Hi just wondering i have a 18 year old stallion. He is 29 inchs. I breed two mares to him last year. They are due any time now. I hope to breed two mares again. I breed in hand so he does not run with the mares or the same guy would cover all day long. He is in great health. What age can a stallion breed up to. Also should i be giving him extra feed at breeding season.