A breeding horse is typically a stallion or a STUD. A stallion is an uncastrated male horse used for breeding, while a STUD is a male horse kept for breeding purposes. Stallions are usually kept in a separate area from other horses and are often used to sire offspring. Studs are usually kept in a stable and are used to breed mares. Both stallions and studs are important for the breeding of horses, as they provide genetic material for the next generation.