bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digestion of polysaccharides, protein and lipids by adult cockerels fed on diets containing a pectic cell-wall material from white lupin (Lupinus albus L.) cotyledon
Authors: Carré B. , Leclercq B. 
Published: September 2005

1. The cell-wall material of white lupin (Lupinus albus L.) cotyledon is characterized by low contents of cellulose (47 g/kg) and lignin (17 g/kg) and a high content of pectic substances (710 g/kg). The digestion of lupin cell-wall material by adult cockerels was estimated using gas-liquid chromatographic analyses of alditol acetates derived from polysaccharide sugars. The analyses were performed in the destarched water-insoluble fractions of feed and excreta. Digestibility measurements were carried out using a 3 d balance period including a 2 d feeding period and a 24 h final starvation period.2. In the first experiment, six animals were given a diet containing 510 g white lupin cotyledon flour/kg which was the only source of protein and cell walls in the diet. The apparent digestibility of cell-wall components was near zero.3. In the second experiment, three diets were prepared by diluting a fibre-free basal diet (diet A) by a semi-purified cell-wall preparation introduced at two different levels: 100 g/kg (diet B) and 200 g/kg (diet C). The semi-purified cell walls were prepared from the white lupin cotyledon flour used in the first experiment. The true digestibilities of polysaccharides measured in birds given diets B and C were near zero. It is suggested that the measurement of the neutral-detergent fibre (NDF) content according to Van Soest & Wine (1967) is not a suitable procedure for estimating the undigestible fibre content in poultry nutrition as the cell-wall pectic substances are not included in the NDF measurement.4. Addition of the semi-purified cell-wall preparation (Expt 2) resulted in a slight decrease in the apparent protein digestibility. This decrease might be explained by the addition of undigestible cell-wall protein.5. Addition of the semi-purified cell-wall preparation (Expt 2) had no effect on the apparent lipid digestibility.6. The metabolizable energy values of the basal diet fraction of diets B and C were calculated assuming that the added plant cell-wall fraction was of no energy value. These calculated values were similar to the measured metabolizable energy value of diet A (basal). Thus, the tested pectic plant cell walls seemed to act as a diluent. It is suggested that, on the point of the digestion yields, all types of plant cell walls would act as diluents, in poultry.
Effects of supplemental dietary energy on leucine metabolism in sheep
Authors: STEVEN Nissen , PIOTR Ostaszewski 
Published: September 2005

1. Mixed-breed wethers (40–50 kg), 9 months old, were maintained on high-energy (HED) and low-energy (LED) diets for 2 weeks.2. After a 15 h fast, a primed-dose constant infusion of L-[U-14C]leucine and α-[4,5-3H]ketoisocaproate (KIC) was given.3. After 2 h, plasma samples were taken and plasma-specific radioactivities of I4C- and 3H-labelled leucine and KIC were measured and analysed by using an open two-pool model.4. Less than 20% of the total leucine-C entering the circulation was converted to the KIC pool, and 42% of the KIC was converted back to the leucine pool; transamination of the leucine to KIC and reamination of KIC to leucine was much less than in other species.5. Additional dietary energy resulted in a decrease in tissue protein synthesis, leucine oxidation and interconversion of leucine and KIC. Total leucine-C entry was also lower in sheep given HED, which was most likely due to a suppression of endogenous proteolysis.6. Plasma glucagon concentration was significantly higher (P < 0.05) in sheep given LED compared with those given HED. The concentration of glucagon was closely correlated in all treatments with the leucine-C entry (proteolysis + absorbed leucine) and also with KIC-C exit (oxidation).
Responses to oral methionine supplementation in sheep fed on kale (Brassica oleracea) diets containing S-methyl-L-cysteine sulphoxide
Authors: Barry T. N. , Manley T. R. 
Published: September 2005

