It seems probable that two of our widely used livestock species were domesticated in the Asian tropics: the zebu or humped cattle in India and the water buffalo in the humid marshlands of northeastern India or Southeast Asia. (Both the chicken and some races of pig may also have a tropical Asian origin, but the exact sites of their earliest domestication is unclear.) There are, however, other, much more localized, domesticated bovines in Asia. These are not well studied and deserve greatly increased recognition.
This section highlights:
· Domesticated banteng
· Banteng-cattle hybrids
It is time for the world's scientific community to study the genetics, evolution, and biochemical parameters of the unique animal resources, that are found in Southeast Asia. ALLEN D. TILLMAN Animal Consultant Stillwater, Oklahoma, USA
Though well adapted for survival in their own harsh tropical environments, many domestic livestock breeds are being neglected in the race to achieve temperate zone levels of productivity. CHARLES HICKMAN Department of Dairy Cattle Breeding Ottawa, Canada
Studies should be made of the present and potential role, productivity and efficiency of all domestic animals and birds, large and small, before they are replaced by imported types. Many wild species also could make important contributions to human welfare with proper management. J. K. LOOSLI Department of Animal Science University of Florida .
The conservation of endangered genetic resources represents a genuine and welcome synthesis of the concerns of the agriculturalist and the wildlife enthusiast.
JOHN TINKER British Journalist
The banteng (*Bos javanicus is now the accepted name, but Bos sondaicus, Bibos banteng, and other synonyms have been used in the past. (See Hooijer, 1956.) The name "banteng" has traditionally referred to the wild form of Bos javanicus; the name "Bali cattle" to the domesticated form. This chapter describes the domesticated form, but we retain the name banteng to reinforce the fact that the animal is not a breed of cattle, but a distinct species. Despite a cattle-like appearance, the animals are at least as genetically remote from cattle as is the bison. Both produce sterile males when hybridized with European cattle. Australia. (N.D. Vietmeyer)) is a bovine that resembles a small cow. It is, however, an entirely different species from either European cattle (Bos taurus) or zebus (Bos indicus).
These docile animals thrive under hot, humid conditions and, like the water buffalo, have high resistance to ticks and tick-borne diseases. In parts of Southeast Asia they have proved acceptable for draft power and meat production, and they may have potential for many other regions of the world.
Appearance and Size
Banteng are remarkably uniform in type and have changed little from their wild ancestors (see chapter 6). Bulls stand from 1.3 to 1.5 m high at the shoulders, while cows are about 1.2 m high. They have the general conformation of beef cattle. The skin is tight, the neck short, and the dewlap inconspicuous. The face is narrow and is carried horizontally with the large ears pointing forward. There is no hump, but the male possesses a distinctive crest over the thorax because the spines of the thoracic vertebrae are unusually elongated.
On both sexes a striking white oval patch covers the rump and all four legs have white stockings. Calves and females are usually light brown with a thin black line along the middle of the back. Bulls are brown when young but usually turn near-black at maturity, unless castrated. Thus, in a herd the sexes - black males and brown females - are strikingly apparent.
Male horns grow sideways, upward, and outward from a horny mass on the forehead. Females lack this horny shield and their horns usually grow upward and back, eventually curving down again toward the head. Polled animals have not been reported.
Mature banteng bulls can weigh from 450 to 500 kg. Under exceptional conditions they may reach 550 kg.
Nearly all the world's domesticated banteng are found in Indonesia. They are particularly important on the islands of Bali, Kalimantan, Lombok, Sulawesi, Sumbawa, and Timor. On Bali and Sumbawa, they are virtually uncontaminated by crossbreeding with other cattle and are thought to have been domesticated there in prehistoric times. Since 1913 government officials have enforced a law that prohibits crossbreeding so as to maintain the purity of the breed.
Small numbers of banteng have been introduced to Sumatra, Malaysia, and northern Australia, and there are experimental herds in Texas, USA, and New South Wales, Australia.
DISTRIBUTION OF DOMESTICATED BANTEG
Domesticated banteng account for about 20 percent of Indonesia's total population of "cattle." The banteng population increased from 1.1 million in 1967 to 1.4 million in 1975 and is now estimated to be more than 1.5 million.
