So I have a Friesian filly, I’m wondering how tall she will end up (roughly) I’ve heard so many different stories so have absolutely no idea at present. Her dam was 15.3 and sire 16.3. She currently stands at 15hh at almost 2 years old.
You can do a string test for a rough estimate-- either the ergot to elbow pivot, or the cannon bone measurement.
There are plenty of tutorials online if you google “string test for horses.”
I agree with the above, a string test may give you an idea… However, I string tested my long yearling when I got her five years ago. She string tested to be 16 hands. She’s coming 7 and just a hair over 15 hands! It’s not always accurate.
Additionally, relying on parent’s height is rarely accurate. The most accurate prediction is to look at siblings.
The general rule for horses is add 2h to the 12 month height, and 1h to the 24 month height.
Beyond that, string testing as described above is pretty accurate, but won’t be for horses who have short or long legs relative to their current/finished height.
JB - I like the add 2h to the 12 month height and will also string test then. I have an 8 month old Friesian filly currently just at 14H. I’m hoping for 16.2ish. Her dam is 15.3, sire is 16.2, but sire throws tall offspring taller than himself frequently. We’ll see!
Did this with Seven when I bought her at two. She was 16.1. Figured I had a big horse on my hands!
She’s still 16.1 at 8 :lol:
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The information I’ve seen on measuring the cannon bone is that it should be done no later than 6 months. You measure from the coronary band to the crease in the knee joint. One inch is one hand. I’ve never tried it, though, to see if it actually works.
Most of the growth plates in the leg fuse by about 18 mos. - 2 years old. The entire horse stops growing around 5 y.o. but they don’t gain a lot of height, the joints are fusing. We have Shire/TB cross who was born on the farm, and until he was around 4 or so he had Shire legs. Then he started filling in more. He’s about 7 now, and it you know your draft breeds you can see the tall legs. Someone told me was a Belgian cross - no way!
It needs to be done after a year, since that’s about how long it takes for the length of the lower leg bones to finish. Growth plates aren’t closed, but all significant length is pretty much done. No later than 6 months doesn’t make sense. You need all the lower bones to be finished growing up.
Most of the growth plates in the leg fuse by about 18 mos. - 2 years old. The entire horse stops growing around 5 y.o. but they don’t gain a lot of height, the joints are fusing. We have Shire/TB cross who was born on the farm, and until he was around 4 or so he had Shire legs. Then he started filling in more. He’s about 7 now, and it you know your draft breeds you can see the tall legs. Someone told me was a Belgian cross - no way!
They don’t actually “fuse”. The cartilage nature of the growth plates finishes turning to solid bone, which is different from joints fusing.
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JB, you are right about calling it fusing. I should know because I do medical coding for a living! I’ll beat myself up with my coding book after lunch.
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Something I learned on COTH is that if horses are gelded young, geldings grow taller than stallions because stallions use more energy bulking up. So geldings and mares with the same genetics will tend to be taller than the equivalent stallion. Thus if the mare and stallion are the same height, a mare or gelding from that pair stands a good chance of being taller than the stud
This is also true of dogs.
My pally string tested to be 15.1. He sticks at 15.3 at 5 years old.
Not really, one reason gelding before two, when the growth plates close, may grow an extra 1/2" is because those long bones tend to take 6 more months to close as geldings and grow that bit more, when the hormone surge doesn’t push them to close earlier.
Tesio was a very prominent race horse breeder and trainer.
He measured with the string over 200 weanlings, then yearlings, then coming twos as they started in training, then followed most of those for several years.
He said that every one of those he measured ended up within 1/2" of the predicted growth by his string measure.
That was the standard way to measure from the middle of the ankle to the point of the elbow, flip the string up and that is where growth should be at maturity, within that 1/2" difference he found, which is very close.
Those were all TB colts and fillies, mostly colts, but the TB and AQHA colts we measured all were right on the dot also.
Now, properly raised and managed, that too may make a difference.
If someone would measure all foals born one year, any breed and some will be cared for right, some half starved, some kept in a little pen, others in large pastures, that is something that could alter the final measurements.
I would say, for most horses managed under most sensible conditions, the string test should be close.
The difference is pretty negligible though. The surge of testosterone as stallions “come of age” hastens the closing of the growth plates, so all else equal, they finish their height sooner than those gelded earlier. But we all know there are stallions taller, and gelding shorter than their genetics would have guessed. It’s less about any bulking up, and more about how the testosterone works.
My coming 2 year old string tests to 16hh, but judging from her sibings I think she will be closer to 15:3hh
My mare string tested between 16.1h and 16.2h using the two methods.
At 6 years old, she was barely 16h. But in her 8 year old year, she shot up to just a hair under 16.2h.
Despite string testing countless horses over the years, she’s the only one who I both had the presence of mind to string test at the right time AND still owned her at maturity for comparison.
I string tested my filly on at 12 months and both coronary to knee and ergot to elbow string tests estimated 17 hands exactly. On her 1st birthday she was 15hh at the wither so if the 1y/o height + 2hh is accurate,17hh would also be expected. Now at 21mo her butt is 15.3+hh and her wither is a little lower. Parents were 16.2 & 16.3, but each sibling out of the dam seems to be bigger than the previous one. My barnmate has a colt 1 day younger & QH, and at 21 months he is just 1" taller than he was 9 months ago, but looks like a small adult horses instead of a lanky baby.
Ok, I stand corrected. The discussion I read seemed to suggest it was a significant hieght difference including in dogs but it’s not something I’ve seen IRL.
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