Most that do switch there feed will feed a Starter up to 12 weeks of age than switch to a grower. A Grower type feed is lower in protein than a Starter and in some cases a Layer type feed, this is to slow growth rate down so that the bird has time to fully fill out and build up strong bones and mussels.
This might help you out some.
Starter --
A balanced feed meant as the sole ration for chicks from hatching to twelve weeks of age.
At 12 weeks of age the birds can be changed to Grower or Developer. Starter can be Medicated or Non-Medicated when Medicated it is with either Amprolium or Lasalocid. Starter is available in Mash, Crumble or Pellet form.
Stater/ Grower --
A balanced feed meant as the sole ration for chicks from hatching to chickens begin to lay, this feed can be Medicated or Non-Medicated. If medicated it will be with either Amprolium or Lasalocid. Starter/ Grower is available mostly in Crumble or Pellet form.
Grower --
Feed as the sole ration to chicks 12 weeks of age as a finisher. Grower feed is meant to feed until the chickens begin to lay, then bird can be switched to a complete Laying. Most Grower feed is Non-Medicated but some are Medicated with Bacitracin. Grower is mostly available in available in Crumble or Pellet form.
Finisher -- See above for Grower
Layer --
Feed as the sole diet to laying hens maximum production of eggs. Do not feed Layer feed to poultry, which are not in production because of the high calcium levels in the diet. This is particularly true of young growing birds. Layer is available in Mash, Crumble or Pellet form.
Layer/ Breeder --
Feed as the sole diet to laying hens and breeders for maximum production and for improved hatchability. Do not feed Layer feed to poultry, which are not in production because of the high calcium levels in the diet. This is particularly true of young growing birds. Layer/ Breeder is available in Pellet form.
Chris