Optimization of the in vitro fertilization protocol for frozen epididymal sperm with low fertilization ability in Ban—A native Vietnamese pigs

• Published in: Animal science journal Vol. 89; no. 8; pp. 1079 - 1084
• Main Authors: Linh, Nguyen Viet, Somfai, Tamas, Nguyen, Thi Hiep, Nhung, Nguyen Thi, Hong, Nguyen Thi, Dat, Nguyen Tien, Thinh, Nguyen Hoang, Van, Nguyen Khanh, Quyen, Dong Van, Chu, Hoang Ha, Son, Nguyen Thanh, Kikuchi, Kazuhiro
• Format: Journal Article
• Language: English
• Published: Australia Blackwell Publishing Ltd 01-08-2018
• Subjects: Alcohols; Animals; Ban breed; Caffeine; Cell culture; Cryopreservation - methods; Culture Media - chemistry; Cumulus Cells; Denudation; epididymal sperm; Experiments; Fertility; Fertilization - physiology; Fertilization in Vitro - methods; Fertilization in Vitro - veterinary; freezing; Gametes; In vitro fertilization; in vitro fertilization; Isotonic Solutions; Lactic acid; Male; Optimization; Penetration; Polyvinyl alcohol; Prolongation; Pyruvic acid; Semen Preservation - methods; Sperm; Sperm-Ovum Interactions - physiology; Swine - physiology; Time Factors; Vietnam; Vietnamese native boar; Ban breed; freezing; in vitro fertilization; Vietnamese native boar; epididymal sperm
• ISSN: 1344-3941; 1740-0929
• DOI: 10.1111/asj.13045

The aim of the present study was to improve the penetration during in vitro fertilization (IVF) of a frozen lot of epididymal sperm with a notoriously low fertilization ability of a Ban boar which is a native Vietnamese breed by optimizing different parameters of the IVF system. In Experiment 1, we determined that Pig‐fertilization medium was superior medium to Tyrode's albumin lactate pyruvate‐polyvinyl alcohol medium for IVF and defined the optimum the sperm concentration (1 × 106 sperm/ml). In Experiment 2, we clarified that partial removal of cumulus cells from cumulus‐oocyte complexes by hyaluronidase treatment before IVF enhances sperm penetration, whereas complete cumulus removal reduces penetration. Finally, in Experiment 3 the elevation of concentration of caffeine in Pig‐fertilization medium from 2 to 5 mmol/L and the prolongation of the co‐culture of gametes from 3 to 5 hr significantly increased the total penetration rate from 15.2% to over 50%. In conclusion, the combination of partial oocyte denudation, an elevated caffeine concentration in Pig‐fertilization medium and an extended interval of IVF with using an optimized sperm concentration was a potent way to improve the fertilization results for a frozen epididymal Ban sperm lot with low fertility.