PSV-8 Effects of Air Exposure and Agitation on Quality of Stored Boar Semen Samples

Abstract

Abstract Recent adoption of post cervical artificial insemination facilitates lowered concentrations of semen inseminated. In order to achieve this reduced concentration, the volume of the insemination dose has been reduced and replaced with additional air in the semen storage container. The objective of this study was to investigate the effects of semen volume, air contact inside semen dose tubes, daily agitation of semen doses and extender type on semen quality, thermo-resistance and bacterial growth in extended boar semen doses over 7 days of liquid storage at 17 C. Ejaculates from 4 terminal cross-bred boars were collected for 4 weeks and used in the 3 x 2 x 2 factorial study. The effects of treatment (CON: 80ml doses sealed at the top of the tube; 40HIGH: 40ml doses sealed at top of tube; and 40LOW: 40ml doses sealed at top of the liquid), extender type (long-term vs short-term), and agitation (agitated vs not agitated) were investigated. The result of the study revealed that motility (P=0.014) and viability (P=0.007) in 40HIGH were lower than CON. pH (P< 0.001) was higher in 40HIGH compared to CON. Agitation did not impact motility (P=0.541), viability (P=0.406) or morphology (P=0.970) while long-term extender maintained higher motility (P=0.034), viability (P< 0.001) and normal acrosomes (P< 0.001) compared to short-term extender. VAP (P=0.039) of 40HIGH was lower than CON in a thermo-resistance test. Bacteria were cultured on both sheep’s blood and MacConkey agar and neither treatment (P=0.798; 0.766) nor agitation (P=0.396; 0.476) impacted bacterial growth in this study. In conclusion, semen doses prepared with 80mL or 40mL of total volume with minimal air contact in the tubes yield more desirable semen quality, as air contact negatively impacts boar semen pH and sperm motility. Additionally, regardless of volume or air exposure, daily agitation of boar semen doses did not affect semen quality.