This year, we decided to get Delaware and New Hampshire chickens so we can do the Indian River cross broilers going forward. We originally had 8 Delaware and 9 New Hampshire roosters. At 12 weeks we weighed them and culled all but the 3 heaviest of each breed since we want to breed the largest broilers possible. Since we want to get down to only 2 roosters of each breed, I weighed them again to see if that would be a good metric. However, there is only 0.2 pounds difference between the lightest and the heaviest of each breed. The New Hampshire roosters were 5.3lbs, 5.4lbs, and 5.5lbs and the Delaware roosters were 5.7lbs, 5.8lbs and 5.9lbs. That small of a difference in weight isn't enough to cull on. None of the roosters stand out as more aggressive than the others. They tussle every now and then, but at 20 weeks, they know their place in the hierarchy and only jump a hen/pullet if they think either of our BO roosters won't see it. I'm really stumped on how to move forward. I would like to cull two of them (plus a late blooming Delaware roo, who is a full pound lighter than the other Delawares) before the end of the month. However, I read somewhere that certain breeds should be allowed to reach 1 year old before deciding on culling or not. Should I wait until they are older to judge which roosters are better formed than others, or is there a way I can make the determination now? I would prefer not to feed more than 6 mature roosters (1 Buff, 2 Delaware, 2 New Hampshire, and 1 Black Cochin) through the winter and I'm sure my hens/pullets (45 of various breeds and mixes) would appreciate a fewer roosters as well.