I think longevity is determined by how a hen is forced to lay. In production environments they are forced to lay year round, which is what "uses" them up so quickly. In a backyard flock, most folks let them go through the normal moult cycle over winter, thus reserving eggs for longer life span. I have a friend who has about 10 hens ranging from 8-10 years old and they still lay eggs..just not every day. Breeds range from hatchery RIR, EEs, Black Sexlinks and Black Australorps. I remember years ago I had an old heritage RIR who lived about 10 years still giving an occasional egg. Many of her eggs were gigantic. That is eventually what killed her..eggbound and she couldn't pass an egg. I feel longevity has more to do with natural living than the breed itself, although some breeds are known to produce lesser eggs to begin with.
Jody
Jody
