bluuebunny/crossref_metadata_2025_split huggingface dataset:
Copper, manganese, zinc, nickel, cadmium and lead in human foetal tissues
Authors: Casey Clare E. , Robinson Marion F. 
Published: May 2005

1. Concentrations of copper, manganese, zinc, nickel, cadmium and lead were measured in samples of liver, kidney, brain, heart, lung, skeletal muscle and vertebral bone from forty foetuses of 22–43 weeks gestation.2. Cu concentrations in the liver were up to 100 times those in other tissues, but only those in the brain showed a significant increase with gestational age.3. Mn concentrations were similar in all tissues; the over-all range was 0.35–9.27 μg/g dry matter (dm).4. Concentrations of Zn in the liver were much higher than in other tissues and decreased with gestational age, whereas levels in skeletal muscle increased.5. In all tissues Ni concentrations were within the range 0.04–2.8 μg/gdmand levels in kidney and muscle decreased significantly with age.6. Cd was detected in most of the tissue samples and concentrations were within the range 0.01–0.58μg/gdm.7. Concentrations of Pb, where it was detected, varied from 0.1 to 2.4 μg/gdmin the soft tissues and from 0.4 to 4.3 μg/gdmin the bone samples.
The effect of simulated altitude on the heat increment of feed in sheep
Authors: Blaxter K. L. 
Published: May 2005

1. Sheep given constant feed were exposed to environments in which the oxygen concentration in air was either 200 or 150 ml/l. There were no differences in daily heat production, methane production, urinary energy or faecal energy losses measured over periods of 4 d.2. When the sheep were fasted there were no differences in heat production to be ascribed to the O2 concentration in air. The thermic response to feed was unaffected by the O2 concentration in the air.
Haematological studies on vegans
Authors: Sanders T. A. B. , Ellis F. R. , Dickerson J. W. T. 
Published: May 2005

1. The concentrations of vitamin B12 and folate in the serum and folate in the erythrocytes were determined and full blood counts made on a series of caucasian vegans and omnivore controls.2. The blood counts and films were normal in all the vegans and no subject had a haemoglobin concentration below the lower limit of normality.3. Although within the normal range, male but not female vegans had lower values for erythrocyte counts and higher values for mean corpuscular volume and mean corpuscular haemoglobin than their controls regardless of whether they were taking vitamin B12 supplements or not.4. The mean serum vitamin B12 concentration was lower in the vegans not taking vitamin B12 supplements and in those using foods supplemented with the vitamin than in the controls, but in no subject was it below 80 ng/l.5. The serum folate concentrations were higher in the vegans than in their controls. The mean value for erythrocyte folate tended to be greater in the vegans not taking vitamin B12 supplements. No subject had an erythrocyte folate concentration of less than 100μg/l.6. It is concluded that megaloblastic anaemia is very rare in caucasian vegans and that a diet consisting entirely of plant foods is generally adequate to promote normal blood formation providing it is composed of a mixture of unrefined cereals, pulses, nuts, fruit and vegetables and is supplemented with vitamin B12.
The effects on chicks of dietary fibre from different sources: a growth factor in wheat bran
Authors: Hegde S. N. , Rolls B. A. , Turvey A. , Coates Marie E. 
Published: May 2005

1. Groups of chicks were given a low-residue diet with or without supplements of dietary fibre in the form of wheat bran, wheat straw or bagasse. Growth and food conversion efficiency (g weight gained/g food eaten; FCE) during the first 4 weeks of life were measured.2. In every one of seven experiments supplementation of the diet with 100 g wheat bran/kg resulted in improved growth, and in three experiments FCE was also increased.3. Supplementation with coarsely-milled wheat straw to provide an amount of unavailable carbohydrate equivalent to that in the bran diet resulted in poorer growth; finely-milled wheat straw had little effect on growth.4. The growth-promoting effect of bran was destroyed by sterilization with heat or gamma-radiation.5. In some experiments weights, lengths and volumes of small intestines were measured. Differences in intestinal dimensions between birds given the diet with and without fibre were not consistent, nor were they correlated with growth rate or FCE.6. Histometric observations on small intestines from a few birds indicated that those given coarse wheat straw had longer villi and thicker muscularis layers, and the caecal tonsils had a greater area of lymphoid tissue and more follicles.
Gastric secretion in suckling pigs and early-weaned pigs given a dry cow's-milk formulaad lib.
Authors: Decuypere J. A. , Bossuyt R. , Henderickx H. K. 
Published: May 2005

