Foodborne illness is a major public health concern in the United States, with an estimated 76 million cases occurring annually. More than 90% of foodborne illnesses of known causes are of microbial origin. Animals used for foods and their manure are leading sources of foodborne pathogens. Recent advances in the investigation of foodborne outbreaks using genetic fingerprinting techniques enable epidemiologists to identify outbreaks and sources of implicated foods that heretofore were undetected. Tracebacks of outbreaks to the point of production place greater liability and responsibility on food producers. Implementation of Hazard Analysis Critical Control Point (HACCP) systems at the point of production is essential to increasing the safety of foods of animal and plant origin.