The typical gestation period for pigs is between 112 and 115 days, with an average of 114 days. The length of the pregnancy can be influenced by several factors including breed, age, parity, and environmental conditions. During gestation, the sow (female pig) experiences several physiological changes, including increased hormone production, uterine development, and fetal growth. The gestation period is divided into three stages: the embryonic stage (days 1-30), the fetal stage (days 30-70), and the placental stage (days 70-114). The embryonic stage is characterized by rapid cell division and the formation of the major organs. The fetal stage is characterized by the growth of the fetus, the development of hair and hooves, and the formation of the placenta. The placental stage is characterized by the exchange of nutrients and oxygen between the mother and the fetus through the placenta.