Veterinarija ir Zootechnika

Bull sperm cryopreservation induces significant cellular damage through reactive oxygen species generation and oxidative stress, compromising motility, membrane integrity, and fertilizing capacity. Bull spermatozoa are particularly vulnerable due to limited cytoplasmic antioxidant defenses and high metabolic activity.The aim of this study wasto evaluate the protective effects of vitamin C, vitamin E, their combination, and vitamin E combined with Rosmarinus officinalis essential oil on bull sperm quality parameters following cryopreservation.Epididymal spermatozoa from ten bulls were collected and divided into five groups: control (Tris-based extender), vitamin E (0.5 mg/mL), vitamin C (0.25 mg/mL), vitamin E+C association (Vit E-C) (0.5 and 0.25 mg/mL), and vitamin E+essential oil association (Vit E-EO) (0.5 mg/mL+1 µl/mL). Post-thaw sperm quality was assessed using computer-assisted sperm analysis for motility and kinematic parameters, hypo-osmotic swelling test for membrane integrity, and thiobarbituric acid reactive substances assay for lipid peroxidation. All antioxidant treatments improved sperm parameters compared to control. Vitamin E+essential oil combination demonstrated the highest total motility (73.8±5.6% vs. control 64.3±3.5%) and progressive motility (33.7±7.1% vs. control 24.4±3.2%). This treatment also achieved superior kinematic parameters including curvilinear velocity (47.8±2.4 vs. 34.3±0.7 µm/sec), straight-line velocity (23.7±1.6 vs. 14.7±0.5 µm/sec), and membrane integrity (23±4% vs. 14±2%). Vitamin E+essential oil showed the greatest reduction in lipid peroxidation(0.26 vs. 0.35 nmol MDA/10⁸ spermatozoa). Antioxidant supplementation, particularly vitamin E combined with essential oil, significantly enhances bull sperm cryopreservation outcomes through synergistic protective mechanisms against oxidative damage and membrane destabilization.