Quick search by citation:

21 U.S. Code § 643 - Registration of business, name of person, and trade names

No person, firm, or corporation shall engage in business, in or for commerce, as a meat broker, renderer, or animal food manufacturer, or engage in business in commerce as a wholesaler of any carcasses, or parts or products of the carcasses, of any cattle, sheep, swine, goats, horses, mules, or other equines, whether intended for human food or other purposes, or engage in business as a public warehouseman storing any such articles in or for commerce, or engage in the business of buying, selling, or transporting in commerce, or importing, any dead, dying, disabled, or diseased animals of the specified kinds, or parts of the carcasses of any such animals that died otherwise than by slaughter, unless, when required by regulations of the Secretary, he has registered with the Secretary his name, and the address of each place of business at which, and all trade names under which, he conducts such business.

(Mar. 4, 1907, ch. 2907, title II, § 203, as added Pub. L. 90–201, § 14, Dec. 15, 1967, 81 Stat. 594.)