[Code of Federal Regulations]
[Title 21, Volume 6]
[Revised as of January 1, 2003]
From the U.S. Government Printing Office via GPO Access
[CITE: 21CFR558.3]

[Page 358-359]
 
                        TITLE 21--FOOD AND DRUGS
 
CHAPTER I--FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN 
                          SERVICES (CONTINUED)
 
PART 558--NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS--Table of Contents
 
                      Subpart A--General Provisions
 
Sec.  558.3  Definitions and general considerations applicable to this part.


    (a) Regulations in this part provide for approved uses of drugs and 
combinations of drugs in animal feeds. Approved combinations of such 
drugs are specifically identified or incorporated by cross-reference. 
Unless specifically provided for by the regulations, a combination of 
two or more drugs is not approved.
    (b) The following definitions apply to terms used in this part:
    (1) New animal drugs approved for use in animal feed are placed in 
two categories as follows:
    (i) Category I--These drugs require no withdrawal period at the 
lowest use level in each species for which they are approved.
    (ii) Category II--These drugs require a withdrawal period at the 
lowest use level for at least one species for which they are approved, 
or are regulated on a ``no-residue'' basis or with a zero tolerance 
because of a carcinogenic concern regardless of whether a withdrawal 
period is required, or are a veterinary feed directive drug.
    (2) A ``Type A medicated article'' is intended solely for use in the 
manufacture of another Type A medicated article or a Type B or Type C 
medicated feed. It consists of a new animal drug(s), with or without 
carrier (e.g., calcium carbonate, rice hull, corn, gluten) with or 
without inactive ingredients. The manufacture of a Type A medicated 
article requires an application approved under Sec.  514.105 of this 
chapter.
    (3) A ``Type B medicated feed'' is intended solely for the 
manufacture of other medicated feeds (Type B or Type C). It contains a 
substantial quantity of nutrients including vitamins and/or minerals 
and/or other nutritional ingredients in an amount not less than 25 
percent of the weight. It is manufactured by diluting a Type A medicated 
article or another Type B medicated feed. The maximum concentration of 
animal drug(s) in a Type B medicated feed is 200 times the highest 
continuous use level for Category I drugs and 100 times the highest 
continuous use level for Category II drugs. The term ``highest 
continuous use level'' means the highest dosage at which the drug is 
approved for continuous use (14 days or more), or, if the drug is not 
approved for continuous use, it means the highest level used for disease 
prevention or control. If the drug is approved for multiple species at 
different use levels,

[[Page 359]]

the highest approved level of use would govern under this definition. 
The manufacture of a Type B medicated feed from a Category II, Type A 
medicated article requires a medicated feed mill license application 
approved under Sec.  515.20 of this chapter.
    (4) A ``Type C medicated feed'' is intended as the complete feed for 
the animal or may be fed ``top dressed'' (added on top of usual ration) 
on or offered ``free-choice'' (e.g., supplement) in conjunction with 
other animal feed. It contains a substantial quantity of nutrients 
including vitamins, minerals, and/or other nutritional ingredients. It 
is manufactured by diluting a Type A medicated article or a Type B 
medicated feed. A Type C medicated feed may be further diluted to 
produce another Type C medicated feed. The manufacture of a Type C 
medicated feed from a Category II, Type A medicated article requires a 
medicated feed mill license application approved under Sec.  515.20 of 
this chapter.
    (5) A Type B or Type C medicated feed manufactured from a drug 
component (bulk or ``drum-run'' (dried crude fermentation product)) 
requires an application approved under Sec.  514.105 of this chapter.
    (6) A ``veterinary feed directive (VFD) drug'' is a new animal drug 
approved under section 512(b) of the Federal Food, Drug, and Cosmetic 
Act (the act) for use in or on animal feed. Use of a VFD drug must be 
under the professional supervision of a licensed veterinarian.
    (7) A ``veterinary feed directive'' is a written statement issued by 
a licensed veterinarian in the course of the veterinarian's professional 
practice that orders the use of a veterinary feed directive (VFD) drug 
in or on an animal feed. This written statement authorizes the client 
(the owner of the animal or animals or other caretaker) to obtain and 
use the VFD drug in or on an animal feed to treat the client's animals 
only in accordance with the directions for use approved by the Food and 
Drug Administration (FDA). A veterinarian may issue a VFD only if a 
valid veterinarian-client-patient relationship exists, as defined in 
Sec.  530.3(i) of this chapter.
    (8) A ``medicated feed'' means a Type B medicated feed as defined in 
paragraph (b)(3) of this section or a Type C medicated feed as defined 
in paragraph (b)(4) of this section.
    (9) For the purposes of this part, a ``distributor'' means any 
person who distributes a medicated feed containing a VFD drug to another 
distributor or to the client-recipient of the VFD.
    (10) An ``animal production facility'' is a location where animals 
are raised for any purpose, but does not include the specific location 
where medicated feed is made.
    (11) An ``acknowledgment letter'' is a written communication 
provided to a distributor by a consignee who is not the ultimate user of 
medicated feed containing a VFD drug. An acknowledgment letter affirms 
that the consignee will not ship such medicated animal feed to an animal 
production facility that does not have a VFD, and will not ship such 
feed to another distributor without receiving a similar written 
acknowledgment letter.

[51 FR 7392, Mar. 3, 1986, as amended at 52 FR 2682, Jan. 26, 1987; 54 
FR 51386, Dec. 15, 1989; 56 FR 19268, Apr. 26, 1991; 64 FR 63206, Nov. 
19, 1999; 65 FR 76929, Dec. 8, 2000]