1. Responses to twice-weekly oral supplementation with 4.0 g methionine were measured with lambs (27 kg) grazing kale (Brassica oleracea) for 10 weeks (Expt 1). In a second experiment with sheep fed on kale at hourly intervals, rumen fractional outflow rates of CrEDTA and ruthenium Tris(1, 10 phenanthroline) markers were measured from the rates of decline in their concentrations. Rumen turnover of S-methyl-L-cysteine sulphoxide (SMCO) and of carbohydrate (CHO) constituents were also measured. The kale fed contained 11.4 g SMCO/kg dry matter and the ratio, readily-fermentable: structural CHO was high at 2.9.2. Severe haemolytic anaemia, associated with low live-weight gain (LWG), occurred in the lambs during the initial 5 weeks of grazing, due to rumen fermentation of SMCO. Oral methionine supplementation raised plasma concentrations of methionine and cysteine, increased wool growth rate, and increased LWG during the initial 5 weeks. Methionine supplementation also increased rumen pool and plasma SMCO concentrations, suggesting reduced rumen SMCO fermentation.3. In Expt 2, rumen degradation rate of SMCO (1.2/h) was calculated to be twice as fast as that of the most rapidly fermented dietary CHO constituents and eight times faster than the rate of water outflow (0.16/h), thus explaining its virtually complete rumen degradation and toxicity in brassica diets. It was estimated that 1.2 g of each 4.0 g methionine administered would have escaped rumen degradation, due to the high rate of water outflow from the rumen.4. Disappearance rates of CHO constituents from the rumen were as predicted for normal ruminant diets, showing that rumen metabolism of SMCO did not have a depressive effect. Hemicellulose disappeared at a slower rate than the other CHO, suggesting that hemicellulose digestion may be rate-limiting for cell-wall digestion.5. It is suggested that the responses to oral methionine supplementation can be explained through methionine reducing rumen SMCO degradation, and through a significant portion of the methionine escaping rumen degradation.
Digestion of the zinc in human milk, cow's milk and a commercial babyfood: some implications for human infant nutrition
Authors: Blakeborough Peter , Gurr Michael I. , Salter Dallyn N. 
Published: September 2005

1. The digestion of zinc present in human milk, cow's milk and a commercial babyfood was compared, using the piglet as a model for the human infant.2. In piglets given human milk the pH of stomach contents was approximately 1 and 0.4 units lower than that of animals given respectively cow's milk and babyfood. The pH values of intestinal contents were approximately neutral and did not vary with the type of feed.3. Hard casein curds were present throughout the stomachs and small intestines of animals fed on cow's milk or babyfood and between 55 and 70% Zn in these digesta samples were recovered in an insoluble form by centrifugation. In contrast, little solid material was observed in the digesta of animals fed on human milk, and 57 and 93% respectively of the Zn in digesta were recovered in a soluble form in the stomach and small intestine.4. Soluble fractions prepared by centrifugation of digesta were analysed by filtration on Sephadex G-150. After any of the three feeds, soluble Zn in stomach contents was mainly in a low-molecular-weight form. In intestinal samples, however, Zn was present in low- and high-molecular-weight forms. Whilst there were similar amounts of Zn in the low-molecular-weight form in all samples, approximately three times as much of the total intestinal Zn was in a soluble high-molecular-weight form complexed to proteins in the animals fed on human milk compared with those fed on cow's milk or babyfood.5. Analysis of protein-bound soluble Zn in intestinal samples on SDS-polyacrylamide gels resulted in a similar pattern of proteins for all feeds. Results indicated that at least some of these proteins were derived from intestinal secretions of the piglet.6. Some implications of these results in respect of the mode of digestion of Zn and its biological availability to the human infant are discussed.
An in vitro method for estimating biologically available vitamin B6 in processed foods
Authors: Ekanayake Athula , Nelson Philip E. 
Published: September 2005

1. An in vitro method which used enzymic digestion of the food matrix to release biologically available vitamin B6 is described.2. Vitamin B6-fortified liquid model foods were thermally processed. After these foods had been freeze-dried, one part was subjected to enzymic hydrolysis at pH 2.0 with pepsin (EC 3.4.23.1) followed by a hydrolysis at pH 8.0 with pancreatin. The vitamins that were found in the supernatant fraction, after an acidified methanol treatment of the hydrolysate, were estimated by high-performance liquid chromatography (HPLC). The other part was given to rats who were kept on a vitamin B6-depleted diet.3. The biologically available vitamin B6 content of the processed model foods, as determined by rat bioassay, showed good correlation with the vitamin B6 determined by HPLC.4. It has proved possible to use this in vitro, two-stage enzymic digestion system followed by HPLC determination to determine biologically available vitamin B6 in vitamin B6-fortified processed model foods.
Extrusion cooking of a high-fibre cereal product
Authors: Sandberg Ann-Sofie , Andersson Henrik , Kivistö Barbro , Sandström Brittmarie 
Published: September 2005

