#### § 558.58 Amprolium and ethopabate.

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

(1) 25 percent amprolium and 8 percent ethopabate or 5 percent amprolium and 1.6 percent ethopabate;

(2) 25 percent amprolium and 0.8 percent ethopabate or 5 percent amprolium and 0.16 percent ethopabate.

(b) *Sponsor.* See No. 016592 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)).

(c) *Related tolerances.* See [§§ 556.50](/on/2024-09-17/title-21/section-556.50) and [556.260 of this chapter](/on/2024-09-17/title-21/section-556.260).

(d) *Special considerations.* Do not use in Type B or Type C medicated feeds containing bentonite.

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

| Amprolium and ethopabate in grams per ton | Combination in grams per ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) Amprolium 113.5 and ethopabate 3.6 | | Broiler chickens: As an aid in the prevention of coccidiosis | Feed continuously as sole ration; as sole source of amprolium. Not for laying chickens | 016592 |
| (2) Amprolium 113.5 and ethopabate 36.3 | | Broiler chickens and replacement chickens: where immunity to coccidiosis is not desired: As an aid in the prevention of coccidiosis where severe exposure to coccidiosis from *Eimeria acervulina, E. maxima,* and *E. brunetti* is likely to occur | Feed continuously as sole ration; as sole source of amprolium. Not for chickens over 16 weeks of age | 016592 |
| (3) Amprolium 113.5 and ethopabate 36.3 | Bacitracin 4 to 50 | 1. Broiler chickens and replacement chickens: where immunity to coccidiosis is not desired; to aid in prevention of coccidiosis where severe exposure to coccidiosis from *Eimeria acervulina, E. maxima,* and *E. brunetti* is likely to occur; for increased rate of weight gain in broiler chickens raised in floor pens | Feed as the sole ration from the time chickens are placed on litter until past the time when coccidiosis is ordinarily a hazard. Not for chickens over 16 weeks of age; do not feed to laying chickens; as sole source of amprolium; not for use as a treatment for outbreaks of coccidiosis. Bacitracin as bacitracin methylenedisalicylate as provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) | 016592 |
| (4) Amprolium 113.5 and ethopabate 36.3 | Bacitracin 4 to 50 | 2. Broiler chickens: As an aid in prevention of coccidiosis where severe exposure to coccidiosis from *Eimeria acervulina, E. maxima,* and *E. brunetti* is likely to occur; for improved feed efficiency | Feed as the sole ration from the time chickens are placed on litter until market weight. Not for chickens over 16 weeks of age; do not feed to laying chickens; as sole source of amprolium; not for use as a treatment for coccidiosis. Bacitracin zinc as provided by No. 054771 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) | 054771 |
| (5) Amprolium 113.5 and ethopabate 36.6 | Bambermycins 1 to 3 | Broiler chickens: As an aid in the prevention of coccidiosis where severe exposure to coccidiosis from *Eimeria acervulina, E. maxima,* and *E. brunetti* is likely to occur; for increased rate of weight gain, improved feed efficiency | Feed continuously as the sole ration; as sole source of amprolium Bambermycins as provided by No. 016592 in [§ 510.600(c) of this chapter](/on/2024-09-17/title-21/section-510.600#p-510.600(c)) | 016592 |
| (6) Amprolium 227 and ethopabate 3.6 | | For broiler chickens and replacement chickens where immunity to coccidiosis is not desired; prevention of coccidiosis | Not for laying chickens | 016592 |

(f) Amprolium and ethopabate may also be used in combination with:

(1)-(2) [Reserved]

(3) Chlortetracycline as in [§ 558.128](/on/2024-09-17/title-21/section-558.128).

[[41 FR 10990](https://www.federalregister.gov/citation/41-FR-10990), Mar. 15, 1976]

###### Editorial Note

#### Editorial Note:

For Federal Register citations affecting [§ 558.58](/on/2024-09-17/title-21/section-558.58), see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at *[www.govinfo.gov](http://www.govinfo.gov).*