(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 major species for which they are approved or are approved for use only in minor species.
(ii) Category II - These drugs require a withdrawal period at the lowest use level for at least one major species for which they are approved, or are regulated on a “no-residue” basis or with a zero tolerance because of carcinogenic concern regardless of whether a withdrawal period is required in any species.
(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 § 514.105 of this chapter or an index listing granted under § 516.151 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, 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 § 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 § 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 § 514.105 of this chapter or an index listing granted under § 516.151 of this chapter.
(6) A “veterinary feed directive (VFD) drug” is a drug intended for use in or on animal feed which is limited by an approved application filed pursuant to section 512(b) of the Federal Food, Drug, and Cosmetic Act, a conditionally approved application filed pursuant to section 571 of the Federal Food, Drug, and Cosmetic Act, or an index listing under section 572 of the Federal Food, Drug, and Cosmetic Act to use under the professional supervision of a licensed veterinarian. Use of animal feed bearing or containing a VFD drug must be authorized by a lawful veterinary feed directive.
(7) A “veterinary feed directive” is a written (nonverbal) statement issued by a licensed veterinarian in the course of the veterinarian's professional practice that orders the use of a VFD drug or combination 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 animal feed bearing or containing a VFD drug or combination VFD drug to treat the client's animals only in accordance with the conditions for use approved, conditionally approved, or indexed by the Food and Drug Administration.
(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 person. Such other person may be another distributor or the client-recipient of a 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 (nonverbal) communication provided to a distributor (consignor) from another distributor (consignee). An acknowledgment letter must be provided either in hardcopy or through electronic media and must affirm:
(i) That the distributor will not ship such VFD feed to an animal production facility that does not have a VFD,
(ii) That the distributor will not ship such VFD feed to another distributor without receiving a similar written acknowledgment letter, and
(iii) That the distributor has complied with the distributor notification requirements of § 558.6(c)(5).
(12) A “combination veterinary feed directive (VFD) drug” is a combination new animal drug (as defined in § 514.4(c)(1)(i) of this chapter) intended for use in or on animal feed which is limited by an approved application filed under section 512(b) of the Federal Food, Drug, and Cosmetic Act, a conditionally approved application filed under section 571 of the Federal Food, Drug, and Cosmetic Act, or an index listing under section 572 of the Federal Food, Drug, and Cosmetic Act to use under the professional supervision of a licensed veterinarian, and at least one of the new animal drugs in the combination is a VFD drug. Use of animal feed bearing or containing a combination VFD drug must be authorized by a lawful VFD.
(13) “Major species” means cattle, horses, swine, chickens, turkeys, dogs, and cats.
(14) “Minor species” means animals, other than humans, that are not major species.
(a) A feed manufacturing facility must possess a medicated feed mill license in order to manufacture a Type B or Type C medicated feed from a Category II, Type A medicated article.
(b) The manufacture of the following types of feed are exempt from the required license, unless otherwise specified:
(1) Type B or Type C medicated feed using Category I, Type A medicated articles or Category I, Type B or Type C medicated feeds; and
(2) Type B or Type C medicated feed using Category II, Type B or Type C medicated feeds.
(c) The use of Type B and Type C medicated feeds shall also conform to the conditions of use provided for in subpart B of this part.
