The donkey or ass, Equus asinus, is a member of the Equidae or horse family, and an odd-toed ungulate. The words donkey and ass are applied to the domesticated E. asinus. The animal considered to be its wild ancestor is the African Wild Ass, also E. asinus.
Colloquially, the term "ass" is often used today to refer to a larger, horse-sized animal, and "donkey" to a smaller, pony-sized one. In the western United States, a small donkey is sometimes called a burro. A male donkey or ass is called a jack, a female a jenny, and offspring less than one year old, a foal (male: colt, female filly).
While different species of the Equidae family can interbreed, offspring are almost always sterile. Nonetheless, horse/donkey hybrids are popular for their durability and vigor. A mule is the offspring of a jack (male) donkey and a mare (female horse). The much rarer successful mating of a male horse and a female donkey produces a hinny.
Asses were first domesticated around 3000 BCE[1], approximately the same time as the horse, and have spread around the world. They continue to fill important roles in many places today and domesticated species are increasing in numbers (although the African wild ass and another relative, the Onager, are endangered species). As "beasts of burden" and companions, asses and donkeys have worked together with humans for centuries
Donkeys vary considerably in size, depending on breed and management. Most domestic donkeys range from 0.9 to over 1.4 m tall, though the Mammoth Jack breed is taller, and the Andalucian-Cordobesan breed of southern Spain can reach up to 1.6 m high.
Donkeys are adapted to marginal desert lands, and have many traits that are unique to the species as a result. Wild donkeys live separated from each other, unlike tight wild horse and feral horse herds. Donkeys have developed very loud vocalizations, which help keep in contact with other donkeys over the wide spaces of the desert. The best-known call is referred to a "bray," which can be heard for over three kilometers. Donkeys have larger ears than horses. Their longer ears may pick up more distant sounds,[citation needed] and may help cool the donkey's blood. Donkeys in the wild can defend themselves with a powerful kick of their hind legs as well as by biting and striking with their front feet.
Donkeys' tough digestive system is somewhat less prone to colic than that of horses, can break down near-inedible vegetation and extract moisture from food very efficiently. As a rule, donkeys need smaller amounts of feed than horses of comparable height and weight. Because they are easy keepers, if overfed, donkeys are also quite susceptible to developing a condition called laminitis
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 (jennet or jenny) to produce a hinny. A female donkey in the UK is called a mare, or jenny.
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).[citation needed] The lower progesterone production of the jenny may also lead to early embryonic loss. In addition, there are less-scientific reasons: 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;[13] 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.[14] 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.
For at least the past century, a few donkeys and burros in Mexico have been painted with white stripes to amuse tourists. These are not hybrids.
An animal which may look like a zebra-donkey hybrid because of its distinctly striped hindquarters and hind legs is the okapi, which has no relationship to either of those species. Okapi are most closely related to the giraffe. In addition to the rear stripes, okapi have some striping near the top of their forelegs
Colloquially, the term "ass" is often used today to refer to a larger, horse-sized animal, and "donkey" to a smaller, pony-sized one. In the western United States, a small donkey is sometimes called a burro. A male donkey or ass is called a jack, a female a jenny, and offspring less than one year old, a foal (male: colt, female filly).
While different species of the Equidae family can interbreed, offspring are almost always sterile. Nonetheless, horse/donkey hybrids are popular for their durability and vigor. A mule is the offspring of a jack (male) donkey and a mare (female horse). The much rarer successful mating of a male horse and a female donkey produces a hinny.
Asses were first domesticated around 3000 BCE[1], approximately the same time as the horse, and have spread around the world. They continue to fill important roles in many places today and domesticated species are increasing in numbers (although the African wild ass and another relative, the Onager, are endangered species). As "beasts of burden" and companions, asses and donkeys have worked together with humans for centuries
Donkeys vary considerably in size, depending on breed and management. Most domestic donkeys range from 0.9 to over 1.4 m tall, though the Mammoth Jack breed is taller, and the Andalucian-Cordobesan breed of southern Spain can reach up to 1.6 m high.
Donkeys are adapted to marginal desert lands, and have many traits that are unique to the species as a result. Wild donkeys live separated from each other, unlike tight wild horse and feral horse herds. Donkeys have developed very loud vocalizations, which help keep in contact with other donkeys over the wide spaces of the desert. The best-known call is referred to a "bray," which can be heard for over three kilometers. Donkeys have larger ears than horses. Their longer ears may pick up more distant sounds,[citation needed] and may help cool the donkey's blood. Donkeys in the wild can defend themselves with a powerful kick of their hind legs as well as by biting and striking with their front feet.
Donkeys' tough digestive system is somewhat less prone to colic than that of horses, can break down near-inedible vegetation and extract moisture from food very efficiently. As a rule, donkeys need smaller amounts of feed than horses of comparable height and weight. Because they are easy keepers, if overfed, donkeys are also quite susceptible to developing a condition called laminitis
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 (jennet or jenny) to produce a hinny. A female donkey in the UK is called a mare, or jenny.
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).[citation needed] The lower progesterone production of the jenny may also lead to early embryonic loss. In addition, there are less-scientific reasons: 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;[13] 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.[14] 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.
For at least the past century, a few donkeys and burros in Mexico have been painted with white stripes to amuse tourists. These are not hybrids.
An animal which may look like a zebra-donkey hybrid because of its distinctly striped hindquarters and hind legs is the okapi, which has no relationship to either of those species. Okapi are most closely related to the giraffe. In addition to the rear stripes, okapi have some striping near the top of their forelegs
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