PS2-11. Effect of L-proline on Boar Semen Quality Post Collection in a Variable Temperature Environment

Previous research has demonstrated that boar sperm supplemented with L-Proline provides beneficial effects on boar sperm parameters when stored at 17 °C post-collection. The objective of this research was to determine if L-Proline conferred these same effects when extended boar sperm was supplemented with Proline and subjected to a variable temperature environment that resembled storage protocols for boar semen during artificial insemination (AI). During the AI process, boar sperm is temporarily stored prior to use in a variable temperature environment of 17 to 18 °C. This temperature range is maintained using a small styrofoam container containing cool packs previously maintained at 17 to 18 °C. When AI is performed, the container is periodically opened and therefore the temperature of the semen can increase above the recommended temperature limit of 18 °C. Proline was added (treatment: 0mM, 70mM and 80Mm) to extended semen collected from sexually mature boars on the day of collection and extension and placed in a semen refrigeration cooler set to maintain the semen between 17 and 18 °C. After a 24 hour equilibration period, the supplemented semen was placed in a styrofoam container with cool packs and measured for motility and morphology over a 24 hour time period at 0 hr, 2 hr, 4 hr and 24 hrs. After storage in the styrofoam container, the semen was returned to the semen cooler and motility and morphology were measured seven days after the initial Proline supplementation. This procedure was replicated three times. Temperatures in the styrofoam cooler ranged from 17 to 21 °C over the 24 hour time period in the styrofoam container. The high range of the temperature occurred at approximately 8 hours after the semen was placed in the styrofoam container. Data were analyzed using the MIXED procedure in SAS. There were no significant differences (P > 0.05) seen for treatment or time or the treatment x time interaction for the motility and morphology parameters measured. The sperm cell measurements were within the normal ranges for total motility (83 to 87%), progressive motility (74 to 83%), normal morphology (77 to 82%) and total abnormal morphology (19 to 24%). In this study, extended boar sperm supplemented with L-Proline and subjected to a variable temperature environment that resembled storage protocols for boar semen during AI did not confer any additional benefit. Due to the conditions, there may not have been enough of an adverse environmental condition for Proline to have an effect. Future research should investigate the effect of L-Proline in either a cold-stress environment with temperatures of 10 °C and lower or a heat-stress environment with temperatures of 29 °C and higher.