FDA’s Enhanced Feed Ban to Curtail Mad Cow Disease
The primary manner in which bovine spongiform encephalopathy (BSE, or mad cow disease) is transmitted is through the ingestion of feed that contains contaminated tissue—eg, meat, bone meal, or nervous tissue from an infected animal. Therefore, to reduce the spread of BSE, the Canadian government banned certain potentially infectious animal tissues, or specified risk material* (SRM), from cattle feed in 1997.
However, cases of BSE in Canada began occurring in cows born after the 1997 feed ban. As a result, the government instituted a wider feed ban last year, in which SRM were to be eliminated from all other animal feeds, pet foods, and fertilizers. This new measure is intended to reduce the risk of any cross-contamination of cattle feed with the BSE-causing agent, and the Canadian Food Inspection Agency estimates that BSE will be eliminated from Canadian cattle by 2017.**
Like Canada, the United States instituted an FDA-mandated feed ban in 1997, which applied only to cattle feed. But as part of the USDA’s BSE surveillance system, 2 cases of BSE in American-born cattle were discovered in 2005 and 2006, respectively. In both cases, the affected cows were born before 1997. Nevertheless, to enhance BSE prevention, the FDA is instituting a more rigorous feed ban in April of next year, consistent with the latest feed ban of the Canadian government.
The FDA’s enhanced feed ban eliminates the following from the food or feed of all animals:
- the entire carcass of a BSE-positive cow;
- the brain and spinal cord of a cow aged 30 months or older;
- the entire carcass of a cow not inspected and passed for human consumption that is 30 months of age or older from which the brain and spinal cord have not been removed;
- the tallow (ie, rendered beef fat) from a BSE-positive cow;
- the tallow derived from other prohibited materials that contain >0.15% insoluble impurities; and
- mechanically separated beef that is derived from prohibited materials.
A recent AP article suggests that next year’s FDA feed ban will pose health risks of its own, because of the new burden of carcass disposal placed on ranchers or dairy farmers. Rendering plants may no longer accept dead cattle owing to the costs of removing SRM before feed production, or these plants may charge higher prices for processing dead cows. Consequently ranchers and farmers may be more likely to dispose of certain dead cattle by burying, composting, or leaving the carcasses out in the open for scavengers. (These measures are already used to avoid rendering-plant fees.) Unfortunately there is no indication in the AP article how Canadian cattle producers have adjusted to their enhanced feed ban during the last year.
* For example, cow brains, eyes, and spinal cords. According to the FDA, ~90% of BSE infectivity is contained in the brain and spinal cord, and ~10% is present in the retina, ganglia, and distal ileum.
** Presumably at a time when cattle born before the 2007 feed ban are no longer with us.
Photo of BSE-affected cow from Wikipedia.