Purdue University Agricultural Experiment Station Lafayette, Indiana
Mimeo AS-295 April 28, 1961 (Progress Report)
THE COMPARATIVE VALUE OF DIETHYLSTILBESTROL, DIENESTROL DIACETATE AND SMILAGENIN FOR FATTENING BEEF STEERS l/
Martin Stob, T. W. Perry, M. T. Mohler and U. M. Beeson Department of Animal Science
-----------------------------------Summary------------------------------------
The data summarizing the effects of oral hormonal treatment on growth and feed efficiency are presented in Table 1.
Treatment with 10 mg. of stilbestrol (lot 2)increased total gain by 6 percent over lot 1.
Treatment with 10 mg. of dienestrol diacetate (lot 3) increased total gain by 1 percent; 15 mg. of dienestrol diacetate improved gain by 3 percent.
Smilagenin treatment was not effective in increasing growth rate.
The hormonal treatments which improved growth also reduced total feed requirements compared to lot 1 as follows:	lot 2, 11 percent; lot 3, 6 percent;
lot 4, 9 percent; lot 5> 2 percent; lot 6, 6 percent.
No hormonal treatment produced a significant increase in growth rate or improvement in feed efficiency in the present experiment. In previous trials, stilbestrol has increased gain by as much as 20 percent. Final judgment on the ability of dienestrol diacetate or Smilagenin to promote growth in fattening steers should be reserved until a more representative response can be pro-educed by concurrent stilbestrol treatment.
Use of Hormones
Increased rate of gain and improved feed efficiency resulting from the treatment of cattle with hormones has been of benefit to thousands of cattle feeders. At times, the use of hormones has been the determining factor between profit or loss of a cattle feeding operation for a given year. The hormones which are the most effective growth stimulators are the estrogens or female sex hormones. Compounds like hexestrol, dienestrol, estradiol and possibly some estrogens found in plants all increase rate of gain in cattle, but the most widely used estrogen in cattle feeding operations is diethylstilbestrol (stilbestrol). New compounds which might have growth promoting activity must be compared to the results obtained with the use of stilbestrol.
The use of stilbestrol as a growth promoter in cattle feeding is not without its problems. One problem is the so-called "side effects," such as
l/ The American Scientific Laboratory, Inc. furnished the dienestrol
diacetate, and Charles Pfizer and Co. furnished the Smilagenin used in this experiment.