The effect of feeding sows a starch diet or a diet with a high level of fermentable non-starch polysaccharides (NSP) during gestation, lactation or both gestation and lactation over the first two parities on the development of stereotypic behaviour was studied in sows housed in groups during gestation and individually during lactation. A total of 119 postpubertal gilts were allotted to a 2 x 2 factorial experiment. Treatments were diet composition during gestation (G-Starch: 274 g/kg starch and 123 g/kg fermentable NSP or G-NSP: 86 g/kg starch and 300 g/kg fermentable NSP) and diet composition during lactation (L-Starch: 293 g/kg starch and 113 g/kg fermentable NSP or L-NSP: 189 g/kg starch and 216 g/kg fermentable NSP). Sows on both gestation diets were fed iso-energetic. During lactation, sows were given free access to the lactation diets. Behavioural measurements were carried out in weeks 3, 12 and 15 after start of the experiment or after weaning in parity 1 and 2 sows, respectively, 3 days before the expected date of parturition and 1 week before weaning in the first 3 h after the morning meal using a scan-sampling technique. Feeding group-housed sows a diet high in fermentable NSP during gestation reduced the frequency of total non-feeding oral activities (=sham chewing + other non-feeding oral activities) in gestation compared with a starch diet (P < 0.001 and <0.05, in parities 1 and 2, respectively). In both parity 1 and 2 sows, the greatest reduction was realised in week 15 and the smallest reduction in week 3. During lactation, the composition of the gestation diet did not affect the frequency of total non-feeding oral activities. Feeding sows a diet high in fermentable NSP during lactation reduced the frequency of total non-feeding oral activities in lactation in parity 2 sows (P < 0.05) but not in parity 1 sows compared with a starch diet. Moreover, it tended to reduce, although not statistically significant (P = 0.15), the frequency of total non-feeding oral activities during subsequent gestation. This study shows that diets high in fermentable NSP during gestation reduce the level of stereotypic behaviour in gestation. It seems that diets high in fermentable NSP during lactation may have an additional reducing effect on the development of stereotypic behaviour in subsequent gestation. (C) 2003 Elsevier Science B.V. All rights reserved.
