The Office of Research (OR) of the U.S. Food and Drug Administration’s Center for Veterinary Medicine (CVM) recently developed a new method for testing animal feed for prohibited materials. The method relies on polymerase chain reaction (PCR), a molecular technique that amplifies small amounts of genetic material (DNA or RNA) to produce larger amounts for analysis. Once the new PCR-based method is routinely used, it will enhance the FDA’s ability to make sure animal feed is safe and free of prohibited materials that may spread the agent thought to cause bovine spongiform encephalopathy (BSE).
On June 5, 1997, the FDA issued a similar feed ban that prohibited most mammalian protein from being used to make animal feed for ruminants (ref 1). In April 2008, the FDA strengthened the feed ban by prohibiting high-risk materials from being used to make all animal feed, including pet food. High-risk materials are those materials from cattle that have the highest chance of carrying the agent thought to cause BSE, such as the brains and spinal cords from cattle that are 30 months of age or older.
To make sure that animal feed manufacturers comply with the feed ban, the FDA tests feed samples for prohibited materials. Feed samples are typically collected by field investigators in the Office of Regulatory Affairs (ORA), the FDA’s investigative arm. The samples are analyzed by feed microscopy, a technique that uses a microscope to visually identify the components in the sample. Samples that test positive for a prohibited mammalian protein by feed microscopy then undergo PCR testing to confirm the positive result.
More information on feed testing is available on the FDA Web site.