What is the ruling on castrating male animals for fattening purposes or because they are bothersome due to their frequent chasing of females of their kind?

There is no religious impediment to castrating an animal for a benefit, such as fattening or repelling harm. The proof for this is that the Prophet, peace and blessings be upon him, sacrificed two castrated rams. However, if it is for no benefit, then it is not permissible.