I might imagine the broodies would keep brooding, even if they don't lay much, provided there are eggs around. If it were me, and I wanted a broody hen to raise chicks, I'd probably keep the best of the broodies and cull the rest of the old ones. They'll still lay as 3 year olds, but not as much as a first year layer, or even a second.I am facing similar situation, I have seven 2.5year old hens. 3 of which are great broody hens ( they are buffs) how long will they continue to be good broodies for? Are they worth keeping after they are done laying? How long do most buffs lay regularly for? Is it worth keeping them through/ after the fall molt? They will be 3 March. Will I get another decent year of laying?