Embryo Transfer Minis into Average Sized Horses?

[Tremor]

I'll start out by saying this.

I'm cross posting this from another forum I frequent with the OP's permission, because frankly I thought we would get more info if I asked the question here.

Hi guys I've noticed this year quite a few mini and/or their foals have died during the birthing process or have had an extreamly though time at it. I was wondering if embryo transfer was possible with them and if so is there anyone that does it with the recepient being an average size horse.

 

Thanks for humoring me

So, has anybody ever transfered the embryo of a miniature horse into an average sized mare (aka not a miniature horse but like a QH, TB, etc....)

If so, what happened?

We were thinking that the foal would actually be bigger than an average miniature horse foal because of the amount of space in the womb of the bigger mare than the mini mare.

Um, please do answer our question. It was purely out of curiousity and well, they're counting on me to find the answer! LOL!

Thanks,

Julia

 

[Raine Ranch Minis]

Interesting

 

[rabbitsfizz]

Well, it would not say much for the "industry" if the mares could not carry their own foals, now would it?

It's a bit like Bulldogs, which can now only be born by caesarian.....if it is not able to birth it's own young, do not breed it, is a pretty good maxim, in my book.

I know what the OP is saying, though, but if the problem is that the mares are having such huge problems (and I do not think there are any more this year than last, or even ten years ago) then we should address the problem, not patch it up.

 

[Raine Ranch Minis]

Well, it would not say much for the "industry" if the mares could not carry their own foals, now would it?

It's a bit like Bulldogs, which can now only be born by caesarian.....if it is not able to birth it's own young, do not breed it, is a pretty good maxim, in my book.

I know what the OP is saying, though, but if the problem is that the mares are having such huge problems (and I do not think there are any more this year than last, or even ten years ago) then we should address the problem, not patch it up.

GOOD POINT!!!

 

[Tremor]

Well, it would not say much for the "industry" if the mares could not carry their own foals, now would it?

It's a bit like Bulldogs, which can now only be born by caesarian.....if it is not able to birth it's own young, do not breed it, is a pretty good maxim, in my book.

I know what the OP is saying, though, but if the problem is that the mares are having such huge problems (and I do not think there are any more this year than last, or even ten years ago) then we should address the problem, not patch it up.

I do see what you're saying and I agree.

I think what sparked this question on the other forum was the fact that us members are very much addicted to MareStare, and well on MareStare there have been more than a couple miniature horse foals and mare lost. I do not think that this is a huge problem at the moment.

 

[Miniv]

It's my understanding that smaller breeds of dogs also have more birthing problems, but I've never heard of embryo transplants for them.......just C-sections.

I happen to also feel Jane/Rabbit makes a very good point. Plus, if someone were to do a successful embryo transplant to a - let's say - 16+ hand mare, how the heck is the poor little mini foal supposed to REACH THE GROCERIES???

 

[disneyhorse]

It's my understanding that smaller breeds of dogs also have more birthing problems, but I've never heard of embryo transplants for them.......just C-sections.

I happen to also feel Jane/Rabbit makes a very good point. Plus, if someone were to do a successful embryo transplant to a - let's say - 16+ hand mare, how the heck is the poor little mini foal supposed to REACH THE GROCERIES???

Ha ha... I was thinking the same thing... first of all it's a LOT more to feed a full size broodmare than a mini broodmare... secondly how is the foal supposed to nurse off of the surrogate mare... thirdly I wouldn't put a mini in with a big horse and sometimes mares discipline their foals a little and that could be deadly with a bigger mare...

I suppose you could just use a larger pony mare as a surrogate though. The only wide-scale surrogate mare use I've had experience with was a Percheron breeder in central CA... he actually used draft PMU mares that he rescued and put full-sibling Percheron embryos in them. He did six that year, so that he'd have a fully-related-and-thus-closely-matched team of six horses to drive in a hitch. I thought that was kind of interesting, and it gave jobs to six grade PMU mares.

