Guess What Breed Our Mustangs Are

Mustangs are like a box of chocolates; you never know what you’re going to get. While a lot of Mustangs have Iberian breeding descending from the original conquistador’s horses, other herds have so many feral ranch and farm horses mixed in that they’re more closely related to Quarter Horses or Draft breeds than they are to an Andalusians.

Texas A&M runs a horse genetics laboratory. According to their website, “Throughout the years we collected and genotyped an extensive number of horse breeds and populations from around the world (see selected publications), however to represent our reference panel for ancestry testing we selected 50 breeds that are most common for the North America and also represent the major horse groups: draft horses; ponies; Oriental and Arabian breeds; Old World and New world Iberian breeds.”

Copyright: Texas A&M

I know a lot of people who have sent their Mustang’s hair in for a genetic test. It’s really easy: You just pluck about 40 hairs from the mane (you need the root), fill out a form, and send it all in with a check for $40. You can do it for any horse you’re curious about, I just only know of people who’ve done it for their Mustangs. I’ve been wanting to do it for a while and finally remembered to pull some mane hairs from Eugene and Levi a few weeks ago.

The tests are not 100% accurate. I really recommend reading this article by Texas A&M if you’re at all interested in horse genetics. It’s fascinating. The test works by comparing your horse’s DNA genotype to the 50 breeds they have in their reference panel. Texas A&M then sends you a report with the “three breeds with the highest probability that the subject horse could have come from the breed in order of their probability of being an ancestral breed.” Closely related breeds can also make the test not completely accurate. Because related breed groups can be so alike, the test can identify a half Belgian/half Suffolk as having Percheron DNA. Here’s a cool chart from Texas A&M on how the breeds relate:

Copyright: Texas A&M

So we knew in advance the test wasn’t going to tell us exactly what breeds our Mustangs are, but I was still curious and wanted to find out at least what they most likely are. I have the test results and I’ll share the results in tomorrow’s post, but today I thought I’d let people guess. I know I had my own guesses before getting the reports back and I’m curious what other people would think.


Eugene was rounded up from Outside of Herd Area in Elko, Nevada in 2009. He’s 15.1hh, bay, and slightly gaited. We actually didn’t realize he was gaited when we adopted him and we never ask him to do it since he does dressage, but he’ll pull out a little running walk sort of gait if he’s in a hurry or more often when he’s spooked.

custom freezemark saddle pad for Mustang


Levi was born in Fallon facility in 2010 and I don’t know his dam’s herd, so he’s truly a mystery. He’s 16.2hh, palomino, and heavy boned.


I’m really curious to hear what breeds you would guess they are. Please leave a comment below.

17 thoughts on “Guess What Breed Our Mustangs Are

  1. julesatthebarn

    Eugene def has Spanish blood, two Peruvians at my barn have the same head, guessing Levi has some sort of cold blood.

  2. Sarah

    I feel like of the mustangs I’ve met, Eugene looks more closely like them, more Spanish type. So I’d guess maybe something Spanish/Morgan/Paso for him. For Levi maybe QH and Belgian. Wild guesses. hahah.

  3. hayflinger

    I question the validity of their flowchart in lumping Haflingers in with the draft breeds. They’re not really “drafty” like that. Me thinks Texas A&M is just using a characteristic type of flow chart, and they don’t know what they’re talking about anyway.

    Part of me wants to send Jet and Mitch’s tail hairs in, for a lark and see what they say. Especially if Mitch comes up as something else. Ha!

    I’d say that they love to use Criollo in their charts, so I’m going to guess that is part of Levi’s “breeding” along with Suffolk Punch.

    Eugene is oh, I dunno … Caspian Pony x Mangalarga Marcharador.

    1. Olivia Post author

      If you read the article they explain that the pony breeds actually have more in common genetically with drafts that with anything else. So it’s not that Haflingers look drafty, but that they have more in common with them genetically

  4. emma

    oooooh i’m terrible at guessing games (for many many reasons, never ever invite me to be on your trivia teams!) but am super curious to hear your results!

  5. L. Williams

    Uhm I’m bad at this stuff so I’m just going to guess that Eugene is Walker something something and Levi is Halflinger something something

  6. Stacie Seidman

    Totally missed this post somehow! I’m late to the party so I won’t guess, but wanted to say how interesting this all is! Also interesting is how most of my favorite breeds are all piled in together there as being pretty similar. Not shocking!

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