My apologies if this has recently been covered. I have six going on 15 week old Barred Rock cockerels that I am fattening up with grower/finisher and additional cracked corn. I've heard that once they reach a certain age and their hormones kick in it will make their meat really tough. what is the general age limit to kill before? My plan is to have them slaughtered in 2 or 3 weeks, am I pushing it?