In vitro maturation and fertilization of porcine oocytes and evaluation of male fertility

The objectives of this thesis were to establish incubation systems for in vitro porcine maturation and for in vitro fertilization (IVF), and utilizing these in vitro matured oocytes and in vitro fertilization techniques to determine the difference of sperm fertility from different boars. In the study of in vitro oocyte maturation, the oocyte maturation process was divided into the stages of germinal vesicle (GV I, GV II, GV III, and GV IV), metaphase I (EPromet I, LPromet I, and Met I), anaphase I (EAna I, MAna I, and LAna I), telophase I (Tel I), and metaphase II (Agg Met II, Not W-sp Met II, and Met II) by the criteria of chromosomal morphology. A morphological heterogeneity among the oocyte population was found before incubation. Cumulus expansion started at 12-16 hours incubation and reached a maximum after 44-48 hours of incubation. After 24 hours incubation, 90-95% of the oocytes had complete germinal vesicle breakdown (GVBD). After 36-50 hours incubation, 71-83% of the oocytes had proceeded to metaphase II with the extrusion of first polar body. Size of cumulus mass, time delay for oocyte selection, and degree of cumulus expansion affected oocyte maturation. Different incubation temperatures (39$\sp\circ$C, 38$\sp\circ$C, and 37$\sp\circ$C) did not affect the oocyte maturation rate. The combination of pure porcine LH and FSH produced greater cumulus expansion and oocyte maturation than addition of the individual hormones. Commercial hormones (porcine FSH, equine LH) could be substituted for the purified hormones without decreasing maturation rate. The addition of serum from estrous and diestrus gilts resulted in greater cumulus expansion and a higher maturation rate than those of fetal calf serum and barrow serum. In the study of in vitro fertilization, the oocytes selected at 4 and 6 hours after ovary collection had higher fertilization rates than those selected at 8 hours. Using the Percoll gradient system, highly motile spermatozoa were separated and tested for fertility by IVF. When spermatozoa from different boars were used to do IVF in parallel oocyte cultures, the difference of sperm fertility could be evaluated by the criteria of fertilization rate, average number of accessory spermatozoa, and average number of fertilizing spermatozoa.U of I OnlyETDs are only available to UIUC Users without author permissio