PHYSICAL AND CULTURAL HISTORY

The yak is considered one of the world’s most remarkable domestic animals.  Able to survive in extremely harsh conditions it thrives at high altitudes and has been credited with allowing humans to colonize areas in which they would have otherwise perished.  Yaks provide food, transportation, fuel and fiber to these herding societies. 

Today’s domestic yak are descended from wild yak which were thought to have been caught and tamed by the ancient Qiang people of Tibet about 10,000 years ago.   Currently upwards of 90% of the world’s yak population of roughly 12 million can be found in China.

 Almost all parts of yak body have cultural or religious value.  Yak horns and skulls are of religious importance and are often carved with mantras and placed in prominent places.  On the Tibetan Plateau nomadic people may hang a yak corpse above the doors of monasteries in order to drive out evil spirits.  Yaks are also indicators of wealth and are often used as a dowry when a Tibetan girl marries a herder.

PHYSICAL TRAITS

Yaks are similar in appearance to other bovine.  Yaks cope with the cold by conserving heat.   They have a compact conformation, thick fleece of coarse outer hair and an undercoat of soft down which increases as winter approaches.  Calves have a fleece composed only of down.  They accumulate a layer of subcutaneous fat before winter that both helps conserve heat and provide fat storage for future use.

Yaks have adapted to living at high altitude where oxygen is low by having a large chest cavity, large lungs and a large heart relative to their body size.  They also have a large rumen volume and are adapted to grazing a wide variety of plant life for long periods of time.  Yak can graze both long grass and short herbage by utilizing their tongues, incisor teeth and lips.  They  walk freely in precipitous places at high altitude which cannot be reached by horse or sheep and also cope very well with marshy ground.  Yak will spread their legs and use the underside of their bodies to prevent themselves from sinking in marshland and use a swimming motion to escape rather than panic and thrash around as other animals might.    This has given them the local nickname “boats of the plateau”.   

Wolves are the yak’s only natural predator.    To enable them to detect wolves from a distance, yaks have developed excellent hearing and eyesight.   They can swim across rapids and can easily trek through snow.   Their hooves are narrow with a sharp hoof tip, hard edges and a close hoof fork which allows them to control their momentum when going downhill.

REPRODUCTION

Yak come into heat every 19-21 days from approximately July thru December and it usually lasts about 1 day.   Once pregnant the gestation period of a female yak averages 258 days.  This short gestation period produces smaller calves and leads to a less stressful and quicker birth.   Twin births are rare accounting for only .5 percent of live births.  Milk production in yak is very low relative to other bovine.

Live an average of 20 years.