THE DETECTION OF ESTROGENIC ACTIVITY IN TISSUES OF STEERS WHICH HAVE BEEN FED DIETHYLSTILBESTROL

Abstract
The immature female rat was used to detect estrogenic residues in the tissues of cattle fed a ration containing diethylstilbestrol. The criterion of response to the estrogen was the increase in uterine weight which resulted from the ingestion of the beef tissues. The weanling rat was twice as sensitive as the ovariectomized mouse to oral diethylstilbestrol. Significant levels of the estrogen were found in lean meat, liver, and kidney 24 hours after the removal of the diethylstilbestrol from the steers'' diet, but such residues could not be detected when this period was extended to 48 hours.