I see a lot of cockerals...brahmas are incredibly hard to sex, but yours are old enough that you can see the sickle feathers flowing down on either side right before their tails start. Its easiest to see in your second picture because that guys sickle feathers have black edging, but I bet if you look at all the others you will see the same feathers in pure white. I agree, I LOVE brahma roosters - the most laid back, mellow cuddle bugs EVER! However, that does seem to be quite a few roosters for you.