Influence of the nature of dietary fibre on digestive utilization, some metabolite and hormone profiles and the behaviour of pregnant sows

Three diets were formulated according to the nature of the fibrous componen ts: a concentrate low fibre diet enriched in starch (diet S, neutral-deterg ent fibre (NDF) proportionately 0.078 of dry matter (DM)) and two high-fibr e diets enriched in either sugar-beet pulp (diet BP, NDF = 0.219 of DM) or wheat bran (diet WE, NDF = 0.187 of DM). In a first experiment, the digesti bility of nutrients in these diets were determined using dry sows. In a sec ond experiment, 24 multiparous Large White sows were offered the experiment al diets in a 3 x 3 Latin-square design during three 21-day periods over pr egnancy in order to evaluate physiological and behavioural effects over the nycthemeral period. On the basis of the first experiment, the daily food s upply was adjusted to 2.44, 2.74 and 290 kg/day for diets S, BP and WE, res pectively, to provide the same amount of metabolizable energy to each treat ment. In the hour prior to the meal, the diet effect was nil on plasma leve ls of glucose, insulin, glucagon and non-esterified fatty acid and limited on cortisol plasma level. After the food delivery, the peak responses of gl ucose and insulin to the meal were delayed in sows given the BP diet, while their level showed a higher increase for S than for WE and BP diets. Sows offered diet BP spent less time standing than sows offered diet S. The occu rrence of nonfeeding oval activities over the 45 min following food distrib ution was significantly reduced with fibrous diets. But nb difference appea red during the 45-min period following the end of each meal. It was conclud ed that the incorporation of beet pulp in the diet was more effective than wheat bran in extending the feeding activity and the absorption of nutrient s. The diet effect was limited to the 2 h after the food delivery for these sows given a restricted amount of food.