Code of Federal Regulations (alpha)

CFR /  Title 21  /  Part 558  /  Sec. 558.342 Melengestrol.

(a) Specifications. (1) Dry Type A medicated articles containing 100 or 200 milligrams (mg) melengestrol acetate per pound.

(1) Dry Type A medicated articles containing 100 or 200 milligrams (mg) melengestrol acetate per pound.

(2) Liquid Type A medicated article containing 500 mg melengestrol acetate per pound.

(b) Approvals. See sponsors in Sec. 510.600(c) of this chapter for use as in paragraph (e) of this section.

(1) No. 054771 for use of products described in paragraph (a) of this section.

(2) No. 000986 for use of product described in paragraph (a)(2) of this section.

(c) Related tolerances. See Sec. 556.380 of this chapter.

(d) Special considerations. (1) Type B or C medicated feeds may be manufactured from melengestrol acetate liquid Type A articles or Type B or C medicated feeds which have a pH of 4.0 to 8.0 and bear appropriate mixing directions as follows:

(1) Type B or C medicated feeds may be manufactured from melengestrol acetate liquid Type A articles or Type B or C medicated feeds which have a pH of 4.0 to 8.0 and bear appropriate mixing directions as follows:

(i) For liquid feeds stored in recirculating tank systems: Recirculate immediately prior to use for no less than 10 minutes, moving not less than 1 percent of the tank contents per minute from the bottom of the tank to the top. Recirculate daily as described even when not used.

(ii) For liquid feeds stored in mechanical, air, or other agitation type tank systems: Agitate immediately prior to use for not less than 10 minutes, creating a turbulence at the bottom of the tank that is visible at the top. Agitate daily as described even when not used.

(2) A physically stable melengestrol acetate liquid Type B or C feed will not be subject to the requirements for mixing directions prescribed in paragraph (d)(1) of this section provided it has a pH of 4.0 to 8.0 and contains a suspending agent(s) sufficient to maintain a viscosity of not less than 300 centipoises per second for 3 months.

(3) Combination Type B or C medicated feeds containing lasalocid must be labeled in accordance with Sec. 558.311(d)(5) of this chapter.

(4) Liquid combination Type B or C medicated feeds containing melengestrol acetate and lasalocid must be manufactured in accordance with Sec. 558.311(d) of this chapter.

(5) Combination Type B or C medicated feeds containing monensin must be labeled in accordance with Sec. 558.355(d) of this chapter.

(6) Liquid combination Type B or C medicated feeds containing melengestrol acetate and monensin must be manufactured in accordance with Sec. 558.355(f)(3)(i) of this chapter.

(7) Liquid combination Type B or C medicated feeds containing melengestrol acetate and tylosin must be manufactured in accordance with Sec. 558.625(c) of this chapter.

(8) Liquid melengestrol acetate may not be mixed with oxytetracycline in a common liquid feed supplement.

(e) Conditions of use--(1) Cattle. ----------------------------------------------------------------------------------------------------------------

Melengestrol acetate in mg/head/ Combination in mg/

(i) 0.25 to 0.5.................. .................... Heifers fed in Administer 0.5 to 054771,

confinement for 2.0 pounds (lb)/ 000986

slaughter: For head/day of

increased rate of medicated feed

weight gain, improved containing 0.125

feed efficiency, and to 1.0 mg

suppression of estrus melengestrol

(heat).. acetate/lb to

provide 0.25 to

0.5 mg

melengestrol

acetate/head/day..(ii) 0.5......................... .................... Heifers intended for Administer 0.5 to 054771,

breeding: For 2.0 lb/head/day of 000986

suppression of estrus Type C feed

(heat).. containing 0.25 to

1.0 mg

melengestrol

acetate/lb to

provide 0.5 mg

melengestrol

acetate/head/day.

Do not exceed 24

days of feeding..(iii) 0.25 to 0.5................ Lasalocid 100 to 360 Heifers fed in Add at the rate of 054771,

confinement for 0.5 to 2.0 lb/head/ 000986

slaughter: As in day a medicated

paragraph (e)(1)(i) of feed (liquid or

this section.. dry) containing

0.125 to 1.0 mg

melengestrol

acetate/lb to a

feed containing 10

to 30 grams (g) of

lasalocid per ton;

or add at the rate

of 0.5 to 2.0 lb/

head/day a

medicated feed

(liquid or dry)

containing 0.125

to 1.0 mg

melengestrol

acetate plus 50 to

720 mg lasalocid/

lb to a ration of

nonmedicated feed

to provide 0.25 to

0.5 mg

melengestrol

acetate and 100 to

360 mg lasalocid/

head/day..

Lasalocid provided

by No. 054771 in

Sec. 510.600(c)

of this chapter..

(iv) 0.25 to 0.5................. Lasalocid 100 to 360 Heifers fed in To administer 0.25 054771,

plus tylosin 90.. confinement for to 0.5 mg 000986,

slaughter: As in melengestrol 016592

paragraph (e)(1)(i) of acetate plus 100

this section; and for to 360 mg

reduced incidence of lasalocid plus 90

liver abscesses caused mg tylosin/head/

by Fusobacterium day:.

necrophorum and 1. Add 0.5 to 2.0

Actinomyces lb/head/day of a

(Corynebacterium) liquid or dry

pyogenes.. medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate/lb to a

medicated feed

containing 10 to

30 g lasalocid and

8 to 10 g tylosin

per ton; or.

