What Is a Mule? Characteristics and Uses of the Hybrid Offspring of a Horse and a Donkey

A mule is the offspring produced by crossing a horse and a donkey, usually referring to the horse mule (hinny) born from a male donkey mating with a female horse; if it is born from a male horse and a female donkey, it is called a donkey mule (mule). The donkey mule is slightly smaller in body size than the horse mule, and in production, horse mules are the majority kept. The appearance of a mule falls between that of its two parents: it has the build and limbs of a horse, along with the long ears and head features similar to a donkey.

In terms of production performance, the mule combines the advantages of both parents well. It is strong and has great endurance, carrying loads and pulling carts more persistently than either a horse or a donkey alone, and it is mostly gentle in temperament and hard-working, with a good ability to digest and utilize coarse feed and relatively strong disease resistance, making it especially popular for carrying supplies in mountainous areas.

As for why mules cannot reproduce, the main reason is that horses and donkeys have different chromosome numbers, and the chromosomes in a mule's body find it difficult to pair normally, with reproductive function developing incompletely; therefore, male and female mules generally have no reproductive capacity. To obtain a mule, one can only cross a horse and a donkey again, which is also why mules need to be continually bred and replenished.

In an era when mechanization was not highly developed, the mule was an important draft animal in rural areas, indispensable for plowing fields, carrying goods, and turning millstones. Today, in some hilly and mountainous areas with inconvenient transportation, the mule is still a good helper for transporting supplies, and with its relatively long lifespan and low feeding cost, it is still recognized by many breeders.