The present study was undertaken to provide detailed information about the effect of dietary fibre (DF) level on the development of the digestive tract, on nutrient digestibility and on energy and protein metabolism of pigs housed in low (13') or high (23") thermal environments. Low-and high-fibre diets (59 v. 268 g DF/kg DM) were studied in three balance periods with fktulated pigs in the weight range 45-120 kg. Heat production was measured using open-circuit respiration chambers. Pea fibre and pectin were used to adjust the D F level in the high-fibre diet. Per kg empty body weight the stomach, caecum and colon and the length of colon were significantly greater in pigs consuming the high-fibre diet than in those on the low-fibre diet. Pigs kept at low temperature had significantly heavier caecums than those kept at the high temperature. Digestibilities of protein, DM and energy were lowest for the high-fibre diet. Only minor amounts of NSP and its constituent sugars were degraded anterior to the ileum, whereas in the hind-gut the fermentation of the total NSP fraction was high, being 0.77 for the high-fibre diet and 0.59 for the low-fibre diet. Feeding the high-fibre diet increased the flow of digesta through the terminal ileum %-fold and an extra 460 g organic matter was fermented daily in the hind-gut compared with pigs fed on the low-fibre diet. The amount of retained energy as a proportion of metabolizable energy decreased in relation to the amount of energy fermented in the hind-gut. Based on the present data it was estimated that the relative value of energy derived from hind-gut fermentation was 0.73 in comparison with energy enzymically digested in the small intestine. There was negligible effect of the temperature -fibre interaction on energy metabolism. However, it could be calculated that the decrease in temperature from 23" to 13" was associated with an increase in heat production by 2.9 MJ/pig per d.

The present study was undertaken to provide detailed information about the effect of fibre source (pea fibre, wheat bran or oat bran) at inclusion levels of 0,187 and 375 g/kg diet on the development of the digestive tract, nutrient digestibility and energy and protein metabolism in broiler chickens. Heat production was measured using open-air-circuit respiration chambers. Diets with increasing levels of pea fibre decreased the DM in droppings and increased excreta output (25fold) relative to DM intake. Adaptation to increased dietary fibre levels included increases in the size of the digestive system, with pea fibre exerting a stronger impact than wheat bran or oat bran. The length of the intestine, and particularly the length and weight of the caecum, increased with the fibre level. The digestibility of all nutrients also decreased with increasing fibre level. The decrease in the digestibility in relation to NSP for the three fibre sources was bigger for oat bran (0.0020 per g dietary NSP) than for pea fibre and wheat bran (04014 and 0.0016 per g dietary NSP) indicating that the cell walls in oat bran (aleurone and subaleurone) had a significant negative effect on the digestibility of cellular nutrients, i.e. protein and fat. The degradation of the NSP constituents was far lower in chickens than found in other animal species such as pigs and rats, thus supporting the view that chickens do not ferment fibre polymers to a great extent. Excretion of organic acids (mainly lactic acid and acetic acid) accounted for up to 2% of metabolizable energy (ME) intake with the highest excretion for the high-fibre diets. H, excretion was related to the amount of NSP degraded and indicated higher microbial fermentation with increasing fibre levels. The chickens' feed intake responded to a great extent to dietary ME concentration but expressed in terms of metabolic body size (W0'75) ME intake was depressed at the high fibre levels. Dietary NSP was able to explain between 86 YO (oat bran) and 96 YO (pea fibre) of the variation in ME concentration.The amount of energy available from fermentation of NSP appears to reach a maximum of 42 kJ/d independent of fibre source and level. Expressed in relation to M E intake the NSP fermentation contributed 3-4 YO. With increasing fibre intake the partitioning of retained energy between body protein and body fat changed in favour of protein.Gutfill: Heat increment: Non-starch polysaccharides: FermentationThe feed ingredients used in poultry diets are mostly of vegetable origin. Plant materials are rich sources of carbohydrates, i.e. low-molecular-weight sugars, starch and NSP, the latter being resistant to digestive enzymes. However, the NSP fraction can, to a certain degree, be broken down by the microbial flora permanently colonizing the gastrointestinal (GI) tract. The end-products of the microbial degradation are various gases (H2, CO,, CH,), lactic acid and short-chain fatty acids (SCFA). The SCFA produced are rapidly absorbed * For reprints.-f Visiting scientist from the Northwest Pla...

Sauln, W. C., JoncENseN A method for measuring protein digestibility of small feed samples was developed with growing pigs fitted with a single cannula in the duodenum. Feed was ground through a 0.8-mm mesh screen and 1-g samples were enclosed in 25 x 40-mm monofilament nylon bags (50-pm mesh). Following pre-digestion in vitro to simulate gastric digestion (0.01 N HCI; pepsin I glL 2.5 h), the bags were inserted into the small intestine vra the duodenal cannula. recovered in feces within 48 h. frozen, lyophilized and analyzed for protein. Apparent

Aims: Postprandial triglyceridaemia is a risk factor for cardiovascular disease (CVD). This study investigated the effects of steady-state liraglutide 1.8 mg versus placebo on postprandial plasma lipid concentrations after 3 weeks of treatment in patients with type 2 diabetes mellitus (T2DM). Methods:In a cross-over trial, patients with T2DM (n = 20, 18-75 years, BMI 18.5-40 kg/m 2 ) were randomized to once-daily subcutaneous liraglutide (weekly dose escalation from 0.6 to 1.8 mg) and placebo. After each 3-week period, a standardized fat-rich meal was provided, and the effects of liraglutide on triglyceride (primary endpoint AUC 0-8h ), apolipoprotein B48, non-esterified fatty acids, glycaemic responses and gastric emptying were assessed. ClinicalTrials.gov ID: NCT00993304. Funding: Novo Nordisk A/S.

