bluuebunny/crossref_metadata_2025_split huggingface dataset:
Comparative biological availability of manganese from extrinsically labelled milk diets using sucking rats as a model
Authors: Raghib. M. Hassan , Wai-Yee Chan , Rennert M. Owen 
Published: May 2005

1. Very little is known about the biological availability of manganese from human milk and other infant milk diets. To determine the relative Mn availability, and to examine whether the age and the duration of previous fasting affect Mn absorption, sucking rats were given human milk, bovine milk and infant formula (regular Similac; Ross Laboratories, Columbus, OH) extrinsically labelled with54Mn.2. Milk diets were given by gastric intubation and the radioactivity of the carcass, liver and digestive tract was measured 3 h after feeding.3. The concentration of endogenous Mn was lowest in human milk (7–10 μg/l) and highest in rat milk (140–165 μg/l). Increasing the non-radioactive total Mn concentrations of either human milk or bovine milk up to 150 μg/l did not affect the absorption of54Mn by 10-d-old rats.4. No significant (P> 0.05) difference in54Mn absorption was found among the three milk diets (human milk, bovine milk, infant formula) in 8- to 11-d-old rats. However, significantly more (P< 0.05)54Mn was absorbed from human milk and infant formula than from bovine milk when 13-d-old rats were used.5.54Mn radioactivity detected in carcasses of 8-, 9-, 10- and 11-d-old rats ranged from 25 to 27% of the dose from various milk diets. The activities of54Mn in the carcasses of 13-d-old rats were 15, 11, and 16% of the dose from human milk, bovine milk and infant formula respectively.6. The trend of54Mn incorporation into liver was similar to that of the carcass and over 60% of the absorbed54Mn was incorporated into the liver regardless of the type of milk used.7. Absorption of54Mn from extrinsically labelled rat milk using 9- or 10-d-old sucking rats was similar to its absorption from infant formula.8. The absorption of54Mn from the three milk diets decreased with age of the neonatal rats and54Mn absorption from human milk, bovine milk, infant formula as well as rat milk was affected similarly by duration of previous fasting.
Effect of guar gum on gastric emptying in growing pigs
Authors: Rainbird Anna L. , Low A. G. 
Published: May 2005

1. Simple gastric cannulas were surgically fitted to four pigs, initially of 30 kg live weight, to examine the effects of guar gum on gastric emptying.2. Four semi-purified high-fat diets based on starch, casein, soya-bean oil and tallow were given to each pig. They contained 0 (control), 20, 40 or 60 g powdered guar gum/kg diet. The meals as fed contained 257 g dry matter (DM)/kg.3. The contents of the stomach were evacuated, with rinsing, before feeding or 0.5, 1, 2 or 4 h after feeding.4. The mean pH of the digesta was unaffected by guar gum until 4 h after feeding when the value increased as the amount of guar gum in the diet rose.5. The only significant effects of guar gum on the emptying of digesta and its components (compared with the control diet) were to reduce the rate of emptying of (a) digesta 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets), (b) dry matter and glucose 1 h after feeding (60 g/kg diet), (c) nitrogen 1 h after feeding (60 g/kg diet) and 4 h after feeding (40 and 60 g/kg diets).6. When expressed on a half-time (T50) basis, the emptying of digesta and N (but not of DM and glucose) were significantly slower for diets containing 40 and 60 g guar gum/kg than for the control diet.7. The apparent viscosity of the gastric digesta ranged between 0.5 and 23.7% of the values for the diets as consumed.8. It was concluded that the effects of guar gum on gastric emptying of high-solid meals were small, and that this was unlikely to be an important aspect of the mechanism by which guar gum reduces postprandial blood glucose concentrations.
Effect of various types of dietary fibre on gastric emptying in growing pigs
Authors: Rainbird Anna L. , Low A. G. 
Published: May 2005

