The effect of different concentrations of laminarin on the quality of cryopreserved ram semen

BACKGROUND: Increasingly, sheep breeders are using artificial insemination to produce lambs, so finding methods that preserve ram sperm can be useful. OBJECTIVE: To determine the protective effects of different concentrations of laminarin on ram sperm motility, viability, abnormalities, membrane, and DNA integrity, superoxide dismutase enzyme (SOD) activity, and malondialdehyde (MDA) production after freeze-thawing. MATERIALS AND METHODS: The ejaculates of four rams were collected and stored at 35 °C. Semen samples were diluted with a tris-base extender containing 100, 200, 400, and 800 μg/mL of laminarin and a control extender containing no laminarin, then frozen in liquid nitrogen after 4 h in the refrigerator. RESULTS: In the treatment of frozen-thawed spermatozoa with 800 μg/mL laminarin, motility, viability, membrane integrity, and DNA integrity were significantly higher than in the control. In spermatozoa that were exposed to 800 μg/mL laminarin after thawing, MDA production was significantly lower than in the control group. The percentage of abnormal spermatozoa in 800 μg/mL laminarin was significantly lower than that in the control. CONCLUSION: The addition of 800 μg/mL laminarin to the freezing extender increases motility, viability, SOD activity, and plasma membrane integrity, while reducing abnormality and MDA production in freeze-thawed ram semen.