{"data":{"id":"us/21-cfr-558.555","jurisdiction":"us","citation":"21 CFR 558.555","heading":"Semduramicin.","body":"(a) Specifications. Type A medicated article containing:\n(1) 22.7 grams (g) per pound (lb) (50 g/kilogram (kg)) semduramicin (as semduramicin sodium).\n(2) 22.7 g/lb (50 g/kg) semduramicin (as semduramicin sodium biomass).\n(b) Sponsor. See No. 066104 in § 510.600(c) of this chapter for use of product described in paragraph (a)(1) of this section as in paragraph (d) of this section; for use of product described in paragraph (a)(2) of this section as in paragraph (e) of this section.\n(c) Related tolerances. See § 556.597 of this chapter.\n(d) Conditions of use in chickens. It is used in chicken feed as follows:\nSemduramicin in grams per ton Combinations in grams per ton Indications for use Limitations Sponsor\n(1) 22.7 (25 ppm) Broiler chickens: For the prevention of coccidiosis caused by Eimeria acervulina, E. brunetti, E. maxima, E. mivati/E. mitis, E. necatrix, and E. tenella. Do not feed to laying hens. 066104\n(2) 22.7 Bacitracin methylenedisalicylate 10 to 50 Broiler chickens: As in paragraph (d)(1) of this section; for improved feed efficiency. Feed continuously as sole ration. Do not feed to laying hens. Bacitracin methylenedisalicylate as provided by No. 054771 in § 510.600(c) of this chapter. 066104\n(e) Conditions of use in chickens. It is used in chicken feed as follows:\nSemduramicin in grams per ton Combination in grams per ton Indications for use Limitations Sponsor\n(1) 22.7 (25 ppm) Broiler chickens: For the prevention of coccidiosis caused by Eimeria tenella, E. acervulina, E. maxima, E. brunetti, E. necatrix, and E. mitis. Do not feed to laying hens. 066104\n(2) [Reserved]\n(f) Semduramicin may also be used in combination with virginiamycin as in § 558.635.","path":["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"],"source_url":"https://www.ecfr.gov/api/versioner/v1/full/2026-08-25/title-21.xml","current_through":"2026-08-25","vintage":"","retrieved_at":"2026-08-27T02:24:47Z","sha256":"9e39e599c957ebf91c444911fb50d7904965b9f9fa173b784f1d15cbd9a65154","source_id":"us-cfr","stale":true,"prev":"us/21-cfr-558.550","next":"us/21-cfr-558.575"},"notice":"GroundRules: Original legal text. Not legal advice."}