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Yak in Mongolia by A. Magash[10]


Mongolia, in Central Asia, extends 1.5 million sq km and a distance of 2 400 km from east to west. The lowest altitude of the country is 560 m above the sea level. The major part of the country is hilly or mountainous, reaching altitudes of 1 500 - 4 000 m in the high mountainous areas. The climate is extreme, with temperatures in winter, the longest season, at around -20oC on average, but it can be much colder. Summer temperatures are relatively warm at around 20oC. Typically, there are large temperature fluctuations across the year and even in the course of a day. The pleasantest time of year is the autumn, with light winds and clean healthy air. Blue skies occur throughout the year with an annual total of 280 - 300 days of sunshine.

Large expanses of grasslands cover around 80 percent of the total territory of the country and contain a wealth of different plants. These vast rangelands meet all the requirements of a traditional, nomadic animal production. Management of the grasslands provides an opportunity to produce large quantities of valuable livestock products with minimal inputs from five different kinds of stock. Livestock production in Mongolia is crucial for the life of the people and for the economy of the country and provides the basis for 80 percent of exports.

Figure 11.2.4 A general view in Mongolia (Photo courtesy of Horst and Barbara Geilhausen)

In this context, cattle production has particular importance with a population of 3.1 million cattle, of which 610 100 are yak. Cattle as a whole supply 40 percent of the meat and 80 percent of the milk products. Yak provide a fifth of the meat from "cattle" and a third of the butter.

Yak are an indispensable part of the animal husbandry in the high mountain regions where yak are used both for transport and for their productive capabilities. In recent years, the textile industry has greatly increased its demand for yak fibre. The production of hybrids between yak and other cattle is also of great significance because of their better meat and milk production relative to that of the parental types. Yak in Mongolia share with yak elsewhere the ability to withstand periods of hunger and to make up quickly in the spring the large weight losses sustained over winter.

The yak represents a high degree of adaptation to the ecosystem. No other domestic animal can utilize the vegetation available at 2 000 - 4 000 m in Mongolia with territories marked by steep, treacherous slopes, moor land, bogs and lakes. The morphological and physiological characteristics of the yak (see Chapter 4) endow the animal with an ability to resist cold, to scrape through snow for fodder (which covers the ground for 100 - 150 days of the year) and to graze very short grass - all essential in these unfavourable conditions.

Yak keeping

The natural grasslands of Mongolia can be divided into mountain and woodland pastures, mountainous steppe and desert steppe. The mountainous pastures are on the mountain plateau at 1 800 - 3 500 m above sea level. The actual yak grazing lands are typically above the tree line at 2 000 m in the north rising to 3 000 m in the Mongolian Altai. The dominant plant species range from grasses, e.g. Festuca spp., and Stipa spp, at lower altitudes to sedges, e.g. Kobresia spp., and Carex spp. at the higher altitudes. A precipitation of 300 mm of rain in the Chovsgol-Changai mountains and in the Altai is enough for reasonable hay production (though lower in the Altai) and perhaps quite high yields under exceptional circumstances (Lhagvajav, 2000).

The grasslands are very suitable for the yak by virtue of composition and location. They provide an adequate diet from May to September and in many areas a surplus of feed above requirements for three months. From October to April there is a deficiency in nutrient availability for the animals. There is, therefore, a significant annual imbalance in the provision of fodder between the short growing season and the longer non-growing periods - accentuated by the body heat loss during the winter period. However, the arid climate allows for the natural freeze-drying of the dead herbage and this supply of feed normally lasts until the spring (Barthel, 1971) and makes it possible to over-winter the yak without supplementary feed.

The grazing ecology and climate make many demands on the yak herder and lead to a transhumance form of husbandry. With the changing seasons, the migrations normally follow a rotation starting in the valley bottom (where the animals are in the winter) and proceeding vertically to the high summer pastures only to return, in good bodily condition, to the lower ground via the autumn pastures. These rotational migrations can be accomplished by the herders without great difficulty with whole yak herds and within a traditional allotment of land for grazing. Large herds might be divided into two groups to allow for a division of labour. The first group consists of the milking and breeding females as well as the stock males. The second group is made up of the cull cows, three-year-old heifers (first insemination), young fattening stock, castrates and old yak for fattening. The second group is taken to the high alpine pastures while the first group is kept on the summer pastures at intermediate altitudes.

