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

The changes in viability, susceptibility to peroxidation and fatty acid com position of total phospholipid were studied in boar spermatozoa during 5 da y liquid storage in a standard or alpha-tocopherol (alpha T) enriched dilue nt. The sperm rich fraction of the ejaculates was collected from 6-month ol d boars. Sperm viability progressively decreased during storage and alpha T inclusion into the diluent significantly inhibited this trend. alpha T inc lusion also decreased significantly peroxidation (TBARS production of sperm atozoa). Spermatozoa stored in the treatment diluent became rapidly enriche d in alpha T with a concomitant decrease of alpha T content in the medium. The proportion of polyunsaturates, mainly 22:6n - 3, decreased with a compl ementary increase in the content of the saturates, mainly 18:0. The inclusi on of alpha T into the diluent was effective in totally preventing the sign ificant decrease of 22:6n - 3 observed in sperm phospholipid in the control samples during the storage period. It is concluded that the alpha T inclus ion in the boar semen diluent increased cell viability through its preventi on of an oxidative reduction in the levels of the major polyunsaturated fat ty acids, namely 22:6n - 3. (C) 2000 Elsevier Science B.V. All rights reser ved.