1. The effect of extrusion cooking of a high-fibre cereal product on digestibility of starch, fibre components and phytate in the stomach and small intestine was studied by in vivo digestion in ileostomy subjects, as well as its effect on ileostomy losses of fat, nitrogen, sodium and potassium.2. Seven ileostomy subjects were studied during two periods (each of 4 d) while on a constant low-fibre diet supplemented with 54 g/d of a bran-gluten-starch mixture (period A) or the corresponding extruded product (period B).3. Extrusion cooking, using mild conditions, did not change the content of starch, dietary fibre components or phytate of the bran product, but the phytase (EC3.1.3.26) activity was lost. During the period using the extruded bran product, there was a significant increase in recovery of phytate-phosphorus (period A, 44% of intake; period B, 73% of intake). The amount of fibre components, fat, fatty acids, N, Na, K, water and the ash weight of the ileostomy contents did not differ between the two periods. Only 0.6 and 0.7% respectively of ingested starch was recovered in ileostomy contents in periods A and B, while the fibre components were almost completely recovered.4. Extrusion cooking, using even mild conditions, may lead to a considerable impairment in the digestion of phytate, probably due to a qualitative change in phytate and a loss of phytase activity. Starch, before and after extrusion cooking, is almost completely digested in the stomach and small intestine while fibre components are digested to a very small extent.
Extrusion cooking of a high-fibre cereal product
Authors: Kivistö Barbro , Andersson Henrik , Cederblad Gitten , Sandberg Ann-Sofie , Sandström Brittmarie 
Published: September 2005

1. The effect of extrusion cooking, using mild conditions, of a high-fibre cereal product on apparent small bowel absorption of zinc, iron, calcium, magnesium and phosphorus was studied.2. Seven ileostomy subjects were studied during two periods (each of 4d), on a constant low-fibre diet supplemented with either 54 g/d of a bran-gluten-starch mixture or the corresponding extruded product.3. The apparent absorption of Zn, Mg and P was significantly decreased (P < 0.05) during the period with extruded product compared with the period with bran-gluten-starch. No difference was found for Fe and Ca.4. The negative effect of extrusion cooking of a product containing phytic acid on availability of Zn, Mg and P was small but could be of nutritional relevance in foodstuffs that are consumed frequently and in infant formulas.
A change in human faecal flora in response to inclusion of gum arabic in the diet
Authors: Wyatt G. M. , Bayliss C. E. , Holcroft J. D. 
Published: September 2005

1. Gum arabic is a water-soluble polysaccharide resistant to human gut enzymes and thus can be described as dietary fibre.2. Using a most-probable-number technique, estimates were made of total anaerobes and of gum-arabic fermenters in the faeces of a volunteer during a contro1 period and during addition of 10 g gum arabic/d to the diet. Using an enrichment technique, the principal bacteria able to utilize gum arabic as the only carbohydrate source were isolated and characterized.3. Faecal samples were analysed for undegraded gum arabic and, following acid-hydrolysis, for total sugars.4. The proportion of the faecal flora able to degrade the gum arabic polymer rose from an initial level of 6.5% to more than 50% during gum-arabic ingestion, and subsequently returned to the control level after ingestion ceased. The principal gum-arabic fermenters were species ofBucteroides and Bifdobucterium.5. Undegraded gum arabic was not detected in any faecal sample nor were there significant differences in the level of total sugars in acid-hydrolysed faeces between gum arabic and control periods.6. The results presented indicate a direct and rapid change in faecal flora in response to a specific change in the diet of a human volunteer.
Studies on iron availability in man, using stable isotope techniques
Authors: Fairweather-Tait Susan J. , Minski Margaret J. 
Published: September 2005

