The composition of ram sperm membrane creates problems during cryopreservation. Reactive oxygen species, which are produced during freezing and thawing, attack spermatozoa, damaging membranes and acrosomes as well as affecting mitochondrial activity. This results in poor yield of sufficient number of viable, morphologically normal spermatozoa for successful insemination. Many different approaches have been attempted to improve the cryopreservation process and protect spermatozoa. Based on previous findings, melatonin works as an antioxidant and can potentially protect spermatozoa by scavenging the reactive oxygen species. In addition, the use of colloid centrifugation, especially centrifugation through a single layer of colloid, helps to improve post-thaw ram semen quality. This study investigated the effect of melatonin addition together with single layer centrifugation on the quality of frozen/thawed ram semen samples. Sperm quality was evaluated by assessing sperm motility, membrane integrity, and morphology. Twenty pooled ejaculates of autochthonous Jezersko-Solčava sheep breed were available for this study. Samples were incubated for six hours, with analyses being carried out at 0, 3 and 6 h. Addition of melatonin improved membrane integrity, progressive motility and normal morphology of the spermatozoa compared with the control group. These parameters are indicators of functional spermatozoa, possibly being able to reach and fertilize the oocyte. However, other research and trials with in vitro fertilization and artificial insemination are needed, to evaluate the full effect and potential of melatonin as a cryoprotectant.
Lea Enenkelová Animal Science - Master's programme
Hello, I come from the Czech Republic. I am interested in the field of reproduction biotechnologies, with a focus on andrology. My goal is to work as a researcher on the topics of reproduction and public health. Feel free to contact me for any additional information: firstname.lastname@example.org