Skip to the content

MULE

Mule
Europe

Breed Organization Information

The American Donkey and Mule Society
P. O. Box 1210
Lewisville, Texas 75067
Tel: (972) 219-0781
Fax: (972) 420-9980

adms@juno.com

About the Breed

Under conditions of domestication it is possible to obtain hybrids between equid species. There are records of onager/ass, onager/horse and zebra/horse (zebroids) crosses, but the cross that has been most significant in human history is one between horses and donkeys. Breeding a male donkey to a female horse results in a mule; breeding a male horse to a female donkey produces a hinny.

Offspring from either cross, although fully developed as males or females, are almost always sterile. Hence, a line of horses and a line of domestic asses must be maintained to perpetuate mule or hinny production.

The mule in most circumstances has been the preferred product of the horse/ass cross. (The breeding is also easier to manage.) The mule has greater endurance and is stronger and less excitable than a horse. Depending on the need, different breeds of horses can be used to produce fine riding mules, heavy draft mules or medium-sized pack animals. In Medieval Europe, when horses were bred large to carry armored knights, mules were the preferred riding animal of gentlemen and clergy. In 1495, Christopher Columbus brought four jacks and two jennies to the New World. They would produce mules for the conquistadores’ expeditions onto the American mainland. Ten years after the conquest of the Aztecs, the first shipment of twelve jennies and three jacks arrived from Cuba to begin breeding mules in Mexico. Female mules were preferred as riding animals, whereas the males were used as pack animals along the trails that tied the Spanish Empire together. Both mules and hinnies were used in the silver mines. Along the frontier each Spanish outpost had to breed its own supply of mules, and each hacienda or mission maintained at least one stud jack.

On the Iberian Peninsula, Catalonia and Andalucia each developed a large breed of ass, putting Spain in the forefront of the mule-breeding industry. Exportation of Spanish jacks was prohibited until 1813. However, the King of Spain presented George Washington with a large black jack in 1785. This animal, “Royal Gift,” is considered the father of the mule industry in the United States.

Mules were once used to pull fire-fighting equipment and were often employed by armies to pull artillery and to remove the wounded from the battlefield. The twenty-mule team that hauled borax from Death Valley and other mining centers in the West has become part of American legend. Indeed, some western towns were originally laid out with extremely wide streets to allow the mule teams to turn around.

The main mule-breeding centers in the United States developed in Tennessee, Kentucky and Missouri to provide work animals for the cotton fields of the Old South. After the American Civil War and the development of tenant farming throughout the South, the mule continued as the major draft animal in American agriculture. “Forty acres and a mule” was all one needed for self-sufficiency. The importance of the mule declined rapidly in the 1940s and 1950s, however, as gasoline-driven tractors became widespread, and mules all but disappeared from the American scene.

Today there is renewed interest in mules for recreation and competition. In the Southeast mules are used for nighttime raccoon hunting, and the mules’ ability to jump over fallen trees or fences is exploited in jumping competitions. Pulling contests using heavy draft mules have created a new demand for large mules. Particularly popular are large red mules produced by crossing American Mammoth Jackstock with Belgian mares.

Reproduced from HORSES THROUGH TIME edited by Sandra L. Olsen with permission of Roberts Rinehart Publishers, 6309 Monarch Park Place, Niwot, Colorado 80503. These excerpts may be read only, any printing or reproduction of this material must be obtained in writing from Roberts Rinehart Publishers.

Breed Characteristics
The Mule is a cross between a donkey stallion (called a jack) and a horse mare. Hinnies are just the opposite – a stallion horse crossed to a donkey jennet. For all purposes, hinnies and mules are classified and shown together under the general term Mule. Mules ears are usually somewhat smaller than a donkeys, longer but the same shape as the horse parents.

The mule?s conformation will be a combination of traits from both parents. The head, hip and legs usually take after the jack. Mules do not have pronounced arches to the neck, even from breeds such as Arabians or Warmbloods. A slight arch or straight neck is preferable to a ewe, or upward curved neck.

