Effect of refreezing extender on stallion sperm quality and embryo production after intracytoplasmic sperm injection

• Published in: Theriogenology 2025-01, Vol.231, p.29-35
• Main Authors: Brito, Leonardo F.C., Felix, Matheus R., Linardi, Renata L., Martinez de Andino, Elena V., Balamurugan, Nithiya Sri, Hernández-Avilés, Camilo, Hinrichs, Katrin
• Format: Article
• Language: English
• Subjects: amides; Animals; blastocyst; Cryopreservation - methods; Cryopreservation - veterinary; Cryoprotective Agents - pharmacology; egg yolk; Female; glycerol; Horse; Horses - physiology; ICSI; Intracytoplasmic sperm injection; Male; milk; Semen; Semen Analysis - veterinary; Semen Preservation - methods; Semen Preservation - veterinary; Sperm; Sperm Injections, Intracytoplasmic - veterinary; sperm motility; sperm quality; Spermatozoa - drug effects; Spermatozoa - physiology; Stallion; stallions; straw; viability
• ISSN: 0093-691X; 1879-3231; 1879-3231
• DOI: 10.1016/j.theriogenology.2024.10.006

Intracytoplasmic sperm injection (ICSI) is a valuable assisted reproduction technology in clinical practice, especially when semen availability is limited. Since the number of sperm required per ICSI cycle is much less than the number of sperm available in a standard straw of frozen semen, refreezing semen at lower sperm concentrations could yield multiple straws for ICSI use. However, there is little data on the effect of sperm refreezing on ICSI outcomes, especially on the effect of extender used for refreezing. The objective of the present study was to evaluate the effect of refreezing extender on stallion sperm quality and embryo production after ICSI. Semen was frozen in a low egg yolk/glycerol/amide extender (Extender 1), then thawed, re-extended, and refrozen in each of three extenders. When sperm were refrozen in Extender 1, the cleavage rate was lower (P