The three housing systems to be evaluated as alternatives to the reference system in each split were presented in randomized order. Evaluation of the reference system and the acceptability of the three alternative housing systems on a 7-point Likert scale from 1 = completely disagree, 4 = partly/partly, 7 = totally agree. Source: a) Free-range: Bildagentur Landpixel (1 & 2), Verein Happy Pigs & Friends; b) Outdoor run: ÖKL-Baupreis 2012, www.oekl-bauen.at, Rudolf Wiedmann, Stephan Fritzsche, KTBL; c) Indoor straw: DVS, Ella Martin, Bildagentur Landpixel; d) Indoor: Bildagentur Landpixel, Jana Denecke, Tierhaltung modern und transparent e.V.