A Comparison of the Effect of Stilbestrol on the Growth Response of Lambs of Different Age and Sex

Abstract

Twelve different trials consisting of 318 treated animals of both sexes and an equal number of controls were conducted in different regions of the state of California. These trails were varied to include animals ranging from an initial weight at the start of treatment of approximately 20 lb. up to approximately 60 lb. In all except one trial, the animals received one 12 mg. pellet or one 15 mg. pellet implanted in the ear. In the exception, an additional group of wether lambs received 3 pellets (36 mg.) of stilbestrol. The results indicate a significant increase in rate of gain due to treatment regardless of age, sex or dietary regime. Animals of younger ages responded as effectively to treatment as older animals. There was no difference in the percent increase in rate of gain of treated animals of either sex, nor did differences in dietary regime affect the response. There was no difference in the rate of gain of wether lambs treated with 12 mg. from those treated with 36 mg. of stilbestrol.