Pens with farrowing crate (FC) and two differently designed free-farrowing pens (LH-pens: 7.3 m², plastic flooring; GH-pens: 5 m², cast-iron and concrete flooring) were compared regarding piglet losses and postpartum sow behaviour (all treatments) and reasons for piglet crushing and postpartum litter behaviour (LH and GH). One-hundred-and-three crushing events were analysed in eight batches concerning sows’ posture changes that crushed piglets and age of crushed piglets. Posture change frequency, amounts of single posture changes and total time spent in different body postures were evaluated for 41 sows (14 FC-sows, 13 LH-sows and 14 GH-sows) in six batches. Litter behaviour (location, active/inactive scoring, resting behaviour next to the sow) was analysed during sows’ posture changes and piglet crushing. Piglet mortality was higher in LH (25.6%) and GH (19.9%) compared to FC (12.3%) due to higher levels of piglet crushing. Most crushing occurred during the three days postpartum in LH (92.7%) and GH (83.9%). However, crushing patterns differed between LH (rolling: 68.2%; sit-to-lie: 18.2%; stand-to-lie: 11.4%) and GH (rolling: 38.2%; sit-to-lie: 30.9%; stand-to-lie: 16.4%) and varying piglet behaviour may be the cause for this. The postpartum period was characterized by inactivity of the sow and behavioural differences were rarely seen between systems.

While group housing (GH) is mandatory in the European Union for the greater part of pregnancy, single housing in farrowing crates (FCs) during lactation that restrict sows in most of their natural behaviour patterns is still practised on a large scale. Research is urgently needed to develop alternative farrowing systems that improve sows’ welfare. Therefore, sows in three different farrowing systems – pens with FC, loose housing (LH) pens and GH for six sows – were compared regarding the level of skin injuries and their active and resting behaviour. A skin injury score was assessed for 15 body parts of 102 sows in six batches on 3 days (days 1, 14 and 34). In total, the active and resting behaviour of 77 sows in six batches was examined on 3 days (days 18, 25 and 32) between 0700 h and 1900 h by means of a scan sampling method. The suckling behaviour and the level of cross-suckling were analysed in GH by means of direct observation in four batches during three 4-h sampling periods (days 17, 24 and 31). No significant differences were found in total skin injuries when the sows entered the systems (day 1), but GH sows showed significantly higher total skin injuries compared to FC and LH sows in the middle (day 14) and at the end (day 34) of the lactation period. A significant difference between FC and LH sows was never seen. Differences were found for the proportion of different body postures between the three systems. The odds for lying in lateral recumbency versus standing and sitting versus standing were significantly higher for FC and LH sows compared to GH sows. Additionally, sows were significantly more likely to be standing as opposed to lying in lateral recumbency as the lactation period progressed. Cross-suckling was a frequent behaviour in GH, seen in 35.0% of all successful suckling bouts. However, only an average of 0.56 piglets per successful suckling bout was observed cross-suckling, suggesting only a few piglets were engaged in cross-suckling. In conclusion, the skin injury score was only moderately increased in GH compared to FC and LH and comparable to pregnant group-housed sows, both free farrowing systems seemed to be an environmental enrichment for lactating sows and good management cannot prevent the occurrence of cross-suckling in a GH system, but can probably reduce it.

The aim of this study was to analyze the air quality in two different commercially available free-farrowing systems in comparison with a conventional farrowing crate system. A group housing system for six lactating sows (GH) and a single loose-housing system (LH) were tested against systems with farrowing crates (FC) under similar conditions. In eight evaluated batches with 148 farrowings, measurements were performed at the beginning, in the middle, and at the end of the occupancy period of 33 days. The mean dust concentration was significantly higher in GH than in LH and FC at the mid-point. The mean ammonia concentration was significantly higher in GH compared to LH and FC at the beginning of occupancy. The mean concentration of endotoxins was significantly higher in FC than in LH and GH at the end of occupancy. Furthermore, the systems did not differ significantly from each other. Spearman’s analysis revealed correlations between dust and time of occupancy, between ammonia and carbon dioxide, and between ammonia and the inside temperature and outside temperature. The new husbandry systems offer animals more opportunities to move without endangering animal welfare through deteriorated air hygiene.

Highlights Farrowing systems without confinement do not impair microbiological air quality. Single loose-housing system proved to be hygienically advantageous. Ventilation and hygiene routines can be kept when changing to free-farrowing systems.

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