Effect of freezing rate on goat sperm morphology and DNA integrity

Authors: BURCU ÜSTÜNER, ZEKARİYA NUR, SELİM ALÇAY, MEHMED BERK TOKER, HAKAN SAĞIRKAYA, MUSTAFA KEMAL SOYLU

Abstract: This study investigates the effect of freezing rates on the spermatological parameters of frozen and thawed Saanen goat semen. Equilibrated semen was frozen at 4 different freezing rates from +5 °C to -150 °C (G10: 10 °C/min, G12: 12 °C/min, G15: 15 °C/min, and G24: 24 °C/min) and stored in liquid nitrogen until use. Semen samples were examined for sperm motility, defective acrosomes (FITC-PSA), and DNA integrity using TUNEL after dilution with extender A at equilibration and postthaw stage. There was no significant difference among the freezing stages in terms of DNA fragmentation (P > 0.05). DNA integrity was partially affected by the freezing rate. The increase of freezing rate from 10 °C/min to 24 °C/min between +5 °C and -150 °C resulted in higher postthaw DNA damage. The study found that the freeze-thawing process is detrimental to postthawed goat semen motility (P < 0.05), acrosome integrity (P < 0.05), and DNA integrity (P > 0.05). Although the freezing rates used in the present study had no effect on postthaw sperm motility and acrosome integrity (P > 0.05), sperm DNA integrity was affected.

Keywords: DNA integrity, freezing rate, goat semen

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