Habitat and Environment
Banteng are found mainly in lowland areas on Indonesian islands straddling the equator. The environment is monsoonal with mean annual temperatures ranging from 23° to 31°C. Most of the region receives heavy rainfall throughout the year, but dry spells as long as five months occur at some locations.
Banteng normally have high conception rates. In northern Australia they regularly achieve 80-90 percent conception, as compared with the 50-60 percent of Brahman-Shorthorn crossbred cattle. Similar conception rates have been recorded in Sulawesi.
Little basic information on the banteng's reproductive physiology has been reported. However, it appears that this differs little from that of cattle. Sexual maturity has been observed as early as 13 months and mating at 16 months.* The gestation period is about one week longer than that of cattle and twinning is not common. At birth, males weigh about 16-17 kg and females about 14-15 kg (about half the size of Brahman-Shorthorn calves). Calves are not weaned at any specific time, and dams may continue suckling a calf until the next birth.
Banteng will crossbreed with domestic cattle, producing hybrids with notable vigor and heat tolerance (see chapter 2).
It has been reported that banteng have the ability to drink water with high salinity," and in northern Australia they have even been seen grazing seaweed on coral reefs at low tide.
On high-quality diets, feed-conversion ratios approach those of other bovine species. For example, banteng bulls on high-concentrate diets have shown daily growth rates of 0.7 kg, compared with 0.7 kg in water buffalo, 0.8 kg in zebu cattle, and 0.9 kg in British cattle bulls.:"
As the banteng matures, its weight remains lower than that of cattle of similar age. However, relative to mature liveweight, this disadvantage is only about 8 percent.§
Banteng cannot be handled as roughly as domestic cattle. Cows and calves are timid and easily upset. When stressed they may run into fences and walls, incurring head and spinal injuries. They also easily get into a state of shock. Special squeeze chutes and other special facilities, along with much care in handling the animals, are essential. However, despite their lively temperament banteng are docile if reared, as in Indonesia, with frequent human contact.
These animals are promising beef producers. Gourmets consider banteng cuts among the finest of meats, and Indonesia cannot export enough to satisfy the demand in Hong Kong and Japan alone. The meat's outstanding characteristics are its tenderness and leanness. When the animals are maintained and finished under traditional village management, total fat content of the meat (both on a liveweight and carcass basis) is usually less than 4 percent. Little of the fat is deposited among the meat fibers (marbling); about two-thirds of it is mesenteric and the remainder is subcutaneous, laid down in small globules. The carcasses have a high dressing-out percentage.
Banteng have proved to be useful as draft animals for the farm but are reportedly less suitable than zebus for hauling carts on roads. Traditionally, both male and female animals are worked, but Balinese farmers normally use females for cultivating light soils only. Banteng are trained when they are about 2 years old and are reportedly easier to train than zebus.
Like water buffaloes banteng can utilize low-quality feeds; they are similar in that they can live off forage unpalatable to cattle. It is rare to see banteng in poor condition. Animals of all ages appear to have an ability to maintain weight and body condition even when pasture quality is poor. In this respect, they have been noted to outperform cattle in Australia's Northern Territory. Moreover, due to their lower milk production banteng cows lose less weight and condition during lactation than, for example, Brahman-Shorthorn cows.
In comparison with cattle (European breeds) kept under similar circumstances in Australia, banteng are less infested with external parasites. Their hair is short and their hide tough, which helps them resist ticks. Under field conditions few adult cattle ticks (Boophilus microplus) are observed on the animals, except on malnourished individuals, and the incidence of tick-borne disease is said to be very low. Sarcoptic mange is known to affect the animals, but it has a low incidence as well.
Banteng also appear to tolerate several internal parasites. Liver fluke is probably the most prevalent. Although the animals themselves appear healthy at slaughter, some 80 percent or more of carcasses are found to have partially infected livers. In addition, intestinal worms are often present.
The animals are only slightly affected by Asian trypanosomiasis (Trypanosoma evansi).
The animals are poor milkers; their udders are almost invisible. The lactation varies from 6 to 10 months and milk production is only 0.9-2.8 kg per day.
To keep from reverting to the wild state, banteng may need close contact with humans or regular handling.
