Poster Presentation IXth International Conference on Boar Semen Preservation 2019

Successful IVF of IVM porcine oocytes with cryopreserved epididymal spermatozoa from Lanyu boars (#8.1)

Yu-Hsin Chen 1 , Hsiu-Lien Lin 1 , Lih-Ren Chen 1
  1. Physiology Division, Livestock Research Institute, Hsinhua, TAINAN, Taiwan

The Lanyu Miniature Pig is an indigenous Taiwanese breed used for biomedical research applications. The purpose of this study was a proof of principle trial to cryopreserve epididymal Lanyu semen and use it to produce embryos following IVM and IVF. Epididymal semen was collected from mature Lanyu boars (n = 4; aged 24 to 36 mo) by retrograde flushing of the vas deferens and cauda epididymides immediately following castration. Semen was diluted (BTS; Minitube, Germany), equilibrated (15 °C for 2 h, and centrifuged (800 X g for 10 min) to remove the supernatant and frozen (0.5 mL straws, 4 cm above liquid nitrogen for 10 min) following equilibration (5°C for 4 h) with the cryomedium (lactose-egg yolk based with 6% glycerol v/v). Sperm motility and viability was assessed before and after freezing. Frozen-thawed spermatozoa (1 × 105 cells/mL) were coincubated (3 h) with in vitro matured oocytes and the resultant presumptive zygotes cultured for 6 d, with cleavage and blastocyst rates assessed. Mean sperm motility and viability were 90.4% and 93.6% before, and 34.0% and 45.0% after cryopreservation, respectively. In vitro fertilization with frozen-thawed epididymal Lanyu spermatozoa resulted in a cleavage and blastocyst rate of 41.56% and 11.13%, respectively. In conclusion, epididymal spermatozoa from Lanyu boars can be cryopreserved and successfully used to generate embryos following IVF of IVM oocytes.  These technologies are a potential resource for genetic conservation of Lanyu pigs.