Effect of Pentoxifylline on Semen with Low Sperm Motility in Asian Elephant (Elephas maximus)

Abstract

Due to the high risks of extinction and increasing concerns about decreasing in genetic diversity of ex situ population, a great effort has been devoted to the establishment of a self-sustaining population of Asian elephants in Thailand. Male subfertility attributed from poor motility and immotile of spermatozoa was found in high proportion of overall ejaculates obtained from a manual collection technique. The searching of motility stimulation for elephant sperm may be improving a quality of the preserved semen. The objective of this study was to investigate the effects of pentoxifyllines (PTX) on stimulating motility in elephant semen with low-motile sperm. Eleven ejaculates were collected from 8 elephant bulls by manual stimulation and were separated into two groups: poor- and low-motile sperm groups. PTX was added to the semen samples at a final concentration of 0.5, 1.0 and 2.0 mg/ml. Samples without PTX were use as control. Semen analysis was performed at 15 and 30 min after incubation at 37 C using computer-assisted semen analysis. PTX did not significantly improve percentage of total and progressive motility, and characteristics of sperm motion in both groups. However, in a low-motile sperm group, PTX treatment could maintain the percentages of total and progressive motility, path velocity (VAP) and progressive velocity (VSL) on the higher level than a control group. The present study indicates that supplementation with PTX has a tendency for partially maintaining rather than increasing sperm motility and sperm motions in Asian elephant semen with low-motile sperm.