Earticle

초록

영어

Background: Cryopreserved semen and embryos are essential tools in livestock reproduction, enabling genetic improvement and herd management. Although these materials are theoretically stable in liquid nitrogen (LN2), viability often decreases over time, particularly in farm settings. Micro-ice crystals (MICs) are hypothesized to form under poor LN2 handling conditions, potentially compromising the survival of frozen genetic resources. However, the extent and impact of MIC accumulation have not been thoroughly quantified. Methods: This study evaluated MIC accumulation and its effects on the viability of cryopreserved bovine semen and embryos under different LN2 storage environments and conditions. MIC content was measured by filtering 10 L of LN2 through nonwoven fabric and weighing the retained crystals and debris. The viability of sperm and embryos were assessed using a computer-assisted semen analysis (CASA) and blastocoel re-expansion. Results: MIC content was 3.5 times higher in farm-stored LN2 than in laboratory LN2, with significantly more debris also detected. Progressive motility and velocity parameters (VCL, VAP, VSL) were similarly reduced. Blastocyst survival dropped significantly under farm conditions after six months (42.4%) compared to laboratory storage (84.4%, p < 0.05). These findings suggest a strong correlation between MIC accumulation and decreased post-thaw viability of cryopreserved materials. Conclusions: MICs formed in LN2 due to environmental exposure and poor handling can severely impair the viability of cryopreserved sperm and embryos. Regular filtration and improved LN2 management, especially in farm environments, are essential to reduce MIC-related damage. These practices may enhance the long-term usability and reliability of genetic resources in livestock breeding programs.

목차

ABSTRACT
INTRODUCTION
MATERIALS AND METHODS
Animals, semen collection, and reagents
Measurement of MICs in the LN2 containers
Cryopreservation and thawing of semen
Production of in vitro-fertilized bovine embryos
Blastocyst freezing and thawing
Evaluation of cryopreserved sperm and blastocysts
Statistical analysis
RESULTS
Measurement of MICs in LN2 containers after six Months of storage in two-year-used tanks
Motility kinetics of frozen semen preserved in LN2 with MICs for two years
Viability of blastocysts after six months of preservation
DISCUSSION
CONCLUSION
REFERENCES

키워드

저자

• Yu-Da Jeong [ Hanwoo Research Center, National Institute of Animal Science, RDA/Department of Animal Resources Science, Kongju National University, Yesan 32439, Korea ]
• Ga-Yeong Lee [ Animal Genetic Resource Research Center, National Institute of Animal Science, RDA/Department of Animal Resources Science, Kongju National University, Yesan 32439, Korea ]
• Bongki Kim [ Department of Animal Resources Science, Kongju National University, Yesan 32439, Korea ] Corresponding Author
• Sung Woo Kim [ Dairy Science Division, National Institute of Animal Science, RDA, Cheonan 31000, Korea ] Corresponding Author

참고문헌

발행기관

간행물

관심저널 등록

• 간행물명

  Journal of Animal Reproduction and Biotechnology

• 간기

  계간

• pISSN

  2671-4639

• eISSN

  2671-4663

• 수록기간

  2019~2026

• 십진분류

  KDC 527 DDC 636