Originally Posted by Faceman
I haven't researched it thoroughly, but my understanding is that breed testing for dogs is very limited and unreliable, and cannot for example determine breeds out of a mutt, although it can determine the two breeds of a 50-50 cross. I don't know why horses would be any different, so I would suspect it might be effective for verifying a horse is a QH for example, if it is all or almost all QH, but I would be surprised if the test were of benefit for a grade horse with several breeds mixed in, or in the case of Appys, where you have Arab, TB, and QH mixed in plus many other breeds prior to the early 1980's.
I'm just speculating of course, as I said I haven't researched it thoroughly, but I would guess the test would be reliable in some cases, but not in others - particularly the cases where a horse has several breeds in his fairly recent ancestry - say 4 or 5 generations...
I am guessing it depends on the breed one is testing for. If it had unique markers that have been 100% verified to be breed specific, then the best they could do for a grade is give someone a "percent probability" - which is at least something
. Either way, it would require extensive genome mapping to be able to even determine the degree of accuracy for breed "x"...which "they" seem to have embarked on for the dog more than the horse to date. Their priorities are confused, imo.
But I agree w you, for some breeds such as QH's - the number of appendix accepted, as well as the breeds that made the "foundation" would make the certainty pretty darn "iffy", imo. And the spanish mustang "verification" is a little overblown. People want to say their mustang is "an original", but I really doubt the test results some base their claims on says, "100%" probability. I think it is more like, "some percentage less than 60", and the owner reports it as "a done deal".