---
title: "What the sources say about the Domestic Yak | AnimalTracks.wiki"
description: "37 claims from the Domestic Yak profile, each beside the words of the source that backs it."
image: "https://animaltracks.wiki/images/animals/yak-1.webp"
canonical: "https://animaltracks.wiki/animals/yak/sources/"
---

# What the sources say about the Domestic Yak (*Bos grunniens*)

> 37 claims from the Domestic Yak profile, each beside the words of the source that backs it. A "..." marks a cut in a quote and [brackets] an insertion.

Profile: [Domestic Yak](https://animaltracks.wiki/animals/yak/)

## Jing et al. (2022). The adaptive strategies of yaks to live in the Asian highlands. Animal Nutrition.

https://doi.org/10.1016/j.aninu.2022.02.002

| The page says | The source says |
| :--- | :--- |
| Oversized heart and lungs | The size of the heart and lungs of yaks are substantially larger than cattle. (note: tagline) |
| up to 5,000 m high | raised at altitudes between 3,000 and 5,000 m above sea level (note: tagline) |
| Asian highlands, 3,000 to 5,000 m above sea level | raised at altitudes between 3,000 and 5,000 m above sea level across the Asian highlands (note: stats.habitat) |
| Forbs and low herbage, grazed with the lips | graze forage using the labia oris , which minimizes exposure of the tongue to the cold environment, as well as enabling them to consume low herbages (note: stats.diet) |
| In one study of grazing yaks, they consumed forbs throughout the year, but especially during the winter. | Ding and Long (2010) used herbage N-alkanes to identify the main dietary components of grazing yaks in a transhumance grazing system, and the results indicated that forage consumed by yaks varied with season. Yaks consumed forbs throughout the year, but especially during the winter. (note: body: scoped to the one study the review reports) |
| a heart that weighs 1.18% of body weight, against 0.39% in cattle | Heart weight in yaks is 1.18% of body weight as opposed to 0.39% in cattle (note: stats.superpower) |
| Not Evaluated | there are approximately 16 million domestic yaks and 15 to 20 thousand wild yaks in the world (note: stats.conservationStatus. The page speaks of the domestic yak as a domestic animal, so no Red List category applies. The prefetch's Red List DOI (taxon 2892, 2016) is Bos mutus, the wild yak (Vulnerable), and is not cited. GBIF had no category for this name. Precedent llama, goat, domestic-cat: no IUCN reference. The quote's 'approximately' belongs to the herd count, not to the status.) |
| People raise the yak (Bos grunniens) 3,000 to 5,000 m above sea level in the highlands of Asia. | The yak ( Bos grunniens ), an indigenous herbivore raised at altitudes between 3,000 and 5,000 m above sea level across the Asian highlands |
| A yak has 15 chest vertebrae, one more than a cow, which makes its chest cavity bigger and leaves room for a large heart and lungs. | Yaks have 15 thoracic vertebrae, one more than cattle, which increases the volume of the thoracic cavity and provides ample space for the large heart and lungs |
| A yak's heart weighs 1.18% of its body weight, where a cow's weighs 0.39%. | Heart weight in yaks is 1.18% of body weight as opposed to 0.39% in cattle |
| Yaks have a greatly diminished response of this kind. | yaks have a greatly diminished hypoxic pulmonary vasoconstrictive response, which cattle do not have, when exposed to low air oxygen content (note: paraphrase of the pulmonary vasoconstriction point; the body explains the term in its own words) |
| Yaks keep a high level of foetal haemoglobin throughout life, while it is generally present in other mammals for only 6 to 7 months after birth. | yaks maintain a high level of foetal haemoglobin throughout life; whereas, it is generally present in other mammals for only 6 to 7 months after the birth |
| This form of haemoglobin, the blood's oxygen carrier, holds oxygen more tightly and can bind and release more of it than other forms. | Foetal haemoglobin has a greater affinity for oxygen, and can bind and release more oxygen than other forms of haemoglobin |
| A yak's tongue is 4 cm long on average, shorter than a cow's, and it grazes with its lips. | Yaks have a shorter tongue (4 cm, on average) than cattle, and graze forage using the labia oris |
| a yak can lose 25 to 30% of its body weight, or even more. | yaks can lose 25% to 30%, or even more, of body weight |
| Genome studies date the yak's domestication to 7,300 years ago. | Based on whole-genome resequencing, yaks were domesticated 7,300 years ago |
| A 2022 review counted approximately 16 million domestic yaks and 15 to 20 thousand wild yaks in the world. | there are approximately 16 million domestic yaks and 15 to 20 thousand wild yaks in the world (note: the year is the review's (Jing et al. 2022, 'At present'); Ayalew et al. 2021 gives 'Over 17.6 million yaks', citing an older count) |
| A 2022 review put the domestic herd at about 16 million animals, against 15,000 to 20,000 wild yaks in the world. | there are approximately 16 million domestic yaks and 15 to 20 thousand wild yaks in the world (note: paraphrase of the quote; 15 to 20 thousand = 15,000 to 20,000) |
| Cattle have a reaction in which lung blood vessels clamp down in thin air, which is called hypoxic pulmonary vasoconstriction. | yaks have a greatly diminished hypoxic pulmonary vasoconstrictive response, which cattle do not have, when exposed to low air oxygen content (note: the quote implies cattle have the response; term explained in the body's own words) |
| That keeps the tongue out of the cold and lets the yak crop low plants. | graze forage using the labia oris , which minimizes exposure of the tongue to the cold environment, as well as enabling them to consume low herbages |
| Yaks are raised 3,000 to 5,000 m up, and a yak's heart weighs 1.18% of its body weight against a cow's 0.39% | raised at altitudes between 3,000 and 5,000 m above sea level (note: vibe.reason) |
| Yaks are raised 3,000 to 5,000 m up, and a yak's heart weighs 1.18% of its body weight against a cow's 0.39% | Heart weight in yaks is 1.18% of body weight as opposed to 0.39% in cattle (note: vibe.reason) |

