Well I'm thinking if he tests positive for cream then I'll have my answer on smokey. If he tests negative for cream maybe I will send samples in to that other lab for brown and see what they say. Not sure if I want to spend that much money on this curiosity of mine, but I think the first $25 sure.
Now I'm curious about brown vs. bay testing and might have to post another thread on this. But since brown is so closely related to bay, if you tested for bay - would browns come back as carrying the agouti gene on those tests from the labs that don't specifically test for brown? And so if a horse came back as not an agouti carrier would that mean brown would not be an option? I'm curious how that works.
You are exactly right.
The labs that run "agouti" tests, not the brown specific, test for the presence of the recessive "a" allele. If they find two, the horse is aa, if they find one the result is a_, and if they don't find any at all, the horse is _ _. The result is then flipped - where no recessive allele is found, a dominant one has to be. Since all three variants of agouti (classic bay, wild bay and brown) are dominant, it doesn't actually specify which of these, just that the recessive is not there.