(d) This paragraph identifies each drug by category, the maximum level of drug in Type B medicated feeds, and the assay limits for the drug in Type A medicated articles and Type B and Type C medicated feeds, as follows:
Category I
Drug | Assay limits percent 1 Type A | Type B maximum (200x) | Assay limits percent 1 Type B/C 2 |
---|---|---|---|
Amprolium with Ethopabate | 94-114 | 22.75 g/lb (5.0%) | 80-120. |
Avilamycin | 90-110 | 7.3 g/lb (1.6%) | 80-110. |
Bacitracin methylenedisalicylate | 85-115 | 25.0 g/lb (5.5%) | 70-130. |
Bacitracin zinc | 84-115 | 5.0 g/lb (1.1%) | 70-130. |
Bambermycins | 90-110 | 800 g/ton (0.09%) | 80-120/70-130. |
Chlortetracycline | 85-115 | 40.0 g/lb (8.8%) | 80-115/70-130. |
Coumaphos | 95-115 | 6.0 g/lb (1.3%) | 80-120. |
Decoquinate | 90-105 | 2.72 g/lb (0.6%) | 80-120. |
Dichlorvos | 100-115 | 33.0 g/lb (7.3%) | 90-120/80-130. |
Diclazuril | 90-110 | 182 g/t (0.02%) | 85-115/70-120. |
Efrotomycin | 94-113 | 1.45 g/lb (0.32%) | 80-120. |
Iodinated casein | 85-115 | 20.0 g/lb (4.4%) | 75-125. |
Laidlomycin propionate potassium | 90-110 | 1 g/lb (0.22%) | 90-115/85-115. |
Lasalocid | 95-115 | 40.0 g/lb (8.8%) | Type B (cattle and sheep): 80-120; Type C (all): 75-125. |
Lincomycin | 90-115 | 20.0 g/lb (4.4%) | 80-130. |
Lubabegron | 87-107 | 908 g/ton | 85-115/80-120. |
Melengestrol acetate | 90-110 | 10.0 g/ton (0.0011%) | 70-120. |
Monensin | 85-115 | 40.0 g/lb (8.8%) | Chickens, turkeys, and quail: 75-125; Cattle: 5-10 g/ton 80-120; Cattle: 10-30 g/ton 85-115; Goats: 20 g/ton 85-115; Liq. feed: 80-120. |
Narasin | 90-110 | 9.0 g/lb (1.98%) | 85-115/75-125. |
Nicarbazin (granular) | 90-110 | 9.0 g/lb (1.98%) | 85-115/75-125. |
Narasin | 90-110 | 9.0 g/lb (1.98%) | 85-115/75-125. |
Nystatin | 85-125 | 5.0 g/lb (1.1%) | 75-125. |
Oxytetracycline | 90-120 | 20.0 g/lb (4.4%) | 75-125/65-135. |
Poloxalene | 90-110 | 54.48 g/lb (12.0%) | Liq. feed: 85-115. |
Ractopamine | 85-105 | 2.46 g/lb (0.54%) | 80-110/75-125. |
Salinomycin | 90-110 | 6.0 g/lb (1.3%) | 80-120. |
Semduramicin (as semduramicin sodium) | 90-110 | 2.27 g/lb (0.50%) | 80-110 |
Semduramicin (as semduramicin sodium biomass) | 90-110 | 2.27 g/lb (0.50%) | 80-120 |
Tylosin | 80-120 | 10.0 g/lb (2.2%) | 75-125. |
Tylvalosin | 90-110 | 3.86 g/lb | 85-115. |
Virginiamycin | 85-115 | 10.0 g/lb (2.2%) | 70-130. |
Zoalene | 92-104 | 11.35 g/lb (2.5%) | 85-115. |
1 Percent of labeled amount.
2 Values given represent ranges for either Type B or Type C medicated feeds. For those drugs that have two range limits, the first set is for a Type B medicated feed and the second set is for a Type C medicated feed. These values (ranges) have been assigned in order to provide for the possibility of dilution of a Type B medicated feed with lower assay limits to make Type C medicated feed.
Category II
Drug | Assay limits percent 1 Type A | Type B maximum (100x) | Assay limits percent 1 Type B/C 2 |
---|---|---|---|
Amprolium | 94-114 | 11.35 g/lb (2.5%) | 80-120. |
Apramycin | 88-112 | 7.5 g/lb (1.65%) | 80-120. |
Carbadox | 90-110 | 2.5 g/lb (0.55%) | 75-125. |
Clopidol | 94-106 | 11.4 g/lb (2.5%) | 90-115/80-120. |
Erythromycin | 85-115 | 4.625 g/lb (1.02%) | 75-125. |
Famphur | 100-110 | 5.5 g/lb (1.21%) | 90-115/80-120. |
Fenbendazole | 93-113 | 8.87 g/lb (1.96%) | 75-125. |
Florfenicol | 90-110 | 9.1 g/lb (2.0%) | Swine feed: 85-115
Catfish feed: 80-110. Salmonid feed: 80-110. |
Halofuginone hydrobromide | 90-115 | 272.0 g/ton (.03%) | 75-125. |
Hygromycin B | 90-110 | 1,200 g/ton (0.13%) | 75-125. |
Ivermectin | 95-105 | 1,180 g/ton (0.13%) | 80-110. |
Maduramicin ammonium | 90-110 | 545 g/ton (.06%) | 80-120. |
Morantel tartrate | 90-110 | 66.0 g/lb (14.52%) | 85-115. |
Neomycin | 80-120 | 20 g/lb (4.4%) | 70-125. |
Oxytetracycline | 80-120 | 20 g/lb (4.4%) | 65-135. |
Neomycin sulfate | 80-120 | 100 g/lb (22.0%) | 70-125. |
Nicarbazin (granular) | 90-110 | 5.675 g/lb (1.25%) | 85-115/75-125. |
Nicarbazin (powder) | 90-110 | 9.08 g/lb (2.00%) | 85-115/75-125. |
Novobiocin | 85-115 | 17.5 g/lb (3.85%) | 80-120. |
Pyrantel tartrate | 90-110 | 36 g/lb (7.9%) | 75-125. |
Robenidine | 95-115 | 1.5 g/lb (0.33%) | 80-120. |
