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The objective of the experiment is to test the hypothesis that gilts (young female hogs) that consume meat from beef steers implanted with estrogenic hormones will have higher levels of estrogenic activity in serum and edible tissue than gilts fed beef from non-implanted steers or a non-meat alternative, tofu. These data will provide evidence to support or refute the hypothesis that implanting beef steers with estrogenic hormones has adverse effects on consumers.
Approach:
Beef steers will be implanted according to FDA-approved label directions and slaughtered in a USDA-inspected facility. Control beef steers will not be implanted. Meat from control and test animals will be fed to gilts on a daily basis from weaning until first estrus. Gilts at first estrus will be slaughtered and serum and tissues analyzed for physiologic reproductive endpoints. In addition, estrogenic activity in serum and skeletal muscle will be measured using the cell-based E-Screen assay.