# Breeding smaller mare to a bigger stallion



## LoriF (Apr 3, 2015)

From what I have read about this subject. The foal will grow in utero to the extent that there is room for. After birth it will grow to it's genetic potential if taken care of properly. Personally, I wouldn't think an eight inch difference is that much at that stage.

How they are being bred may make a difference as a 16.2 hand stallion may be too big for a 14.2 h mare during breeding unless it was done by AI. I say "may" as I really don't know from first hand experience.

There are risks giving birth for any animal which is why we take precautions for minimal loss.


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## Hotrodz4me (Jul 17, 2016)

My SIL gets asked this all of the time. She worked for a woman that would breed all of her saddle mares to a Belgian stallion. It mainly is about conformation that allows for ease of passing through the hips. Even though the hormones relax everything there can be distortions that make it harder for the mare to deliver a larger foal or really any foal in some cases. The mare is supposed to control growth in the uterus but that doesn't always happen effectively enough. The foals are usually bigger than average and just slightly out of correct position combined with that larger size and poor conformation and you lose two. She says if you are going to then AI is better than breeding them together because of what Lori said. Better to buy what is on the ground if you want a cross or use a bigger mare and smaller stallion. You also have to look at what you are breeding for. You don't just get an average of the two.


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## Dreamcatcher Arabians (Nov 14, 2010)

It all depends on the mare. If your mare is 14.2 but built like a 16 hh mare (wide and has a lot of room inside her body), then it really won't make a huge difference to the foal. Especially if she's maiden as that tends to be the smallest foal she'll have, not necessarily small when he grows up, just at birth. Most of the time the "fishbowl" theory applies. The foal will grow to the amount of room he's got and that's it until he's born. That's not 100% but 'too large' foals are fairly rare. But, you can be borrowing trouble in the form of other dystocias, the foal needs room to move while inside and needs to be able to get in the correct position in the birth canal. If he's too big, he can get hung up with a shoulder under the pelvic rim, not be able to turn and come out breech, or not be able to get his legs forward and ready to come out before the mare starts pushing. 










Foal should present like this: 










I bred 2 smaller mares, around 14.1 hh to my stallion who is 15.2-3 hh. We did AI because he was just too big to comfortably be able to use live cover. Not only is he big, but he weighs a LOT and is super muscular. The first mare was not real heavily built or large inside, we rode her right up to the day of delivery, and she delivered a little early (1 week) and delivered everything just fine. The second mare is built like a tank, makes 2 of the smaller mare, she got huge by December (not due until April), had to stop being ridden due to her discomfort, and we had a foreleg retained and had to manipulate the foal to get him out. Once the foal was out, we had no further problems. 

Another thing I've had occur is during the 8th-9th month when the foal is its most active prior to birth, can cause the umbilicus to twist to the point it stops nutrients from reaching the foal. When that happens it causes a late abortion. It seems to involve foals with longer umbilical cords. The only mares that I've had that happen in are the smaller ones.


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## jaydee (May 10, 2012)

I've personally never had a problem breeding up - a smaller mare to a bigger stallion. I had a 15.2 TB mare and a 15.2 TB x Arab/welsh mare and apart from the 14.2 section D we used one year they were always bred to 16.2 stallions and foaled OK. My DH had to help with one foal but that was because his legs were all in the wrong place inside the mare - he was quite a small foal even though he grew to 17 hands, her foal to the Welsh cob grew to over 16 hands.
Where I worked we bred a 15 hand TB/welsh/arabian (what is now called a Sport Pony) to 16.2 TB's and twice to Irish Draft stallions with no problems
I knew someone who used to breed British show cobs from 13.2 - 14 hands welsh pony mares and a Suffolk Punch stallion - no problems.


That doesn't mean to say there would never be a problem but all sorts of things can go wrong when you breed


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## SilverMaple (Jun 24, 2017)

If your cob mare is wide and stout, and the stallion is leaner built, I doubt there will be an issue. One area breeder crosses her small 14-hand cow-bred Quarter Horse mares on a 17h Thoroughbred stallion frequently for barrel horse prospects and has never had an issue. Last year she AI'd one mare with a Perheron stallion and got a nice foal for her husband's future saddle horse. She was so enamored with that cross, she's bought some Percheron mares now, and plans to use the larger mares with smaller studs, primarily so she can use live cover (cheaper) without as much risk to the mare.


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