In the European Union, animal welfare legislation (European Council, 2001) imposes the provision of bulky or high-fibre (HF) diets to pregnant sows to improve sow welfare. Such practices intend to fulfill feeding motivation in sows by increasing the daily feed allowance without increasing the energy intake during gestation, and thus avoiding overweight at farrowing which can be detrimental for piglets’ survival (Dourmad et al., 1994). Many studies have highlighted the beneficial effects of fibrous components in the gestation diet or through the litter on sow welfare (Meunier-Salaün et al., 2001). Dietary fibres are also known to reduce sow digestive disorders such as constipation (Wenk, 2001; Tabeling et al., 2003) as well as excessive body fatness at farrowing, that has been shown to lead to longer parturition length and increased piglet losses (Bilkei Papp, 1990). Approximately 75% of the 8% of stillborn piglets generally reported in usual rearing conditions die during parturition (Van Dijk et al., 2005), mainly as a result of asphyxia (Van Rens and Van Der Lende, 2004). Last-born piglets are more likely to suffer from asphyxia resulting from the cumulative effects of successive contractions or from a rupture of umbilical cord as parturition progresses (Randall, 1971 and 1972; Herpin et al., 1996). The aim of this study was to investigate the impact of feeding a high-fibre (HF) diet during gestation on parturition progress and reproductive performance of sows. Forty-two primiparous sows (Large-White3Landrace crossbred) were fed during gestation either a control diet (C diet; 2.40 kg/day, 3.2% crude fibre, in % of dry matter (DM)), or a HF diet (2.80 kg/day, 12.4% crude fibre, in % of DM). All sows received 33MJ digestible energy per day. Continuous video recordings were done on the parturition day to determine postural changes (standing, sitting, lying) and behavioural activities (nesting behaviour, uterine contractions, restlessness, social behaviour towards piglets) during parturition. Duration of parturition and individual birth intervals were also measured. Piglets’ growth was evaluated by weekly weighing from birth until weaning, at
26.5 days of age. Sows were weighed and backfat thickness was measured at mating, on day 105 of gestation, on the 1st day post partum, and at weaning. Durations of parturition and of birth intervals were not affected by the gestation diet and averaged 211 ± 12 min and 16.5 ± 0.9 min (mean ± s.e.), respectively. During the parturition progress, the gestation diet did not affect the frequency and the time devoted to postural and behavioural activities. Dietary treatment during gestation did not influence duration of gestation and weaning-to-oestrus interval, as well as litter size, and number of stillborn and weaned piglets. Piglet weight at birth did not differ between gestation dietary treatments but piglets nursed by HF sows showed a 13.5% greater growth rate during the 1st week of life (P<0.01) and tended to be heavier at weaning (P=0.06) compared with C piglets. The HF sows were leaner at the end of gestation (P<0.05), but variations of sows’ weight during gestation and lactation were not affected by the gestation diet. All sows lost the same amount of backfat thickness during lactation. During lactation, the average daily feed intake was not significantly affected by the gestation diet. This study shows that substituting a control diet for a HF diet during gestation has limited effects on farrowing progress and reproductive performance, but improved piglets’ growth rate during the 1st week of life and tended to increase their live weight at weaning.