1. Five pigs initially of 40–50 kg live weight were fitted with simple gastric cannulas which permitted complete evacuation and sampling of gastric digesta once daily.2. The effects of addition of four types of dietary fibre(wheat bran (WB; 40 g/kg), sodiumcarboxymethylcellulose (CMC; 40 g/kg), high-methoxy citrus pectin (Pe; 40 g/kg) and granulated guar gum (G; 40 g/kg)) on gastric emptying of a semi-purified diet during 4 h following a meal were measured.3. Each of the test diets and the control diet (C) were given to each pig for 1 week using a 5 x 5 Latin-square arrangement. Digesta were collected before and 0.5, 1, 2 or 4 h after feeding on the last 5 d of each week.4. The mean gastric pH was not significantly affected by diet except 2 h after feeding (CMC higher than C) and 4 h (Pe, G and CMC higher than C).5. Compared with diet C, the rate of gastric emptying of digesta was significantly slower for diet G, 1, 2 and 4 h after feeding, and 2 and 4 h after feeding for diet CMC.6. The rates of gastric emptying of digesta components were not significantly reduced by dietary fibre except for dry matter (DM) (diet CMC 2 h and diet B 4 h after feeding), total nitrogen (TN)(diet G 2 h after feeding) and total glucose (diet Pe 2 h after feeding).7. There were no significant effects of diet on trichloroacetic-acid-soluble N:TN.8. When gastric emptying was expressed in terms of half-time (T59) values, significant increases (compared with diet C) were found for digesta (diets G and CMC), DM (diet WB) and TN (diet G).9. The apparent viscosity of the gastric digesta was significantly higher when diets Pe, G, and CMC were given than diets C or WB. Diets Pe and CMC were very viscous in the meal before ingestion, but diet G was not; its high viscosity developed after it had reached the stomach.10. It is concluded that although those types of dietary fibre which increased meal or gastric viscosity reduced the rate of gastric emptying of digesta, this effect was confined to the liquid phase, because DM, total glucose and TN emptying were largely unaffected. The hypothesis that a reduced rate of gastric emptying may be an important determinant of the decreased rates of glucose absorption observed when such sources of dietary fibre are eaten is not supported by the results presented.
The role of condensed tannins in the nutritional value ofLotus pedunculatusfor sheep
Authors: Barry T. N. , Manley T. R. , Duncan S. J. 
Published: May 2005

1. Vegetative secondary growthLotus pedunculatuswas cut daily, and fed fresh at hourly intervals (600 g dry matter (DM)/d) to three groups each of three sheep fitted with permanent cannulas into the rumen and duodenum. Lotus fed to two of the groups was sprayed with low and high rates of polyethylene glycol (PEG; molecular weight 3350), which specifically binds the condensed tannins (CT). Nutrient intake and faecal excretion were measured directly, duodenal flows estimated from continuous intraruminal infusion of inert ruthenium phenanthroline (Ru-P) and CrEDTA markers, and rumen pool sizes measured at slaughter.2. Dietary concentrations of total reactive CT (i.e. that not bound to PEG) were 95, 45 and 14 g/kg DM, whilst the corresponding values for free CT were 15, 5 and 2 g/kg DM.3. Increasing dietary reactive CT concentration linearly increased duodenal flows of non-ammonia nitrogen, but linearly decreased the apparent digestibility of energy and organic matter, and rumen digestion of hemicellulose but not of cellulose. Rumen digestion as a proportion of total digestion was increased by the higher PEG rate for organic matter, energy, pectin and lignin.4. High dietary CT concentration was associated with increased N retention. Rumen ammonia concentration and pool size showed only a slight decline on this diet, indicating that there must have been increased recycling of N into the rumen.5. Increasing dietary reactive CT concentration had no effect on the rate at which carbohydrate constituents were degraded in the rumen per unit time (FDR), but increased the rate at which their undegraded residues (FOR) left the rumen per unit time. The latter appeared to be the principal mechanism by which rumen digestion as a proportion of total digestion was reduced at high dietary CT concentrations. From a comparison of FDR and FOR of carbohydrate components in lotus andBrassica oleraceadiets, it was concluded that hemicellulose digestion was rate-limiting for rumen cell-wall digestion, probably due to bonding with lignin. However, the considerable post-rumen digestion of hemicellulose was not associated with post-rumen lignin digestion.6. It was concluded that a desired concentration of CT inLotus sp. should represent a balance between the positive effect of CT in improving the efficiency of N digestion and their negative effect in depressing rumen carbohydrate digestion. A recommended concentration is 3WOg/kg DM.
Dissociation of methionine synthetase (EC 2.1.1.13) activity and impairment of DNA synthesis in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced vitamin B12 deficiency
Authors: Van tonder Susan V. , Ruck Angela , Van der Westhuzen J. , Fernandes-costa F. , Metz J. 
Published: May 2005

