In addition to abnormal behaviors, sows in labor can observe whether they are in labor by the method of "three observations and one squeeze" according to years of accumulated experience. That is, "look at the breast, look at the tail root, and look at the behavior; Squeeze your nipples. " The sow's breasts are swollen and shiny, and the nipples on both sides are splayed apart, commonly known as "nipple bang, which will be off soon". The abdominal circumference of parturient sows becomes smaller, the vulva is lax, and the tail root collapses (commonly known as hip collapse). Sows get restless, walk back and forth in the pen, grab grass and litter, and discharge sporadic feces. After this behavior appears, they usually give birth in 6 ~ 12 hours. The sow's vulva is red and swollen, with mucus flowing out and frequent urination. Commonly known as "sow frequently urinates, and the litter is coming."
In general, the sow may give birth about 24 hours after the nipple in front of the abdomen exudes thick milk, about 12 hours after the nipple in the middle, and 3 to 6 hours after the nipple in the back. However, the above time is not absolute, and the amount of milk that appears sooner or later is related to the feed type that sows eat and the physical condition of sows. The more accurate way to judge the sow's farrowing is to squeeze a lot of thick milk when you gently squeeze any nipple of the sow, which means that the sow will give birth soon. As the saying goes, "milk wears an arrow shaft, and giving birth is not far away."