## Ayalew et al. (2021). Adaptation Mechanisms of Yak (Bos grunniens) to High-Altitude Environmental Stress. Animals.

https://doi.org/10.3390/ani11082344

| The page says | The source says |
| :--- | :--- |
| a shaggy coat | the thick fleece covering the entire yak body enhances heat conservation (note: tagline) |
| Yaks have thick outer hair and no working sweat glands | They also have thick outer hair coats and no functional sweat glands |
| The fleece has two layers: long outer hair, and an undercoat of dense, fine down that appears in the colder season. | The thick fleece comprises an outer coat of long hair and an undercoat consisting of a dense layer of fine down fibers that appear in the colder season to contain body heat and repel moisture |
| The body is compact, with relatively little skin for its weight. | their bodies are compact with a relatively reduced skin surface area per unit of body weight (0.016 m 2 /kg) |
| not sweating helps them cope with cold. | The absence of sweating in the yak enhances cold tolerance |
| A 2021 review describes yak sweat glands as non-functional | yaks have large hearts and lungs, compact bodies, thick outer hair covering, and nonfunctional sweat glands (note: 2021 is the publication year of the cited review (Ayalew et al. 2021)) |
| the absence of sweating helps yaks tolerate cold. | The absence of sweating in the yak enhances cold tolerance |
| In winter, a compact body, thick coat and no sweating together minimize heat loss. | Compact body, thick outer hair covering, and nonexistence of functional sweat glands Minimize dissipation of body heat during winter |

## Qiu et al. (2012). The yak genome and adaptation to life at high altitude. Nature Genetics.

https://doi.org/10.1038/ng.2343

| The page says | The source says |
| :--- | :--- |
| A 2012 study comparing yak and cattle genomes found that the yak has more genes in families tied to the senses and to energy metabolism. | Genomic comparisons between yak and cattle identify an expansion in yak of gene families related to sensory perception and energy metabolism, as well as an enrichment of protein domains involved in sensing the extracellular environment and hypoxic stress. |

## AnAge entry for Bos grunniens. Human Ageing Genomic Resources, AnAge.

https://genomics.senescence.info/species/entry.php?species=Bos_grunniens

| The page says | The source says |
| :--- | :--- |
| AnAge lists an adult weight of 667 kg for Bos grunniens. | Adult weight 667,000 g (note: 667,000 g = 667 kg) |
| A newborn weighs about 18 kg. | Weight at birth 18,000 g (note: 18,000 g = 18 kg) |
| The yak reaches full size in 6 to 8 years. | The yak reaches full size in 6-8 years. |
| One captive yak was still living after 26.3 years. | One captive specimen was still living after 26.3 years |
| Gestation lasts about 274 days, a little under nine months. | Gestation 274 days (note: 'a little under nine months' is arithmetic on 274 days) |
| AnAge gives a maximum of 26.3 years for a captive yak. | Maximum longevity 26.3 years (captivity) |