bluuebunny/crossref_metadata_2025_split huggingface dataset:
Influence of diet and microbial activity in the digestive tract on digestibility, and nitrogen and energy metabolism in rats and pigs
Authors: Eggum B. O. , Thorbek Grete , Beames R. M. , Chwalibog A. , Henckel S. 
Published: May 2005

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 (μmol 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.
Comparison of the effects of high- and low-methoxyl pectins on blood and faecal lipids in man
Authors: Judd Patricia A. , Truswell A. S. 
Published: May 2005

1. The effects on blood and faecal lipids of the addition of 15 g of either high- or low-methoxyl pectin to the habitual diets of ten healthy young adults have been studied.2. Serum total cholesterol levels were reduced by a mean of 16% during consumption of low-methoxyl pectin and 18% during consumption of high-methoxyl pectin. High density lipoprotein cholesterol levels and triglyceride levels were unchanged.3. There was no difference in faecal fat and steroid excretion between the two pectins.4. The results suggest that it is the gel-forming properties of the pectins which are important in the cholesterol-lowering effect rather than differences in bile acid bindingdue to different methoxyl contents.
Incubation of NAD(P)H2: glutathione oxidoreductase (EC1.6.4.2) with flavin adenine dinucleotide for maximal stimulation in the measurement of riboflavin status
Authors: Thurnham D. I. , Rathakette Prapimporn 
Published: May 2005

1. Some modifications to the erythrocyte glutathione reductase assay for riboflavin status are described.2. Cusum analysis of results collected on a quality-control (QC) haemolysate, analysedseparately at the beginning and end of each batch of samples over a period of 20 weeks, suggested that the activation coefficient (AC) was higher at the end of a batch than at the beginning.3. The higher AC was due to higher FAD-stimulated enzyme activities of the QC samples measured at the end of the day, by comparison with the beginning, and this suggested that the conditions of assay were not optimal.4. The conditions required to achieve maximal coupling of FAD to glutathione reductase(NAD(P)H2: glutathione oxidoreductase;EC1.6.4.2) were therefore examined and found to be 15 min at 35° by comparison with the 5–7 min incubation used by most workers.5. Alternatively, where samples are prepared in batches, the enzyme and FAD should be pre-incubated in the reaction mixture for 2 h at 4° or 1 h at 25° before the standard incubation of 5 min at 35°.6. Additionally, the use of cummulative sum (cusum) analysis on the QC results suggested that there was a slight deterioration of QC sample after 4-weeks storage. However, theQC results obtained, remained within 2 standard deviations of initial results over a 20-week period, suggesting that the deterioration was very slight.
The effect of heat treatment and particle size of bran on mineral absorption in rats
Authors: Caprez Andrea , Fairweather-Tait Susan J. 
Published: May 2005

1. The effect of heat treatment of bran on true zinc absorption was measured using an isotope-dilution technique. A bran-based breakfast cereal (heated to 204° for 40 min during manufacture) was incorporated into a semi-synthetic diet at a level of 180 g/kg, A parallel diet was formulated containing an identical weight of untreated bran from the same source plus other ingredients used to make the cereal.2. Young male Wistar rats (mean weight 80 g) were injected intramuscularly with 65Zn to label body Zn. They were given the heat-treated- and untreated-bran diets for 9 d. During the last 6 d of this period Zn intakes and faecal and urinary Zn were measured in order to calculate apparent Zn retention. True Zn retention was measured by taking into account losses of Zn of endogenous origin (labelled with 65Zn), by measuring faecal and urinary 65Zn taking the mean specific radioactivity of Zn in kidneys and upper small intestine to represent specific radioactivity of endogenous origin.3. Heat treatment of bran removed approximately one-third of the phytate, but this was not enough to improve Zn absorption from the diet. True Zn retention measured by isotope dilution was significantly higher (P < 0.02) than apparent Zn retention measured bv the conventional balance technique.4. The hypothesis that a reduction in particle size of bran would improve mineral availability was tested by feeding coarse and milled bran (100 g/kg diet) in a semi-synthetic diet to rats and measuring true Fe and apparent Zn absorptions. The importance of phytate was also investigated by feedino a diet containing dephytinized bran.5. Male Wistar rats (mean weight 172 g) were given diets containing coarse, milled or dephytinized bran for 9 d. Fe and Zn intakes were measured and faeces and urine collected for Fe and Zn analysis.6. The mean (±SE) particle size of the bran was reduced on milling from 3.5 (± 1.8) to 0.2–0.5 mm. There were no differences in the fraction of Fe retained between the three groups. Particle size had a small effect on Zn retention which was marginally higher in rats on the milled-bran diet (0.126 (± 0.023)) than in those on the coarse-bran diet (0.087 (± 0.012)). Total removal of phytate had a greater effect and apparent Zn retention from the dephytinized-bran diet was significantly higher (0.182 (±0.027), P < 0.01).
Breakfast and performance in schoolchildren
Authors: Dickie N. H. , Bender A. E. 
Published: May 2005

