Table 1. Population and distribution of yak in Bhutan, by regions

Source LUPP (1997)

The yak-rearing area stretches across the country’s northern belt, extending from Haa district in the northwest to Trashigang in the east. The western region has the highest density, with more than 50 percent of the total yak in Bhutan.

Genetic diversity of yak populations

The genetic diversity within Bhutanese yak populations has been assessed using genetic distance, which was estimated from micro satellite marker allele frequencies. 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., (2000), therefore proposed that Bhutanese yak populations could be categorised into two types, yak of eastern Bhutan, and yak of western and central Bhutan.

Yak from the eastern region of the country are distinctly smaller in size and body weight (239 to 323 kg) compared to those of western Bhutan (264 to 419 kg). About 73% of yak in eastern Bhutan, 65% in central and 60% in western Bhutan are black in colour. Other common colours include a mixture of black and white and brown. Absolute white or albino animals were less than 5%. The proportion of polled animals were 17% in east Bhutan yak while it was less than 10% in central and western Bhutan population. Long, hairy forehead type yak are also frequent among eastern Bhutan yak.

Yak breeding systems

Three distinct yak-breeding systems are recognised in Bhutan. Pure line breeding is practised in the western region. In central and eastern region, crossing with cattle is quite common (Winter and Tshewang, 1989). However, the crossing patterns are not similar. In central Bhutan, hybrids are backcrossed to yak, while in the east they are mainly backcrossed to cattle. Each category of backcrosses has their own local name. Only herders with several years of experience can distinguish later backcrosses (Tshering et al., 1996). Local Nublang cattle (Bos indicus), Brown Swiss crossbreds (Brown Swiss x Nublang), Tibetan Bajo (Bos taurus) and Mithun (Bos frontalis) crossbreds (Mithun x Nublang) are involved in these crosses, making the system more complex.

Cross breeding is practised due to the relatively high milk yield of F1 females (Zom) and good draught capacity of F1 males (Zo) (RNRRC-Jakar, 1999). While Zom are fertile, sterility with Zo create difficulties in formulating a stable breeding program (Win, 1992). Hence, generations of repeated back crossings are necessary to regain male fertility.

The herders frequently exchange their breeding bull with neighbouring farmers to reduce inbreeding in the herd. Herders without their own breeding bull obtain services from the bulls of their neighbouring herdsmen. In exchange for the service, the bull owners usually receive payment in kind. There are well-defined criteria for selecting yak breeding bulls in their herd (Table 2).

In order to improve yak productivity, the government has been procuring and distributing yak bulls from one region to another. Artificial insemination was tried with imported yak semen from China but achieved limited success mainly due to inaccessibility of yak areas (Tshering et.al, 2000).

Table 2. Traditional criteria for selection of yak bull in Bhutan

Production parameters

The normal breeding season for yak in Bhutan 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 % calve annually (Gyamtsho, 1996; Dorji, 2000). Bulls are first put into service when they are 3 or 4 years old. Gyamtsho (1996) recorded a daily milk production of 1.2 kg in July and 0.90 kg in October from yaks in western Bhutan. Highest yield were obtained from animals of 7-10 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 x cattle) in Central Bhutan, respectively.

Harvesting of yak hair takes place in May and June. 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 average wool yield from castrated yak varies from 0.2 to 0.4 kg per year (Dorji, 2000).

Grazing management and pasture ownership

Yaks are often reared along with sheep, cattle and horses. According to Ning (1996) keeping mixed herds (yak, sheep, horses) is an adaptive strategy of the herdsmen against major disease outbreaks, since the different domestic species are generally not susceptible to the same disease. The difference in dietary preferences and foraging pattern of various livestock species also allow for the better utilisation of alpine pastures (Miller, 1998).

The summer pastures are located at high altitudes (4000 to 5000m) while the winter pastures are around the village settlements (2500 to 3000m). Autumn and spring pastures are relatively small and used as transit grazing areas in the intermediate region. Pastures are called by different names and are used during different seasons of the year on the migratory routes. This mirrors elements of modern rotational grazing (Davaa, 1996).

Another strategy adopted in the grazing management is through sub-dividing bigger herds into different categories of animals. Castrates and dry cows are generally driven to the distant pastures, while milking cows and calves are left to graze near campsite pastures.

Herder categories based on the pasture ownerships in two yak-rearing villages in Bhutan (Upper Chokor, Central Bhutan and Soe Yaksa, Western Bhutan) are shown in Table 3. About 50 percent of yak herders in Upper Chokor depend on community pastures. The dependency on community pasture especially occurs in the winter grazing grounds. The same winter grazing areas for yak are utilised by cattle from lower valleys during summer. In many cases, no one is responsible for protecting and conserving the grazing resources in such community pastures. It is grazed on a “first- come first- serve” basis that often leads to overgrazing.

The high proportion of herders (55 percent of respondents) in the private and leased pasture category observed in Soe Yaksa reflect the higher number of yak that belongs to absentee yak owners (Owners residing in lower valleys but their yaks are reared by other people under certain payment).

Table 3. Herder category by pasture ownerships in Soe Yaksa and Upper Chokor

Yak tenant and ownership patterns

Broadly, two types of yak tenurial system can be described in Bhutan, which are either referred as the fixed arrangement (Kemesheme or “no birth no death”) and variable arrangement (Puyiug) (Gyamtsho, 1996; Dorji, 2000). In the fixed arrangement method, herders return certain amount of butter per animal per year to the absentee owners. This is irrespective of sex or reproductive status of the animal. In exchange, the herder’s family obtain grazing rights to the pasture and can keep the remaining animal products. Under variable arrangement, the absentee owners claim yak by-products in terms of a lactating cow per year. The absentee owners include monastic bodies and residents from permanent settlements in the lower valleys.

