Tonyroo can chime in too, I don't want to butt in. I feed all my birds gamebird grower all the time, so yes it can be their staple feed.
I get mine from a feed store and it's called gamebird grower. It can have lots of names.
Interestingly, we had our longest living rooster live to be 15 years old. He ate Layer feed and corn his whole life, before I found out it was wrong. 😨 lol, sometimes I wonder about some advice....