Do farmers usually bond with animals that they will end up killing?

I have had livestock as pets, and livestock for livelihood. Generally, when you have 300 head of cattle, once you finish taking care of their basic needs you don't have time to sit back and cuddle, so no, you do not bond with them. This doesn't mean that farmers are mean or lack compion, they are just doing their jobs. Most farmers I know raise animals for slaughter and breeding but also have pets. They bond with their pets and have a "professional" distance from their livestock. I doubt that the lady you are referring to will slaughter the turkey without a thought, but there will come a time when that turkey will just get too old, and depending on it's breed may even just get too heavy for it's own legs and when that time comes, the humane thing to do would be to butcher it. It's not evil, it's just the way it goes.