Since the permanent fixation of pregnant sows is banned in Europe, it has become a matter of discussion as to whether the permanent fixation of lactating sows is still acceptable. A group-housing system for lactating sows offers the sows and their piglets the possibility to live in a more natural structure. The aim of this study was to compare sows from a group-housing system (GH; n = 80) with sows from a conventional single-housing system (SH; n = 64) with regard to health indicators and saliva cortisol levels. Data were collected in four batches with 20 GH sows and 16 SH sows per batch. All sows were moved one week before farrowing to the GH or the SH system, respectively. The nulliparous sows were housed separately from the multiparous sows during pregnancy. Thus, nulliparous and multiparous sows were unfamiliar when they moved to the GH system. The GH sows were housed in a group of ten sows and were separated into their individual free-farrowing pens from three days ante partum until six days post partum. A running area was shared by all sows and piglets. With regard to health indicators, the GH sows had fewer skin lesions of the udder and of the tail compared to the SH sows (p
