The present work was undertaken to study the gastrointestinal effects of wheat and oat dietary fibre (DF) using 40-50 kg pigs cannulated in the terminal ileum. The variables studied were: chemical characteristics of the DF, ileal and faecal digestibility of nutrients and bulking properties of polysaccharides and other major constituents. The wheat products studied included refined wheat flour and wheat fractions rich in the following botanical components: aleurone, pericarp/testa and bran. The oat products used were rolled oats and oat bran. The products varied considerably in DF content (g/kg dry matter) and composition; non-starch polysaccharides (NSP) and Klason lignin content ranged from 34 and 1 g/kg respectively in wheat flour, to 465 and 92 g/kg in pericarp/testa. The main NSPs in the wheat were arabinoxylans (AX) (64-69%) and cellulose (15-31%) and in oats mixed linked beta(1----3; 1----4-D-glucans (beta-glucans; 46-63%) and AX (28-32%). The lowest content of soluble NSP was found in the lignified wheat fractions (bran and pericarp/testa) and the highest in oat bran. Eight diets were produced using the wheat and oat products and studied in two series of experiments using wheat flour as the DF-depleted control. The diets in Expt 1 were based on wheat flour and three iso-DF enriched diets prepared by adding DF from the fractions rich in wheat aleurone, pericarp/testa or bran. In Expt 2, oat bran was added to wheat flour to achieve the same DF intake level as in Expt 1. This series also included diets based on rolled oats and rolled oats plus oat bran. Starch was almost completely digested in the small intestine (0.97-1.00). However, there was a tendency to a slightly lower digestibility of oat starch compared with wheat starch. The recovery of wheat NSP in ileal digesta was 82-104% compared with 64-66% for oats. The low recovery of NSP in oat diets was primarily due to the low recovery of beta-glucans (25-36%). In the large intestine NSP and starch residues were extensively degraded. For the DF-depleted control diets or diets based on oats, 8-17% NSP survived breakdown while in the diets enriched with aleurone, pericarp/testa or bran fractions, NSP recovery was 33, 50 and 38% respectively. Fermentative breakdown of carbohydrates in the large intestine was estimated to contribute between 10 and 24% of the energy for maintenance. Energy derived from the inflow of organic acids from the ileum contributed an additional 1-4% of maintenance energy.(ABSTRACT TRUNCATED AT 400 WORDS)

/pdf/gastrointestinal-implications-in-pigs-of-wheat-and-oat-pex7kf4pmh.pdf

Gastrointestinal implications in pigs of wheat and oat fractions. 1. Digestibility and bulking properties of polysaccharides and other major constituents.

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 fistulated 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 theDF 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 5-6-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 29 MJ/pig per d

/pdf/the-influence-of-dietary-fibre-and-environmental-temperature-ucltl44efj.pdf

The influence of dietary fibre and environmental temperature on the development of the gastrointestinal tract, digestibility, degree of fermentation in the hind-gut and energy metabolism in pigs

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 (2.5-fold) 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 (0.0014 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. H2 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% (oat bran) and 96% (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 ME intake the NSP fermentation contributed 3-4%. With increasing fibre intake the partitioning of retained energy between body protein and body fat changed in favour of protein.

/pdf/the-influence-of-dietary-fibre-source-and-level-on-the-c7m024zuml.pdf

The influence of dietary fibre source and level on the development of the gastrointestinal tract, digestibility and energy metabolism in broiler chickens.

