By Hitesh Pant
Originating in the “roof of the world,” the yak is an important animal, providing a host of nutritional and practical benefits to the people of the Tibetan plateau. It can withstand freezing temperatures and sparse vegetation, and is a major source of meat, milk, fiber, and hide. Although the population of Bos mustus sharply declined due to the arrival of new farmers who poached their meat for commercial gains, the domesticated yak (Bos grunniens) gradually migrated into Nepal, Bhutan, and Mongolia, becoming an essential driver of economic development in these regions.
Similar in appearance to the North American bison, the yak is characterized by its thick black coat and large dewclaws, both of which are adaptations to the harsh climate of the Himalayas. Perhaps the most striking feature is its round and thick horns, whose open arch gives this bovine an intimidating appearance. The yak reaches sexual maturity by age six, and has an average life span of 23 years.
Seasonal variation of environmental conditions is the biggest limiting factor in yak growth and the main determinant of individual productivity; approximately 25 percent of the body weight gained during the summer is lost over winter and spring, an amount that is difficult to regenerate given the limited availability of year-round grasses. Despite the limitations on growth that they face—low annual rainfall, mean temperatures below 5°C, and seasonal shifts in vegetation—yaks have continued to supplement subsistence farming in the Himalayas and have become an important ecosystem service for the area.
Yak milk is very dense and thick, and its high fat (5.5-7 percent) and protein (4-5.5 percent) content makes it a valuable source of amino acids. Meat, which is primarily derived from castrated or ‘surplus’ males, is an important source of income to the herding families. The thick fur that coats the yak has been extensively used for insulating tin roofs and the growing demand for their fur has resulted in an increase in crossbreeding to bear individuals with the thickest fiber. Although the quality of their hide is lower in comparison to cattle, yak hide is a major source of rawhide in China and is used to pack raw butter, wrap boxes for storage, and felt boots and soles. Farmers use yak feces to make pens and enclosures for winter stocks, and they also paint it on fences to fill cracks.
Known locally as the ‘boat of the plateau,’ the yak serves as an important draft animal and is used for plowing and threshing grain. Likewise, its high endurance makes it ideal to carry loads across large distances without having the need to continually replenish it with water.
Unfortunately, the introduction of motor vehicles in rural Tibet coincided with an increase in commercial poaching, and coupled with the interbreeding of domestic and wild animals, looks to have gradually resigned yaks to the same fate as the bison. Wild yaks are now regionally extinct in Nepal and India, and the demand for domestic pastures has sharply reduced their food source, and with it their population.
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