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.