Purdue University	Mimeo A.H. - 147
Agricultural Experiment Station	April
Lafayette, Indiana
The Effects of Hormones and Hcrmone-Like Substances in Livestock
F. N. Andrews, W. M® Beeson, Claude Harper, T. W. Perry and Martin Stob Department of Animal Husbandry
The importance of natural hormones, secreted within the animal body, on such economically important functions as growth and fattening, reproduction, and milk production has been recognized for over a quarter of a century. The natural hormones are secreted by the endocrine glands and many of the natural hormones can be produced synthetically. A large number of substances which have all or some of the effects of the natural hormones have been produced synthetically or have been isolated from sources such as grasses, legumes, molds, petroleum and other materials. One of the most potent of the synthetic, female-hormone-like substances, diethylstilbestrol, was prepared by the British chemists Dodds and Lawson (1) in 1937* Since that time many other powerful estrogenic (female-hormone-like) substances have been prepared. Among these are hexestrol and dienestrol.
In 1943 Lorenz (2) of the University of California showed that the implantation of pellets of diethylstilbestrol would improve the market quality of chickens and workers at Oklahoma A&M (Jaap, Thayer, et al®) (3) (4) showed that diethylstilbestrol and a large number of other similar substances were effective in chickens when administered in the feed. Studies with chickens at Purdue (Andrews, et al.) (5) (6) in 1945-47 showed that treatment with diethylstilbestrol increased feed intake, increased fat deposition and improved carcass grade, .The administration of diethylstilbestrol in the form of pellets or paste, or the use of dienestrol diacetate in the feed is permitted by the Food and Drug Administration in chickens®
Many attempts to improve rate of gain and carcass quality have been made in cattle, sheep and swine through alteration of hormonal function. Studies at Purdue in 1940 (Andrews and Bullard) (7) showed that rate of gain in beef steers could be increased for short periods of time by partial removal of the thyroid gland. This was followed by a number of experiments with cattle, sheep and swine in which thyroid activity was both increased and decreased with minor, but uneconomic, alteration of rate of gain. It was first demonstrated at Purdue that the implantation of 48 mg. of diethylstilbestrol pellets increased rate of gain and improved feed efficiency in beef heifers (Andrews, Beeson, Dinusson - 1948)
(8) (9) and that the implantation of 12 or 24 milligrams of diethylstilbestrol
liTNature 139 s 627.	1937 o	~	“
(2)	Poultry	Sci.	22 §190.	1943.
(3)	Poultry	Sci.	23s249»	1944®
U)	Poultry	Sci.	24s483®	1945*
(5) U.S. Egg and Poultry Magazine 51s554*	1945*
6)	Poultry	Sci.	26§447*	1947.
w) Proc. Am. Soc. An, Prod. Page 112,	1940,
(8)	Purdue University AH Mimeo 37*	1948®
(9)	J. Animal Sci. 9s321«	1950o