Peripheral serum levels of 17beta estradiol in growing turkey hens.

Broad Breasted Bronze turkey hens 8 to 41 weeks of age were bled at regular intervals and serum 17beta estradiol cencentrations were determined by RIA. The variable levels of estradiol prior to significantly higher concentrations at 28 weeks of age are believed to be characteristic of approaching sexual maturity after which the variability of concentrations is absent. With light stimulation, the concentrations again increase till egg production commences. The estradiol concentrations then decrease and begin to show rhythmic variation during the ovulatory cycle.