You’ve got a whole lot of options. That may make it seem complicated but it’s really simple. Feed them about anything except Layer.
Layer has excess calcium for the hens to use for the egg shells. There are several studies out there that show the excess calcium can harm growing chicks. The only true rule is to not give growing chicks the excess calcium in Layer. Isn’t that simple?
The only significant difference in the other feeds is percent protein. The different feeds normally range from 15% to 24% protein. You can look at the analysis on the feed bag label to see that.
The normal progression is to feed a fairly high percent protein the first month or two to get them started well and feathered out. Then you switch to a lower percent protein feed until they reach laying age. This helps align their body growth with the maturity of their inner organs. The professionals that raise chickens for egg laying want to delay the onset of laying a little to allow the pullet’s body to mature before they start laying. The eggs are a little larger when they do start and they have fewer medical problems. That’s why I suggest you feed them nothing higher in percent protein than 20% after they get that good start as chicks.
You’ll find that most of us feed anything between 15% to 20% protein feed from the stage you are in until they start to lay. Since the only real difference in Layer and the rest other than protein is the calcium, many of us never feed Layer, especially if we have mixed ages in our flock. We just offer one of the others and offer oyster shell on the side for excess calcium. The ones that need the calcium for the egg shells instinctively seem to know to eat it and the ones that don’t need it don’t eat enough to harm themselves.