What is the maximum size a bull calf should be in order to successfully use a burdizzo clamp on it? How long should you clamp each cord?

Calves up to 600 or 700 pounds can be castrated with a burdizzo or emasculatome. It would be easier to castrate smaller calves with a knife or by using a Newberry knife to slit the scrotum and then using an emasculator to crush the cords. Bands can also be used on smaller calves and even larger bulls. A tetanus injection should be given when using non-surgical castration, whether with a band or a burdizzo. The recommendations for use of a burdizzo are:
1) Crush each cord separately for at least 30 seconds.
2) Make sure that the cord does not slip between the jaws of the burdizzo.
3) Do not crush the septum in the center of the scrotum.
4) Administer a tetanus injection.