Rep. Gary Ackerman (D-NY) recently introduced a bill in the House of Representatives which would permanently ban downed animals — animals which fall and cannot get up under their own power — from entering the food supply.
After a cow in the United States tested positive for Mad Cow Disease in 2003, a temporary ban on the slaughter of downed animals for food was put into place by U.S. Department of Agriculture Secretary Mike Johanns.
The bill would require that any downed animals be immediately and humanely euthanized and adds that,
It shall be unlawful for an inspector at an establishment to pass through inspection any nonambulatory livestock or carcass (including parts of a carcass) of nonambulatory livestock.
The USDA would be given one year from passage of the bill into law to promulgate regulations for the humane slaughter of downed animals and their exclusion from the food supply.
The full text of the bill can be read here.