variables of cryopreserved rabbit spermatozoa as affected by nano-curcumin supplementation into Tris-extender containing egg yolk or soybean lecithin extender

This study aimed to assess the impacts of curcumin nano-formulation (CM-NF), type of extender, and their interaction on physical characteristics of cryopreserved rabbit spermatozoa. Ten mature NZW rabbit bucks (6.6–7.8 mo old and 3.45-3.95 kg LBW) were used as semen donors. Pooled semen was diluted with Tris-egg yolk (TEY) or Tris-soybean lecithin (TSBL) extender with CM-NF (0, 1, 1.5, and 2 µg/mL), equilibrated (2h at 5°C), loaded in straws, stored in liquid nitrogen, thawed at 37oC for 30 s, and evaluated for progressive motility (PM), livability (LS), abnormality (SA), membrane integrity (MI), and acrosome integrity after dilution, equilibration, and thawing. Results showed that extender type had non-significant effect on all sperm parameters after all cryopreservation processes. In both extenders, CM-NF (1 µg/mL) recorded significantly the highest PM, LS, MI, and AI, and the lowest SA percentages compared with free-extender. Impact of CM-NF (1.5 µg/mL) on all sperm parameters did not differ from that of free-extender. Increasing CM-NF level to 2 µg/mL adversely affect PM, LS, and SA only in post-diluted semen, and had no effects on all sperm characteristics after equilibration and thawing. The interaction effect of extender type with CM-NF level on all sperm was not significant. Conclusively, there were no differences between TEY and TSBL extenders in maintaining rabbit sperm characteristics after cryopreservation. Supplementation of either TEY or TSBL extenders with CM-NF (1.5 µg/mL) can improve the progressive motility, livability, membrane integrity and acrosome integrity in cryopreserved rabbit semen.