1. The results from two studies are reported of the effects on mental performance of omitting breakfast. The objective of the first study was to compare the performances of schoolchildren who habitually ate or did not eat breakfast. In the second study the effectsof omitting breakfast by those accustomed to eating the morning meal were investigated.2. Mental performance was assessed by two short-term memory tests (a simple cancellation test in which paired letters were marked on a page of random letters) and a memory-search test in which tines containing a group of specified fetters were marked, a series of numerical additions, and an attention-demanding test (in which specified statements had to be verified).3. Neither study revealed differences attributable to the omission or consumption of breakfast.
The flow of endogenous nitrogen in the digestive tract of young pigs
Authors: Leibholz Jane 
Published: May 2005

1. Twenty pigs were given one of five diets containing 0.9–39.2 g nitrogen/kg dry matter (DM) during the period 13–27 d of age.2. The pigs were fed hourly, from 22–27 d of age, with a diet sprayed with an indigestible marker, 103 Ru-labelled Tris (l,10-phenanthroline)-ruthenium (II) chloride. All pigs were slaughtered at 27 d of age.3. Flows of endogenous N estimated by feeding the diet containing 0.9 g N/kg and by regression analysis using results from all diets, were similar.4. Flows of endogenous N were: stomach 1.8. duodenum 4.5, jejunum 4.2, ileum 3.5, caecum 2.7, large intestine 2.6 and faeces 1.7 g/kg dm intake.5. Values are given for the flow of endogenous amino acids to the ileum.6. Of the DM, 70% was digested anterior to the duodenum and for N the value was 10%. The percentage of N digested anterior to the jejunum was 70.
Metabolism of ketone bodies in pregnant sheep
Authors: Pethick D. W. , Lindsay D. B. 
Published: May 2005

1. A combination of isotope-dilution and arteriovenous-difference techniques was used to determine the significance of ketones to energy homoeostasis in fasted pregnant ewes.2. There was incomplete interconversion of D(−) 3-hydroxybutyrate (3HB) and acetoacetate (AcAc) and therefore neither entry rate nor oxidation of total ketone bodies could be estimated by assuming circulating ketone bodies represent a single metabolic compartment. Total ketone body metabolism was satisfactorily summarized using a three-compartment model. In fasted pregnant ewes the mean entry rate of total ketones was 1 mmol/h per kg body-weight and of the ketones entering the circulation 87% were promptly oxidized to carbon dioxide accounting for 30% of the total COaproduction.3. Ketone bodies are readily utilized by hind-limb skeletal muscle such that if completely oxidized, 18±4 and 48±3% of the oxygen utilized could be accounted for in fed and fasted pregnant ewes respectively. For both 3HB and AcAc there was a hyperbolic relationship between utilization and arterial concentration. The apparent Michaelis constant (Km) values were 0·55 and 1–42 mM respectively and the maximum velocity (Vmax) 2·9 and 5·6 mmol/h per kg muscle. The arterial concentration of AcAc is always below theKmvalue and this limits the utilization rate. The D(−) 3HB concentration, however, may surpass that required for maximum utilization and ketoacidosis may be a consequence of this.4. A two-compartment model was used to analyse ketone body metabolism by hind-limb skeletal muscle. The results suggested substantial intercon version and production of AcAc and 3HB.5. The pregnant uterus utilized 3HB which if completely oxidized accounted for 12±2 (fed) and 25±4 (fasted) % of its O2consumption. At least 64% of the net 3HB utilized was oxidized. AcAc was not utilized in significant quantities.
The nitrogen-sparing effect of methionine sulphoxide and some other sulphur-containing amino acids
Authors: Njaa L. R. , Aksnes A. 
Published: May 2005

1. The nitrogen-sparing effect of methionine, methionine sulphoxide, homocystme, cystine and choline was studied in rats by determining daily N excretions during 5 d after changing from a high-protein diet to a protein-free diet, L-glutamic acid was used as a negative control.2. L-, D- and DL-methionine were equally active in sparing N. L-methionine sulphoxide, DL-homocystine and L-cystine were as active as L-methionine. D-methionine sulphoxide was slightly less active than L-methionine sulphoxide, Choline hydrogen tartrate was not different from the negative control.3. It is concluded that in short-term experiments cystine is the key substance in the N-sparing effect.
Studies on the range of tissue protein synthesis in pigs: the effect of thyroid hormones
Authors: Simon O. , Bergner H. , Münchmeyer R. , Zebrowska Teresa 
Published: May 2005

