[gotta a horse]

I always thought breeding mules was impossible. However, I have heard that you can breed a jack to a mare and the mare could get pregnant. My friend's horse was bred to a mule (bought her that way, but will give the foal back) and is pregnant. I asked if he was sure that it wasn't a donkey and not a mule, but it is a mule. He pointed him out to me while I was over there. You can feel the baby moving in there as well so there's deffinately a foal growing. I always thought it was impossible to do so. I'm at a loss as how this could happen, because don't mules have an odd number of chromosomes or something; therefore making it biologically impossible to breed a mule and get a foal out of the deal? This is way over my head.

[Blistering Winds]

there are rare occurances of mules being "repro able" in the female lines.

Is it possible YES

However, there is enough sterility to continue to say "Mules are sterile"


I really hadn't heard of a jack being productive.

[Equine Repro]

Originally Posted by gotta a horse

I always thought breeding mules was impossible. However, I have heard that you can breed a jack to a mare and the mare could get pregnant. My friend's horse was bred to a mule (bought her that way, but will give the foal back) and is pregnant. I asked if he was sure that it wasn't a donkey and not a mule, but it is a mule. He pointed him out to me while I was over there. You can feel the baby moving in there as well so there's deffinately a foal growing. I always thought it was impossible to do so. I'm at a loss as how this could happen, because don't mules have an odd number of chromosomes or something; therefore making it biologically impossible to breed a mule and get a foal out of the deal? This is way over my head.

Better go do a bit more investigating. You are correct in that mules are infertile. While an intact male will breed, as will an intact female mule, they are incapable of reproducting.

If the sire is indeed a mule, then he would be one of only a handful of mules that were able to reproduce (and I "do" mean a handful). So, if they are absolutely sure the sire is a mule, have them get in touch with one of the equine research universities...it would be information that they woudl most assuredly be interested in. It would be one for the record books.

Good luck!

Kathy St.Martin
Equine Reproduction Short Courses
Equine Reproduction

[gotta a horse]

Thank you for your help!

EDIT: Another thing I heard was that any mule stallion can breed a mare and then and only then will it produce a foal. I am assuming that is not true then.

[Mare]

Are you sure that the mare wasnt bred to a Mamoth jack to get a mule?

[gotta a horse]

Positive. He pointed her out to me and it was deffinately a mule. There's not even a donkey on the place where she was bred.

[Top Dun]

A donkey has 2 less chromosomes than a horse. When a donkey is bred to a horse the resulting foal Mule or hinney has one unpaired chromosome. That leaves the Mule/hinney sterile. IN REALLY, REALLY rare occasions basically genetic mutations one of the chromosomes won't split exactly right and the mule ends up with that one extra or one less chromosome that makes them Fertile. To date as far as I'm aware there have been NO documented cases of fertile Male mules. This is normally because most responsible mule breeders will immediately geld male mules due to the fact that the VAST majority will be shooting blanks anyway so why bother testing one to see if he's got that one in a million genetic mutation. There have only been a handful of Molly ( mare) mules that have been documented to be fertile.

In Long ears lingo, A JACK refers to a male ungelded donkey.
Male mules AND gelded Donkeys are referred to as Johns.
Female Donkeys are Jennies
Female mules are Mollys

donkeys come in ALL sizes From Minature to Mammoth
Mammoth is horse sized between 14.2 hands to over 16 hands.
It is Highly likely that the Sire of the foal in question is a Mammoth Donkey

[Top Dun]

Are you sure they weren't Mammoth donkeys? IF this is TRULY a male mule breeding and producing Viable semen, then he's a genetic wonder and would be the first EVER documented male mule ever known. Mammoth donkey looks like this.
Mountain was over 16 hands tall.

Originally Posted by gotta a horse

Positive. He pointed her out to me and it was deffinately a mule. There's not even a donkey on the place where she was bred.

[Top Dun]

nope not true.

Originally Posted by gotta a horse

Thank you for your help!

EDIT: Another thing I heard was that any mule stallion can breed a mare and then and only then will it produce a foal. I am assuming that is not true then.

[idlewild]

Found this, thought it was rather interesting...

Fertile mules
Several female mules have produced offspring when mated with a purebred horse or donkey. Since 1527 there have been more than 60 documented cases of foals born to female mules around the world. Mules and hinnies have 63 chromosomes that are a mixture of one from each parent. The different structure and number usually prevents the chromosomes from pairing up properly and creating successful embryos.

• Cornevin and Lesbre stated that in 1873 an Arab mule in Africa was bred to a stallion and produced female offspring. The parents and the offspring were sent to the Jardin d'Acclimatation in Paris. The mule produced a second female offspring sired by the same stallion and then two male offspring, one sired by a donkey and the other by a stallion. The female progeny were fertile, but their offspring were feeble and died at birth. Cossar Ewart recorded an Indian case in which a female mule gave birth to a male colt. The best documented fertile mule mare was "Krause" who produced two male offspring when bred back to her own sire.
• In most fertile mule mares, the mare passes on a complete set of her maternal genes (i.e. from her horse/pony mother) to the foal; a female mule bred to a horse will therefore produce a 100% horse foal. In the 1920s, "Old Beck" (Texas A&M) produced a mule daughter called "Kit". When Old Beck was bred to a horse stallion she produced a horse son (he sired horse foals). When bred to a donkey, she produced mule offspring. Likewise, a mare mule in Brazil has produced two 100% horse sons sired by a horse stallion.
• In Morocco, a mare mule produced a male foal that was 75% donkey and 25% horse i.e. she passed on a mixture of genes instead of passing on her maternal chromosomes in the expected way. There are no recorded cases of fertile mule stallions. There is an unverified case of a mare mule that produced a mule daughter. The daughter was also fertile and produced a horse-like foal with some mule traits; this was dubbed a "hule". There are no reports as to whether the mule was fertile.
• A comparable case is that of a fertile hinny (donkey mother, horse sire – the reverse of a mule) in China. Her offspring, "Dragon Foal", was sired by a donkey. Scientists expected a donkey foal if the mother had passed on her maternal chromosomes in the same way as a mule. However, Dragon Foal resembles a strange donkey with mule-like features. Her chromosomes and DNA tests confirm that she is a previously undocumented combination.

taken from Mule - Wikipedia, the free encyclopedia