The microbial activity, composition of the gas phase, and gas production rates in the gastrointestinal tract of pigs fed either a lowor a high-fiber diet were investigated. Dense populations of culturable anaerobic bacteria, high ATP concentrations, and high adenylate energy charges were found for the last third of the small intestine, indicating that substantial microbial activity takes place in that portion of the gut. The highest microbial activity (highest bacterium counts, highest ATP concentration, high adenylate energy charge, and low pH) was found in the cecum and proximal colon. Greater microbial activity was found in the stomach and all segments of the hindgut in the pigs fed the high-fiber diet than in the pigs fed the low-fiber diet. Considerable amounts of 02 were found in the stomach (around 5%), while the content of 02 in gas samples taken from all other parts of the gastrointestinal tract was <1%. The highest concentrations and highest production rates for H2 were found in the last third of the small intestine. No methane could be detected in the stomach or the small intestine. The rate of production and concentration of methane in the cecum and the proximal colon were low, followed by a steady increase in the successive segments of the hindgut. A very good correlation between in vivo and in vitro measurements of methane production was found. The amount of CH4 produced by pigs fed the low-fiber diet was 1.4 liters/day per animal. Substantially larger amounts of CH4 were produced by pigs fed the high-fiber diet (12.5 liters/day). Also, the daily rate of CO2 production in the gut was higher for the pigs fed the high-fiber diet than for the pigs fed the low-fiber diet (212 versus 46 liters/day). Although the highest microbial activity was found in the cecum and proximal colon and although hydrogen production is an obligate part of anaerobic fermentation in the hindgut, only small net amounts of hydrogen were produced in these segments. Furthermore, only small amounts of methane were produced in the cecum and proximal colon. This strongly indicates that hydrogen sinks other than methane production are involved in hydrogen removal in the cecum and proximal colon of pigs. The gastrointestinal tract of pigs contains a large and diverse microbial population, with cell population densities in excess of 1010 cells per g of gut content in the large intestine, the vast

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The present investigation was undertaken to study the gastrointestinal and physiologic properties of diets based on soft and crisp wheat and rye breads similar in dietary fiber (DF; 230-235 g/kg dry matter) but with different proportions of the main DF polymers: in wheat, cellulose, and in rye, arabinoxylans (AX). The 2 diets provided all macronutrients; consequently, they had lower fat and sugar contents and a higher DF content than human mixed diets. The nutritional properties were studied in experiments in which pigs with cannulated ilea and catheterized portal veins and mesenteric arteries served as models for humans. The characteristics studied were degradation of nutrients, flow at the ileum, fecal output, absorption of nutrients deriving from the assimilation of cereal carbohydrates, and the insulin response. Apparent viscosity at the terminal small intestine, the ileal flow of water, flow and digestibility of noncarbohydrate constituents, but not of carbohydrates at the terminal ileum or the plasma concentrations of glucose and insulin, were higher when pigs consumed the rye compared with the wheat diet. The 2 diets provided approximately equal amounts of carbohydrates available for fermentation in the large intestine but because AX from the rye diet was more degradable than cellulose from the wheat diet, the quantitative degradation in the large intestine was more than twice as high when pigs consumed the former compared with the latter diet. The consequences included moister feces and significantly enhanced gut production and plasma concentrations of butyrate when pigs consumed the rye diet compared with the wheat diet.

Three experimental diets were used to investigate the digestion of carbohydrates and utilization of energy in sows fed diets with different levels and physicochemical properties of dietary fiber (DF). The low-fiber diet (LF; DF, 16%; soluble DF, 4.8%) was based on wheat and barley. The high-fiber 1 diet (HF1; DF, 41%; soluble DF, 11%) was based on wheat and barley supplemented with the coproducts: sugar beet pulp, potato pulp, and pectin residue, and the high-fiber 2 diet (HF2; DF, 44%; soluble DF, 7.3%) was based on wheat and barley supplemented with approximately 1/3 of the coproducts used in diet HF1 and 2/3 of brewers spent grain, seed residue, and pea hull (1:1:1, respectively). The diets were studied in 2 series of experiments. In Exp. 1, the digestibility and ileal and fecal flow of nutrients were studied in 6 ileal-cannulated sows placed in metabolic cages designed as a repeated 3 x 3 Latin square design. In Exp. 2, energy metabolism was measured in respiration chambers using 6 sows in a repeated 3 x 3 Latin square design. The DF level influenced the ileal flow of most nutrients, in particular carbohydrates, which increased from 190 g/d when feeding the LF diet to 538 to 539 g/d when feeding the HF diets; this was also reflected in the digestibility of OM and carbohydrates (P < 0.05). The ranking of total excretion of fecal materials was HF2 > > HF1 > LF, which also was reflected in the digestibility of OM, protein, and carbohydrates. Feeding HF diets resulted in greater CH(4) production, which was related to the amount of carbohydrates (r = 0.79) and OM (r = 0.72) fermented in the large intestine, but with no difference in heat production (12.2 to 13.1 MJ/kg of DM). Retained energy (MJ/kg of DM) was decreased when feeding HF1 compared with LF and negative when feeding HF2. Feeding sows HF1 reduced the activity of animals (5.1 h/24 h) compared with LF (6.1 h/24 h; P = 0.045).