The He-Ne laser irradiation improves the quality of stored rabbit semen

Abstract

The aim of the study was to investigate the effect of different energy doses of Helium-Neon (He-Ne) laser irradiation on rabbit semen quality during 48 h of storage.From 30 commercial hybrid bucks semen was collected by artificial vagina. The ejaculates of bucks were pooled (3-4 ejaculates/pool) and in total 8 semen pools were used. Each pool was divided into four aliquots. One sample was not irradiated (control), the other ones were irradiated with a single mode continuous He-Ne laser wave (wavelenght 632,8) and exposed to the following energy doses: 3.96, 6.12 and 9 J/cm2 respectively. Samples were kept at 15° C during laser irradiation. They were subsequently stored again at the same temperature for a further 48 h. Samples were evaluated for sperm motility (Accudenz procedure), sperm viability (SyBr-PI procedure) and acrosome integrity (PSA-FITC procedure) at 3,24 and 48h of storage.Laser irradiation at all energy doses utilized significantly improved motility (P>0.01), viability (P>0.01) and acrosome integrity (P>0.05) than in control either at 24 and 48 h of storage. Moreover, the energy dose of 6.12J/cm2 recorded a better semen quality during storage compared to the 3,96 and 9J/cm2 ones respectively. No significant differences for measured seminal quality parameters were found at 3h; this might be due to the fact that irradiation treatment requires a longer period of time to determine modification on semen quality.The present study shows that laser irradiation, as shown in a previous research for turkey semen, seems to improve the quality of rabbit semen stored for up 48h even if higher energy doses were utilized.Therefore, the irradiation laser might be a useful technique to enhance quality of stored rabbit semen, although further studies are need.