With respect to fighting ventures involving live birds in a State where it would not be in violation of the law, it shall be unlawful under this subsection for a person to sponsor or exhibit a bird in the fighting venture only if the person knew that any bird in the fighting venture was knowingly bought, sold, delivered, transported, or received in interstate or foreign commerce for the purpose of participation in the fighting venture.
It shall be unlawful for any person to knowingly use the mail service of the United States Postal Service or any instrumentality of interstate commerce for commercial speech for purposes of advertising an animal, or an instrument described in subsection (e), for use in an animal fighting venture, promoting  or in any other manner furthering an animal fighting venture except as performed outside the limits of the States of the United States.
Notwithstanding the provisions of subsection (c), the activities prohibited by such subsection shall be unlawful with respect to fighting ventures involving live birds only if the fight is to take place in a State where it would be in violation of the laws thereof.
The Secretary or any other person authorized by him shall make such investigations as the Secretary deems necessary to determine whether any person has violated or is violating any provision of this section, and the Secretary may obtain the assistance of the Federal Bureau of Investigation, the Department of the Treasury, or other law enforcement agencies of the United States, and State and local governmental agencies, in the conduct of such investigations, under cooperative agreements with such agencies. A warrant to search for and seize any animal which there is probable cause to believe was involved in any violation of this section may be issued by any judge of the United States or of a State court of record or by a United States magistrate judge within the district wherein the animal sought is located. Any United States marshal or any person authorized under this section to conduct investigations may apply for and execute any such warrant, and any animal seized under such a warrant shall be held by the United States marshal or other authorized person pending disposition thereof by the court in accordance with this subsection. Necessary care including veterinary treatment shall be provided while the animals are so held in custody. Any animal involved in any violation of this section shall be liable to be proceeded against and forfeited to the United States at any time on complaint filed in any United States district court or other court of the United States for any jurisdiction in which the animal is found and upon a judgment of forfeiture shall be disposed of by sale for lawful purposes or by other humane means, as the court may direct. Costs incurred for care of animals seized and forfeited under this section shall be recoverable from the owner of the animals (1) if he appears in such forfeiture proceeding, or (2) in a separate civil action brought in the jurisdiction in which the owner is found, resides, or transacts business.
The provisions of this chapter shall not supersede or otherwise invalidate any such State, local, or municipal legislation or ordinance relating to animal fighting ventures except in case of a direct and irreconcilable conflict between any requirements thereunder and this chapter or any rule, regulation, or standard hereunder.
The criminal penalties for violations of subsection (a), (b), (c), or (e) are provided in section 49 of title 18.