Meeting Abstract

P3.92  Wednesday, Jan. 6  The effect of injecting varying doses of acute corticosterone on offspring sex in the white leghorn PINSON, SE*; WILSON, J; NAVARA, KJ; The University of Georgia, Athens, GA; The University of Georgia, Athens, GA; The University of Georgia, Athens, GA sbmoore@uga.edu

Sex ratio manipulation has been documented across a wide variety of species and birds have demonstrated a remarkable ability to manipulate the sex of their offspring. Previous studies in both wild and captive birds suggest that treatment with hormones can stimulate females to manipulate the sex of their offspring before eggs are even ovulated. In particular, chronic treatments with corticosterone (CORT), the primary stress hormone produced by birds, stimulated significant skews towards female offspring in avian species and it has been suggested that CORT acts by influencing which sex chromosome is donated by the heterogametic female bird into the ovulated ovarian follicle. During previous studies designed to test this idea, CORT treatments were given via an acute injection during meiotic segregation and resulted in a significantly male-biased offspring sex ratio, the opposite of those produced during chronic CORT treatment. The purpose of the current study was to determine whether acute CORT treatments have a dose-dependent effect on offspring sex ratios. We treated laying hens with acute high or low-dose CORT injections or control injections 5h prior to ovulation and quantified the sexes of the subsequently ovulated eggs. We hypothesized that females treated with high dose CORT would produce the largest quantity of males, followed by low-dose females and finally controls. Final results will be discussed.