tourism.

Although the permanent grasslands may have only limited potential for generating higher production, their management will become more important, not least because of the issue of watershed management (hydropower, other needs) and concerns with biodiversity in fauna and flora and with the development of tourism.

Management of the fodder resources will be the main leverage to achieve higher production levels. The finalization of rules and regulations, now drafted, governing the use and maintenance of natural grasslands (relating to ownership and taxation and the management/ownership of tree cover) will contribute substantially towards maintaining the biophysical resources and towards optimizing production from these resources.


Dorji, T. (2000). Genotypic and phenotypic characterization of the yak (Bos grunniens) and yak farming systems in Bhutan. MSc. Thesis. Institute of Land and Food Resources, University of Melbourne, Australia.

Dorji, T. et al, (2002). Genetic diversity of Bhutanese yak (Bos grunniens) using microsatellite markers. Proceedings of the third international congress on yak, in Lhasa, China, 4-9 September 2000. International Livestock Research Institute (ILRI), Nairobi, pp. 197-201.

Gyamthso P. (1996) Assessment of the condition and potential for improvement of high altitude rangeland of Bhutan. Diss. ETH No 11726, Zurich.

Roder, W. (2002). Grazing resources for yak production systems in Bhutan Proceedings of the third international congress on yak, in Lhasa, China, 4-9 September 2000. International Livestock Research Institute (ILRI), Nairobi, pp. 100-103.

Tshering, L. et al. (2002). Artificial insemination trial in yak in Bhutan. Proceedings of the third international congress on yak, in Lhasa, China, 4-9 September 2000. International Livestock Research Institute (ILRI), Nairobi, pp. 363-365.

[6] Tashi Dorji is Livestock Programme Officer at the Renewable Natural Resources Research Centre, Ministry of Agriculture, Jakar, Bumthang, Bhutan; Walter Roder is Advisor Agronomist at the foregoing Centre; Lham Tshering is Deputy Chief Veterinary Officer with the National Artificial Insemination Programme, Wangchutaba, Thimphu, Bhutan.

Previous Page Top of Page Next Page