19 week Brahmas

[homesteading101]

I have Brahma girls that are 19weeks. They are still on starter crumbles with scratch for treat. Free range several hours a day. One roo. At what age should I switch food and to what food? I read that you shouldn’t use layer feed bc it’s bad for the roo to eat. Is this true? So much info out there and it’s confusing. Thanks in advance. Pic just because

Feed them any 20% protein all flock feed. Usually you want to find the best deal and not buy overpriced garbage. Mix the oyster shell with scraps or treats so they get used to eating it.