Iowa's got its share of pig farms. There's no shortage of offal in the meat-growing and -packing states.
Ugh. I still remember the hog farms in Indiana. They would collect the urine, feces, dead pigs in huge tanks, and then pump it onto the soy and corn fields for fertilizer. DAMN!!! That was rancid.
Does Iowa wash the hog poop into huge lagoons? That is what they do in NC. It proved to be a major problem during flooding caused by hurricanes.