Effects of L-carnitine and alpha lipoic acid on ram semen cryopreservation and post-thaw life span

The aim of this study is to evaluate the effects of 25 mM, 50 mM ve 100 mM L-carnitine and 0,25 mM, 0,50 mM ve 1 mM Alpha lipoic acid on ram semen cryopreservation and post-thaw life span to increase survivability of ram semen in female genital tract. Semen was collected from 5 Kıvırcık rams by using electro-ejaculation method. Semen has +++ mass activity, 70% motility ve 1,5 x109 spermatozoa/ml used at pooling stage. After pooling, semen was divided into 16 groups and diluted using two-step dilution method by control and each antioxidant groups or mix groups. After dilution, semen was cryopreserved in straws. Motility, plasma membrane functional integrity (HOST) and acrosome integrity (PSA) were evaluated at after pooling, dilution, equlibration, post thaw and after 3 and 6 hours of incubation. Motility, plasma membrane functional integrity and acrosome integrity negatively effected from cryopreservation process and incubation. At the post-thaw stage, spermatological values of the groups containing only alpha lipoic acid were similar to those of the control group (P> 0.05). Addition of L-carnitine significantly maintained acrosomal integrity (P <0.05) and spermatological findings of other groups were generally lower. At the post-incubation stage, it was determined that the motility and plasma membrane integrity of the antioxidant groups were adversely affected compared to the control group and generally the acrosomal integrity was better preserved in the L-carnitine-containing groups. It was concluded that the addition of L-carnitine and Alpha lipoic acid to ram semen diluents is not suitable for concomitant use due to the rapid decrease in motility and plasma membrane functional integrity. Key words: Ram semen, Incubation, L-carnitine, Alpha lipoic acid