Hair coat properties of donkeys, mules and horses in a temperate climate


There are clear differences between donkeys and horses in their evolutionary history, physiology, behaviour and husbandry needs. Donkeys are often kept in climates that they are not adapted to and as such may suffer impaired welfare unless protection from the elements is provided.


To compare some of the hair coat properties of donkeys, mules and horses living outside, throughout the year, in the temperate climate of the UK.

Study design

Longitudinal study.


Hair samples were taken from 42 animals: 18 donkeys (4 females, 14 males), 16 horses (6 females, 10 males) and eight mules (5 females, 3 males), in March, June, September and December. The weight, length and width of hair were measured, across the four seasons, as indicators of the hair coat insulation properties.


Donkeys’ hair coats do not significantly differ across the seasons. All three measurements of the insulation properties of the hair samples indicate that donkeys do not grow a winter coat and that their hair coat was significantly lighter, shorter and thinner than that of horses and mules in winter. In contrast, the hair coats of horses changed significantly between seasons, growing thicker in winter.

Main limitations

The measurements cover only a limited range of features that contribute to the thermoregulation of an animal. Further research is needed to assess shelter preferences by behavioural measures, and absolute heat loss via thermoimaging.


Donkeys, and to a lesser extent mules, appear not to be as adapted to colder, wet climates as horses, and may therefore require additional protection from the elements, such as access to a wind and waterproof shelter, in order for their welfare needs to be met.

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Donkey skin: the invisible fur trade

Alex Mayers
Faith A. Burden
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Increased levels of personal wealth in China is fuelling demand for luxury products including ejiao, a product made using donkey skin. A traditional medicine, ejiao’s popularity is largely due to its reported ‘anti-aging’ properties. Demand for donkey skins to produce ejiao is conservatively estimated at 4 million per year. This represents a significant proportion of the global donkey population of 44 million. China’s own donkey population has nearly halved in the last 20 years and entrepreneurs are now looking worldwide to satisfy a growing demand.

Despite their essential role in livelihoods and community resilience donkeys are largely invisible in livestock policies, livelihoods and humanitarian projects. It is therefore unsurprising that the emerging trade in skins is also invisible. Donkeys are frequently stolen from owners across Africa and illegally slaughtered in the bush; only the skins are removed and carcasses left to rot. In other areas, donkeys are bought at less than current market value and are transported in inhumane conditions to recently built ‘legal’ slaughterhouses. The invisibility of the legal and illegal markets is compounded by illegitimate export practices and criminal gangs. Due to the lucrative market for skins intensive farms are present in China and are likely to expand to other countries, such rearing creates significant welfare concerns for a species poorly adapted to intensive practices. Even if awareness of this trade improves, in the short term donkey owners are facing donkey prices that have increased up to tenfold within a few years and they are without the means to replace animals they depend on.

This emerging trade is, essentially, a fur trade with animal skins being sourced for human beauty. However while furs are visible, the role of donkey skins in ejiao products is invisible to the end user, mirroring the invisibility of the trade and donkeys themselves.

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