Donkey/Horse Family

Overview

The Donkey (or domesticated ass) is known and used throughout the world for its ability to carry heavy loads over the most demanding terrain. On the other hand, it is also noted for its occasional refusal to budge so much as an inch whether carrying a load or not. The Donkey is an ancient form of equid found in varying local types. It was first domesticated 5,000 years ago, some time before the domestication of the horse. A male donkey (jack) can be crossed with a female horse to produce a mule. A male horse can be crossed with a female donkey to produce a hinny. Donkeys are put to various uses, from carrying burdens in remote areas to performing in elegant harness in shows.

Physical Description

Donkeys are really domesticated wild asses. There are two types, the African and the Asiatic. The African wild ass is considered the original ass. It is called the Nubian due to its place of origin, the Nubian desert. It stands 12 hands high. It has a black stripe on the shoulder and is usually gray with a white belly, large ears and narrow hooves. The Asiatic Wild Ass included the Onagers of Western Asia, and the Kiangs and Kulans of Central Asia. Asiatic asses roam in great herds in remote areas. The Kiang stands up to 14 hands and is brown with a light belly. The Kulan stands only 12.2 hands and is reddish-yellow color with dun lower parts. It should also be noted that donkey hooves are more elastic than those of horses, and do not naturally wear down as fast. Regular clipping may be required; neglect can lead to permanent damage. Working donkeys may need to be shod. Donkey shoes are similar to horseshoes, but usually smaller and without toe-clips.

Origin

It is asserted by some that the ass originally was found throughout the deserts of northern Africa. After it was domesticated, the ass was brought to Asia by traders, where some believe it gave rise to the Asiatic Wild Ass. The Donkey, which appears in great numbers throughout the world, is the domesticated version of the Nubian Ass.

Feral Donkeys and Wild Asses

In some areas domestic donkeys have returned to the wild and established feral populations such as those of the Burro of North America and the Asinara donkey of Sardinia, Italy, both of which have protected status. Feral donkeys can also cause problems, notably in environments that have evolved free of any form of equid, such as Hawaii. In Australia, where there may be 5 million feral donkeys, they are regarded as an invasive pest and have a serious impact on the environment. They may compete with livestock and native animals for resources, spread weeds and diseases, foul or damage watering holes and cause erosion.

Wild asses, onagers, and kiangs

Few species of ass exist in the wild. The African wild ass, Equus africanus, has two subspecies, the Somali wild ass, Equus africanus somaliensis, and the Nubian wild ass, Equus africanus africanus, the principal ancestor of the domestic donkey. Both are critically endangered. Extinct species include the European ass, Equus hydruntinus, which became extinct during the Neolithic, and the North African wild ass, Equus africanus atlanticus, which became extinct in Roman times. There are five subspecies of Asiatic wild ass or onager, Equus hemionus, and three subspecies of the kiang, Equus kiang, of the Himalayan upland.

Donkey Hybrids

Horse-donkey hybrids are almost always sterile because horses have 64 chromosomes whereas donkeys have 62, producing offspring with 63 chromosomes. Mules are much more common than hinnies. This is believed to be caused by two factors, the first being proven in cat hybrids, that when the chromosome count of the male is the higher, fertility rates drop (as in the case of stallion x jennet). The lower progesterone production of the jenny may also lead to early embryonic loss. In addition, there are reasons not directly related to reproductive biology. Due to different mating behavior, jacks are often more willing to cover mares than stallions are to breed jennys. Further, mares are usually larger than jennys and thus have more room for the ensuing foal to grow in the womb, resulting in a larger animal at birth. It is commonly believed that mules are more easily handled and also physically stronger than hinnies, making them more desirable for breeders to produce, and it is unquestioned that mules are more common in total number.

The offspring of a zebra-donkey cross is called a zonkey, zebroid, zebrass, or zedonk; zebra mule is an older term, but still used in some regions today. The foregoing terms generally refer to hybrids produced by breeding a male zebra to a female donkey. Zebra hinny, zebret and zebrinny all refer to the cross of a female zebra with a male donkey. Zebrinnies are rarer than zedonkies because female zebras in captivity are most valuable when used to produce full-blooded zebras. There are not enough female zebras breeding in captivity to spare them for hybridizing; there is no such limitation on the number of female donkeys breeding.

George Washington had some of the most famous donkeys in American history. Washington wished to develop a fine mule for agricultural use. In 1785, he received three asses - a Jack and two Jennies - as a gift from the Spanish king. The Jack was named Royal Gift, and stood at Mt. Vernon and other locations in Virginia. The Marquis de Lafayette sent Washington a Maltese Jack named the Knight of Malta, which was described as having "the fire and ferocity of a tiger," but he was an excellent sire of mules. A quality Jack at this time demanded a large sum of money. Royal Gift got a fee of 15 pounds in 1786. A few years earlier, the imported Thoroughbred sire, Messenger, was getting only 5 pounds.

Influences

1. Eohippus 2. Mesohippus 3. Miohippus 4. Merychippus 5. Pliohippus 6. Asinus

For More Information:

Donkeys aka Ass, Equus Africanus Asinus, Equus Asinus-Used Around the World
Donkey vs Horses in Pain
The American Donkey and Mule Society, Inc.
Donkey, Donkey hybrids, Burro, Wild Ass, Onager, and Kiang

Sources:

Permission given by my dear friend, Cowboy Frank, to use his breeds section.
Oklahoma State University list of livestock breeds