Hi, I am wondering at what age hens and roosters stop being fertile. I know a hen will keep laying but I mean is there a certain age to where she no longer is able to produce chicks? Same question for the rooster, too. I am thinking of buying an older hen (2 years) and I want to make sure I am not wasting $$ My rooster is right at three and I was wondering when/if I need to start rearing a chick for a replacement! Thanks!