On October 6, 2005 the FDA published a notice of proposed rule making: Substances Prohibited From Use in Animal Food or Feed. The proposed prohibitions were to be modified dependent on the age of the cattle and whether the cattle were passed for human consumption. The changes are intended to strengthen existing safeguards to help prevent the spread of bovine spongiform encephalopathy (BSE) in U.S. cattle.

The final rule: Substances Prohibited From Use in Animal Food and Feed was published on April 25, 2008.

On April 9, 2009 the FDA published Docket No. FDA-2002-N-0031 (formerly Docket No. 2002N-0273) Substances Prohibited From Use in Animal Food and Feed; Final Rule: Proposed Delay of Effective Date. The FDA's proposal allowed for a delay of the effective date of the rule due to FDA's awareness of persons experiencing difficulty modifying their operations to comply with the final rule. It was noted in the federal register document that the FDA was providing 7 days for comment solely on the question of whether to delay the effective date.

On April 24, 2009 the Federal Register published Substances Prohibited From Use in Animal Food or Feed; Confirmation of Effective Date of Final Rule. The agency established a compliance date of October 26, 2009, for this rule in order to allow additional time for renderers to comply with the new requirements.

The AVMA commented to the notice of proposed rulemaking, acknowledging FDA's decision not to propose a prohibition on blood and blood products and expressing some concerns that it felt FDA should take into consideration while crafting the rule.

The AVMA supported the proposed delay of the effective date of the rule due to its awareness of persons experiencing difficulty as a result of the rule, particularly due to unintended consequences related to carcass disposal. AVMA is also signatory to a petition requesting that the Commissioner of Food and Drugs stay the effective date of the Agency's final rule.