Sefer Ha’mitzvos Ha’Katzar (The concise book of mitzvos) By the Chofetz Chaim

This book lists the Torah mitzvos that can be observed today

Second Section – the Negative Commandments

143. It is a negative commandment “do not emasculate a male.”

As it states in Vayikra (Leviticus) 22:24, “if his male organ is bruised, crushed, torn, or cut… and you shall not do this in your land.” Our Sages of blessed memory learn from this (in Gemara Shabbos 110b) that this verse means it shall not be done to a Jewish male or any other living being, whether they are ritually pure or impure. Anyone who transgresses this law receives lashes, even if he does this prohibition after someone else had already transgressed this prohibition on a male or another living being. A woman is also forbidden to transgress this prohibition on a man. It is forbidden to give a man or any other living being a drink which causes sterility, but a woman may drink it. It is forbidden to ask a non-Jew to perform this act on a Jewish animal for us. If a non-Jew did it himself, this is allowable, but if a Jew tricked a non-Jew into doing this act, then the Jew is penalized and the animal must be sold to another Jew.

This applies in all places and at all times.