When a male donkey breeds with a female horse, the resulting offspring is called a mule. However, when a male horse breeds with a female donkey, the resulting offspring is called a hinny.
Mules share attributes of both horses and donkeys and are rarely able to reproduce. Male mules are called "jacks" and female mules are called "jennies." Mules are often used as work animals and can generally carry heavier loads than horses or donkeys. They tend to have more stamina than horses, and they are also more resistant to disease and more sure-footed on dangerous terrain when carrying heavy loads.