Sulfadimethoxine | 90-110 | Poultry: 5.675 g/lb
Fish: 85.1 g/lb | 80-115/75-125. |
Ormetoprim | 90-110 | Poultry: 3.405 g/lb
Fish: 17.0 g/lb | 80-115. |
Sulfamerazine | 85-115 | 18.6 g/lb (4.0%) | 85-115. |
Sulfamethazine | 85-115 | 10.0 g/lb (2.2%) | 80-120. |
Chlortetracycline | 85-115 | 10.0 g/lb (2.2%) | 85-125/70-130. |
Sulfamethazine | 85-115 | 10.0 g/lb (2.2%) | 80-120. |
Tylosin | 80-120 | 10.0 g/lb (2.2%) | 75-125. |
Sulfaquinoxaline | 98-106 | 11.2 g/lb (2.5%) | 85-115. |
Thiabendazole | 94-106 | 45.4 g/lb (10.0%) | >7% 85-115; <7% 90-110. |
Tiamulin hydrogen fumarate | 90-115 | 10 g/lb | 90-115/70-130. |
Tilmicosin | 90-110 | 37.9 g/lb (8.35%) | Swine Type B/C feed: 85-115. |
Zilpaterol | 90-110 | 680 g/t (0.075%) | 80-110/75-115. |
1 Percent of labeled amount.
2 Values given represent ranges for either Type B or Type C medicated feeds. For those drugs that have two range limit, the first set is for a Type B medicated feed and the second set is for a Type C medicated feed. These values (ranges) have been assigned in order to provide for the possibility of dilution of a Type B medicated feed with lower assay limits to make a Type C medicated feed.
(e) When drugs from both categories are in combination, the Category II requirements will apply to the combination drug product.
(a) What types of liquid medicated feeds are covered by this section? This section covers the following types of liquid medicated feed:
(1) Type B feed that is intended for further manufacture of other medicated feeds (§ 558.3(b)(3)) or:
(2) Type C feed that is intended for the following:
(i) Further manufacture of another Type C feed, or
(ii) Top-dressing (adding on top of the usual ration) (§ 558.3(b)(4)).
(b) How is liquid free-choice medicated feed regulated? Liquid free-choice medicated feed is covered by this section and by § 510.455.
(c) What is required for new animal drugs intended for use in liquid feed? Any new animal drug intended for use in liquid feed must be approved for such use under section 512 of the Federal Food, Drug, and Cosmetic Act (the act) or index listed under section 572 of the act. Such approvals under section 512 of the act must be:
(1) An original NADA,
(2) A supplemental NADA, or
(3) An abbreviated NADA.
(d) What are the approval requirements under section 512 of the act for new animal drugs intended for use in liquid feed? An approval under section 512 of the act for a new animal drug intended for use in liquid feed must contain the following information:
(1) Data, or a reference to data in a master file (MF), that shows the relevant ranges of conditions under which the drug will be chemically stable in liquid feed under field use conditions; and
(2) Data, or a reference to data in an MF, that shows that the drug is physically stable in liquid feed under field conditions; or
(3) Feed labeling with recirculation or agitation directions as follows:
(i) For liquid feeds stored in recirculating tank systems: Recirculate immediately prior to use for not less than 10 minutes, moving not less than 1 percent of the tank contents per minute from the bottom of the tank to the top. Recirculate daily as described even when not used.
(ii) For liquid feeds stored in mechanical, air, or other agitation-type tank systems: Agitate immediately prior to use for not less than 10 minutes, creating a turbulence at the bottom of the tank that is visible at the top. Agitate daily as described even when not used.
(e) How are chemical and physical stability data to be submitted? The data must be submitted as follows:
(1) Directly in the NADA,
(2) By a sponsor, or
(3) To an MF that a sponsor may then reference in its NADA with written consent of the MF holder.
(f) What will be stated in the published approval for a new animal drug intended for use in liquid feed? The approval of a new animal drug intended for use in liquid feed as published in this subchapter will include the following requirements:
(1) The formula and/or specifications of the liquid medicated feed, where the owner of this information requests such publication; and/or
(2) A statement that the approval has been granted for a proprietary formula and/or specifications.