An experiment was conducted in which the metabolic utilization of energy was measured in individually penned pigs from seven groups that differed in genotype and(or) sex and ranged in body weight between 20 and 107 kg. The animals were fed a diet containing, on a DM basis, 14.7 MJ ME and at least 21% CP. Heat production was measured in an open-circuit calorimeter, and energy, nitrogen, and fat balances were determined at regular intervals over the growing period; a total of 177 measurements were performed. Body composition of the animals was measured by serial slaughter, and these data were used for estimating the body composition of an animal at a given weight through allometric regression. A factorial analysis procedure was used to estimate the utilization of ME by regressing the ME intake on the observed protein and lipid deposition rates. The intercept of this equation is the maintenance energy requirement (MEm) and was represented either as a function of body weight with group-specific parameters (MEm = a(i) BWb) or as a function of the muscle and visceral mass with an additional additive group effect (MEm = aM muscle(b) + a(v) viscera(b) + G(i)). With BW as dependent variable, the exponent b was close to .60 and differed significantly from .75. The regression coefficient (a(i)) averaged 1.02 MJ ME/kg.60 but it was different for most groups, indicating that different groups of animals have different maintenance requirements. Fixing the exponent to .75 consistently underestimated the maintenance requirement. When the exponent b was not fixed to .75 but estimated, the partial efficiencies for protein and lipid deposition were .62 and .84, respectively. Body muscle and visceral mass could explain a large part of the variation in MEm. Viscera contributed three times more to MEm (per kilogram of mass raised to the .70 power) than did muscle. Even though the muscle mass exceeds to a large extent the visceral mass in animals, the contribution of muscle to MEm was lower than that of viscera for most groups.

Metabolic utilization of energy and maintenance requirements in growing pigs: effects of sex and genotype.

The mucous layer that covers the intestinal absorptive surface acts as a barrier against bacterial translocation. The chicken gut contains a diverse bacterial population which interacts with the mucous layer. In this report, we studied the effect of changing the intestinal microbial populations on mucin dynamics by feeding 1-d-old chicks a control diet or that diet containing either antibiotic growth promoter (AGP) or a probiotic product for 14 d. Dietary AGP increased the proportions of Bifidobacterium species in the duodenum compared with the other groups. In AGP-fed chicks, the villous surface area was increased in the jejunum, goblet cell density was greater in the jejunum and ileum, and mucin glycoprotein levels in the duodenum were lower than in the other groups (P < 0.05). Feeding AGP increased the expression of mucin mRNA in the jejunum and ileum compared with controls. The dietary probiotic increased the proportion of Lactobacillus species in the ileum compared with the controls (P < 0.05) and significantly enlarged the goblet cell "cup" area throughout the small intestine compared with the other groups. Expression of mucin mRNA and the levels of mucin glycoprotein were greater in the jejunum of the probiotic-fed chicks compared with controls (P < 0.05). Neither the probiotic nor AGP treatments affected the thickness of the mucous adherent layer. These results indicate that both probiotic and AGP altered processes of mucin biosynthesis and/or degradation mediated via changes in the intestinal bacterial populations. These modifications in mucin dynamics influence gut function and health and may change nutrient uptake.

/pdf/mucin-dynamics-and-microbial-populations-in-chicken-small-3o1im6pu6c.pdf

Mucin Dynamics and Microbial Populations in Chicken Small Intestine Are Changed by Dietary Probiotic and Antibiotic Growth Promoter Supplementation

Zusammenfassung

Die Oxidation von Nahrstoffen und Retention von Kohlenhydraten, Protein und Fett hei wachsenden Schweinen



Die Oxidation von Nahrstoffen sowie deren Beitrag zur Fettretention wurde an Hand von 185 individuellen Bilanzstudien mit wachsenden Schweinen (40–100 kg Lebendgewicht) beurteilt. Der Respirationskoeffizient ohne Berucksichtigung des Proteins (RQnp) lag entweder unter oder uber 1. Die beschriebene Methode basierend auf Gasaustausch sowie Kohlenstoff-Stickstoffbilanz zur Berechnung der Oxidation von Nahrstoffen und Lipogenese ist in beiden Fallen gultig (RQnp > 1 und RQnp < 1).



