The Effect of Oral Administration of Hormones on Growth Rate and Deposition in the Carcass of Fattening Steers

Abstract

The daily oral administration of 10 mg. of either diethylstilbestrol or hexestrol to two-year-old steers on a fattening ration resulted in highly significant increased gains of 50 lb. and 52 lb. per steer, respectively, over the controls receiving no oral hormone, during a 123-day trial. Steers fed 10 mg. of dienestrol daily gained slightly less (39 lb. more than the controls) than stilbestrol or hexestrol-fed steers, but significantly more (odds 5 percent) than the control steers. The estrogen treated steers required from 9 to 12 percent less feed per unit gain. Recognizable pelvic and mammary changes were induced by oral administration of 10 mg. daily per steer of diethylstilbestrol, dienestrol diacetate, or hexestrol. The carcasses from stilbestrol-fed steers were federally graded as slightly inferior to hexestrol or dienestrol-fed steers or to the control steers which received no hormone. Assay of the meat from hormone-fed steers showed no residual hormone in the meat. This was true whether the feeding of hormones to the steers was discontinued 1 or 7 days prior to slaughter. Copyright © . .