case, death. Concerns are described on a scale ranging from no concern, to low level of concern, to moderate level of concern, and to high level of concern.
Interest in the quality and safety of food of animal origin began to develop in the United States in the latter part of the nineteenth century, aimed primarily at meat for export to Europe. Regulatory and inspection systems for domestically produced red meat (but not poultry, eggs, or milk) were initiated in 1906 (Wiser, 1986). The U.S. Food and Drug Administration (FDA) prepared a list of food safety hazards (Foster, 1982) about 20 years ago. Food-borne toxigenic and pathogenic microorganisms were named first and considered to be the greatest danger to consumers. Also included were malnutrition, environmental contaminants, toxic natural constituents, reaction products that are formed during processing or preparation and storage for eating, pesticide residues, and finally, food additives. Food safety concerns raised by the use of animal biotechnology add to this list.
As new threats to food safety were recognized, new technologies and regulatory protocols were developed to enhance the safety of food. The occurrence of parasites was managed with slaughterhouse inspections, new husbandry systems, and parasiticidal drugs (Hagstad and Hubbert, 1981). By 1978, only 12 food-borne cases of parasite infection were documented (U.S. Public Health Service, 1978). Residues from drugs used to improve animal health and productivity arose as a food safety concern, but monitoring and inspection protocols largely have been effective in preventing illegal or unsafe levels of residues in food (Meyerholz, 1983; NRC, 1999; FDA, 2000). Microbial pathogens originating in animal fecal material remain the primary concern for the safety of food of animal origin (Tauxe, 1997).
Microbes pathogenic to humans grow in the animal gastrointestinal (GI) tract, and might or might not cause health problems in the animal (Altekruse et al., 1997). Physiologic stress increases the susceptibility of the animal to pathogens, the growth of pathogens in the GI tract, and their shedding into the fecal material of the stressed animal (Salminen et al., 1998). These same pathogens might enter the human food chain when they are transferred to the surface of the meat during slaughter and processing. The role of human food safety related to pathogens from animal fecal material was fully recognized only in the latter part of the twentieth century (Tauxe, 1997).
Secondary concerns for food safety arise from the disposition of carcass remains after removal of the edible meat, and from the disposal of animal fecal material. (Potential environmental concerns related to fecal material from genetically engineered animals are discussed in Chapter 5.) After the edible meat is removed, carcass remains are processed into other products used in a