Bay to Bay gets...what??

Ok, I am pretty familar with genetics and colors. I was a bit surprised to get a black from a chestnut dam and bay sire. But I see it's possible if the chestnut mare's aa_CCddee [the other possible code is A_CCddee, which would restrict the black to the points only]. Bay being A_CCddE. Now I have a bay mare who has a black foal, which I assume would be aa_CCddEe as the previously mentioned black and possible sire is a rusting black [Ee]. The other possible sire is bay. Is it not impossible for two horses who are A-E to have anything else but bays??? I know I will probably end up having them all dna'd, but I always thought bay to bay gets bay as chestnut to chestnut gets chestnut.

Bay to Bay gets...what??
If the stallion has only had bay and black foals so far, you can be pretty certain he's homozygous for black, and you know he's heterozygous for Agouti (since he is bay but had black offspring). If the mare has only had two foals, its hard to say if she's homozygous for black but you know she's heterozygous for Agouti since she's had a black foal.



So if you bred bay x bay, in most cases people get about 25% sorrel, 75% bay (since the horses are heterozygous black), but in your case, with both being heterozygous Agouti, and probably homozygous black, you would have about 75% bay, 25% black offspring from the cross. Of the bays, 1/3 of them would be homozygous for Agouti, and the others would be hetero.



The bay and black horse are both "black" but the presence of the agouti gene limits the black to the "points" of just the mane/tail, ears, legs, etc. That is why a bay can have red, black, or bay offspring if they are heterozygous for each gene, and depending one what they are bred to. Clear as mud?



Hope this helps.
Reply:horse genetics are a strange thing. here's some stuff that helps you determine what color foal you'll get:

http://www.doubledilute.com/color-chart....

http://www.equinecolor.com/charts.html

http://members.aol.com/mfthorses/sponenb...

http://www.google.com/search?hl=en%26amp;q=hor...



oh yeah- i just found out that bays are black based, so they carry the black gene.
Reply:IDK if this helps or not, but bay is actually black with an agouti gene, restricting the black to the points (mane, tail, forelock, knees / hocks down, and tip of ears.)
Reply:Bay is a dominant gene, which means it can mask the recessive gene - Aa is just as bay as AA. If both parents are Aa, the offspring has a one in four chance of not being bay - aa.



If the mare has had a non-bay foal of any color, she has the masked recessive gene.



If the stud has a non-bay parent, he has the masked recessive. If he does not, he can still have it, as it can be masked for generations before being expressed.
Reply:I once bred a bay mare who was a grade QH type to a bay Arabian stallion who was by one bay and one chestnut. Still, by breeding two bays, I got a chestnut foal. The only "absolutes" in breeding are: chestnut X chestnut = chestnut, in order to have a grey foal, at least ONE parent must be grey,

cremello or perlino X chestnut = palomino, cremello or perlino X bay = buckskin or grulla. Other than that I'm sure genetics get so complex, you have no idea what you'll get.

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