The article talks about methods for fertilizing pig eggs in the lab. Different techniques like putting sperm in a drop of liquid, injecting sperm into eggs, or using straws are used for this. Pigs' eggs are more likely to have multiple sperm compared to other animals. Things like egg maturity, sperm amount, and egg environment affect this. The researchers checked that various factors like egg quality, sperm number, and conditions during fertilization can lead to multiple sperm entering a single egg.