For over-wintering, the animals are penned in sheds or protected in fenced enclosures. In Mongolia, these enclosures are circular and made of brushwood and reeds. The possibility of enclosures using stone walls or wooden paling is being considered.

Yak population

Numerically, Mongolia comes second to China in the size of its yak population. The yak and hybrid yak (F1) population declined in number over the years from 1940 to 1970 but thereafter increased, as shown in Table 11.2.11.

Table 11.2.11 Number of yak and yak hybrids (F1) in different years (in thousands)

Year

Yak

Hybrids (F1)

1940

725.8

73.8

1950

561.0

52.4

1960

495.0

69.2

1970

452.2

69.1

1980

554.5

50.7

1990

566.9

70.0

2000

610.0

66.3

Yak are found in 13 of the provinces of Mongolia and 9 of these have 90 percent of all the yak. There are a few small herds in districts of the central and southern Gobi province. Seventy percent of the yak herds are concentrated in the Hangai and Hovsgol mountains, 29 percent in the Mongolian Altai and only about 1 percent in the Gobi Altai and Hentii mountains. The yak population works out at just under one yak for every three of the human population in Mongolia.

Mongolian yak

Coat colour varies greatly, but black and brown are the predominant colours with black genetically dominant. Spotted and white animals also occur. Black, or mostly black, animals account for 68.5 percent and brown, or predominantly brown, for 16.9 percent of the total; a further 8.9 percent are mostly grey (Bat-Erdene, 1961). Ninety percent of yak of both sexes are polled.

Two types of yak can be distinguished in Mongolia, according to the area where they are raised - the Hangai and the Altai mountain yak.

Hangai yak

The large-framed Hangai yak stems from the traditional yak-keeping provinces of Arhangai, Ovorhangai, Bayanhongor and Hovosgol were yak are found on mountainous and woodland pastures at elevations of 1 800 - 3 000 m, with a dry and cold climate. The type is large and fecund and is used for transport, meat and milk. Colours vary greatly and up to 90 percent of the animals are polled. They are good at compensatory growth and rapidly regain in the spring and summer the weight losses sustained over the previous winter. A breeding station for the improvement of yak production has been in existence in the Ih Tamir district of Arhangai province since 1983. Figure 11.2.5 shows a polled yak cow suckling her calf.

Altai yak

As the name implies, these yak come from the Mongolian Altai region. The climate is characterized by great temperature fluctuations, inadequate precipitation and dry air. The average temperature over the year is 0oC and reaches a minimum of -30oC. The Altai yak is an alpine type and less good on the plateau. These yak utilize the high mountain grazings, which do not provide a secure supply of feed and are frequently overgrazed. The yak are able to withstand long periods of nutritional deprivation. Colours are predominantly black or black and white. The majority have long, well-developed horns. The body is long and covered with thick hair. In reproductive terms, the Altai yak is similar to the Hangai. The Altai yak is thought to be capable of improvement, particularly in relation to meat production.

Figure 11.2.5 A polled yak cow and her calf in Mongolia (Photo courtesy of Horst and Barbara Geilhausen)

Reproduction

An account of reproductive characteristics of yak is given in Chapter 5, which includes many of the results from studies in Mongolia. What follows are some of the particular statistical parameters of the reproductive cycle in Mongolia.

The essential factor in yak reproduction is its seasonality. As reported by Magash (1990a), the mating season lasts from July to November. The frequency of oestrus is highest among yak females in July and August and has markedly declined by October. The altitude of the grazings and the associated vegetation has a large influence on the breeding season. Post-partum anoestrus lasts on average 90.2 days (but from 30 to 172 days) among free-ranging Mongolian yak. The most important factors influencing the duration of this rest period are the time of calving and the age of the female. There are a number of possibilities for reducing this duration. These include: supplementary feeding of yak cows that calve in March or April; not milking first- and second-calving cows with calves at foot for the first 30 - 45 days after calving (the young cows are not yet fully grown); or separating calves from their dams during the period of lactation and rearing them apart.

Yak females can be mated up to three times in a season under Mongolian conditions. Conception to first mating is on average 70.5 percent but can vary over the months from 63 to 81 percent. On average, 29.3 percent of females return for a second mating and of these nearly two thirds conceive, raising the final pregnancy rate by 19.3 percent. Among those remaining non-pregnant, 10.2 percent still develop signs of oestrus and are mated. This increases the final pregnancy rate by another 4.6 percent, giving an overall 94.4 percent of the yak females becoming pregnant, on average, over the season. The month of mating and the age of the cow affect conception rates (cf. Chapter 5).

