Postpartum dysgalactia syndrome (PDS—Postpartum Dysgalactia Syndrome) is a common condition in sows that negatively affects milk production and piglet survival; however, early factors preceding clinical diagnosis remain poorly understood. This study investigated whether prepartum postural patterns, the timing of nest-building onset, and farrowing outcomes could serve as early indicators of PDS in farrowing sows housed in crates and in loose-housing systems.
Materials and Methods: Prepartum posture and nest-building behavior were analyzed in a subgroup of 49 sows using continuous video recordings during the 24 hours before farrowing, while farrowing duration and piglet survival outcomes were analyzed in the full dataset of 219 sows. PDS was diagnosed based on rectal temperature and appetite measured during the 48 hours after farrowing. Mixed models accounted for housing system, parity, and pen nested within batch to account for repeated measurements across parities (farrowing number).
Results: Pre-farrowing postural patterns, postural changes, behavioral variability (Shannon entropy), and repetitiveness (data compression ratio) did not differ between sows that subsequently developed PDS and those that did not. However, the housing system had a strong effect on posture, with loose-housed sows showing greater postural variability, higher entropy, lower compression ratios (indicative of less repetitive behavior), and more postural transitions than caged sows (all p < 0,01). The interval between the onset of nest-building and farrowing was not associated with PDS status but was influenced by the housing system (p = 0,03) and parity (p < 0,01). Placental expulsion occurred later in sows with PDS than incontrol sows within the loose-housed group (p = 0,03), although this finding should be interpreted with caution.
The duration of farrowing was significantly longer in sows with PDS than in those without PDS (p = 0,03) and PDS status was associated with approximately twice the odds of stillbirth (OR = 2,07, p < 0,01). Total litter size was mainly influenced by parity (p < 0,01). These results indicate that pre-farrowing postural patterns and the timing of nest-building onset alone are unlikely to provide reliable early indicators of PDS, whereas farrowing characteristics, placental expulsion, and piglet survival at birth may offer more informative signals. In addition, the results confirm that loose housing allows greater postural flexibility before farrowing, supporting the known animal welfare benefits of loose-housing systems.
Conclusions: Future research should explore automated monitoring tools, such as accelerometry, to detect subtle changes in sow activity and the progression of farrowing in order to identify PDS early under commercial conditions.
Mathilde Coutant, Leslie Foldager, Lene J. Pedersen, Mona L.V. Larsen, Marianne Kaiser, Prepartum postural patterns and farrowing outcomes in sows with and without postpartum dysgalactia syndrome in crated and loose housing systems, Applied Animal Behaviour Science, 2026, 107123, ISSN 0168-1591, https://doi.org/10.1016/j.applanim.2026.107123.