If you have Cornish Cross broilers, they will pretty much get fat and sit around most of the day. I raised twenty-five last year as a 4-H project and they just sat in the coop all day. I wouldn't keep broilers for eggs, because they are most likely to die, before they are even close to five months. Because of a broiler's large size, they're tiny hearts tend to not be able to support them and they eventually have a heart attack and die. We lost two last year and that was before they were fully grown! You're best bet is to butcher all of them when they are 6-8 weeks old. If they die during a heart attack, you won't be able to eat the bird, because the meat will be contaminated with the blood.