I did notice when reading labels that the amount of protein in either grower or layer feed can vary by brand.Here in the UK Grower is often just 16% protein the same as Layer and the only higher one I can get is chick crumb at 18% but it is really difficult to get that unmedicated, so mine only ever get 16% protein once they are off chick crumb and don't seem to be any slower to mature, but I need to go steady on treats.
The important thing is to learn to read the labels on feed bags so that you know what you are getting.
Reading labels is always good advice
