The Effects of Hormones on the Growth and Fattening of Lambs

Abstract

The subcutaneous implantation of 12 or 24 mg. of stilbestrol pellets significantly increased rate of gain and significantly increased feed efficiency. Carcass quality, as expressed by Federal grades, was consistently lowered. The implantation of 30 mg. of testosterone propionate pellets significantly increased rate of gain and significantly increased feed efficiency but the magnitude of the increases was not as great as 24 mg.stilbestrol. Carcass quality was similar to the controls in both experiments. Twelve mg. of dienestrol in one injectable base (Type A) significantly increased rate of gain and feed efficiency but in a second type of vehicle (Type B) dienestrol was not as effective. Carcass quality was inferior to the controls in both trials.