Also, embryo transfer is pretty involved and somewhat expensive. Not that I'm cold-hearted or anything, but the average miniature horse is not "worth" a lot dollar-wise, so while you'd see ET happening with a $80,000 Andalusian mare, I'm not sure you'll see it as often with a $4,000 miniature horse mare. Of course it's totally up to the owners though!

 

[Nathan Luszcz]

Very interesting thoughts.... I've heard of the opposite (drafts to small pony mares), but never ponies into drafts. I'd imagine the process up to birth would be easy. The ET process would be difficult, as it involves a lot of rectal palpation.

As far as the foal reaching, remember that the mare dictates the foal's size.... so it COULD come out almost full sized! It just wouldn't grow very quickly. The end result would be the same size as if it'd had "normal" miniature parents. Very good thought! Now I'm all curious.

 

[Genie]

miniv said what first crossed my mind. I have a 15 inch colt here that wouldn't have a chance if born to a normal sized horse.

 

[minimomNC]

I think if I had a tiny mare that was an outstanding individual but I was afraid of her having a foal due to her size, (and I had the money) I would use a larger mare (not a big horse mare) maybe a smaller B mare that might not be breeding quality as a surragate. It would enable me to have a foal from an outstanding tiny mare and use a mare that shouldn't be reproducing herself.

 

[midnight star stables]

I suppose you could just use a larger pony mare as a surrogate though. The only wide-scale surrogate mare use I've had experience with was a Percheron breeder in central CA... he actually used draft PMU mares that he rescued and put full-sibling Percheron embryos in them. He did six that year, so that he'd have a fully-related-and-thus-closely-matched team of six horses to drive in a hitch. I thought that was kind of interesting, and it gave jobs to six grade PMU mares.

Heh, neat!

As far as the foal reaching, remember that the mare dictates the foal's size.... so it COULD come out almost full sized! It just wouldn't grow very quickly. The end result would be the same size as if it'd had "normal" miniature parents. Very good thought! Now I'm all curious.

Since the real parents are miniatures, the foal would be too. It'd just have more room in the womb, as genetic are genetics... Right?

Neat idea. I wouldn't do it (couldn't afford it) but neat none the less. I have had a miniature mare artificially inseminated though, for what it's worth.

 

[weebiscuit]

It's my understanding that smaller breeds of dogs also have more birthing problems, but I've never heard of embryo transplants for them.......just C-sections.

I happen to also feel Jane/Rabbit makes a very good point. Plus, if someone were to do a successful embryo transplant to a - let's say - 16+ hand mare, how the heck is the poor little mini foal supposed to REACH THE GROCERIES???

This is the exact point that needs to be made! We have a small 14hh horse we just bought last month for our 8 year old granddaughter, and we thought it would be a hoot to do artificial insemination on her with one of our stallions' semen, but after two seconds of considering that I told my daughter in law that even a 14hh cross with a 30" cross would most likely result in a foal unable to reach the milk bar! So it was a quickly dismissed thought.

If an actual miniature embryo were implanted in a full sized mare... no way would the foal be able to nurse.

And like someone else said, if the miniature mares aren't able to carry a foal, I think the purpose of implanting embryos simply defeats the entire purpose of breeding miniatures.

 

[Tremor]

Thank you so much for the replies guys!

I was wondering though if anybody knew if it had been done before, like somebody said earlier about the TB's into Shetlands? Maybe as a study for research? Maybe with a breed that is close to the Miniature Horse?

Or, maybe you could give us some more theories on what would happen to the resulting foal (NOT including feeding help because of height.

