Mare

A mare is an adult female horse, usually defined as a female aged four years or older. More specifically, racing organizations and general equine usage draw the line between a filly and a mare at around age four: younger females are called fillies, and once they reach four, they are considered mares. In Thoroughbred racing, rules often define a mare as any female horse older than four, although in casual and educational contexts “four and up” is standard. Mares can continue racing in mare-only events or open company, and many later become broodmares used for breeding.