The mule will have “combination hair,” usually a thin forelock, coarse mane hair, and a tail more like the horse parent. Both mules and donkeys are shown with a variety of hairstyles from clipped to shaved (roached). Mules may wear their tails “belled” as decoration, left long and full, or clipped at the top to emphasize the shape of the hip.

Voice
Mules try their best to imitate the donkey?s bray, but most have a unique sound that is a combination of the horse?s whinny and the grunting of the wind-down of a bray. Most will start out – Whinee-aw ah aw.

Color
Mules usually have brown or tan-colored points, where in the donkey the light points are a shade of off-white. Some donkeys and mules do not exhibit any light points at all – this is not rare, but is a good identification marker for registration purposes. Old-timers used to call a dark muzzled mule “blue nosed.”

Mules can be any of the colors that either horses or donkeys come in, along with some unique variations of their own. The only colors mules do not come in is true horse pinto (due to the genetic factoring of these colors). Mules from Appaloosa mares often have extremely loud patterns, with spots enlarging or “skewing” in variants of the horse appaloosa. Breeders wishing for a mule with four white feet should try a tobiano mare. The mule will probably have four socks and/or stockings, with the most usual combination being four white feet and a splash of white on the tail. The genes of the mule seem programmed for the unusual, and very strange, loud spotted pinto and appaloosa variants are common. In fact, the best way to produce a spotted mule is to cross a spotted jack to a solid colored mare. The resulting mule may have pinto-like patched in a variation of the donkey-spot pattern. Appaloosa mares crossed to spotted jacks have often produced mule foals that appear to be roan-patched pinto, with dark leopard appaloosa spots over the dark areas.

Size
Mules come in every size and shape imaginable. Miniature mules (even to under 36″) can be seen all the way up to 17 hand Percheron draft (by Mammoth Jacks) Mules. The Poitou donkey was used exclusively for breeding huge draft mules from a breed of draft horse called the Mullasier – the Mule producer. The build of the mule is a combination of both parents. The head resembles both, the eyes being more almond-shaped (inherited from the D-shaped eye socket of the donkey). Male mules may have more prominent brow ridges like those of most donkey jacks. The neck is straight and has little arch, even in mules from Arab or warmblood mares. The overall body shape will be dependent on the conformation of both parents. Due to hybrid vigor, the mule has the possibility of growing taller than either parent.

The rarer Hinnies are often said to be more horselike than the mule, but more often it is impossible to tell them apart. Hinnies may tend to be slightly smaller, simply because of the fact that most donkeys are smaller than horses.

Uses
Mules can be used in exactly the same sports as horses – under saddle, in harness, for cutting, roping or dressage. In actuality, they have more stamina and can carry more weight than a horse of equal size. This is due to the hybrid vigor. There is one particular aspect where the mule actually outshines the horse, and that is high-jumping. Mules have a particular sport all their own called the Coon Hunter?s Jump. It stems from the raccoon hunter moving his mules through the woods. Wooden or stone fences could be taken down, but wire ones could not. The hunter would flag the fence with his coat or a blanket, and jump his string of pack mules over one by one. In the showring, mules jump a single rail standard to increasing heights. The last clean jump is the winner. Mules only 50 inches tall at the withers have been known to clear jumps of up to 72 inches. These jumps are not from a galloping approach, like Puissance, but from a standing start inside a marked area, truly a remarkable feat.

Mules are not really stubborn. They can seem lazy, but they will also not put themselves in danger. A horse can be worked until it drops, but not so with a mule. The “stubborn” streak is just the mule?s way of telling humans that things are not right. Mules are very intelligent and it is not a good idea to abuse a mule. They will do their best for their owner, with the utmost patience.