1. The effects of thyroid hormones on the range of tissue protein synthesis in growing pigs using the constant infusion technique with [14c]leucine and [14C]lysine were studied.2. During a 6 h infusion, samples were taken from blood and, at the end of the infusion, from liver, pancreas, stomach, small and large intestines, kidney cortex, kidney medulla, muscle and skin.3. Lower relative specific radioactivities of free leucine and lysine in several tissues were observed in the hormone-treated group than in the untreated one.4. The range of protein synthesis rate and the daily amount of protein synthesized in tissues was higher in all tissues after application of thyroid hormones.5. Assuming that the organs analysed represented 70% of the total trichloroacetic acid-precipitable protein of the pig, the estimated range of daily protein synthesis was 251–490 and 312–880 g in untreated and hormone-treated pigs respectively.
The use of cowpeas (Vigna unguiculata) in improving a popular Nigerian weaning food
Authors: Oyeleke Oyus A. , Morton I. D. , Bender A. E. 
Published: May 2005

1. A weaning food commonly used in Nigeria was simulated by mixing processed sorghum (Sorghum bicolor) with skim-milk powder (830: 170, w/w).2. Replacing 310 g/kg sorghum with processed cowpeas (Vigna unguiculata) resulted in an increase in protein content from 96 to 113 g/kg and an increase in biological value of the protein from 0.74 to 0.87.3. The two mixtures were compared with an established commercial baby food by a panel of Nigerian mothers and all three foods were found to be equally acceptable.4. Processing the cowpeas by pressure cooking followed by roller-drying reduced the trypsin-inhibitor content to minimum levels.5. It is concluded that the protein content and quality of the weaning mixture popularly used in Nigeria could be improved by partially replacing the sorghum with cowpeas.
Digestibilities of casein and soya-bean protein in relation to their effects on serum cholesterol in rabbits
Authors: Woodward Christopher J. H. , Carroll Kenneth K. 
Published: May 2005

1. Diets containing isolated soya-bean protein induce lower levels of serum cholesterol in animals than diets containing casein. Experiments were conducted to investigate whether differences in digestibility of the proteins might explain this effect.2. At pH 8 with pancreatic enzymes or intestinal peptidase, soya-bean protein was hydrolysed in vitro much less rapidly than casein. However, with pepsin (EC3. 4. 23. 1) at acid pH, soya-bean protein was hydrolysed more rapidly than casein.3. These differences in digestibility may be due to pH-dependent changes in solubility of the proteins. Casein and soya-bean protein were most soluble at alkaline and acid pH respectively.4. Heat treatment of the proteins resulted in lower solubilities and digestibilities. Sonication of soya-bean protein at pH 7.8 increased solubility but only slightly raised digestibility.5. When fed to rabbits, enzymically hydrolysed soya-bean protein induced a 2.3-fold higher concentration of serum cholesterol than did intact soya-bean protein. The hypocholesterolaemic effect of soya-bean protein may be partly attributable to its low solubility and digestibility at alkaline pH.
Low-iodine diet for the production of severe I deficiency in marmosets (Callithrix jacchus jacchus)
Authors: Mano M. T. , Potter B. J. , Belling G. B. , Hetzel B. S. 
Published: May 2005

1. A low-iodine diet consisting of maize, peas (Pisum sativum), torula yeast, meat meal, maize oil and added vitamins, minerals and amino acids was given to eight pairs of adult, common cotton-eared marmosets (Caliithrix jacchus jacchus). Eight control pairs were given the same diet to which potassium iodate was added. Both groups also received low-I apple and deionized water.2. The diet provided adequate nutrition, as confirmed by the maintenance of body-weight and good health.3. In the I-deficient marmosets the concentration of plasma thyroxine was decreased from 140.1 nmol/l to 22.4 nmol/l and thyroid-stimulating hormone increased significantly from 1.8 ng/ml to 9.0 ng/ml compared with control marmosets, thereby indicating severe I deficiency.4. Compared with newborn offspring from control marmosets, the thyroid glands from the I-deficient offspring showed (a) an increase in weight, (b) a decrease in I content and (c), on histological examination, hyperplasia, hypertrophy and a total absence of colloid material in the follicles.
Dose dependence of breath hydrogen and methane in healthy volunteers after ingestion of a commercial disaccharide mixture, Palatinit®
Authors: Fritz Martin , Siebert Günther , Kasper Heinrich 
Published: May 2005

