In vitro assessment of lavender ethanolic extract supplemented semen extender on cryopreserved ram epididymal sperm quality and fertility outcome

This study aimed to investigate the protective role of different concentrations of lavender ethanolic extract (0, 75, 150, and 300 μg/dL) on the microscopic, oxidative stress, structural, and fertility parameters of ram epididymal sperm after the freezing/thawing process. Post-thaw evaluations included motility parameters, membrane integrity, acrosome membrane integrity, abnormality, MDA concentration, superoxide dismutase and glutathione peroxidase enzyme activities, viability, apoptosis stages, mitochondrial membrane potential, DNA fragmentation, ROS levels, and fertility parameters (pregnancy rate, birth rate, and lambing rate). The results indicated that the extender containing 150 µg/dL lavender extract improved motility parameters, including progressive motility and VCL compared to the control extender. In the evaluation of structural and biochemical parameters, the addition of 150 µg/dL lavender extract significantly enhanced plasma membrane and acrosome integrity, as well as superoxide dismutase activity, while reducing sperm abnormalities and MDA concentration compared to the control group. There was no significant difference in glutathione peroxidase activity between different extract concentrations. Furthermore, the presence of 150 µg/dL lavender extract increased mitochondrial membrane potential and sperm viability, while significantly decreasing H₂O₂ free radical levels and DNA fragmentation, compared to the control group. In terms of fertility parameters, the use of an extender containing 150 µg/dL extract significantly increased pregnancy, birth, and lambing rates, although no significant difference was observed in the twinning rate between groups. In conclusion, adding 150 µg/dL lavender extract can improve the quality and fertility of ram semen after freezing/thawing, and its use is recommended.