Date Full Report Received


Date Abstract Report Received



Primary Investigator:

In response to increased sow mortality due to pelvic organ prolapse (POP), the Iowa Pork Industry Center (IPIC) at Iowa State University, with funding from the National Pork Board, assembled a unique team to better understand potential causative factors of sow POP in order to move towards developing and disseminating prevention strategies to help reduce POP incidence. One hundred and four commercial sow farms, representing approximately 385,000 sows across the U.S., were enrolled in a survey-based project. The farms varied in POP incidence rate, production system, geography, genetics, and management practices. This observational study was designed to provide research direction for future projects investigating causative factors of POP and cultivate a collaborative network of multidisciplinary experts within Iowa State University and across the swine industry. Results of the project have allowed better understanding of the degree of the issue and prioritization of risk factors for future research in the pursuit of reducing POP-related sow mortality. During the project period, the average annualized POP incidence for these farms was 2.7% and accounted for 21% of the total mortality. At a farm level, the most apparent relationships with increased POP incidence were farms using untreated water sources and farms whose management strategies included late gestation bump feeding, particularly when targeting thin sows. On an individual sow basis, sows with lower body condition and/or greater swelling and protrusion of the perineal region were more likely to prolapse. Factors with little to no evidence of relationship to POP incidence were herd size and the extent to which sow farms are inducing parturition or assisting in farrowing. A major outcome of this project was direct guidance on the most valuable experimental approaches to better understand the physiology occurring within a sow that precedes POP so that the most effective measurements can be determined when evaluating or testing potential on-farm mitigation strategies. This project also supports the concept of building an ongoing collaboration from commercial farms from multiple production systems across the U.S. swine industry for field research allowing comparisons within and between production systems. Furthermore, the collaborative network to facilitate such investigations has been built.

Producer take home points:
• An industry-wide survey was conducted with 104 sow farms representing approximately 400,000 sows and nearly half of the US swine industry, including large integrated companies and many independently owned sow farms.
• Multiple factors that may contribute to POP in sows were identified, enabling the design of subsequent studies in specific areas of interest.
• Many areas of presumed potential influence on pelvic organ prolapse have been shown to be minimally influential if at all.
• A perineal scoring system was developed that is reproducible and indicative of risk of prolapse for individual sows.