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SAIFEEDA SULTANA BEGUM & MOKHTAR HUSSAIN

It possesses well-developed lungs in a browse on herbs and shrubs depending on large thoracic cavity, and its blood has a availability. Yaks love to stand or wallow in YNONYMOUS with life in the high altitudes, high content of red cells due to persistence running water and sometimes make strange Sthese are the ultimate beasts of burden. of foetal hemoglobin throughout its life. grunting sounds and eat grass and shrubs And if they happen to block your way on the All these features impart the animal with that are available, but when this becomes high hills, there is precious little you can do better oxygen-carrying capacity and a extremely scarce, these animals are than just wait patiently. well-developed body for movement in the capable of surviving on broken and wilted The sturdy yak (Bos grunneins) is a bovid high altitudes. Further adaptation to cold blades of last year’s grass, which have been that dwells in high altitudes in and around the includes the presence of a thick layer of blown by the wind and embedded in the Himalayas (2500-5500 m) at temperatures subcutaneous fat and an almost complete soil, by ploughing the ice with their hooves. rarely climbing above zero, usually above lack of functional sweat glands. Yaks have Yak milk is rich in fat, but its average the tree line. It belongs to the family Bovidae some of the strongest odors of any domestic milk production is less. The milk is slightly and is known as the Tibetan dong, brong animals! acidic and its composition varies from area dong (wild) and pegu (domesticated) in The wild yaks are one of the highest to area and also on the quality and quantity local languages. dwelling animals in the world, and the yak of feed provided. Apart from fluid milk, The animal has a massively built species as a whole have the migratory habit several milk products like ghee (butter) and structure, and is the most important livestock of moving from high altitudes to low during churpi or chura (local wet cheese) are also for the highlands of central Asian countries winter and vice-versa in summer. These prepared from yak milk by the local people. situated between 700 and 1150 of its animals usually live in small herds (except Besides using ghee and churpi as a main longitudes and between 270 and 550 of during spring) and may have a lifespan of constituent of their diet, the locals use the north latitudes. The animal’s body is covered about twenty-five years. ghee for preparation of salted tea and for with shaggy fringes of coarse hair and the They are reared under a free-range lightening lamps in monastery. dewlap is absent. Unlike other oxen, the yak system and no housing is provided for Yak meat is rich in fat content and is has 14 pairs of ribs, while other oxen have them even in the worst parts of the winter. highly relished. Two types of wool can be 13 pairs. They graze on the frost bitten grasses and procured from the yak: i) coarse hair, and ii) 47 SCIENCE REPORTER, JANUARY 2013 Short Feature artificial insemination with frozen semen is Yak milk is rich in fat, but its normal, as the bulls of these breeds have average milk production is not, in the past, survived for long in the mountainous regions. less. It is slightly acidic and its Hybridizing of yak with cattle is composition varies from area advocated in several countries as a means to area of increasing milk and meat output from the mountainous regions. Only the first by 30.77% i.e. from 13,000 to 9000. Of generation of hybrids (F1) is favoured, as the 65,000 yaks, Arunachal Pradesh alone later generations of backcrosses have accounted for 13,000 as per the 2003 Bulgarian Yak poorer performance (and as hybrid males census. This decrease in the population of are sterile). However, the F1 females can the species in Arunachal as well as in some usefully be mated to males specially other parts of the world is alarming. chosen for “meat” production. There are Established in 1989, National Research both economic and biological limits on the Council on Yak, Dirrang, Arunachal Pradesh, extent to which interspecies hybridization is the only institution of its kind in India, can be carried out. The biological limit is set which conducts exclusive research on the by the low reproductive rate of yak and by overall improvement and conservation of survival rates. yak for higher productivity and profitability In Nepal, yak/cow hybrids are bred to improve the socio-economic conditions using yak bulls on domestic cows or, less of the Yak-rearing community. As reported often, domestic bulls on yak cows, and in The Hindu (24th December 2011), Dr. K.K. Baruah, Director, NRCY, said that the Black Yak the meat is considered superior to beef. A Dzomo or fertile female crossed with population of yak is rapidly declining in either a domestic bull or yak bull results in India for a variety of reasons ranging from an Ortoom (three-quarter-bred) and an reproductive disorders, improper nutrition Ortoom crossed with a domestic bull or and degradation of natural grasslands. yak bull results in a Usanguzee (one eighth Reproductive disorders like delayed puberty, bred). As a result, many supposedly pure long post partum anoestrous and repeated yak and pure cattle probably carry a dash breeding are major hindrances for increasing of each other’s genetic material. The Zopkio yak population. He said that through (also from the Nepal region) is a sterile first extensive studies the NRCY has formulated generation male crossbreed of a yak and a special feed for yaks that contains all vital nutrients. The ‘Complete Feed Block’ with White Yak a cow usually used as a beast of burden. The length of an oestrous cycle in the area-specific mineral mixture developed yak ranges from 18 to 21 days, and the by the centre is especially useful during the fine (undercoat) wool. The fine wool is used duration of oestrus varies from 12 to 18 winter when fodder is scanty. for weaving dress materials and is stronger hours. Puberty occurs at 24 to 30 months During the last two decades, the than sheep wool with good tenacity. The of age and the first calving occurs at 4 NRCY has undertaken several research coarse hair is used for making blankets, years. The gestation period is 255 days and programmes to overcome the reproductive carpets, ropes, tents, bags and caps etc. unlike in sheep, the physiology of breeding as well as other health-related problems The skin is used for preparation of leather is determined more by nutritional status and in yaks. Yak semen collection and goods like bags, jackets, belts, ropes, shoes feeding levels than photoperiodicity. freezing and artificial insemination are etc. after tanning by traditional methods. In India there are mainly five types of now routine practices at this institute and The tail of the animal is used commercially yak, which are categorized on the basis of artificial insemination as well as treatment in Buddhist culture and also as a fly-whisk. phenotypic characters: i) Common yak, ii) methodologies have been disseminated Pelts of calves are used traditionally to make Bisonian, iii) Bareback, iv) Hairy forehead to the field level through various extension children’s coats, and the faeces are used as and v) White yak. The former three types camps. manure as well as fuel by the people. are more common, whereas the latter two Yak hybrids have also now been types are insignificant in number. The yak is produced (one horned or Dzo and the other treated as wealth and a sacred animal and Dr (Ms). Safeeda Sultana Begum is a PhD hornless or Zhom) by interbreeding with worshipped as God by the people in the hills Scholar (Veterinary Epidemiology & Preventive domestic cattle. But it is interesting to note of Monpas in Arunachal Pradesh. Medicine) at the College of Veterinary that interbreeding of yak with buffalo is not An increase in India’s overall yak Science, Assam Agricultural University (AAU), possible. All the male offsprings of all breeds population (10.20%) was reported in the Khanapara, Guwahati-781022, Assam; that are produced by crossing with yaks are 17th livestock census of the Ministry of Email: [email protected] sterile (called Dzo), and the females are Agriculture. The census also reported that Dr Mokhtar Hussain is in MVSc (Animal fertile (called Dzomo or Zhom). Bulls of local Arunachal Pradesh constituted 14.2% of Reproduction, Gynaecology & Obstetrics), breeds of cattle are used for natural service. the yak population of the country. But when at the College of Veterinary Science, AAU, But for hybridizing of yak with relatively high- compared with the sixteenth census, the yak Khanapara, Guwahati-781022, Assam; yielding “exotic” breeds of cattle, the use of population in the state showed a decline Email: [email protected] SCIENCE REPORTER, JANUARY 2013 48