Do not emasculate/sterilise/castrate any male creature
“Any testes bruised or crushed or torn or cut….in your land you shall not do this” Vayikra 22:24
The Sages expounded (Talmud Bavli Shabbos 110b-111a) -that this is not to be done amongst the Jews, either to their own bodies or other living creatures impure or pure.
Whoever performs a sterilisation is liable for lashes.
Even if someone does sterilisation after it has already been done is liable for lashes, whether it was done on a person or a living creature.
A woman is forbidden to sterilise a male.
It is forbidden to give a man or animal a cup of liquid to drink that causes sterility, but a woman can drink this liquid.
It is forbidden to tell a non-Jew to sterilise an animal of ours, if the non-Jew took the animal of his own accord and sterilised it, it is permissible.
However, if the Jew influenced him then he is penalised and must sell it to another Jew.
This applies in all places at all time.