)

 

[Lewella]

There was research published in England in 2004 where they transferred embryos from Thoroughbred mares to Pony mares and embryos from Pony mares to Thoroughbred mares. They also used control groups of Thoroughbred in Thoroughbred foals and Pony in Pony foals to compare the results - http://www.reproduction-online.org/cgi/content/full/127/1/67

They found that the pony foals gestated in Thoroughbred mares were larger at adulthood than the pony foals gestated in pony mares. They also found that the Thoroughbred foals gested in pony mares were smaller at adulthood than the Thoroughbred foals gestated in Thoroughbred mares. They concluded that the placental size of the mares had a great deal of influence on the birth size and later adult size of the foals.

So if you were to transfer the embryo of a mini into a significantly larger breed the resultant mini foal would be born much larger than it would have been from a mini mare and mature much larger than it would have from a mini mare.

 

[midnight star stables]

There was research published in England in 2004 where they transferred embryos from Thoroughbred mares to Pony mares and embryos from Pony mares to Thoroughbred mares. They also used control groups of Thoroughbred in Thoroughbred foals and Pony in Pony foals to compare the results - http://www.reproduction-online.org/cgi/content/full/127/1/67

They found that the pony foals gestated in Thoroughbred mares were larger at adulthood than the pony foals gestated in pony mares. They also found that the Thoroughbred foals gested in pony mares were smaller at adulthood than the Thoroughbred foals gestated in Thoroughbred mares. They concluded that the placental size of the mares had a great deal of influence on the birth size and later adult size of the foals.

So if you were to transfer the embryo of a mini into a significantly larger breed the resultant mini foal would be born much larger than it would have been from a mini mare and mature much larger than it would have from a mini mare.

Very interesting! Thanks Lewella!

Interesting about the placentas, must have to do with the increased/reduced hormone levels.

 

[Nathan Luszcz]

Like I said, the mare dictates the size of the fetus, not genetics. The adult size is dictated by genetics, but not foal size.

 

[Lewella]

Like I said, the mare dictates the size of the fetus, not genetics. The adult size is dictated by genetics, but not foal size.

The English embryo transfer study showed that maternal size DID dictate adult size. The Thoroughbred foals gestated in pony mares were scaled down versions of their Thoroughbred gestated in Thoroughbred counterparts as adults - they did not achieve their full genetic potential height. The pony foals gestated in Thoroughbred mares were also LARGER adults than their pony gestate in pony counterparts - they surpassed what their genetic height should have been.

 

[ohmt]

Very interesting, thanks Lewella! I bet it's because they will stick to the same percentage growth of their birth height as a normal mini from mini and thoroughbred from thoroughbred? The thoroughbreds from minis would not be able to get to their 'normal' size because their bodies just would not be able to handle that much growth after gestation. Then the minis from thoroughbreds probably stick to the percentage rule so if they're born larger mature larger.

 

[Eagle]

Not what the op asked but we do this with our show jumpers. last year we had 4 full brother and sisters born from surrogate mothers. They were all different sizes at birth but are starting to even out now. the 3 born the year before are all now taller than their parents and the surrogate mares were all much bigger. the gestation also varies widely. there was nearly 30 days from 2 mares last year that were implanted on the same day.

 

[Margo_C-T]

When my kids were small, I went to look at a pony for them. 'Skeeter' was a 10.2 hand pinto gelding, reported to be sired by a bay QH and out of a little pinto Shetland mare. Just to try him out, I put my 17 lb. Barrel racing saddle on him and rode him myself...for a few minutes(I was much 'trimmer' at the time!)He'd been properly 'broke' by an ex-jockey; had been roped off of and otherwise 'used' like any working horse. We bought him(and he was a GREAT little guy, safe, dependable, well-mannered--always. When my kids outgrew him(the youngest hadn't yet, but lost interest, and we were looking at a move..the one we made to up here), I sold him to a local ranching family w/ several very young kids, who were more than thrilled to get him, and who kept him until he passed of old age!

I went to see his dam right there in town(Safford, AZ). She was an 'original' island-type grade Shetland, and very small...probably not over 34-35" tall, if that. Locals who knew the horses told me the sire was probably 14.2 or so. Sorta proves the point here, I'd say.

Margo