Fattening Cockerels by Stilbestrol Administration

The ability of administered estrogens to produce lipemias in birds has been demonstrated previously (Lorenz, Chaikoff, and Entenman, 1938-b; Zondek and Marx, 1939), as has also the relation of ovarian activity to liver lipid levels (Lorenz, Chaikoff, and Entenman, 1938-a). Zondek and Marx (1939) also reported increased fat content of liver, lung, and muscle tissue of a single cock after prolonged (16 weeks) treatment with high levels of estradiol benzoate, but no interest has been a öused in possible practical applications of such treatment due to the excessive cost of materials. With the recent availability of the relatively inexpensive and highly potent estrogen, diethylstilbestrol, and the labor saving permitted by the pellet implantation technic (Mark and Biskind, 1940; Lorenz, Entenman, and Chaikoff, in preparation), however, it seemed desirable to test the feasibility of using this preparation to hasten the fattening of marked cockerels. Subcutaneous stilbestrol pellet implants (three per bird) . . .