Vintage cookbooks could be the next unplumbed lode of source material! (Don't forget this one.)
This example, from a 1955 publication, offers a chilling portrayal of Eisenhower-era conformity.
The pig's got the let's-not-rock-the-boat basics down: He bears witness to a pork chop recipe, smilingly. But he goes so far beyond the suicidal "food" animal's job description that he deserves special mention.
It's only the occasional animal that allows itself to be presented as though its very being is synonymous with food. Not only edible—that is, transformable into food—but being indistinguishable from food. (Here is an example of this horrifying concept.)
Now look how the Inman pig has outdone this ploy.
He has become one with the very means of his transubstantiation into supper. He is now part of the apparatus that will render him into the main course: He is becoming the shallow pan the recipe calls for. No longer a living organism—or no longer merely a living organism—he has embarked on a hellish journey to a new, lapsarian reality.
(Thanks to Dr. Kat for the referral and image.)