Burial requires machinery costs and must be done under at least 4 feet of soil, a difficult task in frozen winter ground. Ohio State scientists found that carcasses placed in a properly managed sawdust compost pile will completely decompose and all pathogens will be killed within 180 days. The composted material can then be spread on fields as a renewable nutrient source. Nebraska Extension helped provide PQA training on science-based production techniques to avoid disease, improve pork quality and encourage high industry standards. By the end of 1998, about 1,250 Nebraska pork producers who raised nearly 1.3 million pigs annually had participated in the programs.
Similar programs exist in Indiana and Georgia.
Michigan State researchers studied ozonating stored swine manure to remove odor. The team is constructing a full-scale ozonation system. Ozone, a gas used to disinfect drinking water and swimming pools, is bubbled into manure slurry where it renders it odorless by breaking apart the odor-causing molecules. It kills bacteria and greatly reduces bacterial growth. The ozonated manure slurry is environmentally safe and can be spread on fields as a fertilizer.