The rule, which would take effect April 27, is meant to reduce the risk of bovine spongiform encephalopathy (BSE) by prohibiting use of brains and spinal cords from cattle 30 months and older in all animal feed.

The biological materials already are prohibited in feed for ruminants, including cattle, sheep and goats.

Consumption of beef infected with BSE is believed to cause variant Creutzfeldt-Jakob disease in humans.