If given a good diet (fruit & veg, a good quaility pellet and some seed) as well as a good environment (toys, branches, large cage/aviary, ect) they should be able to breed well into their teens. That is provided they are healthy and both birds are fertile (and provided calcium, and other needed things). If you are going to breed do proper and in depth research, find out how other breeders do it, and most importantly be prepared for the worst, should it happen. (Are you prepared to care for, and have the neseccary items required to care for a day old baby should they reject it? Or care for an egg bound hen - and have a vet who can help you treat her? Or able to seperate the birds if the hen decides she doesn't like him? These are just a few of the problems that can occur...)
I'm sorry if it sounds like I'm being mean, but I've seen what can happen when people are unprepared and haven't done the proper research (or don't care to - some think breeding is easy)
Yes to all, as we already have had chicks from our our two ringnecks. They all have fruit vegs and pellets. And our macaw and blue fronted amazon. So yes i am willing to take the bird to a good vet,as we all ready had to take one of the chicks to the vet all was ok. Thank you.