An unidentified banteng disease first appeared on Bali in 1964. Known locally as "jembrana," it spread rapidly, causing mortalities from 10 to 60 percent in certain localities. It was originally thought to be rinderpest; it is now believed to be caused by a rickettsia transmitted by cattle ticks. Outbreaks have occurred with decreasing intensity and virulence since the original outbreak. The disease is under intensive investigation.
"Bali ziekte," a disease affecting only banteng, has also been noted. It is characterized by dry eczema, followed by severe necrosis of the skin and exposed mucous membrances.
Because of their high susceptibility to bovine malignant catarrhal fever, banteng must not be brought in contact with sheep and some other animals. This virus is widely disseminated in sheep and several domestic and wild hoofed mammals.
Research and Conservation Needs
There have been few scientific studies of banteng and no coordinated attempt to improve their performance. They deserve more recognition and they merit testing in tropical locations outside their traditional home in Indonesia.
The herds in northern Australia (descendants of animals remaining from an abortive colonization attempt in the 1820s) are in a relatively disease-free zone, and although they are feral, they can potentially provide animals for breeding and use in other nations. Although these few hundred banteng are a valuable resource, they are vulnerable to destruction if adverse environmental conditions arise or exotic diseases break out in Australia. Representatives of the herd should therefore be distributed and viable breeding stock established at several new locations. (Their genes and gene combinations may even prove valuable for the indigenous herds in Indonesia, and banteng research and development would make a valuable topic for cooperative research between Australia and Indonesia.)
Research is particularly needed to identify the reasons for the banteng's apparent ability to maintain weight and body condition on poor-quality grazing.
The problems of bovine malignant catarrhal fever, Bali ziekte, and jembrana need increased attention, particularly directed toward prevention and control.
Banteng and cattle have the same number of chromosomes, and they will interbreed. Few scientific details on the hybrid progeny are available, but on the Indonesian island of Madura they are a "stabilized crossbreed" because they seem to be genetically uniform. This hybridization took place some 1,500 years ago, when Indian invaders brought zebus of the Sinhala, or Ceylonese, type to Madura and crossed them with the banteng.
These maduras reportedly show better growth rate than the pure banteng species itself. They are thrifty, hardy, and able to perform well under extremes of heat and poor nutrition. Though a hybrid in origin, both sexes of the madura are fully fertile.
For more than 15 centuries the winners of the bull races ("kerapan sap)") have been the herd sires of Madurese villages. This long breeding history has led to an animal with the following characteristics:
· Long legs and small feet
· Elongated muscles of the rear legs
· Heavy muscling over the back, loin, and shoulder
· Quick reactions and nervous temperament
· Great heat tolerance
· The ability to perform well as a work animal.
Appearance and Size
Banteng-cattle hybrids vary in appearance, depending on whether European or zebu cattle are used in the cross as well as on the amount of backcrossing.
Maduras (banteng x zebu) are graceful animals. Their bodies are neat, compact, and deep, with well developed forequarters. The cows attain an average weight of about 210 kg and bulls range from 350 to 375 kg at maturity.
Superficially, maduras are like Jersey cattle, except for having a much smaller udder. In most of them the banteng dominates the body structure and coat color. Bulls have a well-developed hump; females have almost none. There is no distinct dewlap. Horns are medium sized and curve upwards and slightly backwards. Ears are medium length and horizontal. Breeders on Madura accept only red-brown animals.
Today, crossbreeds of banteng and zebu are distributed throughout Indonesia. On the other hand, hybrids between banteng and European cattle have been made only in small programs in the United States and Australia. For example, researchers in central Texas are producing a cross that is one-eighth banteng/seven-eighths Charolais. They believe this will result in a beef animal able to grow well in warm, humid conditions. In the Northern Territory of Australia, no problems have been encountered in mating banteng bulls to Brahman-Shorthorn cows. Calves that are one-fourth banteng/three-fourths Brahman-Shorthorn have since been produced.
Virtually all of the 575,000 "cattle" on the Indonesian island of Madura are hybrid animals resulting from crossing indigenous domesticated banteng with zebus. More than 200 head of banteng/Charolais hybrids are found near Easterly, Texas, and a score or so banteng/ Brahman-Shorthorn hybrids are on a research station near Darwin, Australia.
