The effect of sistein-rainbow trout seminal plasma combination on ram semen freezability

The aim of the current study was to evaluate the effect of unaccompanied or cystein (1 mM) combinated Rainbow Trout's Seminal Plasma's (RTSP) doses (0%, 1%, 10%, 15%) on cryopreservation and incubation resilience of ram semen. Ram semen was collected from ten Kivircik rams via electroejaculator every other day and then collected semen was pooled. After pooling procces the mean of motility, plasma membrane integrity, acrosome defect and DNA fragmentation rates were detected as 83,00%; 89,80%; 8,20% and 3,40% respectively. After pooling process semen was divided into eight equal volumes and diluted with extenders which containing different doses of RTSP (0%, 15, 10%, 15%) and cysteine (0 mM, 1 mM). Diluted samples were cooled to 5 ºC in an hour and rediluted with extender containing 0%, 1%, 10%, 15% RTSP (with or without cystein) and 6% glycerol before two-hour equilibration. After equlibration, semen were placed into 0,25 mLfrench straws and frozen with a programmable freezing device and they were stored in liquid nitrogen tanks. Motility, HOST, defected acrosome and DNA fragmentation rates were assessed after thawing, 3rd hour and 5th hour of incubation. It is detected that the extender containing 10% RTSP-cysteine was more protective on motility and plasma membrane integrity after thawing and 3rd hour of incubation (P<0,05). Although the least defected acrosome rates were detected with 10% RTSP-cysteine containing group, the least DNA fragmentation rates were observed with only 10% RTSP group. At the end of incubation, it is observed that the 10% RTSP-cysteine combination is more efficient for protecting all spermatological parameters without excepting DNA integrity. It was a reached conclusion that, supplementation of RTSP and cystein have a protective effect on cryosurvival of ram semen and on assessed spermatological parameters. Key words: Ram semen, Cryopreservation, Rainbow Trout Seminal Plasma, Cysteine