21 CFR §510.7

1. (a)A new animal drug intended for use in the manufacture of animal feed shall be deemed to be unsafe unless at the time of its removal from the establishment of a manufacturer, packer, or distributor of such drug, such manufacturer, packer, or distributor has an unrevoked written statement from the consignee of such drug, or a notice from the Secretary, to the effect that with respect to the use of such drug in animal feed the consignee:
   1. (1)Holds a license issued under § 515.20 of this chapter; or
   2. (2)Will, if the consignee is not the user of the drug, ship such drug only to a holder of an approved application under § 515.10 of this chapter.
2. (b)The requirements of paragraph (a) of this section do not apply:
   1. (1)Where such drugs are intended for export and/or
   2. (2)When the use of such drug in the manufacture of a finished feed has been exempted from the requirements of section 512(m) of the act under the conditions specified by regulations published in part 558 of this chapter.