effects of centrifugation and different levels of soybean lecithin-based extender on post-thaw sperm quality of ghezel ram semen

The objective of this study was to specify the effects of centrifugation and different surface of soybean leci-thin-based extender on post-thaw sperm quality of ghezel ram semen. semen samples were gathered from 5 mature ghezel ram two/week for 3 weeks. after initial evaluation, the approved semen samples were pooled together and split into equal parts in falcon tubs. three samples were combined with tris buffer at 30 °c and then centrifuged to remove the seminal plama. after centrifugation and removal of the super-natant, samples were diluted with tris-citrate-fructose extender + different concentrations of soybean leci-esthin ( 1%, 1.5% and 2% weight/volume) with 7% glycerol; and residual one samples, which were not centri-fuged, were diluted with the (1.5% weight/volume) soybean lecithin. samples then cooled to 5 °c and fro-zen in 0.25 ml french straws and straws were thawed in a 37 °c water bath. the results of different con-centrations of soybean lecithin showed that total motility (tm) and motion parameters of average path ve-locity (vap), straight-line velocity (vsl), curvilinear velocity (vcl) and lateral head displacement (alh) and and the percentage of spermatozoa with intact acrosomes were significantly higher in soybean lecithin (sl) 1.5% compared to other semen extenders (p<0.05). total motility and sperm-motion parameters (vap, vsl, vcl and alh), in sl1.5% without centrifugation were higher than the groups with 1%, 1.5% or 2% and with centrifugation (p<0.05). generally, the results suggest that sl1.5% extender was better (with or without centrifugation) than other extenders in most in vitro evaluated sperm parameters.