Bei einer den Wachstumsbedarf deckenden Energiezufuhr (ME ≥ 1,2 MJ/kg0.75) ist die Oxidation von Nahrstoffen im Bezug auf die Proteinretention abhangig von der Menge und Qualitat des verdauten Proteins. Weiterhin besteht eine Abhangigkeit von der Menge an verdaulichen Kohlenhydraten. Die Versorgung mit Fett spielt dagegen keine Rolle. Die Oxidation von Kohlenhydraten tragt mit 85%, die von Protein mit 15% zur anfallenden Warmeenergie bei. Eine Fettoxidation findet auch bei hohem Fettgehalt der Nahrung nicht statt. Die Lipogenese aus Kohlenhydraten stellt die Hauptquelle fur die Korperfettretention dar. Da keine Fettoxidation stattfindet, wird das gesamte Nahrungsfett im Korper reteniert.



Bei einer fur das Wachstum zu geringen Energiezufuhr werden Nahrungsfett und Korperfett oxidiert. Um Protein fur die Retention zu erhalten, ist die Oxidation von Protein vermindert. Selbst bei Mobilisierung von Korperfett und Oxidation von Nahrungsfett wird ein Teil der Kohlenhydrate und des Proteins fur die Lipogenese vermutlich zum Aufbau von Strukturfett verwendet.

Estimation of quantitative oxidation and fat retention from carbohydrate, protein and fat in growing pigs

1. Balance trials with respiration measurements were performed with twelve rats and twelve pigs given either low- or high-crude-fibre diets. There were six collection periods with the rats over a live-weight range of 86-264 g and three collection periods with the pigs over a live-weight range of 30-55 kg. Measurements were made on the influence of microbial activity in the digestive tract on digestibility and nitrogen and energy metabolism. Dietary inclusion of the antibiotic Nebacitin was the method used to reduce the microbial population. 2. The microbial activity in the hind-gut (mumol ATP/g air-dry contents) of antibiotic-treated rats was reduced to approximately one-tenth of that of untreated rats. 3. Live-weight gain was not significantly affected in either species by a reduction in the microbial activity, in spite of a reduction in dry matter digestibility in animals with reduced microflora. 4. For rats on low-crude-fibre diets, a reduction in microflora reduced digestibility of all nutrients and energy and metabolizability of digestible energy by approximately 5.4%. All differences were highly significant. On high-crude-fibre diets the decrease was approximately 5.9%. In pigs on both crude fibre levels, the digestibility was also influenced by the level of microflora, but the pattern was somewhat different from that obtained with rats, with the Nebacitin treatment increasing the digestibility of N slightly, and the digestibility of fat markedly. 5. Retained N in rats reached a maximum when the rats were approximately 60 d old and thereafter decreased with increasing age. However, for pigs daily N retention increased with age. The retained N: digested N value decreased linearly with age in the rats, but varied little with age over the range (104-146 d) studied in the pigs. 6. The metabolizability of gross energy (metabolizable energy (ME): gross energy) was significantly reduced with an increase in crude fibre level and by the addition of Nebacitin. 7. Retained energy (RE) in relation to ME (RE:ME), was not significantly affected either by level of microbial activity or by crude fibre. 8. The ratio, RE as fat (RF): RE as protein (RP) increased as the animals grew. In the rat experiment there was a tendency for RP to be higher for animals with normal microflora than for animals with reduced microflora for both crude fibre levels. 9. With rats, the regression analyses indicated that the energy requirement for maintenance could be influenced by both the level of microbial activity in the digestive tract and by the level of fibre in the diet. The net availability of ME for maintenance and growth by rats averaged 0.72 for all treatments. 10. The net availability of ME for growth in the pigs averaged 0.65 for all treatments.

