Well my oldest breeder male, Casanova, is almost 2 years old and just fathered a lovely litter so basically if you keep them healthy, males can breed almost until they end of their lives. We don't put old Nova in with a lot of females but he does occasionally get a turn in the breeder tub. Most of our other males are less than a year old and will likely with good care, father litters for us for a very long time (and won't be boa food at any time).