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.

Background The conventional farrowing crate is criticised due to the limited mobility of sows during farrowing and lactation. The present study aims to investigate the effects of three different farrowing systems on the performance of suckling neonates on the basis of immunocrit (IC; a quantification of immunoglobulins), serum amino acid (AA) concentrations and growth performance. Methods From a total of 149 sows placed in three housing systems (farrowing crate – FC, loose housing – LH, group housing – GH), 18 sows and their respective litters, formed the basis for a two-factorial study design (farrowing system and body weight (BW) of neonates). Therefore, also blood samples of two light (1.0–1.4 kg) and two heavy (≥ 1.4 kg) piglets were taken within 48 h post natum (p.n.) and on the day of weaning (day 26) to determine the immunocrit (IC; a quantification of immunoglobulins) and levels of serum AAs. Results The IC (FC: 0.148 a , LH: 0.153 a , GH: 0.117 b ) as well as serum levels of arginine, leucine, lysine, proline and threonine within 48 h p.n. were significantly lower in GH. Additionally, in general, these piglets showed (except for the first week of life) the lowest average daily weight gain. On the day of weaning, piglets in GH had the lowest levels of arginine (in mg/dL; FC: 3.68 a , LH: 3.40 ab , GH: 2.94 b ) and threonine (in mg/dL; FC: 3.59 a , LH: 3.02 ab , GH: 2.49 b ). The concentrations of leucine, lysine, proline and valine at this time were significantly lower in LH. Conclusion The observed significant lower IC indicates a lower Ig intake of piglets in the tested GH. No significant differences regarding the IC and AA levels within 48 h p.n. of the piglets in FC and LH could be seen. In principle, differences at weaning in AA levels were rather small, although the body weight of GH piglets at weaning was lower. Therefore, further research needs to clarify whether there are medium-term effects on health and performance. Electronic supplementary material The online version of this article (10.1186/s40813-019-0121-1) contains supplementary material, which is available to authorized users.