In humans, we don’t usually castrate them because it throws their hormones out of whack, and causes all kinds of issues, but wouldn’t that also be the case for some animals, since their hormones systems are fairly similar?
Why is it that that we remove the testicles entirely, rather than giving them vasectomies like we do for humans?
Yeah, probably true. It would take a critical mass of sterile males to make a real difference. But neutered males aren’t trying at all, so females in heat are only mating with fertile males now. If a percentage of the fucks were not going to produce kittens, they might have smaller litters at least. Also if the sterile males were successful at fighting off fertile rivals. Again, neutered males aren’t trying.