Viability, susceptibility to peroxidation and fatty acid composition of boar semen during liquid storage

The changes in viability, susceptibility to peroxidation and fatty acid composition of total phospholipid were studied in boar spermatozoa during 5 day liquid storage in a standard or α-tocopherol (αT) enriched diluent. The sperm rich fraction of the ejaculates was collected from 6-month old boars. Sperm viability progressively decreased during storage and αT inclusion into the diluent significantly inhibited this trend. αT inclusion also decreased significantly peroxidation (TBARS production of spermatozoa). Spermatozoa stored in the treatment diluent became rapidly enriched in αT with a concomitant decrease of αT content in the medium. The proportion of polyunsaturates, mainly 22:6n−3, decreased with a complementary increase in the content of the saturates, mainly 18:0. The inclusion of αT into the diluent was effective in totally preventing the significant decrease of 22:6n−3 observed in sperm phospholipid in the control samples during the storage period. It is concluded that the αT inclusion in the boar semen diluent increased cell viability through its prevention of an oxidative reduction in the levels of the major polyunsaturated fatty acids, namely 22:6n−3.