Impact of Supplemented Nutrition on Semen Quality, Epigenetic-Related Gene Expression, and Oxidative Status in Boars

This study investigates the impact of nutritional supplementation on semen quality, epigenetic-related gene expression, and oxidative status in boars. Thirty boars were divided into a control group and a treatment group receiving Espermaplus (a supplement containing various vitamins, amino acids, omega-3 fatty acids, and trace elements with antioxidant properties). The experiment was performed for 12 weeks. Semen samples were collected at four moments: before starting the supplementation and after 3 weeks, 8 weeks, and 12 weeks. Spermatozoa concentration, motility, and kinematics were assessed using the CASA system. The measured parameters included curvilinear velocity-VCL; straight-line velocity-VSL; average path velocity-VAP; curvilinear distance-DCL; straight line distance-DSL; distance of average path-DAP; amplitude of lateral head displacement-ALH; beat-cross frequency-BCF; and head activity-HAC. Moreover, superoxide dismutase (SOD) and glutathione peroxidase (GPx) activity in seminal plasma, as well as the concentration of thiobarbituric acid reactive substances (TBARS), were measured to assess oxidative stress levels in boar's seminal plasma. The expression of epigenetic-related genes such as Protamine 1 (<i>Prm1</i>), Protamine 2 (<i>Prm2</i>), and DNA-methyltransferase 3 alpha (<i>Dnmt3a</i>) were evaluated using real-time PCR. The treated group showed a significant increase in spermatozoa concentration (<i>p</i> = 0.003), total motility (<i>p</i> = 0.001), and progressive motility (<i>p</i> = 0.002) after 12 weeks compared to the control group. Kinematic parameters such as VCL, VSL, and VAP were also significantly higher (<i>p</i> < 0.001; <i>p</i> = 0.028; <i>p</i> < 0.001, respectively) in the treated group by the end of the experiment. SOD and GPx activities were consistently higher (<i>p</i> < 0.01; <i>p</i> < 0.001, respectively) in the treated group, indicating enhanced antioxidative capacity. TBARS levels as an indicator of lipid peroxidation and oxidative damage were significantly lower (<i>p</i> < 0.01) in the treated group by the end of the study. Significant changes were observed in the expression of epigenetic-related genes. The supplementation of boar diets with Espermaplus significantly improved semen quality, reduced oxidative stress, and had an impact on the expression levels of certain epigenetic-related genes, suggesting that dietary antioxidants and bioactive compounds can enhance boar semen.