1. Twelve gastric-cannulated litter-mate pigs were used to study secretion and proteolytic activity in the stomach of suckling and early-weaned pigs in relation to age and food intake.2. Results demonstrate that from the first observation at day 8, piglets were able to secrete acid. pH and acid concentration did not change during the first 4 weeks of life.3. Proteolytic activity was low during the first 2–3 weeks of life and rapidly increased thereafter.4. Two phenomena differentiated suckling pigs from pigs given dry cow's milk: (1) a low buffering capacity the gastric contents, beginning 1 h after feeding the dry cow's-milk formula, results in a low total acid concentration in the weaned pigs and (2) the increase in proteolytic activity in relation to the age is much more pronounced in the artificially-reared pigs.5. These two phenomena are discussed and related to the formation of a hard casein clot in the stomach of the cow's-milk-fed pigs, which has a long retention time and stimulates gastrin release.
The effect of dihomo-γ-linolenic acid (20: 3,n-6) on the composition of phospholipid fatty acids in the liver of rats deficient in essential fatty acids
Authors: Hassam A. G. , Crawford M. A. 
Published: May 2005

1. Rats were fed on either a diet deficient in essential fatty acid (EFA) or one supplemented with dihomo-γ-linolenic acid (20:3,n-6) at levels that represented 0.25, 0.5, 1.0 and 2.0% of the dietary energy.2. Supplementation of the diet of EFA-deficient animals with 20:3,n-6 reversed most of the fatty acid changes induced in the liver phospholipid fraction.3. The EFA potency of 20:3,n-6 was found to be similar to that of γ-linolenic acid (18:3,n-6) which has been shown to be higher than that of linoleic acid (18:2,n-6).
The effects of plane of nutrition and environmental temperature on the energy metabolism of the growing pig
Authors: Close W. H. , Mount L. E. , Brown D. 
Published: May 2005

1. Measurements of energy and nitrogen balances were made on thirty-eight individually housed pigs (initial body-weights 21–38 kg) at environmental temperatures of 10, 15, 20, 25 and 30° with four levels of feeding at each temperature. Values for energy retention (ER), protein (P) and fat (F) deposition and body weight gain (δW) were calculated at each temperature at metabolizable energy (me) intakes equivalent to once (M; 440 kJ/kg0.75 per d), twice (2M), three (3M) and four (4M) times the thermoneutral maintenance energy requirement.2. ER at each plane of nutrition increased with temperature to maximal values between approximately 20 and 25° ER was negative at four of the five environmental temperatures at M.3. P increased significantly with increase in me intake but was dependent on environmental temperatures only at intakes of M and 2M. The increase in P per unit increment in me intake decreased from 0.16 at 10° to 0.12 at 30°. The net efficiency of protein utilization also decreased with increase in environmental temperature from 0.54 at 10° to 0.39 at 30°.4. F increased significantly with increase in me intake, but was more temperature-dependent than P, increasing to maximum values estimated to be between 20 and 25° at each level of intake; F at 30° was less than that at 25°. The increase in F per unit increment in me intake decreased from 0.63 at 10° to 0.51 at 30°.5. The optimum temperature for ΔW was dependent upon me intake, varying from above 30° at M to less than 20° at 4M. The reduction in ΔW per 1° at 15° was also dependent upon the level of intake decreasing from 1.63 g/kg0.75 per d at M to -0.09 at 4M.6. For a 35 kg pig the reduction in P, as a result of a 1° decrease in temperature at 15° at an intake corresponding to 2.5M, was equivalent to a 4 g/d reduction in food intake; the corresponding equivalent for F was 28 g/d.
Absorption of magnesium by the young steer
Authors: Horn Jane P. , Smith R. H. 
Published: May 2005

1. Steers with rumen and simple duodenal cannulas were allowed to graze pasture or were given diets of dried grass or flaked maize with or without hay. For an experiment a solution or suspension of magnesium chloride, polyethylene glycol (molecular weight 4000) and either 144Ce (as cerous chloride) or chromic oxide was added to the rumen with a morning feed. Conditions in the rumen were sometimes modified by adding sodium chloride or hydrochloric acid.2. Changes in magnesium: marker in samples of strained rumen contents with time interval after adding the dose were due partly to changes in Mg distribution between different phases. Results indicated, but not unequivocably, that negligible amounts of Mg were absorbed in the first few hours.3. Relative recoveries of Mg and markers at the duodenum indicated that proportions of Mg intake absorbed (net) varied from approximately zero for pasture to 0.2–0.5 for flaked maize. Significant correlations between absorption efficiency and sodium: potassium in rumen contents (positive) and rumen pH (negative) were observed.4. Steers with simple duodenal and re-entrant ileal cannulas were given a diet of flaked maize and hay supplemented with different amounts of magnesium oxide. Little net change in Mg relative to an unabsorbed marker was found between these sites even for a diet containing an Mg supplement of 8 g/kg dry matter.
Subcutaneous fat accumulation during pregnancy in a malnourished population
Authors: A P. , GarcÍa Deyanira , Llerena C. , Quiroz Sara E. 
Published: May 2005

