FEED BEEF - MGA in MFA Beef Feeds

   MGA in MFA Beef Feeds

Click for printable version

Find Your Local MFA Store

    What is MGA?

MGA is the abbreviation for the compound melengestrol acetate.

    What Is It For?

The compound is a feed additive labeled for increased rate of weight gain, improved feed efficiency and suppression of estrus (heat) in heifers fed for slaughter. In addition, with special instructions, the compound can be utilized in a program to synchronize heat in heifers for a tighter breeding schedule.

It is classified as practically non-toxic and it has a wide margin of safety in cattle and other species when used at recommended doses.

    How Does It Work?

MGA improves performance by the natural steroid effects of its progesterone-like structure, and by suppressing estrus activity that can be detrimental to feedlot performance.

    How Much Do Heifers Need to Receive Its Benefits?

MGA should be thoroughly mixed in the supplement of feedlot heifers to provide 0.3 to 0.5 mg of melengestrol acetate per head per day.

For estrus synchronization programs, constant daily intakes of 0.45 to 0.5 mg per head per day for 14 days give a high degree of estrus suppression. Feeding 4 lbs. Cattle Charge Estrus Control Ration per head per day will provide .5 mg MGA/hd/day.

    What Else Can I Feed with MGA?

MGA may be legally fed in the following combinations:

  • MGA + Rumensin

  • MGA + Rumensin + Tylan

  • MGA + Rumensin + Optiflex

  • MGA + Rumensin + Tylan + Optiflex

  • MGA + Bovatec

  • MGA + Bovatec + Tylan

  • MGA + Tylan

  • MGA + Terranycin

  • MGA + Zilmax

  • MGA + Rumensin + Zilmax

  • MGA + Rumensin + Tylan + Zilmax

Each combination has specifically approved levels related to other official and legal claims.

    Are There Safety Cautions to Observe?

This product is only for use in heifers being fed for slaughter and is not effective in spayed heifers or steers.

There is no required withdrawal period for MGA prior to slaughter. Withdrawal periods of three to five days or more should be avoided to prevent the possibility that the heifers may come into estrus at loading time.

For more detailed information, contact an MFA veterinarian.

You can also contact Janice Spears at for more information.

Return to Beef Introductory main page.


 Show List

Industry Links

Premises Registration


"Achieve maximum net return per acre utilizing the most cost effective resources."

The MFA PowerCalf program provides access to the latest technology along with products and services to increase profit for the cow/calf producer. Combining best management practices with detailed records, MFA staff can assist in digitizing, analyzing and benchmarking herd improvement for increased profit. PowerCalf helps producers measure and manage all aspects of their operation, from forage quality to herd genetics, health & nutrition protocols, and reproductive efficiency.

PowerCalf is a menu of products and services producers can choose from to fit their needs, it is not a specific set of requirements or protocols.

PowerCalf is also where the most current best management practices are outlined so that producers can choose the tools they need to deploy the practices they wish to use.

PowerCalf can help:

  • Utilize all applicable whole herd best management practices.
  • Capture data points necessary for measuring key production activities.
  • Digitize, standardize, and manage production data to facilitate decision making.
  • Determine and access the genetics most able to improve desired performance and quality.
  • Prepare your calf crop for marketing at the point of maximum return.
  • Maximize the efficiency, quality, and sustainability of your forage base.

Call toll free 1-888-514-2333 for more information.
Health Track Program Requirements PDF Download
Health Track Program Brochure 2015

Return to main Beef page


Click here for our upcoming show list.

Top of Page



    Breed Associations Links

American Angus Assoc.
American Gelbvieh Assoc.
American Hereford Assoc.
American-International Charolais Assoc.
American Simmental Assoc.
North American Limousin Assoc.
Red Angus Assoc. of America


    Popular Press Links

Beef Magazine
High Plains Journal
Successful Farming
Today’s Farmer



    Market News



Missouri Department of Ag Market Reports


    Online Resources

 Merck Veterinary Manual

Return to main Health Track page

Top of Page


Arkansas (go to very bottom of the page)
Oklahoma (go to very bottom of the page) 

Return to main Health Track page

Top of Page




 "When my buyer says they are MFA Health Track cattle, I don't do anything to
them and I have never had a problem."

David Schneider, Heifer Development
Feedyard - Tribune, KS

Return to main Health Track page

Return to Top



Ag Info Link site Micro Beef Technologies Site