Habitat and Environment
The environment in Madura, where most of these hybrids occur, is monsoonal, with mean average temperatures as high as 31°C in the hot season, and dry spells as long as 5 months. It seems likely that judicious selection of the cattle breed could result in hybrids suitable for many other environments.
As noted, the animals on Madura are bred to be raced. They are probably the fastest running bovines. From a standing start, a yoked pair pulling a sled can reach 50 kph by the end of the 130-meter course. An unencumbered individual can approach the speed of a horse (about 68 kph).
When compared with other bovine genotypes in Indonesia, the performance of these hybrids is more closely related to the banteng than the zebu ancestry."
In the cross between banteng and European cattle all F1 bulls are sterile; their sperm development ceases at the secondary spermatocyte stage. Infertility also exists in most one-fourth banteng (although some sperm are present) and in all three-fourths banteng bulls. The fertility of the F1 cows, on the other hand, is high - 90 percent as compared with 70 percent for Brahman-Shorthorn cows.
The hybrids have a lively temperament. However, when they are reared with other domestic cattle or handled on a regular basis, they are almost as docile as cattle. For instance, they remain calm even in Madura's extremely crowded towns. Nevertheless, personal contact probably must be maintained to keep them accustomed to human management.
The cows are very protective of their calves.
Several reports from the livestock service of the former Dutch colonial government, as well as several books on the East Indies, state that meat from the madura is the tenderest of any known breed. In addition, the hides are pliable and superior to those of cattle and are used in the highest quality leather goods. They command a price about 20 percent higher than zebu hides.
The breed is reportedly one of the best draft animals for its size in the world.
Maduras have several desirable traits, including those outlined below:
· Feed efficiency. With grain rations, yearling bulls can gain 1 kg on less than 7 kg of ration.
· Thriftiness. The breed can maintain its body condition on low quality forages.
· Heat tolerance. The madura has a high rate of cutaneous evaporation and is therefore well adapted to the tropical monsoonal climate. Teams of madura can plow or cultivate land for more than 6 hours, even at high temperatures.
· Carcass quality. The madura fattens readily on a high-quality diet and produces carcasses with high dressing percentages, a large rib-eye area, and high yields of lean meat.
· External fat thickness. A well-finished madura normally has only a slight covering of fat over ribs and lower round. Maximum thickness (over the top round) is less than 1.5 cm.
· Intelligence. These animals are responsive and easily trained. The famous dancing cattle of Madura, for instance, are actually these banteng-cattle hybrids.
· Parasite resistance. Despite often high levels of fluke infections, the animals continue to work, reproduce, and maintain body condition.
Maduras have been bred for one thing - speed. Some of their genetic limitations are:
· Low birth weight. The calves begin small, weighing 12-14 kg at birth, and they continue to be slow weight gainers. [Feeding trials with yearling bulls have shown daily gains of over 600 g for 180 days.
· Poor lactation. Milk production is normally less than 1.5 lifers per day and lactation ends after about 4 months. The cows often fail to produce milk. Much of this is probably caused by poor nutrition.
Research and Conservation Needs
One of the important features of the madura is that its genetic variation has been largely removed during 1,500 years of continuous breeding; with study much valuable information could be obtained that is beneficial to all bovine breeds.
The following topics need further study:
· Fertility levels
· Crossbreeding to test the effect of using a wider range of cattle breeds*
· Assessment of the hybrid's advantages over the pure banteng
· Performance under a wide range of environments.
The mithan (Bos frontalis) is believed to be a domesticated form of gaur (see chapter 6).t (However, it resembles the banteng and some authors have proposed that it is a gaur-cattle cross, others a gaur-banteng cross.) The mithan is a domestic animal indigenous to parts of India, Burma, and Bangladesh. Because of large size and the high butterfat content of its milk it is widely used to crossbreed with cattle in Bhutan. It deserves greater recognition both in Asia and elsewhere.
Appearance and Size
The mithan is a handsome animal. Bulls may occasionally exceed 1.7 m at the shoulder and weigh 1,000 kg, but the average bull is about 1.5 m tall and weighs 540 kg. Cows are shorter and weigh less.
