Reduction of post-thawed sperm quality of Kacang goat using the addition of epigallocatechin-3-gallate into the skim milk–egg yolk extender

Background: One native goat species in Indonesia that faces extinction as a result of cross-breeding is the Kacang goat (Capra hircus). In addition to ensuring food security as meat-producing livestock, artificial insemination (AI) of the Kacang goat could simultaneously conserve it and improve genetic quality. Aim: The purpose of this study was to investigate how adding epigallocatechin-3-gallate nanoparticles (EGCG) to skimmed egg yolk (SM-EY) extender affected the quality of post-thawed Kacang buck spermatozoa for artificial insemination. Methods: The findings indicated that there were no significant differences in pre-equilibration sperm motility, viability, or IPM between groups (p > 0.05). Following equilibration, sperm motility, viability, and IPM were all greater (p < 0.05) in the EGCG group than in the control group. Compared to the control group, EGCG groups showed higher sperm viability, motility, DNA, and IPM integrity in post-thawed semen and lower MDA levels (p < 0.05). There was no difference in the chromatin density between the groups (p > 0.05). Results: The analysis of variance (P < 0.05) showed no significant effects at T0, T1, and T3, indicating that T2, the treatment group supplemented with extract green tea (Camellia sinensis), produced the most notable results. This group maintained is better than another group on parameters sperm motility, viability, plasma membrane integrity, and minimized necrosis, alongside increased catalase enzyme and SOD activity. Conclusion: The addition of 100 mg EGCG/dL SM-EY extender significantly improved the quality of Kacang buck post-thawed spermatozoa.