Any color experts still around? Gotta color question

[Mona]

Well I thought in another thread, I just read that At was a form of A?? UGH! I doubt I'll EVER get this stuff all straightened out!!

 

[lil hoofbeats]

I think a bay with the mealy gene? he sure is cute,

 

[lil hoofbeats]

these color genetic people are coming out with new stuff all the time, i am not even sure they are using the term mealy anymore, or if i am actually spelling it right!!!!LOL!!!!, or maybe it was wild bay, not sure,

 

[Lewella]

"At" isn't another form of A but is another option at the Agouti locus. Likely there are at least FOUR different options at Agouti - A=Bay, At=Brown, A+=Wild Bay, and a=black. A horse could be any combination of two of the four. A is dominant to At, A+ and a. At is dominant to a. Not enough is known about A+ (Wild Bay) to determine where it falls other than we know it is dominant to a.

The buckskin sire could be A/At and contribute the At to produce a brown based foal or the dam could have an At and contribute it.

The chestnut base color shade isn't influenced by any of the variations at the Agouti locus as they only effect black pigment. I'm going to use the Michigan ponies, particularly the Modern lines, to illustrate one of the ways we know shade on a chestnut isn't effected by the horses Agouti status. Think about it for a minute - you've all seen TONS of Michigan Moderns in the Journal. Bays, a few browns, and some of the darkest shades of chestnut you'll ever find in small equine but have you ever seen a black? They are very few and very far between! What does that tell me? That tells me the Michigan Modern herd is A/A and A/At and At/At with very few "a" genes. If Agouti could influence the shade of chestnuts and make them lighter we'd see it in a herd of A/A - A/At - At/At ponies like this but we don't.

On a bay though shade can be influenced by a horse being Aa or AA - AA bays have a tendancy to be lighter in shade than Aa bays. Since A changes black pigment though that makes sense.

Edited to add: Mealy is still used but a lot of horses that used to be called mealy are now known to be other things. Browns are very often lighter on their "soft parts" - in fact it is one of the clues that can be used to determine if it is a good idea to test your nearly black horse to see if he's really brown.

 

[chandab]

On a bay though shade can be influenced by a horse being Aa or AA - AA bays have a tendancy to be lighter in shade than Aa bays. Since A changes black pigment though that makes sense.

Ok, so would this guy be considered "lighter", he tested AA:

Here's a really chunky monkey picture from summer 2010



Here's a picture from 2006:



And, his baby picture, looking almost anything but bay (breeder registered him as dun, and he has absolutely no dun factors).



Lewella, we discussed this colt (now gelding) previously when I was trying to determine his color and you suspected wild bay, which I haven't actually sent out for testing to see (now that he's gelded, it doesn't really matter, except for curiosity).

He tested Ee, AA, no cream, didn't test for silver (and dun wasn't available at the time, and likely would be a waste of $).

[He is definitely lighter than my new stallion, but as the new stallion hasn't been tested for anything but LWO, I don't know what his status is. Actually, I should, as his dam is black, sire buckskin, so he can't be AA, he has to be Aa.]

Here's a couple pictures of Topper (Top Cat son - first at LKF; and second, the next summer here):





I guess the only thing I don't know is his black status, as he could be EE or Ee (not likely to have cream or silver with that coloration).

 

[Lewella]

Hi Chanda,

I still think your gelding is Wild Bay. His points are still pretty washed out and not real high. Every Wild Bay I've seen has been light so with him that could be it or it could be a combo of Wild Bay and another Agouti since he tests AA (remember the test actually tests for 'a' and everything else is reported by default as 'A').

Your other boy would be a good candidate to test for Brown!

 

[chandab]

Hi Chanda,

I still think your gelding is Wild Bay. His points are still pretty washed out and not real high. Every Wild Bay I've seen has been light so with him that could be it or it could be a combo of Wild Bay and another Agouti since he tests AA (remember the test actually tests for 'a' and everything else is reported by default as 'A').

Your other boy would be a good candidate to test for Brown!

Well, if I ever have the desire to know for sure, I can always send in to the AZ company for brown testing. My other stallion we think might be a silver brownskin, as he doesn't look the same color as typical silver buckskins. [i had him tested for cream only.]

Here's Che` (I think this is a natural, unclipped coat picture, I don't clip him very often, so likely natural coat):

 

[minimule]

Thought since I finally got a full side photo I'd go ahead and post it. I like the way this guy is put together and he is going to stay tiny but I still plan to geld him. He is SO full of himself!

This is him "taking on" my 16hh mule.

 

[ohmt]

Now in that pic he looks like a bay and the lighter lower legs is just the typical light foal legs that most foals have when born. Cute little guy!