I can sympathize with the farmers because it's really hard to have a rational conversation in the face of strong emotional reactions to graphic imagery. People feel empathy for many things they shouldn't, such as robots[1], and the feeling of empathy is not a reliable way to determine something's moral status. Nevertheless, the natural way people make decisions on moral issues like this is to accept their emotional reaction and then rationalize their decision after the fact[2][3][4].

I wonder how much of the shift in public opinion on animal rights is a result of people not being exposed to farm animals anymore. The vast majority of people these days, myself included, meets only pets (and occasionally wild animals). If the only examples of animals you have in your personal life are companions, it's natural to want to treat animals well.

[1] E.g. How Anthropomorphism Affects Empathy Toward Robots http://www.cl.cam.ac.uk/~pr10/publications/hri09.pdf [2] The emotional dog and its rational tail: a social intuitionist approach to moral judgment http://www3.nd.edu/~wcarbona/Haidt%202001.pdf [3] The Status of Moral Emotions in Consequentialist Moral Reasoning http://www.law.yale.edu/documents/pdf/Intellectual_Life/Fran... [4] The Secret Joke of Kant's Soul http://www.fed.cuhk.edu.hk/~lchang/material/Evolutionary/Dev...