Effects of the soy phytoestrogen genistein on the reproductive development of immature female broiler chickens

Abstract

Developmentally inappropriate exposures to estrogenic compounds are known to alter morphology and function of the reproductive tract in various species. Chickens are continually exposed to the relatively potent estrogenic soy isoflavones through the diet. It has been shown that the primary soy isoflavone genistein induces proliferation of the chick oviduct. However, information is lacking as to the specific reproductive tract developmental effects of genistein exposure in chicks.

Three experiments were done to compare specific oviduct morphological and functional responses to genistein exposure with responses elicited by a classical estrogen, diethylstilbestrol (DES) in female broiler chicks. To avoid the effects of dietary soy isoflavones, the experimental diets were formulated with dried egg white, rather than the usual soybean meal, as a protein source. These experiments examined the effects of genistein in the on the morphology and growth of the oviduct and functional responses to estrogen consisting of plasma vitellogenin content and oviductal ovalbumin synthesis.

From the three experiments, it was determined that genistein acts as a weak estrogen in the immature female chick. It has effects on the growth and morphology of the oviduct. Genistein can also induce the synthesis of estrogen-dependent secretions in the chick including vitellogenin and ovalbumin.