The animal has a dorsal ridge on the crest of the shoulders, a small but pronounced dewlap, and a generally flat forehead. Mithan horns are often of unusual girth; they are straight or gently curving, and many have an enormous base that practically covers the top of the skull.
Most calves and females are brown, but adult males are generally black with white stockings on all four legs. Some, however, are light brown, white, or piebald.
In the hill ranges of Assam, where gaur are still plentiful and interbreeding between mithan and gaur frequently occurs, the mithans are massive and gaurlike. But in the Chin Hills, where gaur are scarce, the mithans have lost their bulky proportions, probably by interbreeding with cattle. With them, the high dorsal ridge on the shoulder (which lends so much to the imposing stature of the gaur) has disappeared, the horns are cowlike, and the varied coloring of the domestic cow begins to appear.
Mithan are kept in a domesticated condition by the hill tribes of northeastern India (Mishmis, Mizo, Nagas), the Chittagong Hill tracts, and some Burmese hill ranges (Arakan and Chin Hills). It is the main domestic animal of the Nagas of Nagaland.
In India feral herds totalling some 50,000 head roam the jungles of Arunachal Pradesh. Recently the Royal Government of Bhutan has established two herds by purchasing animals from Arunachal Pradesh. Bhutanese farmers have some 60,000 head of animals that are hybrids of mithan and the local breed of cattle.
The government of Bhutan is breeding mithans on government farms and distributing males to private breeders to improve the genetic base.
Habitat and Environment
The mithan is a grazing animal, but in some areas herds are allowed to browse freely in the woods; some return to the villages for protection at night, while others remain largely in the forests. The villagers keep the forest mithans nearby by providing salt, for which the animals have an insatiable craving.
Feral mithan live in the same habitat as gaurs and are said to move equally skillfully in mountainous terrain. Usually they are found at elevations from 600 to 3,000 m. However, in the Chittagong Hill tracts and the Mishmi country they descend to 300 m and lower, while in Bhutan they have been reported grazing in summer at altitudes as high as 3,300 m, for example around Thimphu.
Mithan distribution. (after Simoons and Simoons, 1968)
Mithans are fully fertile amongst themselves. Also, they interbreed freely with the gaur, banteng, yak, and cattle of both the taurus and zebu types. Naga owners encourage the interbreeding with gaur, regarding it as an improvement of the race. (They arrange this by placing salt licks in the forest. After gaur bulls have formed a habit of coming to the licks, mithan cows are left there and in due course mating takes place.)
The crosses between mithan and zebu are also encouraged in certain districts. Unlike most crosses between bovine species, those between mithan and cattle result in fertile male and female offspring (although some owners indicate that the F1 male is not a reliable breeder).
This is an unusually gentle animal with a quiet disposition, as revealed in the Chin tribe's expression "gentle as a mithan." Normally even a stranger is safe to approach one; if he gives it a bit of salt, it will usually follow him about. Thus, mithans are easily managed in a regular cattlerearing operation.
Many mithans are not domesticated in the strict sense. Their herds live in a semi-tame state near jungle villages and come to settlements only in the evening to lick salt.
In some regions of northern India, mithans are used for field work and as draft animals. They are also important as a meat supply. The Bhutanese government is establishing a national dairy-mithan breeding program, which could result in a valuable dairy animal.
To many tribes of northeast India and Burma, mithans serve mainly as sacrificial animals. The Nagas use them as a kind of "currency" to pay for goods, to buy brides, and to pay penalties.
Hybrids resulting from backcrossing mithan with common cattle are also used as work animals. For at least a century, Bhutanese livestock breeders, particularly those in the eastern section, have mated mithan bulls to siri cows (Bos taurus) from India. This produces very profitable hybrid offspring that have high milk production. The milk is rich in total solids and produces exceptional yields of cheese and butter.* The male of the cross (called "jatsha") is a powerful draft animal, and the female ("jatshum") is a prized milk cow. To this day, extensive crossing continues.
