The Food & Drug Administration's Center for Veterinary Medicine (CVM) released a "CVM Update" Oct. 29 that clarified how the approved animal drugs melengestrol acetate, monensin and tylosin can be combined in animal feed. Melengestrol acetate/monensin/tylosin and melengestrol acetate/monensin combinations are fed to heifers in confinement for slaughter for several approved indications, as listed in the Code of Federal Regulations.
CVM said melengestrol acetate can only be fed to heifers in confinement for slaughter as a topdress that is then added to medicated feed containing monensin and tylosin, or monensin alone, at feeding. Adding the melengestrol acetate topdress to medicated feed containing the other approved animal drug(s) can only be done on the farm or feedlot. A commercial feed company or feed mill cannot manufacture, pack or ship a complete Type C medicated feed containing a combination of melengestrol acetate, monensin and tylosin, or melengestrol acetate and monensin, CVM explained.
Additional details of CVM's clarification can be found at www.fda.gov/AnimalVeterinary/NewsEvents/CVMUpdates/ucm372660.htm.