These are cows, not someone's wife or child. It's not a medical "treatment." The "yahoo farmers" (oh, the condescension) weren't treating human beings or even cows for cancer. Why bring up breast cancer - and presume that's what the poster referenced - when all we're talking about is inseminating cattle?
Farmers don't have the luxury of calling a veterinarian every time they need to treat their animals, by the way. Perhaps you should watch a few episodes of Dr. Pol.
My rancher son-in-law has had to stick his entire arm in a cow’s hoohaw to pull out a calf in distress. There ain’t no time to wait for a vet. He’d lose both cow and calf. Every single cattle owner has had to do this at one time or another.
Ranchers love their cattle. They are devoted to their cattle. Most vets in rural America understand this and will do whatever they can to assist the rancher in becoming somewhat self-sufficient.