Effects of Exogenous Estrogen on the Differentiation and Development of the Right Oviduct in Female Chickens

On day 5 of incubation, 0.64mg of estradiol benzoate (EB) was administered to fertilized eggs to investigate its effects on the differentiation and development of the oviduct in female chickens. The increases of body and ovary weights of treated females in 0 to 366 days old were similar to those of females not treated with EB(control). However, thirty one % of the mature treated females did not produce any eggs. The egg production rate of the treated females that produced eggs was low, and the first egg production was delayed, although there were large individual variations among the treated females. A right oviduct at various developmental stages was seen in every treated female; there was a significant negative correlation between egg production rate and the weight of the right oviduct(p