Sow behaviour, parturition process and management in free farrowing systems

The pig industry is increasingly transitioning from traditional farrowing crates to free farrowing systems, driven by growing concerns for animal welfare and regulatory pressures to enhance sow well-being. Free farrowing systems, which allow sows greater freedom of movement, have emerged as a welfare-oriented alternative to traditional farrowing crates. These systems enable the expression of natural behaviours, particularly nest-building, which is hormonally driven and peaks shortly before parturition. Adequate provision of diverse nesting materials facilitates nest-building, optimizes endocrine preparation for farrowing, and can shorten farrowing duration, improving piglet vitality and colostrum intake. Farrowing in sows encompasses three stages: preparatory behaviour and cervical dilation, active piglet expulsion, and placental expulsion. Free farrowing systems are associated with lower maternal stress, higher endogenous oxytocin, and more natural behavioural expression, potentially influencing parturition kinetics. However, dystocia incidence remains comparable to crated systems, indicating that careful management is still required. Key indicators for monitoring farrowing in free farrowing sows include piglet birth intervals, placental expulsion timing, litter-level meconium scoring, umbilical cord integrity, and maternal physiological markers such as progesterone. Excessive or routine administration of exogenous uterotonics is discouraged due to the risk of overly strong contractions, increased stillbirths, and reduced colostrum intake. Placental expulsion patterns offer additional insights, with sows expelling the first placenta before or alongside the last piglet, or with more than four placental parts, exhibiting prolonged farrowing. While free farrowing systems improve welfare and allow more natural parturition, effective management based on sow behaviour and physiology remains essential to mitigate risks and optimize reproductive outcomes. In conclusion, free farrowing systems represent a significant advancement in sow welfare, facilitating natural maternal behaviours and promoting better physiological preparation for parturition. Continued research is needed to refine monitoring strategies, define intervention thresholds, and fully harness the potential of these systems to enhance both sow and piglet health, demonstrating that improved welfare can coexist with productive performance.