ECFR pet food poultry byproduct

21 CFR 589 covers substances prohibited from use in animal food or feed; its BSE-related sections frame what rendered proteins may enter pet food: 589.2000 (animal proteins prohibited in ruminant feed — the "ruminant feed ban", which bars most ruminant-derived protein from cattle and other ruminant rations but does not restrict use in dog and cat food, since pets are not ruminants) and 589.2001 (cattle materials prohibited in animal food or feed to prevent BSE — the specified-risk-material rule covering materials such as brain, skull, eyes and spinal cord from older cattle and material from non-ambulatory disabled cattle, which applies to all animal food including pet food). Other part 589 entries: 589.1 (substances prohibited from use in animal food or feed), 589.1000 (gentian violet) and 589.1001 (propylene glycol in or on cat food). Poultry-, fish- and pork-derived ingredients are not subject to these BSE restrictions. Importers of rendered bovine material must additionally satisfy USDA/APHIS and FDA import conditions with BSE documentation from approved sources; the parsed corpus indexes the section numbers and titles, so current compliance details should be read from the eCFR text of 589.2000/589.2001.