Has anyone tried to caponize an adult rooster? One that hasn't 100% stopped growing, but has done most of its growing already. Do you think they would stop crowing? Become more docile? Become more tender? Fatten up more?
One article said that the older they are, the more likely they are to bleed to death from severing the artery to the testicles.
I think that 9 weeks was the top age in the optimal range. The 'value added' after that was not worth the risk to the bird. I'll see if I can dig up the reference.
The testicles in a young male where they usually do the procedure is probably the size of a pea or lima bean at most. By the time the rooster hits it's growth spurt and surpases puberty to a big ol roo, those limabeans are no longer limabean sized, think more of thumb or egg yolk size. Sure it can be done, you can neuter your rooster, but the process will be more involved. Not as simple as a slice between ribs and some digging for the goods, well, similar, but it's not going to fit between ribs anymore. It may or may not stop crowing, as much as neutering an adult dog may or may not stop it from lifting it's leg on every tree. Personally, not worth the risk if it's a pet, or worth the time/investment if it is food.