My buddy is a 3rd generation hog farmer (2nd or 3rd largest in Ohio) and he says the hog farming is incidental, the majority of money comes from the government by buying land and letting it lay fallow. They "farm" just for extra cash so they can sell their pork for literally whatever anyone wants to pay, which makes the pork I sell (we raise 3-4 pigs a year) about 100X more expensive. Same with corn, the US government is paying farmers to burn fuel and produce food that essentially has $0 value at the source.
Much like other externalities, it's good to remember that you're paying either way.