45.6 Thursday, Jan. 5 Hormone Content of Rooster Seminal Plasma and Effects on Sperm Quality and Fertility ANDERSON, EM*; NAVARA, KJ; University of Georgia, Athens; University of Georgia, Athens email@example.com
It has been demonstrated that female birds adaptively allocate hormones to eggs to enhance offspring quality and survival, but the hormone content of fluids contributed with gametes by the male has received less attention. First, we measured the concentrations of four reproductive steroid hormones, including progesterone, testosterone, dihydrotestosterone, and estrogen, in seminal and blood plasma collected from White Leghorn roosters. Progesterone was the most abundant hormone in seminal plasma. To determine the effect of progesterone in seminal plasma on fertility, we then inseminated hens with semen samples that were supplemented with either a high physiological dose of progesterone or a control vehicle, and fertility was evaluated using a perivitelline sperm hole penetration assay. Progesterone exhibited an inhibitory effect on fertilization of the egg. Finally, to determine the mechanism by which progesterone inhibited fertility, we then explored how concentrations of progesterone related to sperm mobility, concentration, and viability. Progesterone concentrations in blood and plasma were inversely related to sperm mobility, indicating that males producing more progesterone have poorer quality sperm, which would likely impair the ability of sperm to reach and penetrate the egg. The implications of this work and potential adaptive value of steroid hormones in seminal plasma will be discussed.