Effect of Extender Supplemented with Boron on Post-Thaw Motility, Viability, DNA Damage and Fertilization Ability of Cryopreserved Brown Trout (Salmo trutta macrostigma) Spermatozoa.

Background: Boron has been considered as an essential nutrient for decreasing lipid peroxidation and improving antioxidant mechanism in different animal species. On the other hand, its effect on quality or DNA damage following cryopreservation process in fish sperm is still unclear.

Objective: Experiments were designed to analyse the effect of an ionic based extender supplemented with boron on post-thawed motility, viability, fertility and DNA integrity of cryopreserved brown trout (Salmo trutta macrostigma) sperm.

Materials And Methods: Sperm samples were cryopreserved with the ionic extender containing different boron concentrations (0.1, 0.2, 0.3 and 0.4 mM) using a controlled freezer at two different freezing rates (FR-I: 10°C min from +4°C to -40°C and FR-II: 15°C min from +4°C to -40°C). Sperm motility, viability, fertilization, eyeing and DNA fragmentations were determined in post-thawed samples.

Results: Freezing rate-I provided significantly higher fertilization and eyeing rates compared to freezing rate-II (p<0.05). Higher post-thaw motility (62.8±1.4%) and fertilization (75.2±0.9%) rates were obtained with the 0.4 mM boron concentration at freezing rate-I.

Conclusion: Supplementation of the extender with boron increased fertilization and eyeing rates and also decreased DNA damages at both freezing rates.