L-carnitine improves quality parameters and epigenetic patterns of buck's frozen-thawed semen

Buck sperm cryopreservation is an effective method to distribute qualified sperm for reproductive purposes, but this procedure reduces sperm quality. The current study was conducted to investigate the effect of L-carnitine (LC) on the quality and epigenetic patterns of buck's post-thawed semen. Semen samples were collected from five male goats twice a week and diluted in extenders supplemented with 0 (LC-0), 1 (LC-1), 5 (LC-5) and 10 (LC-10) mM LC. Samples were cryopreserved according to standard protocol. After thawing, motility characteristics, lipid peroxidation, membrane functionality, abnormal morphology, mitochondrial activity, acrosome integrity, epigenetic modifications, viability, apoptotic-like changes and DNA fragmentation were assessed. Samples supplemented with 5 mM LC showed greater (P ≤ 0.05) total motility, progressive motility, membrane functionality, mitochondrial activity, acrosome integrity, DNA methylation, viability, and lower (P ≤ 0.05) apoptotic-like changes. Lipid peroxidation was lower (P ≤ 0.05) in LC-5 and LC-10 compared to the control group. Addition of LC to the cryopreservation extender had no effect (P > 0.05) on velocity parameters, abnormal morphology, histone modifications, or DNA fragmentation. In conclusion, supplementing the cryopreservation extender with 5 mM LC significantly preserves the quality of buck sperm after the cryopreservation process.