by Kristin Berkery

Most people have heard of a mule, but do you know what a hinny is?

Miniature hinny

Pearlie Mae, a hinny foal sired by a miniature horse. Photo courtesy of the American Donkey and Mule Society

First, let’s review mules. A mule is the hybrid result of a donkey jack (stallion) bred to a horse mare. Male mules are sterile, so they are usually gelded (making them “johns”) to decrease their interest in female horses and donkeys. There are a few anecdotal cases of female mules (mollies) being fertile and able to produce foals when bred to a donkey or a horse, but for the most part mules are sterile.

donkey stallion + horse mare = mule

Why would someone want to produce a sterile hybrid foal? Due to hybrid vigor, mules tend to inherit the best characteristics of their parents. Donkeys are tougher than horses and well adapted to living in arid climates with sparse vegetation. It’s believed that their ears not only capture far-off sounds better, but they may also help cool the animal in hot weather. Donkeys are generally less prone to colic and can digest scrubby grasses much better than horses. From the horse side, mules get strength and courage. The result is an animal that tends to be smart, strong, tough, and sure-footed. Mules can be used for farm work, endurance racing, and as pack animals.

A hinny pictured with its donkey jenny dam in the background. Photo courtesy of the American Donkey and Mule Society

So what exactly is a hinny? A hinny is the result of breeding a horse stallion to a donkey mare (jenny). They tend to be smaller animals, probably because the donkey mother has a smaller womb than a horse. Some mule and hinny enthusiasts say hinnies have a more horse-like head with smaller ears and more horse-like manes and tails than mules have. But overall, hinnies are considered genetically identical to mules.

horse stallion + donkey mare = hinny

There are a few theories why hinnies are uncommon. One debatable reason is that donkey jennies are more selective in choosing their mates. But the most likely reason is that most mule breeders want a larger animal for riding or carrying heavy loads and hinnies just aren’t big enough for those tasks. Because of their smaller size, hinnies are often sired by Miniature Horses and kept as pets.

It’s possible to breed a larger hinny by using a Mammoth donkey jenny as the dam, but Mammoths are rarer and most breeders want to reserve Mammoth jennies for producing other Mammoths, not sterile hinnies.

To learn more about hinnies, mules, and donkeys, visit the American Donkey and Mule Society‘s website. More hinny photos