(g) When is a medicated feed mill license required for the manufacture of a liquid medicated feed? An approved medicated feed mill license is required for the manufacture of the following types of feeds:
(1) All liquid medicated feeds that contain a Category II drug, and
(2) Liquid medicated feeds that contain a Category I drug and use a proprietary formula and/or specifications.
(h) What measures are in place to prevent certain drugs, approved for use in animal feed or drinking water but not in liquid medicated feed, from being diverted to use in liquid feeds? Any product containing any form of bacitracin, oxytetracycline, or chlortetracycline, intended for oral administration via animal feed and/or drinking water, and not approved for use in a liquid medicated feed must include in its labeling the following statement: “FOR USE IN ___ ONLY. NOT FOR USE IN LIQUID MEDICATED FEEDS.” The blank may be filled in with the words: “DRY FEEDS”, “DRINKING WATER”, or “DRY FEEDS AND DRINKING WATER”.
(i) Can the labeling provisions of paragraph (h) of this section be waived, and how can I apply for a waiver? (1) The labeling provisions of paragraph (h) of this section may be waived if there is evidence to indicate that it is unlikely a new animal drug would be used in the manufacture of a liquid medicated feed.
(2) To obtain a waiver, you must submit a letter requesting a waiver to the Office of New Animal Drug Evaluation (HFV-100), Center for Veterinary Medicine, Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855.
(3) The letter must include a copy of the product label; a description of the formulation; and information to establish that the physical, chemical, or other properties of the new animal drug are such that diversion to use in liquid medicated feed is unlikely.
(j) What else do I need to know about the labeling provisions of paragraph (h) of this section? The labeling provisions of paragraph (h) of this section may be implemented without prior approval as provided for in § 514.8(c)(3) of this chapter.
(a) General requirements related to veterinary feed directive (VFD) drugs. (1) Animal feed bearing or containing a VFD drug or a combination VFD drug (a VFD feed or combination VFD feed) may be fed to animals only by or upon a lawful VFD issued by a licensed veterinarian.
(2) A VFD feed or combination VFD feed must not be fed to animals after the expiration date on the VFD.
(3) Use and labeling of a VFD drug or a combination VFD drug in feed is limited to the approved, conditionally approved, or indexed conditions of use. Use of feed containing this veterinary feed directive (VFD) drug in a manner other than as directed on the labeling (extralabel use) is not permitted.
(4) All involved parties (the veterinarian, the distributor, and the client) must retain a copy of the VFD for 2 years. The veterinarian must retain the original VFD in its original form (electronic or hardcopy). The distributor and client copies may be kept as an electronic copy or hardcopy.
(5) All involved parties must make the VFD and any other records specified in this section available for inspection and copying by FDA upon request.
(6) All labeling and advertising for VFD drugs, combination VFD drugs, and feeds containing VFD drugs or combination VFD drugs must prominently and conspicuously display the following cautionary statement: “Caution: Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian.”
(b) Responsibilities of the veterinarian issuing the VFD. (1) In order for a VFD to be lawful, the veterinarian issuing the VFD must:
(i) Be licensed to practice veterinary medicine; and
(ii) Be operating in the course of the veterinarian's professional practice and in compliance with all applicable veterinary licensing and practice requirements, including issuing the VFD in the context of a veterinarian-client-patient relationship (VCPR) as defined by the State. If applicable VCPR requirements as defined by such State do not include the key elements of a valid VCPR as defined in § 530.3(i) of this chapter, the veterinarian must issue the VFD in the context of a valid VCPR as defined in § 530.3(i) of this chapter.
(2) The veterinarian must only issue a VFD that is in compliance with the conditions for use approved, conditionally approved, or indexed for the VFD drug or combination VFD drug.
(3) The veterinarian must ensure that the following information is fully and accurately included on the VFD:
(i) The veterinarian's name, address, and telephone number;
(ii) The client's name, business or home address, and telephone number;
(iii) The premises at which the animals specified in the VFD are located;
(iv) The date of VFD issuance;
(v) The expiration date of the VFD. This date must not extend beyond the expiration date specified in the approval, conditional approval, or index listing, if such date is specified. In cases where the expiration date is not specified in the approval, conditional approval, or index listing, the expiration date of the VFD must not exceed 6 months after the date of issuance;
(vi) The name of the VFD drug(s);
(vii) The species and production class of animals to be fed the VFD feed;
(viii) The approximate number of animals to be fed the VFD feed by the expiration date of the VFD. The approximate number of animals is the potential number of animals of the species and production class identified on the VFD that will be fed the VFD feed or combination VFD feed at the specified premises by the expiration date of the VFD;
(ix) The indication for which the VFD is issued;
(x) The level of VFD drug in the VFD feed and duration of use;
(xi) The withdrawal time, special instructions, and cautionary statements necessary for use of the drug in conformance with the approval;
(xii) The number of reorders (refills) authorized, if permitted by the drug approval, conditional approval, or index listing. In cases where reorders (refills) are not specified on the labeling for an approved, conditionally approved, or index listed VFD drug, reorders (refills) are not permitted;
(xiii) The statement: “Use of feed containing this veterinary feed directive (VFD) drug in a manner other than as directed on the labeling (extralabel use) is not permitted.”;
(xiv) An affirmation of intent for combination VFD drugs as described in paragraph (6) of this section; and
(xv) The veterinarian's electronic or written signature.
