Researchers at Rodale Institute, Iowa State University, and the University of Minnesota are in the third year of a four-year project titled "Integrating Crops and Livestock in a Systems Approach to Enhance Organic Farm Stability, Safety and Resilience." Funded by the USDA Organic Research and Extension Initiative, this project evaluates the production, environmental, and economic benefits of growing cash crops with forage crops for grazing, including small grains and hay crops for livestock feed. They are comparing two crop rotations—pasture-winter wheat-soybean-pasture and pasture-winter rye/hairy vetch-corn-pasture—and grazing dairy steers on the cover crops as a method of integrating livestock and organic cropping systems.
Because organic livestock are not treated with antibiotics, particularly prophylactic antibiotics, there is concern that the organic meat or dairy products may contain higher levels of potential human pathogens such as E. coli and Salmonella. Researchers collected manure and forage samples throughout the study as well as swabs from the meat after slaughter and before processing. Samples were sent to Dr. Angela Shaw, Assistant Professor of Food Safety at ISU, for analysis. Throughout the grazing period, the prevalence of both E. coli and Salmonella in forage and manure samples were far below the rates for previously reported for organically-raised livestock in the U.S.