Mule Terminology

Mule: The hybrid animal produced when a male ass (Jack) is crossed with a female horse. The mule is a sterile hybrid, meaning it cannot reproduce. Mules come in both male and female. A tiny percentage of female mules have had foals, but this is considered a freak genetic accident. Mules are a combination of traits of the parents with the most obvious donkey traits being long ears, narrower body and smaller hooves. The horse contributes size, speed and muscle. Other characteristics such as the head and voice (an odd combination of the bray that ends as a whinny) are a blend of the parent features. You can always tell a donkey from a mule by the fact that a donkey has a tail in essence like a lion or a cow (long tail with a tassel) and the mule has a tail like a horse (short tailbone with long hair).

Hinny: This is the term used for the hybrid animal produced when the female ass (jennet) is mated to the male horse (stallion) to produce a foal. There are both male and female hinnies. The genetic inheritance of the hinny is exactly the same as the mule. Scientists think the differences in hinnies and mules may be from the result of maternal influences on the fetus, and in the upbringing of the foal. Some hinnies tend to look like horses with long ears, but most cannot be told apart from mules. Untraced animals can not be verified as hinnies. For all purposes, hinnies are classified with mules. Hinnies do not differ from mules in endurance, or other useful traits, but are bred more rarely because the donkey dam tends to make the offspring smaller. Donkeys do not as readily conceive to horse stallion as to donkeys. The equine hybrid is easier to obtain when the lower chromosome count (the donkey) is in the male.

Horse Mule: The proper term for the male mule. All male mules should be gelded, since stallion mules are very sexually active, even though they are sterile. Many people refer to a male mule as a john mule, but the term is informal.

Mare Mule: The proper term for the female mule. The common informal term for the female mule is molly mule, and is frequently used.

Mare Hinny or Horse Hinny: The terminology for the hinny follows that of the mule for clarity.

Mule Colt or Mule Filly: The young male or female mule under the age of three. When show classes are listed they are frequently listed as “Mare Mule under one year of age” etc. This is of course correct but more difficult to use in speech.

Miniature Mule: Bred from various types of pony mares or Miniature Horse mares. 50″ at the withers is considered the cut-off height for miniature mules.

Saddle Mule: Bred from mares of riding horse breeding. These vary in size from small to very large but have riding type confirmation.

Pack/Work Mules: Bred from mares with some draft blood or of heavy work types rather than for saddle type confirmation.

Draft Mules: These are the largest mules and are bred from various Draft mares. Belgian mules are the most common, valued for their bright sorrel color, but mules from Percheron, Clydesdale, Shire and other draft breeds are also seen. The larger and heavier the better with these mules, but refinement is desired as well.

Gaited Mules: Bred from the saddle-gaited horses including Tennessee Walking, Foxtrotter, Paso Fino and Peruvian Paso. A jack exhibiting a smooth singlefoot type gait is desirable as the sire of these mules. Gaited mules have their own registry in the American Gaited Mule Association, which requires qualification testing of the animal to show gait, as well as video evaluation of the sire and dam. These mules may also be registered in the American Mule Registry (ADMS) as Saddle Mules of gaited breeding.

Breed Organizations
The American Donkey and Mule Society was founded in 1967 for the purpose of being a national Breed Society and registering donkeys and mules. Today it is still going strong, with over 22,000 donkeys and 2,100 mules registered.

The Society’s services include three main registries and two newer registries that are expected to grow quickly. The Miniature Donkey Registry of the United States is specifically for those animals of miniature breeding and under 36″ in height. The American Donkey Registry covers the Standard to Mammoth breeds of donkeys. The American Mule Registry is for all sizes and types of mules and hinnies. The newer registries are the Race Mule and Zebra Hybrid books. In addition to the Registries, the Association has lots of information available on all breeds and types, as well as a catalog of books on long-ears. The donkey, mule, and zebra are all members of the equine family. Donkeys, horses and zebras all have unique breeds within the general term (i.e., the Arabian as opposed to just Horse or Poitou as opposed to just Donkey). The mule and zebroids are hybrids, the former being a horse/donkey cross, the latter a cross of zebra/other equine.