Use of an outdoor run by fattening pigs kept in large group housing systems with announced access through computer-controlled gates

• Published in: Applied animal behaviour science Vol. 277; p. 106345
• Main Authors: Höne, Ulrike, Schrader, Lars, Hölscher, Richard, Traulsen, Imke, Krause, E. Tobias
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.08.2024
• Subjects: Computer-controlled gates; Large groups; Outdoor run soiling; Outdoor runs; Pen soiling; Computer-controlled gates; Pen soiling; Large groups; Outdoor runs; Outdoor run soiling
• ISSN: 0168-1591; 1872-9045
• DOI: 10.1016/j.applanim.2024.106345

Access to outdoor runs for small groups of fattening pigs, particularly in organic farming systems, are applied in practice and has been the subject of several studies. Access to an outdoor run has been shown to improve the welfare of pigs. However, little is known about the use of outdoor runs in large groups of up to 450 pigs. The aim of this study was to examine the usage of an outdoor run with restricted access in such a large group housing system, which involved using an indoor ventilation system when outdoor run access was restricted. A total of 900 pigs kept in two large groups of 450 pigs each were observed during the fattening period. Access to the outdoor run was provided by computer-controlled gates programmed to open at regular intervals during the day between 7:00 a.m. and 6:00 p.m. Opening phases of the gates to the outdoor run were signalled by a visual-acoustic signal. Restriction to the outdoor run was only on the way out, while access from the outdoor run to the inside area was continuously available. In addition to investigating the usage of the outdoor run, we also examined whether the pigs reacted to the visual-acoustic signals indicating the opening of the gates and whether the opening phases caused crowding in front of the gates. Furthermore, we evaluated the soiling of both the indoor area and the outdoor run. In these large group housing systems, the fattening pigs used the outdoor run continuously during the day, despite the restricted access. On average, 13.6 % of the fattening pigs were present in the outdoor run. No crowding, i.e., exaggerated accumulation of pigs, was observed at the gates during the opening phases. The fattening pigs mainly soiled two areas: an outdoor area near the fence and an uncovered lying area inside the barn. Our results from two large groups of pigs revealed, for the first time, important insights into how such groups use outdoor runs and automated gates. •Despite limited access, fattening pigs used the outdoor run.•On average, 13.6 % of the fattening pigs were present in the outdoor run.•Announcing the opening and closing phases influenced the number of pigs in front of the gates.•Fattening pigs in a large group housing system created functional areas