The mithan is potentially an animal that can be used in difficult terrain where most domestic cattle breeds do not perform well. Mithans are superior when it comes to feeding on steep slopes and cliffs and for grazing native grass and the leaves of local fodder trees. They are also adapted to tropical and subtropical environments. And they are able to maintain themselves in small herds (6-10 head) in dense jungle.*
The mithan could prove valuable in other parts of the world, and it could be important particularly for the genetic improvement of cattle in the tropics.
If they are disturbed, mature mithans can be temperamental. They can be difficult to hold with normal fences or chutes, because of their size. When given injections or otherwise subjected to pain, they are liable to bolt to the jungle and not return.
Research and Conservation Needs
The productivity of these animals needs to be better characterized and defined. Attention should be given to their grazing efficiency as compared with that of cattle.
The two farms the Bhutan government has established for breeding mithans provide an opportunity to gather genetic information on the species and to have experimental matings take place to establish the most suitable animal for various conditions.
The genetic relationship of mithan to gayal, gaur, and cattle needs to be clarified. Although it is believed that the mithan and gayal are the same animal, one of this report's reviewers points out that the mithan of Bhutan are strikingly different in color, body shape, and horn structure from gayals seen in zoos in Europe and India. Although the mithan is now considered a domesticated gaur, many in the past have claimed it as a gaur-cattle hybrid. Physiological research could remove lingering doubts.
The yak (Bos grunniens), is a grazing animal that is accustomed to traveling great distances in a harsh environment. Nothing is known about when it was first domesticated, but there has probably been a close association between man and yaks ever since the first humans migrated into the high mountains of Asia.
Appearance and Size
Domesticated yaks are about the size of ordinary cattle and rarely exceed heights of 1.3 m at the shoulder. Their liveweight is generally 250-550 kg for the males and 180-350 kg for the females. They differ little from wild yaks except that they are smaller, have shorter and thinner horns, and may be rusty brown, black, silver grey, or piebald instead of black. Often they have whitish spots on their faces.
The yak's hair is long, especially on the flanks, where it forms a shaggy fringe that often reaches the ground. This, together with an underlying layer of thick, fine wool, protects the animal from the bitter cold of its native region. The yak has an enormous tail with a brush of long hair coming from its root, which is rare in bovines.
Long extensions of the thoracic vertebrae give the yak shoulders that look like a hump, but this is different from the boneless hump in zebus. The body is long, short-legged, and compact, with particularly large forequarters because, like the bison, the yak has 14 or 15 pairs of ribs instead of the 13 of domestic cattle.
The horns spread outward and upward, and the head is held low, like that of the bison. While no hornless domestic yaks have been reported in Nepal, more than 90 percent of those found in Mongolia lack horns.
Most yaks are found especially in the mountains and plateaus of Tibet and western China, however they occur from northern Afghanistan, Pakistan, India, and Bhutan to Mongolia, and the Soviet Union.
There are more than one million domestic yaks in the world.
Habitat and Environment
In the Himalayas the domestic yak is almost always found above 2,000 m elevation. Males are sometimes brought as low as 1,700 m for mating with cattle (see chapter 6), but they do not fare well at such altitudes. In Mongolia and Buryatiya (U.S.S.R.), however, they are found as low as 1,500 m elevation.
Yak distribution. (after J. Bonnemaire, 1976)
The wild yak lives in desolate mountain areas at altitudes of 4,000-6,000 m. Its habitat is the alpine tundra and the cold desert regions of the northern part of the Tibetan plateau. These barren mountain regions are remote and at higher elevations than the zones of human habitation.
Yaks look ungainly, partly because they are covered with long hair, but they are agile climbers and can maneuver narrow mountain paths. Their long hair is one adaptation to the cold climate. Other adaptations are the small, compact scrotum of the male and udder of the female, the small teats (only 2-3 cm long) and covering of hair over the udder, and the covering of short hair over the muzzle, except just around the nostrils.
In early summer yaks graze the lush grass in valley bottoms, but for much of the year they live on dry, coarse mountain grass and for long periods obtain water by eating snow.
The gestation length is 258 days - slightly shorter than that of cattle.
Domestic yaks are docile and easily managed.
Yaks are especially useful as riding and pack animals; they can manage loads of more than 150 kg. At altitudes up to 6,000 m they may carry a pack or a person at a steady pace for days and still remain in good condition. In some regions they are the only feasible pack animal. Yak bulls (generally castrated) are also used for plowing and for threshing grain.
