The effect of supplementing poly vinyl alcohol and poly ethylene glycol to the cold storage extender of ram epididymal sperm on the sperm motility parameters

One of the advantages of using epididymal sperm is helping to preserve the genetic resources of elite animals and endangered species after death. This study aimed to investigate the probable protective effect of polyvinyl alcohol (PVA) and polyethylene glycol (PEG) on epididymal ram sperm under liquid storage at 4 ° C for 24 hours. Sperms were collected by making an incision on the epididymis of slaughtered rams and extended in extenders supplemented with 0 (control), 0.5, 1, 2, 5 and 10 mg/ml polyvinyl alcohol or polyethylene glycol then refrigerated for 24 hours. We found that only 0.5 mg/ml of PVA group had higher motility parameters comparing to control group (P <0.05). The lowest motility in PVA groups was observed at the concentration of 10 mg/ml. Extenders supplemented with PEG in different concentrations had no significant effect on the most kinetic indices. Both compounds were lethal to sperm at 15 mg/ml.