Effect of pentoxifylline on the motility characteristics and viability of spermatozoa in Asian elephants (Elephas maximus) with low semen quality

Abstract

To investigate the effects of pentoxifylline (PTX) to enhance the motility and fertilization capacity of semen samples with the low-motile sperm in Asian elephants, fourteen semen collection attempts in 9 elephant bulls by manual stimulation were undertaken and eleven ejaculates fitted the criteria of investigation (0-30% motility). They were divided into two groups: poor-motile (0-9% motility) and low-motile (10-30% motility) sperm groups. Fresh semen samples were divided as a control group and 3 experimental groups that were supplemented with PTX at a final concentration of 0.5, 1.0 and 2.0 mg/ml, respectively. The semen samples were incubated at 37°C for 15 and 30 mins and stained with VIADENT media for viability assessment. Sperm motility and viability were tested using computer-assisted semen analysis. PTX added to the semen did not significantly improve the percentage of the total and progressive motility, motility characteristics and viability of sperm in either the poor-or low-motile groups. However, at 30 min, in the low-motile sperm group, PTX treatment could maintain the percentage of total and progressive motility, path velocity and progressive velocity at a higher level than the control group. The present study indicated that PTX added to low motility semen did not increase elephant semen quality. However, it may partially have a tendency to maintain sperm motility and sperm movement characteristics.