You can’t, and I’m not recommending, get rid of sheep overnight. That’s a scenario you made up on your own.
If you would castrate all domestic sheep today, that would be akin to what we do to cats and dogs. Slowly the population would dwindle.
People who kill and exploit animals every day are always so ready to defend animals. Raising animals for killing, even if you take their wool during their lives, is genocide.
Raising animals to harvest is cruel and unusual punishment but it isn’t genocide. Genocide is the systematic and widespread extermination of a specific group. The fact that livestock animals outnumber us and their numbers are only growing should tell you we’re not genociding them. Words have meaning.