Heritage breed question?

[Chickensandbirds]

We purchase from our local feed store. I've had red stars/golden comets (production hens), and heritage breeds as well. Two of the production birds died at 4 and 5, the other lived to be 9. Most all of my feed store day old chicks reached 8-9 years, and enjoyed good health. The above posters have given good information, and I would concur.