New Animal Drugs for Use in Animal Feeds; Melengestrol Acetate, Monensin, and Tylosin

The Food and Drug Administration (FDA) is amending the animal drug regulations to reflect approval of a supplemental new animal drug application (NADA) filed by Pharmacia & Upjohn Co. The supplement provides for the use of separately approved Type A medicated articles containing melengestrol acetate (dry form only), monensin, and tylosin to manufacture certain combination drug, dry, meal Type B medicated feeds for use in making Type C medicated feeds. The feeds are for heifers fed in confinement for slaughter for increased rate of weight gain, improved feed efficiency, suppression of estrus, and reduced incidence of liver abscesses.