Troubled Process of Parturition of the Domestic Pig

Abstract

Over the past three decades, efficient breeding and management have almost doubled the litter size of sows. Simultaneously, duration of farrowing has increased markedly. The expulsion phase of parturition in the hyper prolific sow is now 3 to 5 times longer than it was in the early 1990s. There has also been a constant downward trend in piglet birth weight, along with a similar trend in colostrum intake, which is an important risk factor for piglet mortality. Together with these trends, an increase in farrowing complications, such as postpartum dysgalactia and retention of placenta, has been reported. This paper investigates group housing of sows during gestation, farrowing and lactation, focusing on management strategies of the sow. In short, the sow needs to be given space and enrichment materials for adequate expression of nest-building behavior. Maternal characteristics may be utilized to improve the success rate of reproductive management during farrowing and early lactation. The lower piglet birth weight and compromised immunity of newborn piglets warrant investigation in the search for novel management tools. Robust breeds with somewhat lower litter size, but improved resilience and increased birth weight may be needed in the near future.