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21 year old maiden mare breeding-experience

Hi everyone,

It’s my first post so please excuse literally any missteps I make. I’m also on the spectrum so I love concrete answers and evidence but please be gentle! I would love first hand experience, as I’ve already read the doom and gloom horror stories of what CAN happen.

I share ranch management with my father. So we have been going back and forth at each other about the breeding of my 21 year old maiden mare. (Her great grandmother was his college rodeo horse, her mother was my childhood/teen horse, so there’s a lot of sentimental value but she also has really excellent breeding)

I am only now back at home and helping to manage so that’s why I am looking into breeding her now. (i know it’s the end of the season, I am not entering the foal in any futurities so I am not worried about birth month.)

He wants to let her carry and foal out by herself. I originally wanted to let my 5 year old OTTB be the recipient and carry. We are at an impasse and since it is shared management it’s a whole thing.

Okay, first my older mare-
-Has been checked, is still cycling
-Her mother had her as a maiden 18 year old
-Is in incredible body condition, people think she is much younger
-but has arthritis in one leg that worries me if she gained weight.

My worries are
-uterine torsion resulting in her death (something about the uterus dropping as they age combined with the stress of birth)
-abortion of the foal

My thoughts about embryo transfer
-how much will the cost skyrocket of trying to settle an older mare and then transferring as breeding her is statistically more difficult

(This is literally my only worry)

Thank you for reading my novel. If anyone has dealt with a similar issue before, I would love some guidance. I can work myself into a frenzy with worry and it can occasionally blind me to things that will probably not be a big deal.

EDIT: moved to sport horse breeding as I’m looking for firsthand experience.


She’s 21. DON’T do it.


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Don’t do what? Don’t embryo transfer either?

What is your plan for getting a viable embryo to transfer?

I planned to take her to a very well respected breeding facility and let them do the transfer, I’ve spoken to them and they didn’t seem to think getting a viable embryo would be an issue. All initial checks from my personal vet led him to say that it shouldn’t be an issue. His personal 22 year old mare is in foal right now.

I posted here hoping to find people who could give first hand experience with this–I’ve read a lot of stuff online that is third hand information in forums but I thought perhaps I’d try here! Do you have experience breeding older mares or working in equine repro? crosses fingers

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If you really value the mare and her bloodlines and want to breed the mare, I think embryo transfer to a recipient mare is a sane, logical step. A lot of the cost associated is with paying for a recipient mare - you already have that. I’d speak to your vet about the expenses as it does depend a lot on the area you are in and who does the repro work. Even if you inseminated the mare and had the mare carry the foal, you may still be looking at somewhere around equal cost if multiple inseminations are needed. I have personally bred a 19 year old maiden mare in excellent health without any issues but she did require 4 insemination attempts to get her in foal. Had I not had a LFG contract, my costs could have been extremely high. All that to say that an embryo transfer may not be much more expensive in comparison. IMO she is not a good candidate to carry a foal regardless of age because of the soundness factor.


Thank you so much! These were my concerns as well and I am glad to get info from someone who has been through it! Her arthritis is well controlled with meds but I don’t know if she’d have to go off of them when pregnant so it’s weighed on my mind for sure.

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I agree with this regarding attempting embryo transfer.
But I agree with the other posters who are saying DON’T breed your elderly maiden mare to carry the foal.
I personally would not do it.


I have first-hand experience with breeding an older maiden mare and all went well. But my mare was 14 (and had no health issues, in fact is fit and rideable 3 years later) and even that made me fairly nervous. No way in the world would I breed a 21-year-old maiden.

I don’t have first-hand experience with doing a recip transfer but I have been told that one of the reasons that breeding facilities are able to do this efficiently is that they usually have access to several recipients at once and aren’t needing to use a specific mare; it is sometimes very tricky and expensive to get those two specific mares cycling on the the same page the way you will need.


In order to do an ET you have to get the mare pregnant in the first place. I think one difficulty is a tight cervix in a maiden mare that old. Also I think that you have older eggs that reduces the chances for a viable embryo. Just because a mare is cycling does not mean she will get pregnant. I think it may be possible but maybe expensive with multiple tries and leasing a recipient mare. It can be extremely hard to just have one recipient mare and make the ET work because the two mares have to be synced up very closely for the ET to work and that is pretty hard to do with just one mare. That is why the repro vets that do ET have herds of mares to use. I don’t have that much money to throw away!


I would NOT breed the mare to carry.
embryo transfer? Maybe depending on how much $$ I. Have to spend/lose.
Former BO where I boarded bred
A very fit, healthy 20 yr.old show horse. Horse foundered severely and was euthanized. A beloved
Farm favorite was lost.
I’m sure this BO would advise NO.


OP, you might move this to the Sport Horse Breeding tab… might get more answers from breeders there who work with multiple mares each year.

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I will share I have a friend who bred her 21 year old maiden mare. All went well. She re-bred her at 22. That also went well.

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Thank you! I really appreciate you sharing your experience.

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Thank you! I’m new so I didn’t even see that! I will!

I’m aware of all of this, I was hoping for firsthand info. And if I get a healthy baby and mother then it is money well spent imho. Thanks!

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First, rather late in the year to be thinking about getting started getting a 21yo maiden in foal. It may take several cycles to get the donor pregnant, flush a viable embryo, and scan the recipient safely in foal. You can run into issues with any of those steps. I would probably wait until next year and get an early start. I would not let my 21yo mare, maiden or prolific, carry a foal. Worked for decades on a breeding farm and in addition to the tragedies, the old mares are so unhappy and uncomfortable. For longer before and longer after foaling than the younger mares. I couldn’t do that to my own mare.


There’s a great website here:

And they have a bunch of articles that might help you in your decision to breed your mare. Like this one:

And this one:

But spend some time poking around, it’s a great education.

I agree I wouldn’t have a 21 year old maiden carry her own foal. But you’ll want a pre breeding exam on both her AND your recipient before starting down this path, because it’s awfully easy to just light money on fire when there’s actually no chance of achieving a pregnancy. Cross your Is and dot your Ts to make sure it’s actually got a chance of success first.

And @Bonnie2 definitely brings up a good point–it’s awfully late in the year to start this process.


Wow! This is incredible information, thank you. I’ve been pro ET from the get go, but this arms me with sources. And it is late in the year…it couldn’t be helped but I wish it wasn’t so–I will do some thinking on it! Thank you again!