# Bay horse question



## QHDragon (Mar 6, 2009)

There is probably no easy answer to this, but I am curious, what makes one bay horse be a deep almost black looking bay, and what makes another horse be a firey red bay? And when breeding bays together, if you breed two dark bays are you going to get a dark bay? Or could they be any shade of bay? :lol:


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## Poseidon (Oct 1, 2010)

If you breed two bays, you'll get either bay, chestnut, or black. My friend's thoroughbred is a flaxen chestnut and both of her parents are bay.


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## Chiilaa (Aug 12, 2010)

You're right. There is no easy answer. 

Sooty is one factor that can make horses different shades. Countershading is another. Both of these put dark hairs into the coat. Given that both of these are thought at this time to be independent of any specific colours, they may or may not be passed down to offspring.


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## lilkitty90 (Nov 11, 2009)

even without sooty at all. i always wondered the same. like a dark/black bay and a "blood" bay. whats genetically the difference? is this what you mean? i would like to know myself as well!


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## NdAppy (Apr 8, 2009)

As of right now (I am prefacing with this as you never know what they will discover about color genetics in the future), there is no genetic difference between the shades of bay (or shade of chestnut/sorrel or shade of black).


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## TheLastUnicorn (Jun 11, 2010)

I was under the impression that there are genes which can alter the amount of dark/light "shading" on any horse? (like Sooty, or Pangere (sp?))


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## NdAppy (Apr 8, 2009)

Sooty and pangere can do that. BUT those are not the genes that affect what shade a color is expressed as. They modify it.

Basically black and red (chestnut/sorrel) are the only two base colors. Everything else is a modification of those color, i.e. a bay is a black that has had the color modified by agouti into restricting black to the "points," and so on and so forth with the rest of the genes.


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## TheLastUnicorn (Jun 11, 2010)

Ah...yes, that's right. I think I was not quite "getting" the original question at first so I reread it, I understand, now, what's being asked.


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## CheyAut (Nov 26, 2008)

A "black bay" is caused by the At allele, while a bright bay is caused by the A allele. A is dominant over At. Pet DNA of Az is the only lab who tests for At, with all other labs, they only test for a (no agouti, so black stays black vs being bay) and so anything not a is reported as A, even if it's At.


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## NdAppy (Apr 8, 2009)

CheyAut said:


> A "black bay" is caused by the At allele, while a bright bay is caused by the A allele. A is dominant over At. Pet DNA of Az is the only lab who tests for At, with all other labs, they only test for a (no agouti, so black stays black vs being bay) and so anything not a is reported as A, even if it's At.


At is *brown*.

Black bay is a misnomer. There are three variations to agouti. Bay (A), Brown (At), and Wild Bay (A+)


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## CheyAut (Nov 26, 2008)

Yes, but most people call them "black bays" which is why I had it in quotes


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## NdAppy (Apr 8, 2009)

;-) Figured that, but continuing to refer to them by "black bay" instead of brown, which is what they are, is continuing to enforce they aren't brown when infact they are.


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## trailhorserider (Oct 13, 2009)

Okay, I'm confused again!

I don't understand the term "brown." The points are still black. The mane/tail are still black. The body is brown. But it's still a bay, correct? 

Case in point, here is my old Arabian gelding (in both summer and darker winter coats). I always thought of him as a dark bay. But I since I have joined this forum, I think he is "brown." But he's still a bay, right? Afterall, he has black points. 

So anything that is any shade of brown with black points, I call a bay (unless it is something like buckskin of course). So is that correct? Or is "brown" totally something different? And if that is the case, how do you know you are looking at a brown vs. a dark shade of bay?

In other words, is "brown" simply a variation of bay? Or is "brown" NOT a variation of bay?


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## Eastowest (Mar 26, 2009)

*Brown and bay are genetically different. brown is At, bay is A. However there are still varying shades of both due to other factors-- it can be hard to visually differentiate between the darkest A bays and the lightest At browns. *

*I have read somewhere that there is some evidence that a homozygous brown AtAt is usually LIGHTER than a heterozygous brown....?*


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## NdAppy (Apr 8, 2009)

I think I might have heard that too Eastowest. I just have no clue where I heard that.


On the Brown thing...

trailhorserider - Your guy looks brown. See how inn his winter coat he has lightening in the stifle area? That is usually a good indication of brown as well as the lightening of the color around the nostrils.

Brown can and _do_ had black points.


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