[tweiderh]

Yesterday afternoon I read a small blurb in the Novemer issue of Horse Illustrated and yes... it was about a mule mare that reproduced much to the surprise of her owners... how is that possible? I can't remember the name of the farm and I don't have the magazine handy at work here, but the colt born was named Amos. Anyone else come across this? thoughts?

[Top Dun]

It's a genetic mutation.
A donkey has 62 chromosomes and a horse has 64 so a mule USUALLY has 63 and that makes them sterile. BUT occassionally the chromosomes don't seperate correctly leaveing them with either 62 or 64 chromosomes and that then makes them fertile. It's really rare and there is still like a one in a million chance of that happening, but it does happen.

[tweiderh]

I wonder if the sire was also a mule... ? or a horse.. I don't remember if it said.. I was always under the impression that mules are ALL sterile, then again I've never ran into anyone that knew the gentetics so well. Thanks

[prairienights]

Originally Posted by Top Dun

It's a genetic mutation.
A donkey has 62 chromosomes and a horse has 64 so a mule USUALLY has 63 and that makes them sterile. BUT occassionally the chromosomes don't seperate correctly leaveing them with either 62 or 64 chromosomes and that then makes them fertile. It's really rare and there is still like a one in a million chance of that happening, but it does happen.

Exactly. It was probably a trisomy or something somewhere, meaning instead of two chromosomes for every pair, one pair had 3, giving the mule 64 chromosomes.

Do you know what the sire was? A stallion or a jack? I suppose it's possible that the foal might be fertile too.

[Top Dun]

As of yet there has not been ANY documented fertile male mules because usually they are gelded early to prevent studish behavior. However it's quite common in many places to put the mare mules in with both stallions and/or Jacks (male donkeys) for companion animals Because they know the mule usually can't produce a foal. If the sire of the foal from a mule is a horse, generally the foal will look MORE horse like. If the sire of the foal is a donkey then generally the foal will look more donkey like.

I haven't seen the article you read so I"m not sure what the specifics are, but there was a mule at Texas A&M quite a while back who produced two or three foals. One from a donkey and at least one or two from a horse.

Originally Posted by tweiderh

I wonder if the sire was also a mule... ? or a horse.. I don't remember if it said.. I was always under the impression that mules are ALL sterile, then again I've never ran into anyone that knew the gentetics so well. Thanks

[Little Red Dun]

Here's another article about the mule mare (Kate) and her foal.

NPR : Befuddling Birth: The Case of the Mule's Foal

I thought it was very interesting myself.

[Top Dun]

COOL I'd be interested to see if that foal (as a male) would also be fertile. He looks quite "mule like". And he's CUTE!!!!