1. The effect of methylcobalamin inactivation by the anaesthetic gas nitrous oxide on the activity of the cobalamin-dependent methionine synthetase (5-methyltetrahydrofolate homocysteine methyltransferase; EC 2.1. I. 13) reaction, and on DNA synthesis, in the fruit bat Rousettus aegyptiucus, was examined.2. Methionine synthetase activity in the liver of bats exposed to N2O—oxygen (50: 50, v/v) for 90 min/d averaged 32% of that of controls after 4 d of exposure and only 5% after 12–14 weeks of exposure.3. DNA synthesis in the bone marrow, as reflected by the deoxyuridine suppression test, was unaffected by 4 d of exposure to N2O and only minimally affected after 5–10 weeks of exposure.4. These results suggest that DNA synthesis in the fruit bat is unusually resistant to inhibition of methionine synthetase and imply the existence of a non-methylated circulating folate pool in this species.
Studies on the measurement of 25-hydroxy vitamin D in human saliva
Authors: Fairney Angela , Saphier P. W. 
Published: May 2005

1. A competitive protein-binding assay for 25-hydroxy vitamin D (25-OHD) in saliva has been established by adaptation of that previously described for 25-OHD in serum (Fairneyet al.1979).2. Random values of salivary 25-OHD in patients attending hospital for venesection showed a wide range of results (105–1000 pg/ml,n55). These values corresponded to 1.2% of the total serum values with which they showed a significant relation (r 0.45, P < 0.001).3. There was no relation between salivary 25-OHD and measured serum free 25-OHD in eighteen pairs of saliva and serum studied.4. Studies in two individuals showed that salivary 25-OHD values varied throughout the day and that a vitamin D load (19.5 μg), given as pickled herrings at lunch, produced a marked rise in 25-OHD values 5–8 h later.5. Diurnal profile studies of salivary 25-OHD in Caucasian and Asian 11-year-old male schoolchildren showed lower values in Asian children eating a vegetarian diet, and a significant variation with time and ethnic group(P< 0.001).6. It is concluded that 25-OHD is present in saliva and that the values vary throughout the day. The values obtained may relate to dietary intake of vitamin D and the subject's ethnic origin.
The importance of the non-protein components of the diet in the plasma cholesterol response of rabbits to casein
Authors: Samman S. , Roberts D. C. K. 
Published: May 2005

1. To characterize further the effect of protein-mineral interaction on plasma cholesterol, four groups of rabbits were placed on cholesterol-free, semi-purified diets for 12 weeks. The diets were similar in proximate composition with either casein or soya-bean protein isolate as the protein source (250 g/kg).2. The dietary zinc content of the casein diets was increased to 22 mg/kg to equal that of the soya-bean diets. The copper content was set at 2 and 6 mg/kg. There were no differences in weight gain; all animals grew at a similar rate.3. When the dietary Zn content was equalized, the plasma and liver cholesterol responses were similar regardless of the source of protein.4. Differences in liver Cu and Zn were observed. As dietary Cu increased, Cu decreased and Zn increased in the liver. Hepatic Zn was also higher in soya-bean-fed than in casein-fed animals.5. No effects on plasma Cu and Zn were seen.6. The addition of Zn to the casein diet resulted in a similar plasma cholesterol to that of animals fed on the soya-bean diet, suggesting that casein-induced hypercholesterolaemia is due to a marginal Zn intake.
Comparative effects of dietary wheat bran and its morphological components (aleurone and pericarp-seed coat) on volatile fatty acid concentrations in the rat
Authors: Cheng Bing-Qin , Trimble Rodney P. , Illman Richard J. , Stone Bruce A. , Topping David L. 
Published: May 2005

1. Adult male rats were fed on diets containing 100 g dietary fibre/kg either as α-cellulose or wheat bran or the pericarp-seed coat or aleurone layers prepared from that bran by sequential milling and air elutriation and electrostatic separation.2. After 10 d, concentrations of total volatile fatty acids (VFA) in caecal fluid were significantly different between groups and fell in the order: aleurone > wheat bran > pericarp-seed coat > cellulose. This ranking probably reflected the ease of fermentation of fibre polysaccharides by colonic bacteria which also resulted in a considerably higher faecal bacterial mass in the aleurone group.3. Because of the differences in the volume of caecal digesta, the mass of caecal VFA was considerably the highest in the aleurone group, intermediate with wheat bran and equally low in the pericarp-seed coat and cellulose groups.4. The diet based on aleurone gave a relatively higher proportion of propionate but with both pericarp-seed coat and wheat bran the contribution of butyrate was raised.5. VFA concentrations in hepatic portal venous plasma were proportional to caecal concentrations with very high (> 3 mM) values being recorded in the aleurone group.6. The findings are discussed in relation to the apparent susceptibility of the morphological components of wheat bran to fermentation by large bowel bacteria.
The effects of intraruminal infusions of urea, casein, glucose syrup and a mixture of casein and glucose syrup on nitrogen digestion in the rumen of cattle receiving grass-silage diets
Authors: Rooke J. A. , Lee N. H. , Armstrong D. G. 
Published: May 2005

