Castration
It is the process consisting in the removal of the testicles that is normally carried out when males pigs are young (soon after their birth) in order to avoid boar taint.
In some countries castration is regulated by law (age of the animal, analgesia/anesthesia, etc.)
Chemical castration or immunocastration is based on the arrest of the testicular function by inducing an immune response against GnRH hormone.
Castration is also the process consisting in the removal of the ovaries in sows.