 Although it depends on the individual animal, it has been reported that mules trained by the Army of Pakistan can carry up to and walk without resting.The average equine in general can carry up to approximately 30% of its body weight in live weight, such as a rider.A female mule that has estrus cycles and thus, in theory, could carry a fetus, is called a "molly" or "Molly mule", though the term is sometimes used to refer to female mules in general.