(4) The veterinarian may, at his or her discretion, enter the following information on the VFD to more specifically identify the animals authorized to be treated/fed the VFD feed:
(i) A more specific description of the location of animals (e.g., by site, pen, barn, stall, tank, or other descriptor that the veterinarian deems appropriate);
(ii) The approximate age range of the animals;
(iii) The approximate weight range of the animals; and
(iv) Any other information the veterinarian deems appropriate to identify the animals specified in the VFD.
(5) For VFDs intended to authorize the use of an approved, conditionally approved, or indexed combination VFD drug that includes more than one VFD drug, the veterinarian must include the drug-specific information required in paragraphs (b)(3)(vi), (ix), (x), and (xi) of this section for each VFD drug in the combination.
(6) The veterinarian may restrict VFD authorization to only include the VFD drug(s) cited on the VFD or may expand such authorization to allow the use of the cited VFD drug(s) along with one or more over-the-counter (OTC) animal drugs in an approved, conditionally approved, or indexed combination VFD drug. The veterinarian must affirm his or her intent regarding combination VFD drugs by including one of the following statements on the VFD:
(i) “This VFD only authorizes the use of the VFD drug(s) cited in this order and is not intended to authorize the use of such drug(s) in combination with any other animal drugs.”
(ii) “This VFD authorizes the use of the VFD drug(s) cited in this order in the following FDA-approved, conditionally approved, or indexed combination(s) in medicated feed that contains the VFD drug(s) as a component.” [List specific approved, conditionally approved, or indexed combination medicated feeds following this statement.]
(iii) “This VFD authorizes the use of the VFD drug(s) cited in this order in any FDA-approved, conditionally approved, or indexed combination(s) in medicated feed that contains the VFD drug(s) as a component.”
(7) The veterinarian must issue a written (nonverbal) VFD.
(8) The veterinarian must send a copy of the VFD to the distributor via hardcopy, facsimile (fax), or electronically. If in hardcopy, the veterinarian must send the copy of the VFD to the distributor either directly or through the client.
(9) The veterinarian must provide a copy of the VFD to the client.
(c) Responsibilities of any person who distributes an animal feed containing a VFD drug or a combination VFD drug. (1) The distributor is permitted to fill a VFD only if the VFD contains all the information required in paragraph (b)(3) of this section.
(2) The distributor is permitted to distribute an animal feed containing a VFD drug or combination VFD drug only if it complies with the terms of the VFD and is manufactured and labeled in conformity with the approved, conditionally approved, or indexed conditions of use for such drug.
(3) The distributor must keep records of the receipt and distribution of all medicated animal feed containing a VFD drug for 2 years.
(4) In addition to other applicable recordkeeping requirements found in this section, if the distributor manufactures the animal feed bearing or containing the VFD drug, the distributor must also keep VFD feed manufacturing records for 1 year in accordance with part 225 of this chapter. Such records must be made available for inspection and copying by FDA upon request.
(5) A distributor of animal feed containing a VFD drug must notify FDA prior to the first time it distributes animal feed containing a VFD drug. The notification is required one time per distributor and must include the following information:
(i) The distributor's complete name and business address;
(ii) The distributor's signature or the signature of the distributor's authorized agent; and
(iii) The date the notification was signed.
(6) A distributor must also notify FDA within 30 days of any change in ownership, business name, or business address.
(7) The notifications cited in paragraphs (c)(5) and (c)(6) of this section must be submitted to the Food and Drug Administration, Center for Veterinary Medicine, Division of Animal Feeds (HFV-220), 7519 Standish Pl., Rockville, MD 20855, FAX: 240-453-6882.
(8) A distributor is permitted to distribute a VFD feed to another distributor only if the originating distributor (consignor) first obtains a written (nonverbal) acknowledgment letter, as defined in § 558.3(b)(11), from the receiving distributor (consignee) before the feed is shipped. Consignor distributors must retain a copy of each consignee distributor's acknowledgment letter for 2 years.