Laser researches on livestock semen and oocytes: A brief review

This article presents a brief review of the past and present literature pertinent to laser effects on sperm motility parameters, improvement of oocyte maturation and characterization of semen in livestock. The aim was, on one hand, to make the readers aware of such knowledge and on the other hand to trigger the interest of the animal reproduction scientific community in attempting some laser techniques that have not yet been fully exploited in the field of artificial insemination. With respect to the conventional methods, laser is a more sensitive and less costly technology that can be used for improving artificial insemination and embryo production system. Since 1980s, laser treatment came on the biological samples scene; its applications have continuously been developed thereafter. Exploitation of laser light by various researchers for improving the reproductive efficiency of sperm cells and the maturation rate in different livestock is demonstrated herein. Laser irradiation, in principal, can increase the production of adenosine triphosphate (ATP) and consequently increases the energy provided to the cell. Since sperm motility and oocyte maturation depend on the energy consumption, an increase in the energy supply to the cells will be of great importance. In addition, the authors also discuss the use of laser spectrochemical analytical techniques, such as laser induced breakdown spectroscopy (LIBS) and laser induced fluorescence (LIF), in characterization of semen samples.