2. Add 0.5 to 2.0

lb/head/day of a

liquid or dry

medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate plus 50 to

720 mg lasalocid/

lb to 4.5 to 18 lb

of a dry medicated

feed containing 10

to 40 g tylosin

per ton; or.

3. Add 0.5 to 2.0

lb/head/day of a

dry pelleted

medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate (from a

dry Type A

article), 50 to

720 mg lasalocid,

and 45 to 180 mg

tylosin/lb to a

ration of

nonmedicated feed..

Lasalocid provided

by No. 054771, and

tylosin provided

by Nos. 000986 and

016592 in Sec.

510.600(c) of this

chapter.(v) [Reserved]...................

(vi)-(vii) [Reserved]...........(viii) 0.25 to 0.5............... Oxytetracycline 75.. Heifers fed in Add at the rate of 054771

confinement for 0.5 to 2.0 lb/head/

slaughter: As in day a medicated

paragraph (e)(1)(i) of feed (liquid or

this section; and for dry) containing

reduction of liver 0.125 to 1.0 mg

condemnation due to melengestrol

liver abscesses.. acetate/lb per

pound to a feed

containing 6 to 10

g oxytetracycline

per ton; or add at

the rate of 0.5 to

2.0 lb/head/day a

dry medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate plus 37.5

to 150 mg

oxytetracycline/lb

to provide 0.25 to

0.5 mg

melengestrol

acetate and 75 mg

oxytetracycline/

head/day..

Oxytetracycline as

provided by No.

066104 in Sec.

510.600(c) of this

chapter..

(ix) 0.25 to 0.5................. Tylosin 60 to 90.... Heifers fed in To administer 0.25 054771

confinement for to 0.5 mg 000986

slaughter: As in melengestrol 016592

paragraph (e)(1)(i) of acetate with 60 to

this section; and for 90 mg tylosin/head/

reduced incidence of day:.

liver abscesses caused 1. Add 0.5 to 2.0

by F. necrophorum and lb/head/day of a

Actinomyces liquid or dry

(Corynebacterium) medicated feed

pyogenes.. containing 0.125

to 1.0 mg

melengestrol

acetate/lb to a

medicated feed

containing 8 to 10

g tylosin per ton;

or.

2. Add 0.5 to 2.0

lb/head/day of a

liquid or dry

medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate/lb to 4.5

to 18 pounds of a

dry medicated feed

containing 10 to

40 g tylosin per

ton; or.

3. Add 0.5 to 2.0

lb/head/day of a

liquid or dry

medicated feed

containing 0.125

to 1.0 mg

melengestrol

acetate (from a

dry Type A

article) plus 45

to 180 mg tylosin/

lb to a ration of

nonmedicated feed..

Tylosin provided by

Nos. 000986 and

016592 in Sec.

510.600(c) of this

chapter.(x) 0.25 to 0.5.................. Monensin 50 to 480.. Heifers fed in Add at the rate of 054771

confinement for 0.5 to 2.0 lb/head/ 000986

slaughter: As in day a medicated

paragraph (e)(1)(i) of feed (liquid or

this section; and for dry) containing

the prevention and 0.125 to 1.0 mg

control of coccidiosis melengestrol

due to Eimeria bovis acetate/lb to a

and E. zuernii.. feed containing 10

to 40 g of

monensin per ton

to provide 0.25 to

0.5 mg

melengestrol

acetate/head/day

and 0.14 to 0.42

mg monensin/lb

body weight,

depending on

severity of

coccidiosis

challenge, up to

480 mg monensin/

head/day..

...................

Monensin provided

by No. 000986 in

Sec. 510.600(c)

of this chapter..(xi) 0.25 to 0.5................. Monensin 50 to 480, Heifers fed in Feed continuously 054771

plus tylosin 60 to confinement for as sole ration 016592

90. slaughter: As in (liquid or dry) at

paragraph (e)(1)(i) of a rate of 0.5 to

this section; for the 2.0 lb/head/day to

prevention and control provide 0.25 to

of coccidiosis due to 0.5 mg/head/day

Eimeria bovis and E. melengestrol

zuernii; and for acetate; 0.14 to

reduction of incidence 0.42 mg monensin/

of liver abscesses lb body weight/

caused by day, depending on

Fusobacterium the severity of

necrophorum and the coccidiosis

Arcanobacterium challenge, up to

pyogenes.. 480 mg/head/day;

and 60 to 90 mg/

head/day tylosin.

The melengestrol

acetate portion of

this Type C

medicated feed

must be mixed into

a complete feed

containing 10 to

40 g/ton monensin

and 8 to 10 g/ton

tylosin in the

amount of complete

feed consumed by

an animal per day..

...................

Monensin provided

by No. 000986 and

tylosin provided

by Nos. 000986 and

016592 in Sec.

510.600(c) of this

chapter..----------------------------------------------------------------------------------------------------------------

(2) Melengestrol may also be used with:

(i) Ractopamine as in Sec. 558.500 of this chapter.

(ii) Zilpaterol as in Sec. 558.665 of this chapter. [42 FR 28535, June 3, 1977]

Editorial Note: For Federal Register citations affecting Sec. 558.342, see the List of CFR Sections Affected, which appears in the Finding Aids section of the printed volume and at www.fdsys.gov.