Meeting Abstract
56.5 Thursday, Jan. 6 Seminal Plasma Progesterone Influences Sperm Hole Penetration in White Leghorns ANDERSON, E.M.*; NAVARA, K.J.; University of Georgia, Athens; University of Georgia, Athens erinma@uga.edu
While there has been significant interest in identifying the hormonal contributions passed on with gametes by female birds, the hormone content of fluids contributed during reproduction by the male remains relatively unstudied. We aimed to characterize the hormone content, and the potential function of those hormones, in avian seminal plasma. First, we measured the concentrations of five hormones within White Leghorn rooster seminal plasma, including progesterone (P4), testosterone (T), dihydrotestosterone (DHT), estrogen (E) and corticosterone (B). P4 levels were higher in seminal plasma compared to other hormones analyzed, ranging from 0 to 14.8 ng/ml (all other levels were < 1.1ng/ml). We then attempted to determine how this high concentration of progesterone in seminal plasma may affect fertility. White Leghorn hens were assigned to two treatment groups: progesterone-treated or control (n=24 hens per treatment). Semen was collected from 24 White Leghorn roosters. Each semen sample was divided into two equal volumes, one treated with progesterone (0.4 ng/50µl) and the other with a control diluent and artificially inseminated into each hen treatment group. Eggs were collected two days post-insemination. A perivitelline layer sperm hole assay, a method that can be used as a predictive measure of fertility, was performed for each egg and a sperm hole number was counted microscopically. The effects of treatment were analyzed and the number of sperm holes were significantly less in the progesterone treated group than the control on the second day post-insemination (P=0.034). These results suggest that progesterone has a detrimental effect on the ability of sperm to penetrate the egg, and that males depositing more progesterone into seminal plasma may have a decreased fertilization capabilities.