1. In an incomplete 5 x 5 Latin square experiment, four cattle were given grass silage in two meals per d to satisfy 1.15 maintenance energy requirements. In addition, water or casein (21 g nitrogen and 0.17 kg organic matter (OM)/d) or urea (U; 28 g N/d) or a glucose syrup (G; 0.87 kg OM/d) or casein and glucose syrup (CG; 17 g N and 0.93 kg OM/d) were infused intraruminally at a constant rate.2. A 24 h collection of duodenal digesta was made using chromic oxide for flow estimation and 35S as a marker of microbial N entering the small intestine. Samples of rumen fluid were also taken for estimation of rumen pH, and concentrations of ammonia-N and volatile fatty acids.3. The intraruminal infusions had no significant effects on rumen pH, concentrations of volatile fatty acids or their molar proportions. Infusion of either C or U significantly (P < 0.05) increased rumen NH3-N concentrations whereas infusions of either G or CG lowered rumen NH3-N concentrations.4. Infusions of C or U had no significant effect on the quantities of OM, acid-detergent fibre (ADF) or N constituents which entered the small intestine.5. Infusions of G or CG increased the quantities of OM (G P < 0.05, CG P < 0.01), ADF (CG P < 0.05), non-NH3-N (G P < 0.05, CG P < 0.01), amino acid N (G P < 0.05, CG P < 0.01) and microbial N (G P < 0.05, CG P < 0.01) which entered the small intestine.6. The efficiency of rumen microbial N synthesis was unchanged by the infusion of C, U or G (P > 0.05) but increased significantly (P < 0.05) when CG were infused.
Net absorption from portal-drained viscera of nitrogenous compounds by beef heifers fed on diets differing in protein solubility or degradability in the rumen
Authors: Huntington Gerald B. 
Published: May 2005

1. The objective of the present study was to evaluate effects of in vitro rumen solubility or degradability of dietary protein on net absorption of nitrogenous compounds from portal-drained viscera of beef heifers.2. Four protein sources, casein, soya-bean meal, maize-gluten meal and blood meal provided about two-thirds of total dietary nitrogen in semi-purified diets given to four beef heifers in a 4 x 4 Latin square design.3. Although in vitro degradability of dietary N ranged from 842 (casein) to 310 (blood meal) g/kg total dietary N, net absorption of ammonia-N or α-amino-N was not significantly different (P > 0.10) among diets. However, net absorption of NH3-N tended to decrease and net absorption of α-amino-N tended to increase as intake of in vitro undegradable N increased. Net transfer of urea-N from plasma to portal-drained viscera was greater (P < 0.10) when heifers were fed on soya-bean meal than when fed on maize-gluten meal or blood meal.4. The findings show with all diets that the non-protein-nitrogenous compounds, NH3 and urea, played a substantial role in absorption and transfer of N. Overall, net absorption of NH3-N was 61% of net absorption of α-amino-N, and transfer of urea-N from plasma to portal-drained viscera was 80% ofnet absorption of α-amino-N.
The effect of condensed tannins on the site of digestion of amino acids and other nutrients in sheep fed onLotus corniculatusL
Authors: Waghorn G. C. , Ulyatt M. J. , John A. , Fisher M. T. 
Published: May 2005

1. Sheep were used to evaluate the nutritional consequences of a low condensed-tannin concentration (22 g/kg dry matter (DM)) in lotus (Lotus corniculatusL.) (control group) compared with lotus given to sheep receiving intraruminal polyethylene glycol (PEG) infusion (PEG group). PEG selectively binds to tannins and prevents tannins from binding proteins.2. DM intakes (1430 (SE 28) g/d) and digestibility of energy (663 (SE 4.5) kJ/MJ intake) were similar for both groups but the apparent digestion of nitrogen was lower in the control sheep (0.70) than in the PEG sheep (0.78;P< 0.001).3. The proportion of N apparently digested before the abomasum (i.e. in the rumen) was lower (P< 0.05) in control sheep (0.12) than in PEG sheep (0.21;P< 0.05). Rumen ammonia concentrations were lower (P< 0.001) in control sheep than in PEG sheep. The proportion of neutral-detergent fibre (NDF) digested in the rumen was similar for both groups (0.48 (SE 0.012)) but less energy was digested in the rumen of the control (0.42) than of the PEG sheep (0.47;P< 0.05).4. The flux of essential amino acids (EAA) through the abomasum of control sheep was 50% greater than that in PEG sheep; flux of non-essential amino acids (NEAA) was 14% higher in control than in PEG sheep. Apparent digestibility of EAA in the small intestine was similar for both treatments (0.67), but NEAA were less well digested in the control (0.55) than in the PEG sheep (0.69).5. The presence of tannins in the control group increased net apparent absorption of threonine (57%), valine (89%), isoleucine (94%), leucine (30%), tyrosine (41%), phenylalanine (93%), histidine (90%) and lysine (59%), and reduced NEAA absorption by 10%, compared with PEG sheep.
A comparison of the effects of soya-bean protein and casein on bile composition, cholelithiasis and serum lipoprotein lipids in the vervet monkey (Cercopithecus aethiops)
Authors: Jaskiewicz K. , Weight M. J. , Christopher K. J. , Benadé A. J. S. , Kritchevsky D. 
Published: May 2005

