So you already know there are benefits to slow growth - so many folks are just so excited for those first eggs, they'll go ahead and feed them layer feed, which has calcium in it, much too early. The feed companies don't help in this regard, as the bags will tell you to being feeding layer feed at 18 weeks. I wait until I see the very first egg in each hatch. In fact, I will often continue feeding NON layer feed if they are a bit too young in my opinion, and just leave a bowl of oyster shell for them to eat free choice. It's said that the ones who need it will eat it, and those that do not, won't. I am unsure whether that's true or not.
I feed a flock-raiser type feed (18% protein) to all of my layers, with a protein boost (I am currently using Purina fish chow, which is 32% protein) mixed in to up the total protein percentage to about 22%. I strongly believe that once they are laying, they require more protein. Before then, however, I feed the flock raiser feed alone, which is lower protein than chick feed. So, at about 8-10, sometimes 12 weeks, I switch from chick feed to the flock raiser. For adults (hens laying and males as well), I prefer to feed the flock raiser type feed as it does not have extra calcium in it, like layer feeds do. The extra calcium isn't needed for males, and can damage organs if fed to birds that are not fully developed yet. So, giving a bowl with oyster shell separately, free-choice, allows them to eat what they need, separately from their feed.
This works for me and is simple; but everyone has different comfort levels on how much they're willing to put into feeding. I would love to have the time to mix my own feed, grow greens for them, ferment feed....but I simply do not, and the above system works well for me.
