TO CLONE A MULE: HISTORY OFFERS MIXED MESSAGES
MOSCOW, Idaho – For a mule, the only option for reproduction is cloning. A mule is the sterile hybrid that results from the crossing of a horse and donkey.
Of millions of mules produced through the millennia, only a tiny fraction have proven fertile.
A basic tenet of biology, in fact, argues that mules must be sterile because horses and donkeys are considered separate species. A key test of a species is whether it can produce fertile offspring when paired with a close relative.
In the case of a mule, a mare horse is the mother and a male donkey, a jack, is the father. If horses paired with donkeys routinely produced fertile offspring, they could be considered the same species.
The basic reason nearly all mules are sterile is genetic incompatibility. A donkey has 62 chromosomes and a horse has 64. Mules typically have 63.
So rare are fertile mules that cultures have developed apocryphal myths surrounding their offspring. In November, a woman in Morocco greeted the arrival of her mule’s new foal with horror because superstition said such an event presaged the end of the world.
Farmers in Albania in 1994 considered executing a mule there that aborted a foal because village elders feared the fetus was an evil omen.
Near Champion, Neb., the owners of a mule named Krause saw things differently when she produced a foal, Blue Moon, in 1984. They saw it as an event blessed enough to be announced from the pulpit of the United Methodist Church in Imperial, Neb. In 1987 Krause produced another foal, White Lightning.
Two mule foals were also documented in China. In October 1985, the Journal of the Royal Society of Medicine reported one of them produced a foal that was named Dragon Foal.
Many people prize mules because they are considered more deliberate than horses. Mule advocates say their animals inherit their donkey sires‚a tendency to stop and analyze situations before reacting. Horses, in contrast, yield quickly to a powerful instinct to flee. Their horse mothers give mules greater size and strength.
Prized as saddle animals by many, mules also can work longer, harder and in greater heat than horses, according to research by the late Melvin Bradley, a University of Missouri professor of animal science for 42 years, who died in March.
Recorded praises of mules‚ abilities exist since at least Roman times. The mules heyday in the U.S. occurred in the late 19th and early 20th centuries. Missouri became a focal point for mule breeding.
Bradley found that one town, Lathrop, Mo., shipped 350,000 mules to Britain to aid forces engaged in World War I. The Missouri mule answered the bugle again in World War II when some 8,000 served Allied forces hauling howitzers and supplies in the rugged highlands of Burma, China and India.
In the United States, Mule Days, held since 1969 in Bishop, Calif., serves as one of the new epicenters for mule enthusiasts. Organizers scheduled this year’s event May 21 to 25, the week before Memorial Day, and expect to draw some 30,000 competitors and fans.
Bishop is northwest of Death Valley National park where the image of borax wagons hauled by 20-mule teams still persists.
The University of Idaho also has a Bishop connection. The UI mule project was chosen as grand marshall of the parade in 1994, the event’s 25th anniversary. The year before, the Northwest Equine Reproduction Laboratory had produced four sibling mules using embryo transfers and surrogate mares. Representing the UI project were Post Falls businessman Don Jacklin, the owner of a stable of racing mules, and UI Professor of Animal and Veterinary Science Gordon Woods.