Background: The preservation of boar semen is essential for optimizing artificial insemination outcomes and maintaining sperm functionality during liquid storage. Glucuronic acid (GA) is involved in cellular detoxification and homeostasis regulation and may relate to oxidative processes. However, its effect on boar semen preservation remains unclear. This study aimed to investigate the effects of GA addition on sperm viability, acrosome reaction, and intracellular ROS level during liquid storage in pigs. Methods: Boar semen was collected by the gloved-hand method and transported at 17℃. Samples were diluted with extenders containing 0, 0.5, 1.0, 2.5, and 5.0 mM GA and stored at 17℃ for 7 days. Sperm viability, acrosome reaction, and intracellular ROS levels were detected using SYBR-14/PI, FITC-PNA/PI, and DCFDA/PI double staining and analyzed by flow cytometry. Results: Sperm viability was higher in the 0.5 mM GA group than in the 0 mM group at 72 h, with no difference at 120 h and 168 h. Acrosome reaction showed no difference at 72 h and 120 h, but was lower in the 5.0 mM group than in the 0 mM group at 168 h. Intracellular ROS levels were similar among treatments at 72 h and 168 h, but were higher in the 5.0 mM group than in the 0 mM group at 120 h. Conclusions: GA supplementation showed concentration- and storage-dependent effects, with a transient viability increase at 0.5 mM (72 h) and a reduced proportion of acrosome-reacted sperm at 5.0 mM (168 h), while ROS was not decreased and was elevated at 5.0 mM at 120 h, suggesting the need for dose optimization.

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
    Sperm preparation
    Treatment for liquid preservation
    Viability
    Acrosome reaction
    Intracellular ROS
    Flow cytometry
    Statistical analysis
RESULTS
    Effect of glucuronic acid on sperm viability
    Effect of glucuronic acid on sperm acrosome reaction
    Effect of glucuronic acid on intracellular ROS of sperm
DISCUSSION
CONCLUSION
REFERENCES

• Joon-Hee Lee(Department of Animal Bioscience, College of Agriculture and Life Sciences, Gyeongsang National University, Jinju 52828, Korea, Institute of Agriculture & Life Science, College of Agriculture & Life Sciences, Gyeongsang National University, Jinju 52828, Korea) Corresponding author
• Minwoo Sin(College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea)
• Eunju Seok(College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea)
• Sang-Hee Lee(College of Animal Life Sciences, Kangwon National University, Chuncheon 24341, Korea, School of ICT, University of Tasmania, Hobart 7005, Australia) Corresponding author