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U.S. Department of Health and Human Services

CFR - Code of Federal Regulations Title 21

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The information on this page is current as of Dec 22, 2023.

For the most up-to-date version of CFR Title 21, go to the Electronic Code of Federal Regulations (eCFR).

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Help | More About 21CFR
[Code of Federal Regulations]
[Title 21, Volume 6]
[CITE: 21CFR558.363]



TITLE 21--FOOD AND DRUGS
CHAPTER I--FOOD AND DRUG ADMINISTRATION
DEPARTMENT OF HEALTH AND HUMAN SERVICES
SUBCHAPTER E - ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS

PART 558 -- NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS

Subpart B - Specific New Animal Drugs for Use in Animal Feeds

Sec. 558.363 Narasin.

(a) Specifications. Type A medicated articles containing 36, 45, 54, 72, or 90 grams narasin per pound.

(b) Sponsor. See No. 058198 in § 510.600(c) of this chapter.

(c) Tolerances. See § 556.428 of this chapter.

(d) Special considerations. An expiration date of 2 months (8 weeks) is required for narasin Type C medicated swine feeds.

(e) Conditions of use. It is used as follows:

(1) Chickens -

Narasin
grams/ton
Combination in grams/ton Indications for use Limitations Sponsor
(i) 54 to 90Broiler chickens: For prevention of coccidiosis caused by Eimeria necatrix, E. tenella, E. acervulina, E. brunetti, E. mivati, and E. maximaFor broiler chickens only. Feed continuously as sole ration. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal058198
(ii) 54 to 72Bacitracin methylenedisalicylate, 10 to 50Broiler chickens: For prevention of coccidiosis caused by Eimeria necatrix, E. tenella, E. acervulina, E. brunetti, E. mivati, and E. maxima, and for increased rate of weight gain and improved feed efficiencyFor broiler chickens only. Feed continuously as sole ration. Do not feed to laying hens. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal. Bacitracin methylenedisalicylate as provided by No. 054771 in § 510.600(c) of this chapter054771
(iii) 54 to 72Bacitracin zinc, 4 to 50Broiler chickens: For prevention of coccidiosis caused by Eimeria necatrix, E. tenella, E. acervulina, E. brunetti, E. mivati, and E. maxima, and for increased rate of weight gain and improved feed efficiencyFor broiler chickens only. Feed continuously as sole ration. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal. Bacitracin zinc as provided by No. 054771 in § 510.600(c) of this chapter054771
(iv) 54 to 72Bambermycins, 1 to 2Broiler chickens: For prevention of coccidiosis caused by Eimeria necatrix, E. tenella, E. acervulina, E. brunetti, E. mivati, and E. maxima, and for increased rate of weight gain and improved feed efficiencyFor broiler chickens only. Feed continuously as sole ration. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal. Bambermycins as provided by No. 016592 in § 510.600(c) of this chapter016592

(2) Swine -

Narasin
grams/ton
Combination in grams/ton Indications for use Limitations Sponsor
(i) 13.6 to 27.2Growing-finishing swine: For increased rate of weight gain when fed for at least 4 weeksFeed continuously for at least 4 weeks to swine during the growing-finishing period as the sole ration. No increased benefit in rate of weight gain has been shown when narasin concentrations in the diet are greater than 13.6 g/ton. Effectiveness has not been demonstrated when fed for durations less than 4 weeks. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal. Not approved for use in breeding animals because safety and effectiveness have not been evaluated in these animals. Swine being fed with narasin should not have access to feeds containing pleuromutilins (e.g., tiamulin) as adverse reactions may occur. If signs of toxicity occur, discontinue use058198
(ii) 18.1 to 27.2Growing-finishing swine: For increased rate of weight gain and improved feed efficiency when fed for at least 4 weeksFeed continuously for at least 4 weeks to swine during the growing-finishing period as the sole ration. No increased benefit in rate of weight gain has been shown when narasin concentrations in the diet are greater than 13.6 g/ton. Effectiveness has not been demonstrated when fed for durations less than 4 weeks. Do not allow adult turkeys, horses, or other equines access to narasin formulations. Ingestion of narasin by these species has been fatal. Not approved for use in breeding animals because safety and effectiveness have not been evaluated in these animals. Swine being fed with narasin should not have access to feeds containing pleuromutilins (e.g., tiamulin) as adverse reactions may occur. If signs of toxicity occur, discontinue use058198

(3) Narasin single-ingredient Type A medicated articles may also be used in combination with:

(i) Avilamycin as in § 558.68.

(ii) [Reserved]

[83 FR 64741, Dec. 18, 2018, as amended at 86 FR 14825, Mar. 19, 2021]

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