Eating layer feed won't hurt your rooster...it doesn't have a large enough amount of calcium in it to do any harm to him...if it did we wouldn't have to supplement the hens w/ oyster shell. My chicks go into the big coop around 8 weeks and that's when they start eating layer crumbles...I've never had any problems, even though some people will tell you otherwise. I think it's just a matter of personal preference.