1. Breath hydrogen and methane were determined by gas chromatography in eleven normal individuals given a low-fibre, mixed diet (control) and after ingestion of 20–50 g Palatinit®/d, an equimolar mixture of D-glucosyl-α(1 → 1)-D-mannitol and D-glucosyl-α(1 → 6)-D-glucitol (Isomalt®).2. A linear relation was found (r0.85;P< 0.001) between the amount of Palatinit ingested and breath H2per 10 h in subjects who did not exhale methane. If methane was formed in addition to H2, the sum of both gases followed a linear dose-effect relation.3. The mouth-to-caecum time, indicated by the first increase in breath H2, after ingestion, was shortened by about half, yet no sign of diarrhoea was observed. Stool weight and stool frequency did not change significantly.4. The linear relation between a dose of 20–50 g Palatinit and exhalation of H2(eventually plus methane) indicated that a relatively constant fraction of the dose given underwent cleavage and absorption in the small intestine, the remainder being transported into the large bowel. Microbial gas formation in the colon as well as the fractional transfer of these gases into the expiratory air occurred at fixed proportions, thus allowing an insight into colonic microbial contributions to carbohydrate utilization in the human large bowel.
Gastric emptying of barley-soya-bean diets in the pig: effects of feeding level, supplementary maize oil, sucrose or cellulose, and water intake
Authors: Low A. G. , Pittman R. J. , Elliott Rosemary J. 
Published: May 2005

1. A technique for measuring gastric emptying in growing pigs by complete removal of digesta through a gastric cannula is described.2. Four pigs were fitted with gastric cannulas and each was used in three trials.3. The effects of level of feeding (trial 1), cellulose (C), maize-oil (MO) or sucrose (SU) supplementation (trial 2) and the level of water intake (trial 3) on gastric emptying of digesta, dry matter (DM) and nitrogen from a barley-weatings-soya-bean (B) diet were measured during 4 h after the morning feed.4. In trial 1, pigs were given 0.66, 0.83, 1. 00 or 1. 17 times their standard level of feeding. As the level of feeding rose, so the weight of digesta, DM and N emptied in the first hour after feeding increased. This trend continued to some extent in the second hour, but no effects of level of feeding were seen in the third and fourth hours.5. In trial 2, maize-oil addition to the diet significantly reduced the gastric-emptying rate of DM in the second hour after feeding, compared with the rates for diet C. The rate of N emptying was significantly slower for diets MO and SU than for diet C.6. In trial 3 there were no significant effects of water intake level (1. 75, 2. 50 and 3. 25 times the weight of diet) on the rate of DM or N emptying from the stomach. The rate of digesta (and thus of water) emptying in the first hour after feeding increased significantly as the water intake rose.7. It was concluded that because the pattern of gastric emptying was very similar despite large differences in nutritional inputs, an important property of the process appeared to be resilience.
Absorption and metabolism of glucose by the mesenteric-drained viscera of sheep fed on dried-grass or ground, maize-based diets
Authors: Janes A. N. , Weekes T. E. C. , Armstrong D. G. 
Published: May 2005

1. Sheep fitted with re-entrant canulas in the proximal duodenum and terminal ileum were used to determine the amount of α-glucoside entering, and apparently disappearing from, the small intestine when either dried-grass or ground maize-based diets were fed. The fate of any α-glucoside entering the small intestine was studied by comparing the net disappearance of such a-glucoside from the small intestine with the absorption of glucose into the mesenteric venous blood.2. Glucose absorption from the small intestine was measured in sheep equipped with catheters in the mesenteric vein and carotid artery. A continuous infusion of [6-3H]glucose was used to determine glucose utilization by the mesenteric-drained viscera and the whole-body glucose turnover rate (GTR).3. The amounts of α-glucoside entering the small intestine when the dried-grass and maize-based diets were given were 13.9 (SE 1.5) and 95.4 (SE 16.2) g/24 h respectively; apparent digestibilities of such α-glucoside in the small intestine were 60 and 90% respectively.4. The net absorption of glucose into the mesenteric venous blood was —2.03 (SE 1.20) and 19.28 (SE 0.75) mmol/h for the dried-grass and maize-based diets respectively. Similarly, total glucose absorption amounted to 1.52 (SE 1.35) and 23.33 (SE 1.86) mmol/h (equivalent to 7 and 101 g/24 h respectively). These values represented 83 and 11 1% of the a-glucoside apparently disappearing from the small intestine, determined using the re-entrant cannulated sheep.5. Total glucose absorption represented 8 and 61% of the whole-body GTR for the dried-grass and maize-based diets respectively. Endogenous glucose production was significantly lower when the sheep were fed on the maize-based diet compared with the dried-grass diet.6. The mesenteric-drained viscera metabolized a small amount of glucose, equivalent to 234 and 17% of the total glucose absorbed for the dried-grass and maize-based diets respectively.7. It is concluded that a large proportion of the starch entering the small intestine of sheep given a maize-based diet is digested and absorbed as glucose, and thus contributes to the whole-body GTR.