True Roans and White Markings

Linda_D · Posted: Sat Aug 01, 2009 5:58 am Post subject: True Roans and White Markings

Is it just me, or does it seem that most true roans don't have lots of white markings? I don't think I've ever seen a true roan that had also looked to be sabino or splash. Is it possible that minimal white on head and legs is an effect of the Roan gene?

I'm most familiar with AQHA true roans, so maybe the bloodlines have something to do with the modest markings since I think that most AQHA true roans today trace back to the Joe Hancock sons, Roan Hancock, and especially, Red Man, through Blue Valentine. Although Joe Hancock had a blaze, I don't believe Roan Hancock or Red Man did. Blue Valentine didn't. None had much in the way of white on their legs if they had any at all.

Are there true roan paints?

NZ Appaloosas · Posted: Sat Aug 01, 2009 7:03 pm Post subject:

Linda_D, I asked your question (well, linked to this thread) on a colour forum, and here are the responses so far: http://www.equine-color.info/phpBB3/viewtopic.php?f=3&t=987 There are some photo examples in their answers.

Diane
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Linda_D · Posted: Sun Aug 02, 2009 9:08 am Post subject:

Thanks, Diane!

It seems that others have noticed that most true roans don't have a lot of white markings on their heads and legs ... except for those that get a shot of tobiano or maybe frame which produce true roan paints.

x factor fan · Posted: Fri Aug 07, 2009 7:12 am Post subject:

Interesting observation.

Base coat color (red, black) sabino, Dominiant White, and Classic Roan reside on chromosome 3. It may be that classic roan supresses the activity of sabino on the other chromosome 3. Or that classic roan + high levels of sabino is also a embryonic lethal.

A horse can only have one copy of the roan gene, two are lethal. (Yes there are a handful of exceptions, but the majority of roans only have one roan gene)

Inyureye · Posted: Tue Aug 18, 2009 12:26 pm Post subject:

INteresting. Does having white absolutely mean sabino? I mean, these roans, on the other page, could be roans with white markings. What is the difference between having white, say stockings or white patches and having gthe sabino gene? Maybe not all white patches are sabino...
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NZ Appaloosas · Posted: Wed Aug 19, 2009 3:49 pm Post subject:

Nope, having white doesn't absolutely mean having sabino. However, rabicano roaning/ticking seems to always have the white barring in the tail, so without that, sabino is the more likely culprit. Splash blazes tend to have certain characteristics that sabino blazes don't have (i.e., wanting to cover the eye/nostrils, sliding off to one side or the other), and blazes where sabino and splash are 'fighting' are even more interesting <g>

With a test available for only one form of sabino (SB-1), and that really only being in a handful of breeds, it could easily end up that the word "sabino" turns into being a word like "overo"--something to describe that which does not fall into other categories (i.e., tobiano, splash, etc.).

Diane
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Robin · Posted: Fri Oct 30, 2009 12:12 pm Post subject:

You are right a lot of roans do have very little white. It is mostly because of the bloodlines. Most people who breed roans want them to have very little white. They feel that a horse having white feet is a weakness.

Roan, Sanbino & Rabicano are 3 different genes. A horse can carry a roan gene long with a Sanbino or Rabicano gene.
White marking such as blazes, stars, socks have nothing to do with any of these genes.

Also it has been proven that a horse can carry 2 roan genes. The lethal roan gene is a myth. Some people do still believe that it is so & that horses that produce 100% roans are freaks of nature who survive the lethal roan gene factor.
The Rabicano gene is what causes horses to have coon tails & ticking
At this time there is still no test for a homozygous roan, but US Davis is working on one.
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NZ Appaloosas · Posted: Fri Oct 30, 2009 2:08 pm Post subject:

As there's no test for classic roan yet, it hasn't been proven whether classic roan is lethal or not.

Diane
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Robin · Posted: Fri Oct 30, 2009 2:38 pm Post subject:

I stand corrected UC Davis does now have test for homozygous roan LOL well kind of
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