Pasture Breeding If you own a pasture and put eligible Stallions and eligible Mares into that same pasture, there is a chance they will randomly breed. This can be bad, if you were not intending the mare to be bred, or, good, if you prefer a natural style of breeding. Only mares that are at least 3 years of age, not on Cycle Suppressant, and have not yet been bred for the year, may breed. Stallions must be at least 3 years of age to pasture breed, and will stop breeding once they reach 20 foals. There will be a 1 in 10 chance daily that the breeding pair will produce a foal. You will recieve game mail when the breeding occurs. Also, your horses will continue to breed even if you have no space left. The resulting foal will escape.