Exogenous Individual Lecithin-Phospholipids (Phosphatidylcholine and Phosphatidylglycerol) Cannot Prevent the Oxidative Stress Imposed by Cryopreservation of Boar Sperm

For artificial insemination (AI), boar semen is prepared in rather simple extenders, kept at 16-20°C and usually used in liquid form for up to 3 days from extension. Routine freezing of boar semen is occasionally used for gene banking, replacement of lost genetics or long-distance transport [1]. The reason behind this meagre use of freezing is the low tolerance of the ejaculated boar sperm to current methods used which, consequently, leads to lower conception rates and smaller litter sizes after AI, compared with fresh semen [2]. While freezing leads to severe physical changes in osmolality due to asymmetric ice formation and deleterious concentration of solutes [3] thus affecting cell survival, simple cooling cause’s oxidative stress mainly produced for the generation of reactive oxygen species (ROS) [4]. In this regard, lipoperoxidation of membrane lipids could lead to membrane destabilization, directly affecting sperm survival post-thaw but also the function of the surviving sperm. The high sensitivity to cooling (cold-shock) depicted by boar sperm probably owes to their peculiar lipid composition of the sperm membrane, rich in palmitic acid (C16:0), stearic acid (C18:0) and oleic acid (C18:1 n-9) as well as about 25% docosapentaenoic acid (C22:5 Exogenous Individual LecithinPhospholipids (Phosphatidylcholine and Phosphatidylglycerol) Cannot Prevent the Oxidative Stress Imposed by Cryopreservation of Boar Sperm