Occasionally the yak is slaughtered for meat. The meat is particularly important in parts of the USSR and in Mongolia, where in the cold, high-altitude environments it reportedly costs only half as much to produce as beef.
In most areas milk production is an essential aspect of yak husbandry. Yields vary considerably according to management and nutrition, but they average about 600 kg and can be more than 1,000 kg per lactation. Yak milk is golden colored. It is much richer than cow's milk; a typical analysis is: total dry matter, 17.35 percent; fat, 6.5 percent; protein, 5.3 percent; and sugars, 4.6 percent. The fat globules are much larger than those in cow's milk. People of Tibetan stock use yak butter as a food staple and as a lighting fuel.
Yak hide, though apparently not as good as that of cattle, is used for many purposes. It makes outstanding saddles. Yak hair is used for making ropes, saddle blankets (purportedly the best in the world), grainstorage bags, and tents. The fine wool that occurs beneath the long hair is used for making felt. The annual yield of adult females and males is about 750 g and 1,600 g of hair and about 350 g and 600 g of wool, respectively.
Because yaks are often found above the timberline their dung is an important fuel in many areas.
Yaks can live and work hard in a cold climate. They are the only bovines to thrive at high altitudes. In cold, high areas they can work and produce meat and milk more efficiently and cheaply than cattle.
Yaks are not well able to eliminate surplus heat because their heavy coat reduces their ability to sweat. In warm climates their respiration rate and body temperature increase and they become exhausted and susceptible to infections. At low altitudes in Nepal yaks die of a variety of diseases. Apparently not even yak-cattle hybrid animals (see next chapter) can successfully live below 700 m in that part of the world. This is probably due to overheating, since during the first half of this century yaks grew successfully in trials at low altitudes in Alaska and northern Canada.
Research and Conservation Needs
· Yak improvement programs are much needed. It seems probable that the genetic potential of the species is far from realized because Buddhist beliefs oppose the deliberate killing of stock. Techniques for deep freezing yak semen have been successfully developed at Regents Park Zoo, London and should prove invaluable for improving the breed.
· As a result of uncontrolled hunting the wild yak is endangered and is now restricted to remote barrens on upland plateaus and highlands in northern Tibet and Chinghai, inhospitable even to domestic yaks. The numbers of wild yak are unknown. They require total protection throughout their range and the establishment of adequately protected reserves with good pasture. To preserve their genetic purity, it is important to isolate wild yaks from domestic yaks and thus keep them pure.
· A primary need is to catalog the numbers and locations of purebred yaks. Today we have little idea of the total breeding population. Gathering such information is difficult, owing to the geographical isolation of the communities involved.
· It is also important to catalog the movement of yaks between different areas to see if enough genetic exchange occurs to prevent inbreeding of the population. Exchanges between local pastoralists were much more frequent in the past (for example, between Tibet and Nepal), but this is now more difficult because of border restrictions and because many yak herders that used to move herds long distances have become sedentary farmers.
· Breeding strategies, herd management, product processing, and herd hygiene in Nepal, Bhutan, Sikkim, northern India, and northern Pakistan, Tibet, Mongolia, and the Soviet Union all differ greatly. It is important to get an overall perspective so that the strengths of the different systems can be judged and the weaknesses reduced.
· There are clearly different domestic yak "breeds" in terms of their appearance, and these need to be identified and compared systematically.
Yaks and cattle have the same diploid number of chromosomes (60). And in the regions where yaks are found, they are often interbred with cattle, either the humpless cattle (Bos taurus) of Tibet and Mongolia or the zebu (Bos indicus) of South Asia. As with mules, the hybrid offspring of cattle and yak surpass their parents in strength and vigor. Yakows* grow faster than their parents, and they suffer less from high temperatures than yaks. The hybrid cow reaches sexual maturity earlier and yields larger quantities of milk than the yak cow. The males, however, are sterile.
Appearance and Size
The yakow's appearance varies with the type of cattle used in the cross. But because of the phenomenon of hybrid vigor (heterosis), the hybrids are considerably bigger than the mean size of their parents. (For instance, in one test the liveweight was approximately 18 percent higher than the average weight of the parents.) The hybrids also excel in hardiness, working ability, growth rate, and milk production.
