Which breed of chickens has the shortest natural lifespan?

[Ms Ellen]

I was wondering if there is any particular breed of chickens with a shorter lifespan than most?

 

[MrChicken207]

If you're talking about "pure breeds" then I'm not sure. If you count hybrids in there as well, then it is the cornish rock cross, typically about 12 weeks, but only because that's the butchering age for most of them.

 

[eKo_birdies]

i have heard that "commercial" leghorn layers have a life-span of 3 years.. i don't know if this is true or not.. and i doubt many commercial layers make it to that age anyway!

 

[Ms Ellen]

I ask because I am reading a study on aging using some commercial laying hens and they end the study at 200 weeks or 3 and a half years. This study is looking for ovarian cancers.