It is important for the profitability of yak production that the cows should, as far as possible, calve annually. The calving interval of 215 cows, involved in one of our experiments, averaged 355.6 days (range from 299 to 442 days). The length of gestation and the inter-pregnancy interval strongly influence this parameter. For intensive reproduction, the calving interval should not exceed 365 days. Only about two thirds of the yak cows achieve this optimum annual calving interval.

As shown in Chapter 5 (Table 5.13) from the work of Magash (1990b), young yak bulls mount each cow more often than do the older bulls, and they have a higher fertilization rate (90.7 - 96.3 percent for young bulls, compared to 76.3 - 96.8 percent for the older bulls). The adult bulls, however, serve many more cows, partly because they drive the young bulls away. These studies suggest that yak bulls should not be allowed to run with the herd in an uncontrolled way and that the number of cows per bull should be restricted to 10 - 15.

Calving takes place in Mongolia from March to August, but the main period is in the months of April and May when, on average, 68.2 percent of the pregnant females calve. Also on average, calving occurs in 80.9 percent of the cows that had been mated and did not return to service. Brucella abortus and Clamydia psittaci were isolated by blood tests on cows that aborted and from aborted foetuses.

There has been significant research in Mongolia on the use of technical aids to assist reproduction in yak, such as oestrus synchronization, artificial insemination and pregnancy diagnosis by hormone treatment (Magash, 1991). Results from this work are also referred to in Chapter 5.

Size and meat production

According to Bat-Erdene (1961) the body weights of adult Mongolian yak range from 400 to 500 kg for males and from 270 to 280 kg for females. Body measurements of Mongolian yak are shown in Table 11.2.12.

Table 11.2.12 Body dimensions (mean ± s.e. and range) of Mongolian yak [Source: after Bat-Erdene, 1988]


Height (cm)

Length (cm)

Heart girth (cm)

Bulls (5)

128.2 ± 0.96
(123 - 130)

152.4 ± 0.64
(146 - 162)

204.0 ± 0.83
(198 - 210)

Cows (160)

108.1 ± 0.41
(102 - 118)

120.9 ± 0.48
(114 - 132)

168.8 ± 0.79
(157 - 187)

Castrates* (37)

127.4 ± 096
(115 - 139)

137.3 ± 0.12
(120 - 150)

189.1 ± 0.53
(177 - 219)

* Three to six years old.

Slaughter of yak in Mongolia is seasonal and occurs at the end of the pasture growing season. After each winter, the animals intended for slaughter are collected into groups according to age and sex and taken to the high mountain regions where vegetation is sufficient to provide a good level of nutrition. During this grazing period, live weight gains are between 43 and 88 kg and live weights at slaughter between 190 and 440 kg. Table 11.2.13 shows some weights for animals in above-average condition.

Table 11.2.13 Average live weight and dressing percentage of Mongolian yak in above-average condition [Source: after Bat-Erdene, 1988]

Class of animals

No.

Live weight (kg)

Dressing percentage

Mature male castrates

12

440.0

53.4

Mature females

13

334.7

49.3

1.5-year-old male castrates

22

190.2

51.3

Yak meat has an average composition of 65.1 percent water, 19.5 percent protein, 14.5 percent fat and 0.9 percent ash. The fat content of the yak meat is lower than that from cattle in the same region. The energy content of yak meat is around 2 450 kcal per kg (Bat-Erdene, 1988).

The meat from the yak is red, or deep red, because of a high haemoglobin and myoglobin content. The muscle fibres in yak meat are thicker than those of other cattle, and there is no intermuscular fat. The subcutaneous and internal fat is yellow. In Mongolia, there is thought to be no difference in taste between yak meat and beef from cattle.

Several high-quality products are derived from yak meat. Because of the seasonal slaughter, yak meat is dried in thin slices, called Borts, which can be kept for more than a year and is carried by the herders as they move from one location to another during the grazing season.

Demand for meat is high in Mongolia and yak meat plays an important role. Nyamgerel (1999) estimated the annual production of yak meat in Mongolia at 40 000 tonnes. To achieve high meat output requires the exploitation of the far-distant summer pastures in the alpine and subalpine regions.

