HGG Community Forums

You are correct about it referring to bays! Agouti is a term referring to a gene locus that occurs on many different kinds of mammals (horses and rabbits included). Agouti works with Extension (black pigment) to modulate the amount of pigment in the hair shaft. For rabbits, that creates the banded hairs. For horses, the effects of Agouti are restricted to the body area, leaving black points on the ear tips, legs, muzzle, mane, and tail. The hair shafts on the body are light at the base with a darker tip (which is why coats of body-shaved bay horses look lighter than their natural coat). In HaJ, wild bay (A+), classic bay (A), and brown (At) all restrict pigment to varying amounts. The addition of pangare, sooty, DP, or sooty+ also affects how dark or light a horse with agouti is.