mulesuk

any one can help

The site you've promoted looks interesting or you could try Dave at Stonehill Dokeys who's linked to it,he had a 13hh Jenny off me a few years ago.
What part of the country are you in?

do you think a mammoth 15 hands could serve my 12 hand jenny

Easily I should think but I'd prefer to use something closer to her own size for ease of birth

"horsey" people usually say a difference of two hands is the maximum but there is no doubt that people do cross small pony mares with large stallions and most get away with it with no problems. I'd also want to consider the age of the donkey mare, whether she has foaled before, has she had any problems foaling before, and have a good look at type - so I'd say no if you have a little narrow Jenny and the donkey sire is built like a brick sh*t house with a head like an elephant!!!!

I Have expereince here..excuse any typos..my glasses are lost!
ONCE I would have said should be ok .I have since researched this as much as possible.It is not an expert opinion just my considered observations expereince and conclusions from what little reseach I could find.
I would say-think carefully as to your particular situation the anwser is yes maybe or no
First of all--there is little research done on donkeys BUT fact they are already known to have a higher rate of dystocia then horse mares -reasons unknown.perhaps because of the steepness of the croup in some ..perhaps its because if they carry fat much of it is internal ,crowding the birth passage.
Or maybe becuse their cervix protudes out further then a horse mares,therefore more likely to be injured and have adhersions.
Donkeys pelvis are not as wide as horses or ponys to begin with... We did use a mammoth jack over that size and had no problem,but other pwners did have stuck foals(dystocia)
Donkeys foals have big heads compared to horse foals..and to a mammoth or similar ,can be big boned.

Now ,I do not want to pursue mixing in smaller genes for on-breeding other reasons..such as having the foal get its size from ancestors while being carried by a jenny who may be tallish but not nearly as roomy as she need be.

A Mammoth jacks may be eg 14.2:""hh but does his line contain bigger aniamals,up to 16hh and some quite drafty ?lThe foal can be of that potential size. ..some Mammoth foals can be 10.1hh born.See the possible problems?.
If you are looking to breed for a bigger foal as a terminal cross for riding etc ..some may be a few inches taller then their dam,also gelding early seems to make them even a bit more taller.
A few of ours were up to a hand bigger, some only inches ,and one was actually smaller then its mother -the small genes can come though in the next generation too...so if you want to breed on a predicatble line of large donkeys thats a possibilty .
In adding it all up-I found was better to bite the bullet and get the breed and size meant to carry big fpals.Thats way hopefully lessen the chamce of problems and also have more predicatbile outcomes.
If breeding a smaller jenny to a big jack these are the main points I consider-Has she foaled before?easily?Whats her conformation over the croup etc?
Is she carrying fat-as what you see on the outside is half of what will be unseen inside.If you are using a big jack you may be wise to use a breeding roll.I never paddock serve.As above mentioned, Jennys have a cervix that protrudes and could be injured by a large jack ,may not affect her this time,but cause problems for further pregancies..as could a stretched uterus from a large foal/Keep her active all through pregnacy for good muscle tome and avoid obeseness.Good luck.