Meat production is highest when calves are allowed to suck their dams to the full as this maximizes calf growth. The requirements of milk production from the yak, however, demand that calves are allowed as little as possible of their dams' milk. The common practice in Mongolia is for calves to be weaned quite early and herded separately from their mothers during the milking season - apart from the presence of the calf to initiate milk let-down. The needs of meat and milk production therefore compete, but the emphasis can be varied depending on the relative value of the two products in particular circumstances. The strategy for rearing young stock so as to provide the best compromise for both meat and milk production is, as yet, unresolved.

Meat packing plants exist in the urban areas, but yak herds are normally remote from these. Opportunities for herdsmen to market their own dairy products in central markets are also limited as such markets can be as much as 1 000 km distance. The problems of marketing yak produce so as to provide herders with a better income still need resolution.

Milk production

Yak make an important contribution to the supply of milk and milk products in Mongolia. Lactation length is determined by the date of calving, as the end of milking coincides with the end of the grazing season. Early calving thus allows longer lactations, about 200 - 230 days when calving in May or June. For the sake of their calves, cows are not milked at the beginning or end of lactation, thus reducing the milk off-take to less than the potential. The main milk production period is from June to October. If an estimate of the milk taken by the calf is included, the milk yield of Mongolian yak cows varies between 560 and 740 kg (Table 11.2.14).

Table 11.2.14 Milk yield of yak (mean and range) by month of calving [Source: after Bat-Erdene, 1993]


March
N = 34

April
n = 26

May
n = 12

June
n = 11

Lactation length (days)

283
(232 - 331)

258
(210 - 300)

231
(180 - 285)

206
(171 - 280)

Milk yield (kg)*

737
(635- 1 018)

673
(526 - 754)

607
(488 - 711)

564
(382 - 645)

* Includes an estimate of the milk taken by the calf.

As shown in Chapter 6, yak cows have their highest daily milk yield in July because of the good grazing available then. Regardless of calving date, the milk production by the cow declines from September to November. Yak cows become dry around then.

Also as seen for other yak rearing areas (cf. Figure 6.3), lactation yield among first calvers is only around 77 percent of the yield of cows in their third lactation. Composition of yak milk in Mongolia is similar to that shown in Chapter 6.

In addition to butter and cream, cheese and yoghurt are also made. Traditionally in Mongolia, yak milk is also fermented in a leather pouch and distilled as a "milk wine" (Archi) into a clear alcoholic drink.

Other uses of the yak in Mongolia

Draught

As in other countries of central Asia, yak are sought after as pack animals in Mongolia to carry a variety of different goods over mountain passes. Yak are also used for the wagon transport in moving the herders from one encampment to the other. Yak have to carry wood, food, wool, milk and drinking water for long distances. Yak are also used in forest work to loosen heavy tree trunks. In distant mountainous regions, where other forms of transport are not available, a yak will carry 100 kg without a problem and can haul up to 150 kg on its back. The walking speed of a fully loaded yak is approximately 4 - 5 km per hour and 20 - 30 km can be covered in a day.

Fibre, skin and horn

In Mongolia, yak are shorn in the spring and between 1 310 and 1 750 g of fibre are obtained from adults, though this consists of the three components: coarse outer hair, wool and down and the proportions of these vary with age (see Chapter 6). The uses to which the fibre, hide, horn and dung are put in Mongolia are similar to their uses in China.

Hybridization

Yak have been mated with other cattle in Mongolia since earliest times. However, mating of pure yak cows to bulls of "improved" cattle breeds is not normally practised in Mongolia.

For the first generation of hybrids (F1), a distinction is made between yak cows mated to bulls of domestic cattle (Saran Hainag) and the reciprocal mating of females of domestic cattle with yak bulls (Naran Hainag). In both cases there is a heterosis effect on body size, meat and milk output, capacity for work, vitality and longevity, all of which are increased relative to both the parental types. The sterile, hybrid males are castrated and are larger in mass and height than yak. They have a quiet temperament, which makes them attractive for use as draught oxen.

The milk of the hybrids contains between 5 and 8 percent fat. The F1 with the yak dam withstands lower temperatures better than the F1 with the (Mongolian) cattle dam, but it is less good at withstanding the high summer temperatures. The herder has to consider these maternal effects when deciding on the type of hybrid required.

The hybrid (F1) cows distinguish themselves from both the yak and the domestic cattle in Mongolia by calving annually with similar feeding and management. They also have a higher milk yield (816 kg per lactation on average) and are heavier (on average 80 kg more than yak females and 70 kg more than Mongolian cows).