1. Iron absorption from 10 mg Fe (as ferrous sulphate), labelled with 1.3 mg58Fe, was measured in fasting, non-anaemic adult subjects by the faecal-balance technique. The measurement was performed twice, each subject being given, in random order, either 50 mg Fe or a placebo 18 h before the58Fe-labelled FeSO4.2. The 50 mg Fe load significantly reduced Fe absorption the following day (P< 0.01), from a mean of 35.4 (SEM 4.6)% to 29.0 (SEM 5.1)%. This points to the importance of strict dietary control during Fe-absorption studies to eliminate bias in results.3. In a separate study, the feasibility of using S6Fe-enrichment of erythrocytes, measured by neutron activation analysis (NAA), 10 d after a meal labelled with 0.69 mg58Fe as an index of Fe absorption was examined. The levels of58Fe in the blood were detectable by NAA. Regression analysis showed a significant relation between58Fe-enrichment of blood and58Fe absorption, calculated as the difference between intake and faecal excretion (R0.59,P< 0.05).
Absence of effects of dietary wheat bran on the activities of some key enzymes of carbohydrate and lipid metabolism in mouse liver and adipose tissue
Authors: Stanley John C. , Lambadrios Jacqueline A. , Newsholme Eric A. 
Published: September 2005

1. The effects of a 100 g/kg dietary substitution of wheat bran on the body-weight gain, food consumption and faecal dry weight of mice given a high-sucrose diet and on the activities of some key enzymes of carbohydrate and lipid metabolism in liver and adipose tissue were studied.2. Wheat bran had no effect on body-weight gain, food consumption or faecal dry weight.3. Wheat bran had no effect on the activities of hepatic glucose-6-phosphate dehydrogenase (EC1.1.1.49), 6-phosphogluconate dehydrogenase (EC1. 1.1.44), malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+) (EC1. 1. 1.40), ATP-citrate (pro-3S)-lyase (EC4.1.3.8), pyruvate kinase (EC2.7.1.40) and fructose-1, 6-bisphosphatase (EC3.1.3.11). The activity of hepatic 6-phosphofructokinase (EC2.7.1.11) increased but only when expressed on a body-weight basis.4. Wheat bran had no effect on the activities of adipose tissue glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase, malate dehydrogenase (oxaloacetate-decarboxylating) (NADP+), (ATP-citrate igro-3S)-lyase, hexokinase (EC2. 7. 1. 1), 6-phosphofructokinase and pyruvate kinase.5. These results suggest that unlike guar gum and bagasse, wheat bran does not change the flux through some pathways of lipogenesis in liver and adipose tissue when mice are given high-sucrose diets.
Biochemical observations on rat aorta: interaction of dietary protein and cholesterol
Authors: Bydlowski S. P. , Stivaletti V. L. G. , Douglas C. R. 
Published: September 2005

1. The effect of cholesterol feeding during and after a period of protein malnutrition lasting 4 weeks was examined in the rat. Indices measured were plasma total cholesterol, triglycerides and protein levels, and aorta total cholesterol, triglycerides, hexosamine and hydroxyproline concentrations.2. In both plasma and aorta, total cholesterol and triglycerides levels were higher in the low-protein diet group than in the standard-protein diet group, when cholesterol was supplied in both diets.3. During the malnutrition period, cholesterol feeding led to a greater decrease in plasma protein than that promoted by the low-protein diet without cholesterol, while aorta hexosamine levels decreased to a lesser extent.4. Cholesterol feeding with a standard-protein diet promoted a slight and temporary increase in aorta hydroxyproline levels, while a decrease in aorta hexosamine concentration was observed. Cholesterol feeding with the low-protein diet, on the other hand, also promoted a decrease in aorta hexosamine levels but to a lesser extent.5. During the recovery period, cholesterol feeding impaired the return of plasma protein, aorta hexosamine and lipid levels to that of the control values.6. These findings demonstrate that cholesterol feeding promotes different changes in aorta and plasma, depending on whether or not protein is supplied by the diet in adequate amounts. This point could be important in relation to the development of atherosclerosis during recovery from a period of malnutrition.
Effect of infection with lungworms (Dictyocaulus viviparus) on energy and nitrogen metabolism in growing calves
Authors: Kroonen J. E. G. M. , Verstegen M. W. A. , Boon J. H. , Van Der Hel W. 
Published: September 2005

