From what I understand, if you have more than one rooster, you will have more crowing because they are also crowing at each other. Also, it sounds like you've been rewarding them for their crowing by coming out on demand... So the first step would be to stop doing that, and then perhaps move one rooster on to another farm? I'm not sure really, just an idea. I only have one roo and he crows to call his hens, at dawn, and when they are moving to another territory, and then to secure that territory. Luckily, my neighbor likes it... reminds him of his childhood, which is always nice at 87. He actually crows back at "Moon".