That would sure make a lot of sense! Thank you so much for your thoughts on this! I bet you are right about the larger birds/production egg layers. My barred rocks are BEASTS when it comes to laying-- every single day-- even thru this insane heat. They just never miss. That will be sad when they go. I'll have to get more BR's again for sure when these guys die. I love that they lay a nice dark brown egg with good size to them and that they are daily. Great layers... just not nice to my Polish. Ah well, thank goodness for pinless peepers for the meanies. I hate to sound mean... but it's kind of nice that if they are done laying, they are at the end of their life expectancy. I already have a horse that is a welfare case! I don't need more animals not doing their jobs! LOLHawkeye, that is wonderful news about your DH's job and that you might be able to stay after all!!!
Regarding life expectancy, my understanding is that a chicken *can* live up to about 12-15 years of age. That said, they rarely do, due to predation, illness etc. As with dogs, size counts too. SpeckledHen lost her big 'ol roo last week, who was 6 years old and she said that was a long life for a boy of his size. I have heard of people on the forum with 6-year-old hens that are still laying the occasional egg.
Depending on breed, they do get burned out faster. The production egg layers like Red Sexlinks and Barred Rocks, will lay like crazy for their first season or two and then the lay rate drops drastically. This is the point where most people get rid of them. I did have a BR in her third season who was still laying pretty well though. The heritage breeds, that often don't churn out the eggs at the rate of the production egg layers (maybe 3 per week rather than 6), will lay for a lot longer. No doubt the anecdotal stories of 6-year-old hens that are still laying, are heritage birds that never laid that prolifically even when they were younger.
I suspect that the high lay rate of the production layers does also shorten their lives though. Reproduction takes its toll on the body and egg-laying is of course a feature of reproduction, even when no rooster is around. So it makes sense that a hen who is putting all of that energy into laying an egg-a-day is also aging faster than one whose body is able to recuperate a little more in between eggs.
Just my thoughts....
Sad about Speckled Hen's rooster. She sure loves her birds.