You can band a buckling up to the point where you can't get the band over this nuts. That is the cut off point for banding. If you want to actually cut the nuts out then you have a much bigger window. I have found that if you go much longer than 2 oe 3 months that the band won't go over the nuts. IF you want to you can cut the nuts off to castrate a buckling probably up to and after he is 1 year of age. I never had much luck with the crimping. I have actually cut 4 month old buckling. However, from what I have read, if you are going to use the buckling for meat, that you can let them go to six months of age and still harvest them without any taint in the meat. I have not tried this.
From personal
experience, I have have not had any luck getting Boers (which I have given up on) or Kiko's to breed until October or November. Depends on the breed. I do have a La Manch doe that is looking very prego right now (May) so she probably bred in December of January. MY Saanens seem to only breed in the fall as do my Alpines.
I have banded bottle calves and helped with castrating geldings in addition to castrating my goats. Haven't tried pigs yets.......but that day might be coming.
goodluck
bonnie