STEREOTYPIES IN PREGNANT SOWS - INDICATIONS OF INFLUENCE OF THE HOUSING SYSTEM ON THE PATTERNS EXPRESSED BY THE ANIMALS

Patterns of stereotypy were observed in pregnant sows maintained in di fferent housing systems in commercial farms, Comparisons were made amo ng females of the same genotype: stalls vs. tethers for Large White (r espectively 124 and 68 sows) and stalls vs. group-housed for Large Whi te/Landrace crosses (respectively 81 and 71 sows) for two farms in eac h case, The patterns of stereotypy were observed for 1 h after food di stribution. The proportion of sows developing stereotypies did not dif fer between stall-housed and tethered females (89.5 vs, 94.1%), but wa s lower in group-housed compared with stall-housed sows (66.2 vs. 92.6 %). The stereotypies presented by tethered sows were predominantly lic king and rubbing, whereas in stalls or group-housed, they were most fr equently biting and vacuum oral activities. The function of stereotypi es, the effect of the environment and the origin of the heterogeneity of the patterns displayed are discussed.