The influence of exogenous estradiol on bobwhite quail (Colinus virginianus) reproductive systems

Mean plasma 17-beta-estradiol (E2) concentrations of nonphotostimulated adult bobwhite quail were less than 31.2 and 119.9 pg/ml for males and females, respectively. Dietary beta-estradiol-3-benzoate (E2 beta) dosages of 10, 100 or 500 micrograms/bird/day caused mean plasma E2 concentrations of females to increase by 1.2, 2.0 or 5.6 times. Oviduct weights were significantly increased in females fed E2 beta dosages of greater than 100 micrograms/bird/day for five days. Gonad weights were not significantly effected in either sex. Ten- to fifty-fold greater doses of dietary E2 beta were required to induce oviduct growth responses equivalent to those produced by injected E2 beta.