Yak ownership patterns in two yak-herding villages in Bhutan are summarized in Fig 1. Most of the valley residents are wealthy landlords. Such ownership patterns distribute wealth within a given community and provide resource poor families with access to vital yak products (Pal and Madan, 1996).

Similarly, Dzongs (Forts) and other monastic institutions maintain ownerships of yak due to their need for large amounts of butter for Sudja (traditional butter tea) and other religious offerings.

Figure 1. Yak ownership pattern in Soe Yaksa and Upper Chokor (Source: Dorji, 2000)

Yak herd size and composition

Compositions of yak herds studied in two yak rearing locations in Bhutan are shown in (Table 4). The ratio of milking to dry cows is approximately 1:1. The high proportions of castrates indicate their importance as pack animals. Use of pack yak for high altitude tour and the trekking industry is increasingly gaining momentum. In addition, castrates serve as insurance and can be sold for cash or bartered for food items in times of emergency. A slightly lower proportion of castrated yak in Soe Yaksa might be the result of higher numbers being sold in the market for meat.

Lower proportions of animals aged between 1-4 years can be the result of higher calf mortality before three years of age. Calf mortality occurs mostly due to gid disease (Multiceps multiceps), diarrhoea and over-wintering. The sale of young animals to Sephu (another yak herding village, central Bhutan) by herders in Upper Chokor also reduces the number of animals in this age group within their herd.

Table 4. Average herd sizes and composition in Soe Yaksa and Upper Chokor

Source: Dorji, 2000

Yak feeding and nutrition

To supplement grazing, herders in some areas often make hay out of wheat and oats grown in their limited area. Turnips and radish are cut into small pieces, dried and stored for winter-feed. Native grasses species such as Stipa, Festuca, Poa spp; Pleurossperum ambile, Selinum cortiodes and Heraculem nepalensis are collected during August and September, and made into hay. Hay making includes hanging these grasses from tree branches, piling on rooftops and making temporary sheds. Hay is fed to milking cows and sick animals during winter. Milking cows also receive an assortment of mixes made of flour, oil cake, powdered dry hay leaves and salt. Calves are fed with wheat or maize flour in the form of dough. Gruel, made of minced and boiled yak head and pork fat, is also fed occasionally to milking animals. Dry cows, castrates and other non-producing animals do not receive any feed supplementation.

In general, rates of supplementary feeding for yak are very low and are inadequate to meet the nutritional requirements in winter. Herdsmen express the lack of winter feed as one of their major constraint in improving their yak productivity.

Housing

In most regions, adult yak are not housed. Shelters for calves are constructed in a variety of forms depending on the availability of resources (wood, bamboo, stone). Temporary calf sheds of wooden poles roofed with wooden shingles are common. Enclosures with stonewalls, bushes and wooden shingles are mostly without a roof. Herdsmen often share part of their own shelter with calves. In these sheds, calves are roped to a small peg on one side, while the herder and his family stay next to them after making a small compartment. In winter camps, they also use bamboo mats as an enclosure for calves. The calf shelters are always near the campsite for ease of milking in the morning and as protection from wild predators.

Yak health and veterinary services

Gid disease (Multiceps multiceps) is the most important disease causing high yak mortality rates in some regions of Bhutan (Table 5). About 70% of the gid cases were reported in young animals of 1 to 2 years old (Tenzin, 1979). A gid eradication program consisting of deworming yak calves with albendazloe and fenbendazole, and dog with niclosamide was introduced with some success (Wangdi, 1999).

Poisoning by plants or contaminated water (locally termed as baduk and chuduk) is another major cause of mortality, especially in the central region (Dahl, 2000). Such disease conditions occur at the end of winter to onset of spring season when grazing resources are in short supply. Animals consume plants, such as Senecio species, which they normally avoid when other pastures are available. The Senecio species is found to contain Pyrrolizidine alkaloid, a highly toxic chemical (Winter et al., 1994)

The government provides free veterinary health care. However, remoteness and scattered herds make it difficult for the livestock person to attend to special animal health care needs. In most cases, herders are left to nurse sick animals using their local knowledge or seek help from traditional healers, who perform religious rituals.

Table 5: Causes of mortality in yak during 1997-98.
Results from a survey of 22 herds (1353 animals) in western and 32 herds (1879 animals) in central Bhutan (Dorji, 2000).

Marketing of yak and yak products

The marketing strategies for different yak products vary depending on whether it is for sale by barter or for cash.

In western Bhutan, culled yak are driven to the motor able road. Licensed butchers are hired to slaughter the animal at a payment of Nu 500-600 per animal or given some portions of the meat. In terms of cash, herders earn Nu 13,000-17,000 and 8,000-12,000 from adult males and females, respectively when sold as meat.

In central Bhutan (especially in Bumthang district), farmers are strongly against killing due to religious reasons. Meat vendors from other regions visit their herds and purchase young male yak and backcrosses. Herders report that they receive Nu 4,000-6,000 for each young live animal.

Traditionally, butter and hard cheese are bartered for red rice or other cereals with the downstream communities. In recent years herders are increasingly selling their products for cash. Households with larger quantities often go to distant markets in Phuntsholing (border town near India) and Kalimpong in India to sell their products fetching substantial income.

Conclusion

Yak is an important source of livelihood for high altitudes residents in Bhutan. Although it will remain to play significant role, inadequate winter-feeds, lack of quality breeding bulls and yak health problem are some challenges in the effort to raise yak productivity. Interventions in grassland management and sound breeding programs may contribute substantially in the improvement of sustainable yak production in Bhutan.

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