High-fiber diets in pregnant sows: Digestive utilization and effects on the behavior of the animals

Twelve pregnant, multiparous saws were assigned during gestation to three d ietary treatments in a 3 x 3 Latin square design to evaluate the effect of increasing levels of crude fiber (CF): a conventional diet low in CF (L, 15 .8 MJ DE/kg of DM, 3.3% CF), a diet with a medium level of CF (M, 14.4 MJ D E/kg of DM, 10.6% CF), and a high-fiber diet (H, 12.9 MJ DE/kg of DM, 18.1% CF). The daily feed supply was adjusted to provide the same 33.4 MJ of dai ly digestible energy (2.4, 2.7, and 3.0 kg/d for diets L, M, and H, respect ively). Over the day, a shorter time standing was spent when sows received the H diet (291 min/d) compared with the L (363 min/d) and M diets (324 min /d). Duration of feeding was longer with the high-fiber diet. Mastication r epresented the main part of the feeding activity in sows fed the H diet (56 %) and was reduced with the M and L diets (40% and 25%, respectively). Feed ing rate increased when fiber level decreased (67, 120, and 152 g/min for t he H, M, and L diets, respectively). Feeding the fibrous diet reduced the i ncidence of nonfeeding oral behaviors. These results show that high-fiber d iets can reduce apparent feeding motivation of pregnant sows and, thus, imp rove the welfare of sows subjected to feed restriction.