1. Ten Friesian male calves of about 100 kg and 3 months old were reared similarly and were worm-free. From 13 weeks of age five calves received a dose of 640 infective larvae (L3) of lungworms (Dictyocuulus viviparus) twice weekly for 8 weeks to simulate continuous infection. Animals not infected were fed to the same level as the infected animals (about 1.2–1.3 kg concentrates and 14–1.5 kg good-quality hay/d).2. Heat production was measured twice weekly during 48 h (days 2 and 3, and days 5 and 6) in each group of experimental animals.3. Infection caused considerable damage to the lungs, increased respiration frequency and clearly produced antibody titres against D. viviparus.4. Animals infected with lungworms had on average a lower rate of weight gain, reduced by 70 g/d per animal. Digestibility was not affected. Nitrogen retention was much lower in infected animals (12.0 v. 14.6 g/d per animal in controls).5. Metabolizability of energy was slightly reduced in infected animals. Heat production as found in infected animals may be associated with an increased maintenance energy requirement of 30 kJ/kg live weight0.75 per d or reduced partial efficiency of feed conversion above maintenance in animals infected with lungworms (58.5 v. 64.1 % in the control animals).6. It was concluded that the depression in rate of gain was related to reduced intake of feed and to decreased N retention.
Physiological zinc-binding proteins of medium molecular weight in the rat gut
Authors: Jackson Malcolm J. , Holt Daphne , Webb Michael , Carter Nicholas D. 
Published: September 2005

1. Gel filtration on Sephadex G 75 was used to separate the medium-molecular-weight zinc-binding proteins from the soluble fractions from the duodenal and jejuno-ileal segments of the rat gut at 30 min after the intragastric administration of a tracer dose of 65Zn. These proteins were resolved by ion-exchange chromatography on DEAE cellulose.2. In both the duodenum and jejuno-ileal segment an appreciable fraction of the total soluble Zn was bound in a protein fraction that resembled metallothionein [MT] in its behaviour on gel filtration. These fractions, however, were not homogeneous, but contained several medium-molecular-weight Zn-binding proteins. In the duodenum, but not in the jejuno-ileal segment, two ofthese proteins appeared to be the isometallothioneins, ZnMT-I and ZnMT-11.3. These results suggest a possible role for MT in the binding of newly-absorbed Zn in the duodenal mucosal cells. They also show that gel filtration alone is insufficient for the identification of MT in the intestine.
Metabolism of dehydroretinyl ester in white leghorn chicks
Authors: Goswari Bhabesh C. , Barua Arun B. 
Published: September 2005

1. The metabolism of dehydroretinyl ester has been studied in vitamin-A-deficient white leghorn chicks. Dehydroretinyl ester was metabolized to 3-hydroxyretinol diester, 3-hydroxyanhydroretinol and rehydrovitamin A2which were isolated from the intestines and livers of chicks.2. The metabolism of 3-hydroxyretinol diester and 3-hydroxyanhydroretinol, which were immediate metabolites of dehydroretinol, was studied in chicks.3. Retinol was not detected in these experiments.
Metabolism of lactic acid isomers in the rumen of silage-fed sheep
Authors: Gill M. , Siddons R. C. , Beever D. E. , Rowe J. B. 
Published: September 2005

1. Four mature sheep were offered perennial ryegrass (Lolium perenne, cv. S23) silage (885 g dry matter/d) at hourly intervals. The silage was well fermented with a pH of 4.0, a lactic acid content of 139 g/kg dry matter and an organic matter digestibility of 0.766.2. Continuous intraruminal infusions of14C-labelled sodium salts of [U-14C]acetic acid, [2-14C]propionic acid, [2-14C]butyric acid and D- and L-[U-14C]lactic acid and an intravenous infusion of [U-14C]glucose were made on separate occasions to estimate the fluxes of rumen acetate, propionate, butyrate and lactate as well as plasma glucose. The data were resolved by the use of appropriate four-compartment (rumen) and three-compartment (rumen-plasma) models.3. Irreversible loss rate (g C/h) of rumen acetate (5.32 g C/h) was considerably greater than values obtained for propionate (2.58), butyrate (2.80) and lactate (2.91).4. Total flux of lactate (1.83 mol/d) exceeded the amount of lactate consumed in the diet (1.37 mol/d) indicating a net synthesis of 0.46 mol lactate/d. Approximately 0.90 of total lactate flux was metabolized in the rumen, with 1.00 mol/d converted to acetate, 0.57 to propionate and 0.08 to butyrate. The flux to acetate was significantly (P < 0.05) greater than that to propionate. Both the D- and L-isomers appeared to have similar metabolic fates.5. Lactate appeared to make no direct contribution to glucose flux in the animal, but 0.10 of total lactate was converted to glucose through propionate.6. The results are discussed in relation to overall lactate metabolism, and it is suggested that almost 0.30 of ruminally digested organic matter may be fermented via lactate.