I reintroduce as a group, but when depends on what preditors you have. I wait until the chicks are big enough a cat won't go after them. The main flock can see the broody and the chicks w/ just a fence between them helps w/ re introduction that they can see each other, and that they go back in a group.
So if you didn't have any preditors, you would introduce them to the flock right after hatch? I ask because I don't have any that could get to the run. I will only have to wait until they can't get throught the fencing?