# Zilpaterol.
**AGENCY:**
Food and Drug Administration, HHS.
**ACTION:**
Final rule.
**SUMMARY:**
The Food and Drug Administration (FDA) is amending the animal drug regulations to reflect approval of a new animal drug application (NADA) filed by Intervet, Inc. The NADA provides for use of zilpaterol, monensin, and tylosin in three-way combination Type B and Type C medicated feeds for cattle fed in confinement for slaughter.
**DATES:**
This rule is effective February 1, 2008.
**FOR FURTHER INFORMATION CONTACT:**
Gerald L. Rushin, Center for Veterinary Medicine (HFV-126), Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855, 240-276-8103, e-mail: *[email protected]* .
**SUPPLEMENTARY INFORMATION:**
Intervet, Inc., P.O. Box 318, 29160 Intervet Lane, Millsboro, DE 19966, filed NADA 141-276 that provides for use of ZILMAX (zilpaterol hydrochloride), and RUMENSIN (monensin), and TYLAN (tylosin phosphate) Type A medicated articles to make dry and liquid three-way combination Type B and Type C medicated feeds used for increased rate of weight gain, improved feed efficiency, and increased carcass leanness; for prevention and control of coccidiosis due to *Eimeria bovis* and *E. zuernii* ; and for reduction of incidence of liver abscesses caused by *Fusobacterium necrophorum* and *Arcanobacterium (Actinomyces) pyogenes* in cattle fed in confinement for slaughter during the last 20 to 40 days on feed. The NADA is approved as of January 10, 2008, and the regulations in 21 CFR 558.355, 558.625, and 558.665 are amended to reflect the approval.
In accordance with the freedom of information provisions of 21 CFR part 20 and 21 CFR 514.11(e)(2)(ii), a summary of safety and effectiveness data and information submitted to support approval of this application may be seen in the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852, between 9 a.m. and 4 p.m., Monday through Friday.
The agency has determined under 21 CFR 25.33(a)(2) that this action is of a type that does not individually or cumulatively have a significant effect on the human environment. Therefore, neither an environmental assessment nor an environmental impact statement is required.
This rule does not meet the definition of “rule” in 5 U.S.C. 804(3)(A) because it is a rule of “particular applicability.” Therefore, it is not subject to the congressional review requirements in 5 U.S.C. 801-808.
**List of Subjects in 21 CFR Part 558**
Animal drugs, Animal feeds.
**21 CFR Part 558**
Therefore, under the Federal Food, Drug, and Cosmetic Act and under the authority delegated to the Commissioner of Food and Drugs and redelegated to the Center for Veterinary Medicine, 21 CFR part 558 is amended as follows:
**21 CFR Part 558**
**PART 558—NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS**
1. The authority citation for 21 CFR part 558 continues to read as follows:
**Authority:**
21 U.S.C. 360b, 371.
**21 CFR Part 558**
2. In § 558.355, add paragraph (f)(7)(iv) to read as follows:
§ 558.355
(f) * * *
(7) * * *
(iv) Zilpaterol alone or in combination as in § 558.665.
**21 CFR Part 558**
3. In § 558.625, add paragraph (f)(2)(ix) to read as follows:
§ 558.625
(f) * * *
(2) * * *
(ix) Zilpaterol alone or in combination as in § 558.665.
**21 CFR Part 558**
4. In § 558.665, revise paragraph (e) to read as follows:
§ 558.665
(e) *Conditions of use in cattle* . It is administered in feed as follows:
| Zilpaterol in grams/ton | Combination in grams/ton | Indications for use | Limitations | Sponsor |
| --- | --- | --- | --- | --- |
| (1) 6.8 to provide 60 to 90 mg/head/day | | Cattle fed in confinement for slaughter: For increased rate of weight gain, improved feed efficiency, and increased carcass leanness in cattle fed in confinement for slaughter during the last 20 to 40 days on feed. | Feed continuously as the sole ration during the last 20 to 40 days on feed. Withdrawal period: 3 days. | 057926 |
| (2) [Reserved] | | | | |
| (3) [Reserved] | | | | |
| (4) 6.8 to provide 60 to 90 mg/head/day | Monensin 10 to 40, plus tylosin 8 to 10 | Cattle fed in confinement for slaughter: As in paragraph (e)(1) of this section; for prevention and control of coccidiosis due to
and
; and for reduction of incidence of liver abscesses caused by
and
. | As in paragraph (e)(1) of this section; see §§ 558.355(d) and 558.625(c) of this chapter. Monensin and tylosin as provided by No. 000986 in § 510.600(c) of this chapter. | 057926 |
Dated: January 24, 2008.
Bernadette Dunham,
Director, Center for Veterinary Medicine.