1. Two groups of vervet monkeys (Cercopithecus uethiops) were fed on high-cholesterol diets which differed only with respect to the protein source. In one group casein was the only protein source, while the other group received only soya-bean protein.2. Samples of blood, bile and liver biopsy material were collected at the commencement of the study and at 3-monthly intervals until termination 12 months later.3. At the end of the experimental period all the animals (n19) had high plasma cholesterol levels and had developed pigment gallstones, the compositions and weights of which were not related to the protein source or to plasma cholesterol levels. Gallstone weight was related to the presence of acidic and sulphated mucins in gallbladder mucosa. We were also unable to confirm the hypocholesterolaemic effect of soya-bean protein which has been demonstrated previously in rhesus monkeys and hamsters. Bile composition, and plasma lipids did not differ significantly between the casein-fed and soya-bean fed animals. Lithogenic index was below 1 for both groups and did not differ significantly between the two groups.4. No significant difference was found in the severity ofcholelithiasis between the casein-fed and the soya-bean-fed animals.
The influence of a high-protein, low-carbohydrate diet on bone development in the fetuses of rat dams with streptozotocin-induced diabetes
Authors: Harvey W. Keith , Nakamoto Tetsuo 
Published: May 2005

1. The purpose of the present study was to determine the effects of diet on the mandibles and growth centres of the long bones in the fetuses of diabetic rat dams given a normal diet compared with those given a high-protein, low-carbohydrate diet.2. On the 9th day of gestation, the controls, groups 1 and 3, were injected with citrate buffer and given 200 and 600 g protein/kg diets respectively. Groups 2 and 4 were injected with 40 mg streptozotocin/kg body-weight and pair-fed with groups I and 3 respectively on the 200 and 600 g protein/kg diets.3. On day 22, some dams were injected with either 45Ca or [14C]proline. Mandibles and long bones were removed and weighed and analysed for Ca content, 45Ca uptake, collagen and collagen synthesis.4. The body-weights, and mandibular and long-bone weights of the fetuses in the diabetic 200 g protein/kg group were smaller than those of the non-diabetic 200 g protein/kg group, whereas those of the diabetic 600 g protein/kg group showed no difference from the non-diabetic 600 g protein/kg group.5. The rate of collagen synthesis was higher in the fetuses of the diabetic 600 g protein/kg group than those of the non-diabetic group. Bones of the diabetic 200 g protein/kg group were lower in collagen content when compared with the non-diabetic group, whereas there was no difference between the diabetic and non-diabetic 600 g protein/kg groups.6. Ca uptake and total Ca contents in the mandibles and long bones showed no difference between diabetic and non-diabetic groups fed on both diets.7. A high-protein, low-carbohydrate diet appeared to have a certain beneficial effect on bone development of the growing fetuses from diabetic dams.
Haematological and tissue abnormalities in chicks caused by acute and subclinical folate deficiency
Authors: Maxwell M. H. , Whitehead C. C. , Armstrong J. 
Published: May 2005

1. Haematological, histological and ultrastructural findings in young chicks fed on a purified diet severely deficient in folate are reported.2. Growth of the birds was greatly depressed and they had a macrocytic anaemia. Other haematological changes included abnormal nuclear formations in erythrocytes, numerous mitoses and hypersegmented granulocytes.3. Megaloblasts were observed in bone marrow and their fine structure is described for the first time in an avian species.4. Morphological changes occurred also in the liver. The parenchyma had damaged sinusoidal endothelium, inflammatory cells and no glycogen. Mitochondria were damaged and many were associated with unusual crystalline structures.5. Chickens fed on a semi-purified diet of low folate content showed no growth depression or clinical signs of deficiency but had abnormal haematological values and morphological changes that resembled those seen in birds fed on the purified diet.6. These abnormalities responded to dietary supplements of pteroylmonoglutamic acid in a dose-related manner and may be useful in diagnosing subclinical folate deficiency.