Mule Mule A mule is the offspring of a male donkey (jack) and a female horse (mare). Horses and donkeys are different species, with different numbers of chromosomes. Of the two F1 hybrids (first generation hybrids) between these two species, a mule is easier to obtain than a hinny, which is the offspring of a female donkey (jenny) and a male horse (stallion). The size of a mule and work to which it is put depend largely on the breeding of the mule's female parent (dam). Mules can be lightweight, medium weight or when produced from draft horse mares, of moderately
Mare Mare A mare is an adult female horse or other equine. In most cases, a mare is a female horse over the age of three, and a filly is a female horse three and younger. In Thoroughbred horse racing, a mare is defined as a female horse more than four years old. The word can also be used for other female equine animals, particularly mules and zebras, but a female donkey is usually called a "jenny". A broodmare is a mare used for breeding. A horse's female parent is known as its dam. An uncastrated adult male horse is called