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Web Feature

Every quarter, we publish on the Web one story from our print magazine in its entirety. Here is this issue's Web Feature

Smooth Movin’ Mules!
By Audrey Lee

Now, we love our horses, but there are those who say once they met a good mule, horses seemed to them a little...boring?

Many people already know the benefits of owning a long-eared companion, as mules have always been popular mounts for their endurance, dependability, and superior strength. Up in the mountains, packing or riding, or out in the fields plowing, mules have been around for as long as most horse breeds. In fact, George Washington bred mules to work his lands. Now days, people use their mules for just about anything. Riding, driving, cutting and jumping mules are finding their way into show rings and competitions all over the world!

Why mules?
Mules hold a special place in the lives of their owners, and as those owners tell it, hold a deeper bond with their person. They are very dependable mounts, and have vibrant personalities, but there’s something deeper in those eyes that you have to take the time to get to know and love to understand fully.

For those who don’t know what a mule is, it is a cross between a female horse (Mare) and a male donkey (Jack). Crossing a female donkey (Jenny) and a male horse (Stallion), results in a “hinny”. Although similar, they differ from each other in appearance and temperament. A mule is said to have the body of a horse and the extremities of a donkey, whereas a hinny is said to have the body of a donkey and the lower extremities of a horse. Hinnies typically have shorter ears than mules, thicker manes and tails, and in general a broader range of appearance.

Perhaps mules are more intelligent than the average horse, or just have a slightly different way of thinking. Called “self thinkers” by mulefolk, they are quick to figure out that they are not going anywhere running circles in a round pen. They won’t waste the energy. You have to be smarter than a mule to train one and that’s not always so easy!

Gaited Horse Vs. Gaited Mule
Some people just prefer mules. Breeders are crossing ambling jacks to gaited mares to produce some very nice, smooth-gaited mules. If you want a Paso Mule, Rocky Mountain Mule, or Walker Mule, you can breed your gaited mare to a nice ambling jack, but you may have to get in line for a good one. Gaited Mules are becoming one of the fastest growing “Breeds” on the market, especially in the Southeast!

One advantage mules have over horses is called heterosis, (the benefit that crossbreeding two different species has on vigor, strength, and overall physical excellence) also known as hybrid vigor. A mule can grow taller than both of its parents, will be stronger than any horse its size, and be willing to go longer on less fuel. They are also quite resilient, and have excellent immune systems — heterosis is not found in all hybrids — in fact, hinnies are not considered to have hybrid vigor.

Mule Gaits
Some of the gaits mules can execute are single-foot, fox trot, running walk, fino walk, stepping pace and racking walk, among others. Any smooth intermediate gait makes them eligible for registration in a few different associations for mules. The gait is affected by what breed of gaited mare produces the mule foal. Marie Lanier of R&M Gaited Mules in Corvallis, MT, breeds mainly Tennessee Walking Horse mares to her gaited jack. Her preferred gait is a running walk, but finds a good percentage of foals will have a fox trot or rack. She cautions that breeding for mules can be difficult, as you can’t predict certain traits like you might with horses. “You can repeat the same breeding again and again, and get something a little different every time”, she says.

You can’t always predict what you are going to get with horses either, but certain laws of genetics help to narrow it down. A Jack will produce certain consistencies as well, but not close to the same degree. This is most likely due to how mule chromosomes are paired, and what influences dominance between gene traits when breeding hybrids.

Gaited Jacks
Just like horses, donkeys either have the ability to gait or not. Somewhere down the line, the ambling genetics developed in the donkey, just as the horse developed its gaits, and the camel evolved it’s pace. Donkeys can perform just about any recognized horse gait, from a running walk to a fast rack. Some even have multiple gaits.

Breeding Mules
You can’t "breed" mules, you have to breed for them. Mules and hinny’s are infertile. You may have heard that this was because they have an odd number of chromosomes, or because they are a cross between two different species. Both of these explanations, although they seem plausible, have been proven untrue.

Some believe hybrids in general are sterile, but there are fertile hybrids — for instance, a cross between a horse (with 64 chromosomes) to a Prezewalski's (wild) horse (with 66 chromosomes) produces a hybrid with 65 chromosomes, which is normally fertile. Several domestic horse breeds have 65 chromosomes, as well, such as the Norwegian Fjord, the Caspian Pony and the American Tarpon, all capable of reproduction.

Despite the fact that internal and external sexual organs develop normally, and both have normal sexual urges, (male mules are routinely gelded) mules and hinnies are incapable of reproduction because the males lack certain germ cells for normal sperm production, and females are usually incapable of producing an egg.

The best possible explanation for this is not due to excess chromosomes, but in how they pair up. Chromosomes come in different shapes and sizes, such as metacentric, submacentric, and acrocentric autosomes (non-sex chromosomes); the normal horse has 30 submetacentric and metacentric autosomes, and 32 acrocentric autosomes. The chromosomes in donkeys and horses don’t match in shape (a mule inherits 13 metacentric chromosomes from the mare and 19 from the Jack) this could affect what traits and genes are passed to the offspring, and is possibly the best explanation for their infertility.

Horse breeders rely on foresight into successive generations to breed for their “ ideal.” Seven or eight generations into a breeding program, one can produce wonderful results with hard work, careful selection, and did I mention a lot of patience! Unfortunately, Mule breeders do not have the luxury of combining generations of bloodlines for desirable traits. Mule breeding is a constant experiment.

 

Mule Fertility Facts: Mules and hinny’s have 63 chromosomes - 31 from the donkey, 32 from the horse, leaving one "extra" (unpaired) chromosome. From 1527 to1990 there were 60 reported live births to female mules in the world. It is suspected that most of these “mule” mares were horses with mule characteristics. In extremely rare circumstances, if a mule conceived and delivered a foal, the sire would be a Stallion (horse). It is believed that if female mules reproduce, they had developed reproductively like a horse mare, therefore being able to reproduce with a male horse.

Crossing Breeds
While it seems Peruvians were perhaps the first gaited breed to be crossed with donkeys, many breeders are using Rocky Mountains, Tennessee Walkers, Paso Finos, Missouri Fox Trotters, and even part bloods. There are breeders using Percheron/gaited cross mares to produce stronger rear-ends in the mule foals. If a mare has solid gait, and the jack has natural ambling ability, your chances of getting a gaited foal are not just good, they are very good!

 

Peruvian Mules: The first gaited mule “breed”? The First National Tournament of Peruvian Paso Horses in 1945 offered classes for Peru’s Paso Mules. There were a few exceptionally well-gaited donkeys in parts of South America, and those who owned them were wealthy. Only the best horses were used for crossing, so that the Paso mules of Peru carry some of the same renowned and desired heritage of the best Peruvian horses.

Breeders agree that a much greater percentage of gaited foals come from crossing a gaited jack to gaited mares, versus breeding a gaited jack to a trotting mare, or even a non-gaited jack to a gaited mare.

Of course, the only sure way to get a gaited mule is to get in line and buy one already on the ground and gaitin’. Just be prepared to wait, pay a good price and quite possibly to be upstaged and outwitted. And hopefully to find the mount of your dreams.