Columbia subject headings:
Harvard subject headings:
Agricultural ecology--United States
Agricultural industries--United States
Agricultural pollution--United States.
Agriculture--United States
Animal industry--United States
Animal welfare--United States.
Diet--United States.
Factory farms--United States.
Food industry and trade--United States
Livestock--United States
Princeton subject headings:
Agricultural ecology--United States.
Agricultural industries--United States.
Agricultural pollution--United States.
Agriculture--United States.
Diet--United States.
Factory farms--United States.
Food industry and trade--United States.