I have adult Australorps (1 year old) I have 2 sets of chicks in brooders right now. The first are RIR at approximately 4-5 weeks old. The second I just got and are Mariana and Calico Princess about 1-2 weeks old. I know they need different temperature controls right now. I would like to integrate the two sets of chicks before I integrate them with the adults. At what age can I start putting the chicks together? This will be my first time adding to my flock.