When is a mare too old to breed on howrse?

If you want to know who to breed your mare on howrse.com:You can breed your mare whenever you want but it has to be 3 years or over to mate. If you do decide to breed your mare then you have to click Coverings and then find a horse you want the father to be. It will cost you around 200e to cover your mare. At birth you also have to pay the vet 500e so keep around 800e in your account.