I feel even battery hens, if cared for as backyard chickens, can be much longer lived. I don't think it's the breed. It's the conditions and feeding that I believe shortens their usefulness, if not their lives. Using lights on 24/7 and the other conditions that have been scientifically proven to push them to lay out their entire life's worth of eggs over a 2 yr period is a good part of it. Even those great layers can take a break if allowed and live a good bit longer if they were cared for in a manner that would support a longer life. I wouldn't even say more productive because there "is" a finite number of eggs they were born with to lay so I think they can either blow them all out in a short time, or lay more naturally over a longer period of time. In both cases, their nutrition should meet the needs. Even a backyard chicken owner who is selling eggs may need to use layer mixes to produce those harder shelled eggs for their customers, and they may use lights in the winter or have breeds that lay well in the winter so they are not as confined as battery hens but they are expected to put out the eggs for sure.
I have had hens 10 yrs+ that laid. Not every day but good layers through the laying season. I am very casual about my hens laying. I understand their differences and know some lay hard and heavy for short periods, some lay infrequently but they don't have long periods that they're not laying at all. I do want mine to be healthy and long lived and I try to breed for that. I even prefer that in my cows, I have Brahman and they're known for productivity far into their teens when most cattle here are smooth mouthed and done Long before that. I think it requires good care and nutrition to support that kind o long life so I constantly look into ways to do better.
I have some yeast/probiotic cultured on cornmeal from Western Yeast Company. A little goes a long way and it's for any sort of livestock, my Arabian mare needs the "extra" that my foxtrotter mares don't seem to need to stay fat. I put a little in with grains to ferment and it's awesome stuff. I haven't been growing it a couple of weeks because of my recent surgery, but I have been growing fodder from barley grains too. I'm planning to put up another pen that my spare roosters can be confined in this spring on the days I can turn my penned flocks out to forage, to alternate every other day. My spare cocks free range between duty time and they are robust and healthy and I believe that has also been part of the reason for my good fertility without trimming vent feathers.
I worm twice a year here and if the need is indicated. I fixed the hens up with the coolest dust bath in the coop with the outside pen that isn't covered. I used an old dog house that wasn't in use for it, wood ashes, DE, sand and stuff and they seem to love it. I'm always looking for better ways to make them happy and that makes me happy too.
I love these forums because you never know what you're going to learn every day. Welcome to the group Anniebee! Do you have Araucana's there in Australia?