Melengestrol acetate (MGAF) - Medicating Ingredient Brochure

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Status: Over the counter

Revised June 2022

Table of approved species and claims
Approved livestock species Approved claim(s)
(abbreviated)Table note 1
Withdrawal time Name of approved brand(s)
Feedlot heifers
  1. Growth stimulation improved feed utilization and suppression of estrus (heat)
24 hours (meat) MGA 100 Premix

Feedlot beef heifers

Table of approved claims and brands
Approved claims Name of approved brand(s) Drug concentration in DIN product
Claims 1 MGA 100 Premix Melengestrol acetate at 220 mg/kg

Approved for use in meal or pellet feed

Claim 1

For growth stimulation, improved feed utilization and suppression of estrus (heat) in heifers fed for slaughter.

Level of medicating ingredient in the complete feed

0.40 mg melengestrol acetate per feedlot heifer per day in supplements or complete feeds.

Directions for use in the complete feed

Feed continuously throughout the time that heifers are being fed for slaughter at a rate so that each animal will receive 0.40 mg of melengestrol acetate per head per day.

Note (not required to appear on medicated feed labels)

  • The use of pellet binders may be limited to Agri-Colloid when feeds include both monensin and tylosin, according to the accepted compatibility, due to their respective Caution statements.

Warning

  1. Discontinue the use of this medicated feed at least 24 hours before slaughter.
  2. Keep out of reach of children. (Required on supplement and premix label only)

Caution

  1. Used only in heifers being fed for slaughter. Not effective in spayed heifers or steers.
  2. Do not feed this medicated feed to heifers treated with other hormone drugs.

Accepted Compatibilities

Melengestrol acetate is compatible in single combination with any of the following drugs. In cases where there are differences in withdrawal time for the compatible medicating ingredients, the longer withdrawal time is the one that must be used, and is the only one that is to appear on the label of the finished feed. For details, refer to the MIB as indicated.

Melengestrol acetate (feedlot beef heifers)
Name of medicating ingredient MIB code Name of approved brand(s) Applicable claims
Lasalocid sodium LAS
  1. Avatec 20 Lasalocid Sodium Premix
  2. Bovatec 20 Lasalocid Sodium Premix
Claim 1
Lubabegron LBGF
  1. Experior 10 Lubabegron Premix
Claim 1
Monensin MOS
  1. Coban Premix
  2. Monensin Premix
  3. Rumensin Premix
  4. Monovet Monensin Premix
Claim 1
Salinomycin sodium SAL
  1. Coxistac 6% Premix
  2. Posistac 6% Premix
Claim 1
Tylosin TYL
  1. Pharmasin 40 Tylosin Phosphate Premix
  2. Pharmasin 100 Tylosin Phosphate Premix
  3. Tylan 40 Tylosin Phosphate Premix
  4. Tylan 100 Tylosin Phosphate Premix
  5. Tylosin 10 Tylosin Phosphate Premix
  6. Tylosin 40 Tylosin Phosphate Premix
  7. Tylosin 100 Tylosin Premix
Claim 1

Melengestrol acetate is compatible with multiple drugs in the following combination. In cases where there are differences in withdrawal time for the compatible medicating ingredients, the longer withdrawal time is the one that must be used, and is the only one that is to appear on the label of the finished feed. For details, refer to the MIB as indicated.

Melengestrol acetate (feedlot beef heifers)
Name of medicating ingredient MIB code Name of approved brand(s) Applicable claims
Lubabegron, and with LBGF
  1. Experior 10 Lubabegron Premix
Claim 1
Monensin, and with MOS
  1. Coban Premix
  2. Monensin Premix
  3. Rumensin Premix
Claim 1
Tylosin TYL
  1. Pharmasin 40 Tylosin Phosphate Premix
  2. Pharmasin 100 Tylosin Phosphate Premix
  3. Tylan 40 Tylosin Phosphate Premix
  4. Tylan 100 Tylosin Phosphate Premix
  5. Tylosin 10 Tylosin Phosphate Premix
  6. Tylosin 40 Tylosin Phosphate Premix
  7. Tylosin 100 Tylosin Premix
Claim 1