Here's something I have not read anywhere on the web or in print (as of now): When a cockerel starts to kazoo crow, each of his testes are about the same size as his heart. After barely a week of kazooing outside in the morning, each teste will be larger than his heart. Keep in mind a chicken's heart is four or five times larger than its brain ... all of a sudden, cockerel behavior makes a lot more sense.
I slaughtered "puffy" the half-cockerel red broiler this morning, and attempted to get his remaining teste out. Even using the larger rib spreader, it would not fit through the incision. To his credit, he made quite the spectacular Logan's Run, jumping over hubby (talons first) when he opened the door to the cage and then trying his darnedest to fit through the neighbor's field fencing, which is 4 by 4 gaps.
I had three more cockerels ready to try live caponizing, but my back started acting up with just "puffy," so those three went into the cage with food and water and will simply be pre-slaughtered for the operation, along with the rest of the red broiler cockerels.