Nevertheless, their appearance and performance is closer to that of the mother than of the father. Because of this, the yakows can be "custom designed" for various altitude zones. For example, the farmer at lower altitudes may produce cattle-like yakows by breeding yak bulls to domestic cows, while farmers at higher altitudes would use the reverse cross.
Yakows have shorter hair and a much less downy undercoat than purebred yaks. They are similar in color to yaks. (In Nepal, black is most frequent, but brown shades and even white may occur.)
Yakows are found in parts of northeastern Afghanistan, northern Pakistan, northeast and northwest India, Nepal, Sikkim, Bhutan, Tibet, western China, Mongolia, and southeastern Russia. They are found notably in the Himalayan region of Nepal, where they are bred by people of Tibetan culture and language. Sherpas, for instance, supply hybrid cows and heifers to dairy farmers throughout northeastern Nepal. Hybrids are also much bred in Ladakh (northern Pakistan) and Mongolia.
Whereas farmers in Nepal tend to use zebus to cross with yak, the inhabitants of the Tibetan plateau generally use Bos taurus cattle. People in some areas favor mating yak bulls to cows, while those in other areas prefer the reverse. But even within one village there can be a degree of specialization by different families, depending on wealth and the location of traditional grazing grounds. Generally, however, the crosses between domestic cattle bulls and yak cows are the predominant ones.
The number of yak-cattle hybrids in the world is unknown.
Habitat and Environment
Like the yak, the hybrid can live in cold, barren, upland terrain, but it has the advantage of being able to adapt to lower altitudes. In winter, caravans of hybrids may come down as low as 1,600 m in some parts of Nepal, and hybrid herds (especially those resulting from crossing yak bulls with zebu cows) can spend several weeks grazing at altitudes as low as about 1,700 m in winter.
Female hybrids are fertile when mated with either parent stock. Male hybrids, however, are sterile. Although they have fully developed secondary sexual characters and show libido, their testes do not produce spermatozoa because the seminiferous tubules are poorly developed and the spermatogonia and their nuclei are degenerate.
A few normal or motile spermatozoa may be found in the semen of backcrosses of the F1 hybrids to either parent, but as a rule the spermatozoa are normal and dead.* Backcrossing is reportedly not common, however, as the progeny do not retain hybrid vigor.
Tibetan farmers prefer the hybrids for plowing because of their docile temperament. The yak is said to be more stubborn.
The hybrids are valued as beasts of burden and draft, and are often preferred over yaks. Male hybrids are generally castrated at about 3 years of age so as to increase their strength and size.
Where pastures occur over areas of greatly varying altitude, the use of hybrid livestock is likely to be more efficient, in biological terms, than the use of yaks or cattle. By judiciously selecting cattle, yaks, or hybrids all altitudes from sea level to above 5,000 m can be utilized with best efficiency.
The hybrid's milk is intermediate in composition between that of its parents. However, hybrids yield up to 7 kg of milk per day against the yak's 3 kg. (It seems that the hybrid derived from cattle bull and female yak produces considerably more milk, with a higher fat content than that derived from yak bull x cattle female.) Also the female hybrids produce larger quantities of milk than Nepalese zebu cows on the same hill pastures. They also produce a calf each year, while under normal herd management yaks tend to produce a calf every 2 years.
Hybrids do not tolerate extremes of altitude or cold as well as purebred yaks.
The normal gestation period for yaks is about 1 month shorter than that of cattle, and the gestation period for a hybrid is intermediate between that of the parents - hence there may be problems at calving when a female yak is sired by a bull from a large cattle breed.
Research and Conservation Needs
Research is needed to identify differences in altitude tolerance between various hybrids. This should include measurements of hemoglobin count, respiration rate, and pulse rates at different altitudes.
Studies are also needed on all production characteristics, particularly on the meat and milk production potentials.
Cataloging the breeding strategies of different areas where hybrids occur would be useful, along with a historical perspective.
Research to determine the most productive hybrids by crossing different yak and cattle "breeds" in areas with different environmental conditions could be extremely useful.