Backcrossing of the hybrids is of less interest to herders, as the heterosis effect largely disappears. In spite of the less good performance of the backcrosses, they tend to be retained in the herd because calves are not slaughtered in Mongolia, as calf meat is not liked.

In order to investigate whether a more productive backcross could be made, various breeds of cattle have been used experimentally. Ivanova (1956) used Simmental bulls and recorded an improvement in meat output and particularly in milk yield (but with reduced fat percentage) relative to backcrosses using bulls of Mongolian cattle or yak on the F1. Bat-Erdene (1988) tried bulls of the Alatau breed with the F1 cows and noted a small increase in body weight and milk yield relative to the F1 (but it is not recorded whether the differences were statistically significant). Most recently, Dagviihorol (1999) investigated the use of the Hereford breed in various combinations as shown in Table 11.2.15.

As seen from Table 11.2.15, by age 30 months, animals of the backcross to the Hereford were heavier than the other groups and especially the backcross to the yak. It is of interest, however, that the backcrosses appeared to lose more weight over winter (24-month weight minus 18-month weight) than the F1.

Table 11.2.15 Body weight (mean ± s.e. [kg]) of various hybrids [Source: after Dagviihorol, 1999]

Age

F1 × H*
n = 10

(F1 × Y*) × H*
n = 8

F1 × Y*
n = 13

F1*
n = 12

At birth

26.1 ± 0.7

19.8 ± 0.5

21.1 ± 0.3

17.7 ± 0.5

6 months

106.6 ± 5.3

75.4 ± 6.2

81.0 ± 6.2

102.3 ± 7.2

12 months

115.3 ± 3.2

94.6 ± 4.4

94.2 ± 11.0

112.3 ± 5.6

18 months

226.0 ± 8.8

203.4 ± 6.8

167.7 ± 11.9

220.3 ± 7.9

24 months

197.0 ± 6.5

170.4 ± 7.0

150.5 ± 9.1

206.0 ± 3.7

30 months

306.0 ± 8.3

276.5 ± 8.5

228.5 ± 7.7

288.0 ± 4.2

* F1 = Yak cow mated to Mongolian domestic cattle bull; H = Hereford bull; Y = Yak bull.

In practise, hybrids account for between 9 and 13 percent of the yak population. Only pluriparous yak cows are used for mating to cattle in order to avoid problems at parturition

References

Barthel, H. (1971). Land zwischen Taiga und Wuste. Geographische Bausteine, Nene Reihe, H. otha, Leipzig (in German).

Bat-Erdene, T. (1961). Biological peculiarities of Mongolian yak and their hybrids. Synopsis of MS degree thesis, Moscow (in Russian).

Bat-Erdene, T. (1988). Biological and farming peculiarities of yak. Synopsis of doctorial thesis, Moscow (in Russian).

Bat-Erdene, T. (1993). Yield, composition and technological quality of yak milk. Uliastai Hot, Mongolia.

Dagviihorol, V. (2000). Rost i miasnaia produktivnost molodniaka gerefordsirovannogo. Skota. Synopsis of MS degree thesis (in Russian).

Ivanova, V.V. (1956). Gibridi simmentalskogo skota s yakami. In Simmental-sirovanii skot. Moscow (in Russian).

Lhagvajav, T. (2000). Ondor uulin busiin beltseeriin urgamalin torol ba garts. Synopsis of MS degree thesis. Ulaanbaatar (in Mongolian).

Magash, A. (1990a). Statische Massmalen diagnostischer Zuchthygienemerkmale bei Yak Kühen in der Mongolei. Wiss. Zeitschift der Humboldt-Universität zu Berlin R. Agrarwiss, 39: 359-366.

Magash, A. (1990b). Beitrag zur Physiologie und Biotechnologie der Fortpflanzung beim weiblichen Yak. Synopsis of doctorial thesis, Berlin (in German).

Magash, A. (1991). Anwendung biotechnischer Verfahren bei der Reproduction des Yaks. Monatschefte für Veterinärmedicin, 46: 257-258.

Nyangerel, E. (1999). Sarlagiin buteegdehuun uildverlel ba tuunii sah seel. Synopsis of MS degree thesis. Ulaanbaatar (in Mongolian).


[10] A. Magash is Director of the National Yak Research Centre, Agricultural University of Ulaanbaatar, Mongolia.

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