Understanding the process of pigs in labor is essential for any swine producer, whether managing a few breeding animals or operating a large commercial facility. The journey from the first signs of farrowing to the delivery of a healthy piglet requires knowledge, preparation, and attentive observation. This guide provides a detailed look at the physiological and practical aspects of porcine parturition, ensuring you are equipped to support a successful birth.
Signs of Approaching Farrowing
Recognizing the pre-labor indicators in sows and gilts is the first critical step in managing the birthing process. Unlike some species, pigs often do not display dramatic changes hours in advance, but specific behaviors and physical signs are reliable predictors. Close monitoring during the final week of gestation allows for timely intervention if complications arise.
Physical and Behavioral Changes
In the 12 to 24 hours preceding labor, a noticeable drop in the sow’s abdominal temperature typically occurs, falling below 100°F (37.8°C). This is often the most accurate physiological sign. Concurrently, the animal will exhibit nesting behavior, which involves scraping the floor with her hooves and arranging bedding material into a comfortable mound. She may also become restless, refuse feed, and seek out a quiet, secluded area within the farrowing crate or pen.
The Three Stages of Labor
The farrowing process is divided into three distinct stages, each with specific characteristics and required human involvement. Understanding these stages helps differentiate between normal progress and situations requiring veterinary assistance.
Stage One: Dilation and Preparation
This initial stage involves the dilation of the cervix and the positioning of the fetus for delivery. It is generally the longest stage, lasting anywhere from two to twelve hours. During this time, the sow may appear uncomfortable, lying down and getting up frequently. No pups should be visible during this phase, but the expulsion of the amniotic sacs may occur near the end.
Stage Two: Expulsion of the Fetus
Stage two is the active delivery period. Strong contractions propel the piglet through the birth canal. The interval between the birth of individual piglets typically ranges from 15 to 30 minutes. A key observation during this stage is the amniotic sac; it usually breaks before the piglet’s head emerges, and the sow will often bite through the sac to clear the piglet’s airways.
Stage Three: Passage of Placental Material
Following the delivery of each piglet, the sow will expel the corresponding afterbirth. While the placenta for each piglet is usually delivered within a few hours of birth, it is not uncommon for the entire mass to be passed 12 to 24 hours later. Retained placentas can lead to infection and should be monitored closely by the producer. Common Complications and Interventions Even with meticulous management, farrowing can present challenges that require quick thinking and proper technique. Knowing how to assist a sow without causing harm to her or the piglets is a vital skill for any stockperson.
Common Complications and Interventions
Managing Dystocia
Dystocia, or difficult birth, occurs when a piglet is too large or positioned incorrectly to be delivered naturally. If a piglet is visible but not progressing within 30 minutes, or if there is a foul-smelling discharge, intervention is necessary. Manual rotation or traction applied with OB sleeves and lubricant can resolve many positional issues. However, excessive force can cause injury, making it crucial to assess the situation carefully or contact a veterinarian.
Post-Farrowing Care
The work does not end with the last piglet hitting the floor. Immediate postpartum care ensures the health of the sow and the vitality of the newborn litter.
