How can mules breed

They began doing research and found that in the past two centuries about 50 cases of mules giving birth have been recorded. Only two of those were proved with genetic testing. Genetic testing at the University of Kentucky and the University of California at Davis confirmed that Kate is indeed a mule and that the still unnamed foal really is her offspring.

That ruled out factors that have explained away some of the past births mistakenly attributed to mules. Those mules had stolen foals or they were not really mules themselves. They were donkeys or mulish-looking horses. Now, the Amoses are waiting for chromosome testing from the University of California to determine exactly what is the fast-growing foal cavorting clumsily around their corral.

He could be a smidgen of horse and a lot of donkey or mostly horse with just a bit of donkey genes. Oliver Ryder, associate director of the Conservation and Research of Endangered Species division at the San Diego Zoo, said the answer to how Kate could give birth could be surprising.

There were very unexpected — and still unexplained — findings when a molly mule gave birth to two foals in Nebraska in the mids. Ryder said that tests in the Nebraska case showed there was no evidence the mother passed along any genetic markers from her father — a donkey that was also the father of the foals. There was no reassortment. A mule gave birth to a mule when the sire was a donkey and then to a horse when the sire was a stallion.

Mules require less food and have more stamina than horses of the same weight and height, making them resilient working animals in some of the harshest environments. Over the centuries, owners have experimented with crossbreeding different sizes and breeds of horses — from miniature horses to draft horses — to create different sizes and strengths of mule. This makes mules a dependable option for owners who work outside in harsh weather and strong sunlight.

Although SPANA vets still see a lot of injuries as a result of poorly fitting equipment, mules are slightly less sensitive to the elements. Although the average lifespan for mules is between 35 and 40 years, some mules have been known to live until 50, especially if well looked after.

For many owners around the world who may not be able to regularly replace horseshoes, this means that mules are cheaper to keep. In addition to whinnying like a horse and braying like a donkey, mules make sounds that combine both calls and have even been known to whimper when excited or worried.

China breeds more than seven million mules each year where they are commonly used on small farms and for transport. Visit China and help our work by taking part in our Great Wall of China charity walk.

Although mules are usually docile, an angry mule can kick both backwards and to the side. Donate today to help SPANA provide the care and education needed to give mules across the world a better quality of life. What is a mule? Sometimes though, a child can survive with an extra chromosome. For example, people with an extra chromosome 21 have Down syndrome. Having all of the extra genes on that extra copy of chromosome 21 cause the symptoms associated with Down syndrome.

The extra genes must not be that big a deal for the mule. In other words, the extra genes on the horse chromosome do not cause problems for the every day life of a mule. So mules are sterile because horse and donkey chromosomes are just too different. But they are alive because horse and donkey chromosomes are similar enough to mate. Simple meiosis animation Chromosomal changes in new species Mitosis vs.

A mule can not make sperm or eggs. Horse and donkey chromosomes are too different to let mules breed successfully. Extra chromosomes usually lead to problems.

Here we show the chromosomes of someone with Down syndrome. Note the extra chromosome The Tech Interactive S. Market St. San Jose, CA The Tech is a registered c 3. Federal ID Its content is solely the responsibility of the authors and does not necessarily represent the official views of Stanford University or the Department of Genetics.

The Tech Interactive. Chimeras, Mosaics, and Other Fun Stuff. The mule has a set of horse chromosomes from its mom. And a set of donkey ones from its dad. So this is a big reason for a mule being sterile. But how is the silly thing alive at all? So having extra chromosomes often leads to real problems.

But the mule is by and large OK. Monica Rodriguez. More Information Simple meiosis animation Chromosomal changes in new species Mitosis vs. Search Ask a Geneticist.