Kinetin improves motility, viability and antioxidative parameters of ram semen during storage at refrigerator temperature Elham Zadeh Hashem . Mohsen Eslami Received: 24 September 2016 / Accepted: 21 November 2016 Ó Springer Science+Business Media Dordrecht 2016 Abstract The present experiment was conducted to evaluate the effect of kinetin on ram semen quality during cold storage. Ejaculates were collected using an artificial vagina from five Qezel rams. Ejaculates which met the criteria (volume of 0.75–2 ml; minimum spermatozoa concentration of 2.5 9 109 spermatozoa/ ml and forward progressive motility of 80%), were pooled, diluted with extender without kinetin (control) or enriched with 25 (K 25), 50 (K 50), 100 (K 100) and 200 (K 200) lM kinetin at a final concentration of 500 9 106 spermatozoa per mL. Spermatozoa motion characteris- tics were evaluated by computer-assisted sperm analysis. In addition, percent of viability (spermatozoa showing no color was considered to be alive) and spermatozoa with intact plasma membrane (spermatozoa with curled/ swollen tail was considered healthy) were determined. Moreover, amounts of malondialdehyde (MDA), total antioxidant activity (AOA), nitric oxide (NO) and superoxide dismutase (SOD) activity were determined in the seminal plasma and spermatozoa at 0, 24, 48 and 72 h of storage. Higher percent of total and forward progressive motility was observed in K 25, K 50 and K 100 groups compared to control group at 72 h of storage (P \ 0.001). Moreover, K 25 (78.61 ± 1.11%), K 50 (82.46 ± 1.08%) and K 100 (82.96 ± 1.49%) groups showed higher percentage of viability compared to control (72.38 ± 1.49%) at 72 h of storage (P \ 0.05). Semen enrichment with kinetin resulted in the higher percent of intact plasma membrane of spermatozoa at 48 and 72 h (P \ 0.001). Amounts of MDA were lower and amounts of AOA were higher in K 50 and K 100 groups compared to control at 48 and 72 h (P \ 0.05). There were no significant differences in NO levels and SOD activities of seminal plasma and spermatozoa among groups during the experiment. The present experiment revealed that kinetin at proper concentration could enhances spermatozoa kinematics, viability, spermato- zoa plasma membrane functionality and amounts of AOA and reduces the level of lipid peroxidation during chilled storage of ram semen. Keywords Kinetin Á Ram semen Á Antioxidant activity Á Malondialdehyde Introduction Storage of diluted semen has been widely used in artificial insemination programs. Artificial insemina- tion makes the widespread dissemination of valuable genetic material from a small number of superior sires to a large number of females possible, leading to an increased rate of genetic gain (Maxwell and Watson 1996). When the insemination is done within a short E. Zadeh Hashem (&) Department of Basic Sciences, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran e-mail: e.zadehhashem@urmia.ac.ir M. Eslami Department of Theriogenology, Faculty of Veterinary Medicine, Urmia University, Urmia, Iran 123 Cell Tissue Bank DOI 10.1007/s10561-016-9604-3