21 CFR § 558.555 - Semduramicin.

---
identifier: "/us/cfr/t21/s558.555"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 558.555 - Semduramicin."
title_number: 21
title_name: "Food and Drugs"
section_number: "558.555"
section_name: "Semduramicin."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "E"
subchapter_name: "ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS"
part_number: "558"
part_name: "NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 354, 360b, 360ccc, 360ccc-1, 371."
regulatory_source: "40 FR 13959, Mar. 27, 1975, unless otherwise noted."
cfr_part: "558"
---


# 558.555 Semduramicin.

(a) *Specifications.* Type A medicated article containing:

(1) 22.7 grams (g) per pound (lb) (50 g/kilogram (kg)) semduramicin (as semduramicin sodium).

(2) 22.7 g/lb (50 g/kg) semduramicin (as semduramicin sodium biomass).

(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.

(c) *Related tolerances.* See § 556.597 of this chapter.

(d) *Conditions of use in chickens.* It is used in chicken feed as follows:

| Semduramicin in grams per ton | Combinations in grams per ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) 22.7 (25 ppm) |  | Broiler chickens: For the prevention of coccidiosis caused by /, and | Do not feed to laying hens. | 066104 |
| (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 |

(e) *Conditions of use in chickens.* It is used in chicken feed as follows:

| Semduramicin in grams per ton | Combination in grams per ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) 22.7 (25 ppm) |  | Broiler chickens: For the prevention of coccidiosis caused by | Do not feed to laying hens. | 066104 |
| (2) [Reserved] |  |  |  |  |

(f) Semduramicin may also be used in combination with virginiamycin as in § 558.635.

[59 FR 17477, Apr. 13, 1994, as amended at 60 FR 57928, Nov. 24, 1995; 61 FR 29481, June 11, 1996; 61 FR 43451, Aug. 23, 1996; 61 FR 66584, Dec. 18, 1996; 62 FR 66985, Dec. 23, 1997; 64 FR 48296, Sept. 3, 1999; 66 FR 47964, Sept. 17, 2001; 69 FR 13221, Mar. 22, 2004; 70 FR 41961, July 21, 2005; 73 FR 812, Jan. 4, 2008; 74 FR 41631, Aug. 18, 2009; 79 FR 10983, Feb. 27, 2014; 79 FR 13546, Mar. 11, 2014; 81 FR 17609, Mar. 30, 2016; 81 FR 95013, Dec. 27, 2016; 86 FR 14826, Mar. 19, 2021; 87 FR 17948, Mar. 29, 2022]