carcasses from such animals. Entry of surplus animals into the food chain poses a concern because of the possibility of people in the general population being exposed to the transgene and its expressed products.
The committee attempted to identify potential human health and food safety concerns for meat or animal products derived from animal biotechnology (see Chapter 4). The species considered include ruminants, such as beef and dairy cattle, sheep, and goats; poultry and eggs; swine; rabbits; and a wide array of finfishes and shellfishes. Specifically, the committee considered non-genetically engineered animals that are propagated by nuclear transfer or other cloning techniques, genetically engineered animals developed primarily for meat or animal products such as milk and eggs, and genetically engineered animals developed to produce pharmaceuticals and other medical or non-medical products. The nature of concern for all foods or food products is that they should be free of agents—chemical or biologic—which affect the safety of the food for the human or animal consumer. The committee notes that the primary food safety concern in the U.S. currently is microbial pathogens primarily originating from animal fecal contamination.
The principles for assessing the safety of food from genetically engineered animals are qualitatively the same as for non-engineered animals, but animals genetically engineered for non-food products (e.g., pharmaceuticals) might present additional concerns relating to the nature of the products which they express. Female animals might be genetically engineered to produce non-food products in their milk or eggs. The males produced through this process or the unused females might enter the food supply. The safety of food products that are derived from animals engineered for non-food purposes might present a concern. Since expression of the transgene only has limited predictability, there is a concern that the product of the transgene might enter the animal’s general circulation.
A small percentage of proteins present in food can exert effects beyond nutrition, including allergenicity, bioactivity, and toxicity. The genetic engineering of animals intended for use as food will involve the expression of new proteins in animals—hence the safety, including the potential allergenicity of the newly introduced proteins, might be a concern. Allergenicity only can be reasonably assessed when the protein is known to trigger an immune response in sensitive subjects. The committee notes that the range of immune responses (allergic reactions) triggered by these novel proteins are likely to be consistent with those triggered from known allergens. The possibility that particular novel gene products might trigger allergenicity or hypersensitivity responses in some consumers will vary with the gene product at issue, and because of the