I found they need to be around 6 months or older for processing them, but It depends on preference. I found theirs not much meat to them doing it to soon if your putting in the work processing them. I have read alot of people Fillet them which im going to try next. Meaning they kill them, and just split down the front and take the breasts out, saving time. Doing it that way you dont need to defeather or gut them which is the time consuming part if you dont have the equipment. My problem with waiting the 6 months or so is that my Roosters always eat so much to me its not as worth it cost wise to grow them out. But during summer its not as bad (my chickens free range alot when its nicer out).