You'll get differing opinions on how to feed chickens on this forum, whether when they are growing, laying, or molting. A lot of it is just personal preference and most of it does no harm. There is a very wide range of what percent protein you can feed chickens and them do OK.
My personal preference is to not feed really high protein levels to growing chicks after they have fully feathered out and have a good start. If they are going to become layers, I want their internal organs and their skleleton to mature on pace with body weight. This helps keeps them from starting to lay really early too, which can be a bit risky for them. Obviously the person you got the chicks from feels differently.
I don't up the percent protein during a molt. Many people do. My chickens stop laying eggs when they molt so the protein that was going into egg production can be used for making feathers. Again, personal preference.
I have seen a study where protein levels above 30% does damage to a chicken's internal organs. I don't know what the actual threshhold is for damaging the internal organs, but that 30% is pretty high. I doubt your turkey grower is that high. But think about it just a minute. Do you think there is a reason chicikens are not listed on that bag of turkey grower? Or maybe they are. I'm not looking at it.
Will feeding that higher percent protein hurt your laying flock during a molt. I seriously doubt it. One bite won't kill them. It takes eating most stuff consistently over time to have bad effects.
Another thing that may come into play is what else they are eating. If they forage for a lot of their food or you give them a lot of low protein treats, they can certainly tolerate higher percentages of protein in their feed. The critical thing is how many total grams of protein they eat in a day, not the percentage in part of their feed.
Good luck!!!