/pdf/influence-of-diet-and-microbial-activity-in-the-digestive-58ey2wwbol.pdf

Influence of diet and microbial activity in the digestive tract on digestibility, and nitrogen and energy metabolism in rats and pigs

Heat production in growing pigs calculated according to the RQ and CN methods

Energy metabolism in eight adult mink, fed different protein-energy proportions (18, 34,61%), feeding levels (150, 200, 250 g feed/d) and kept at different temperatures (20, 10, 0°C), was measured in 62 respiration experiments. Carbon dioxide production and oxygen consumption in relation to metabolic weight (kg 0.75 ) increased by about 40% when the temperature decreased from 20 to 0°C. Metabolizable energy (ME) was about 80% of gross energy (GE) for mixtures A (18% protein-energy) and B (34%) and was found to be independent of feeding levels. ME decreased to 72% for mixture C (61%) which was caused by a lower digestibility of the energy. ME was found to be independent of temperature for mixture B (34%). Retained energy (RE) was dependent on protein level, being highest for mixture B (34%) on all feeding levels, and on temperature, decreasing from 311 kJ at 20°C to −324 kJ at 0°C for mixture B (34%). The maintenance requirement based on 33 measurements with positive energy balance in the thermoneutral zone (20°C) was estimated as:

Energy metabolism in adult mink in relation to protein-energy levels and environmental temperature

Zusammenfassung

Energieumsatz von Schweinen im Gewichtsbereich von 20 bis 120 kg



1
Im Lebendmassebereich von 20 bis 120 kg wurde an insgesamt 27 Schweinen, aufgeteilt auf zwei Gruppen mit unterschiedlicher Futterungsintensitat, der Energieumsatz in jeweils sechs eng begrenzten Gewichtsabschnitten untersucht. Die Messungen wurden nach der Methode der indirekten Kalorimetrie in einer nach dem offenen System arbeitenden Respirationsanlage durchgefuhrt. Die Untersuchungen umfasten insgesamt 110 Bilanzversuche, wobei die Tiere nicht ununterbrochen bei eingeschrankter Bewegungsfreiheit gehalten wurden.

2
Eine lineare Regression, abgeleitet fur jede einzelne Gewichtsgruppe, zeigte, das mit dem Anstieg der Lebendmasse von 20 auf 120 kg der Erhaltungsbedarf an umsetzbarer Energie (MEm von 630 auf 440 kJ/kg0.75 sank.

3
Eine lineare Regression von MEm/d auf das metabolische Korpergewicht ergab folgende Gleichung: ME, kJ = 3143 + 359 kg0.75 mit einem hochsignifikanten Intercept. Hieraus geht hervor, das eine Proportionalitat zwischen MEm und dem metabolischen Korpergewicht iber eine langere Wachstumsperiode nicht gegeben ist.

4
Die Gleichung fur MEm in Fitterungsversuchen mit Schweinen liegt 10 bis 25% uber der Gleichung, die in Hungerversuchen gefunden wurde.

5
Eine multiple Regression mit drei Variablen ergab folgende Gleichung: ME, kJ = 2015 + 345 kg0.75 + 1.82 RPE + 1.16 RFE. Wegen der hohen Signifikanz des Interceptes ist es nicht zulassig, das Modell einer Regressionsgeraden durch den Ursprung zu wahlen. Deshalb kann auch keine biologische Interpretation vorgenommen werden.

6
Eine multiple Regression von ME auf RPE und RFE ergab eine parallele Regression mit b1 = 1.48 und b2 = 1.33 was kp = 0.68 und kf = 0,75 entspricht. An Hand der verschiedenen Intercepte, aus denen MEm fur die betreffenden Gruppen abzuleiten ist, wurde festgestellt, das MEm/kg0.75 bei steigendem Korpergewicht von 631 auf 435 kJ herabsank.

S. Henckel

Papers

Estimation of quantitative oxidation and fat retention from carbohydrate, protein and fat in growing pigs

Influence of diet and microbial activity in the digestive tract on digestibility, and nitrogen and energy metabolism in rats and pigs

Heat production in growing pigs calculated according to the RQ and CN methods

Energy metabolism in adult mink in relation to protein-energy levels and environmental temperature

Energetics of growth in pigs from 20 to 120 kg live weight.