Help me figure this out!?!

[love4horses]

Okay,

So Baylee is bay, carries the agouti gene which is dominant. What if I bred her to a Homozygous b/w tobiano stallion.... Would I get a bay tobiano???

I want to know this so I can convince my mother to breed Baylee to the toby!

[chev]

Agouti is dominant in the sense that if it occurs on a black base, the black base will be modified to be bay. But if a horse carries just one copy of agouti, there's no guarantee they'll neccessarily pass it on to their offspring.

So; if Baylee has two copies of agouti, and the stallion has two copies of black *and* two copies of tobiano, than yes, you're guaranteed a bay tobiano foal.

If Baylee only has one copy of agouti, the foal could be black and white or bay and white.

If both Baylee and the stallion have a hidden red gene, you could even get red and white from that pairing, regardless of how many bay genes Baylee has.

Is the stallion homozygous for black, tobiano, or both?

[love4horses]

I believe he is homozygous for tobiano. Seems like I saw two of his foals that looked like they were a brownish spotted tobiano. I will email the farm tonight and get their input about if he is homozygous for black and white!

[love4horses]

Well, I emailed her tonight and this is what she said:

You could get black, bay or sorrel. It would definitely be spotted, but the base color could go any of the 3 ways!


So I guess that means he isn't homozygous for black and white???