There is an in-between feed for when they hit 6 weeks - grower feed.
How old are the chickens you want to integrate them with? I integrated my babies at about 4 weeks (I think, can't remember now). The older ones were 4 months old. I put the babies in a wire dog kennel inside the hen house and they stayed in it for a week or so. Then I let the babies out, watched carefully to make sure the older girls weren't going to hurt them, and ta-da!! They were integrated.
I got one of those plastic shoe box type of containers and made a hole on the side of it big enough for my silkie babies to get in, but not hens and whenever mine felt threatened they just ran in there.
For the first couple of days I put food and water in it as well, just in case.
Thanks for that info..I was wanting to add 3 5 week old with momma hen and a roo but I don't have the time to build a cage inside the run to intigrate them and wait a week so Im gonna add somthing that the lil ones can hide from the roo id needed. Thanks I'll be doing this tomorrow also!