I did not use lights my first year, but have done so every year since then. However, I don't start my lights until October when their production drops way down. I may start lights earlier this year. I agree that in the long term, it really doesn't matter. If the flock has good nutrition, I'd...
You might start by looking at Henderson's chicken breeds chart. Heritage quality birds are most likely to give you what you are looking for. Consider this: hatcheries are cranking out just as many chicks of a particular breed as they can. So, they are focused on using breeders that are heavy...
For the very same reason that a woman stops menstruating... can no longer get pregnant. Want to extend the years of fertility in your flock?: provide the best nutrition and environment possible. Genetics also plays a role... same with humans. Put a human in a stress filled environment...
While ova degrade in the body over time, I doubt that any hen would ever "run out" of ova. I have no science to back this up, just my personal thought. I know that the female human has far many ova than she would ever be able to release in a life time. I assume it's similar for chickens...