The researchers studied how different factors affect the maturation and freezing of pig oocytes in the lab. They found that using a certain medium with 10% ECS led to higher maturation rates compared to 10% NCS. Adding porcine follicular fluid to the maturation medium hindered oocyte maturation. Oocytes from larger follicles had better maturation rates than those from smaller ones. Oocytes in the MⅡ stage were better at surviving freezing compared to those in the GV stage or cultured for 24 hours. The survival rate after freezing and thawing was higher for oocytes in the MⅡ stage than those in the GV stage or cultured for 24 hours. The rate of normal-looking oocytes after thawing was higher for those in the MⅡ stage or cultured for 24 hours compared to those in the GV stage.