1. Total skinfold thicknesses (sum of seven sites) were measured in fifty-seven pregnant women with low energy and protein intake, at weeks 24, 30 and 35 of gestation.2. Women were classified in two groups (overweight and low weight), according to their weight-for-height at week 24 of gestation.3. Half of the women did not increase, or even reduced the amount of subcutaneous fat during the observation period. The lowest mean value of total skinfold thickness was found in the low-weight women who showed a reduction of the subcutaneous fat.4. This finding shows that a significant proportion of malnourished women do not follow the average pattern of subcutaneous fat accumulation seen in healthy pregnant women without food intake restriction, during the second half of pregnancy.
Behaviour, brain and body growth of guinea-pigs after prenatal growth restriction
Authors: Byrne Elizabeth A. , Smart J. L. , Dobbing J. , Sands Jean 
Published: May 2005

1. Guinea-pigs were growth-retarded in early life by feeding their mothers a restricted quantity of food during the second half of pregnancy. After birth, all animals were fedad lib.Body-weights were recorded weekly and behavioural tests were made on adult males. The animals were then killed and their brains dissected into forebrain, cerebellum and brain stem. These regions were weighed and DNA-phorphorus content measured.2. At 14 weeks each male was paired with another male for 10 min on four consecutive days and their social behaviour scored. Tests 1 and 2 were on like-treatment pairs and tests 3 and 4 on unlike-treatment pairs. At 25 weeks the same animals were subjected to six graded series of brief, unavoidable shocks and their responses recorded. After 3 d, thresholds of aversion to electric shock were measured by recording the period of time spent on the ‘safe’ side of a rectangular box at five shock levels.3. Undernourished guinea-pigs were significantly lighter than controls at birth but not at adulthood. Regional brain weights and DNA-P content of previously-undernourished guinea-pigs were significantly lower than those of controls, with the greatest deficit in brain stem.4. Pairs of previously-undernourished guinea-pigs began to interact more quickly and threatened and nosed each other more often than pairs of controls. In mixed pairs previously-undernourished animals chased controls more than their control partners chased them. There were no differences between groups in responsiveness to unavoidable shock or in aversion thresholds.
The influence of a maternal diet rich in linoleic acid on brain and retinal docosahexaenoic acid in the rat
Authors: Sanders T. A. B. , Mistry M. , Naismith D. J. 
Published: May 2005

1. Female rats were given throughout pregnancy and lactation a semi-synthetic diet, in which the fat was provided entirely by a soft margarine rich in linoleic acid (18:2ω6) or by mixture of butter and lard, and the influence on the fatty acid composition of fetal and pup brain and retinal phosphoglycerides was studied.2. The percentage of docosahexaenoic acid (22:6ω3) was much lower but that of docosapentaenoic acid (22:5ω6) was correspondingly higher in the brains of the day-22 fetuses and the 21-d-old pups from the margarine group compared with those from the group given the animal fats. Similar changes were noted in the synaptosomal and retinal phosphoglycerides, being most marked in the ethanolamine phosphoglycerides.3. The remaining pups from two groups were weaned on day 21 post partum on to the same stock diet that contained preformed 22:6ω3. After 9 weeks of this diet, the differences between the two groups in the fatty acid composition of the brain phosphoglycerides were barely discernible. The percentage of 22:5ω6 had decreased and had been replaced by 22:6ω3.4. It is concluded that the consequences of consuming a diet rich in linoleic acid and almost devoid of 22:6ω3 on brain fatty acid composition deserve consideration in man.
Intestinal radiocalcium absorption in the goat: measurement by a double-isotope technique
Authors: Hove Knut 
Published: May 2005

1. Intestinal radiocalcium absorption was measured in goats by a double-isotope technique involving injection of45CaCl2intravenously and47CaCl2into the abomasum. Cumulative absorption of radiocalcium was calculated by deconvolution analysis form curves of plasma radioactivity.2. Repeated measurements at 2 d intervals gave highly reproducible results (r0.94,P< 0.001). No systematic difference between two consecutive measurements was observed. A good agreement between absorption of radiocalcium from simultaneously administered47CaCl2and45Ca-labelled hay (r0.93,P< 0.001) seems to justify the use of inorganic47Ca as a tracer for Ca in ruminant diets.3. Two- to three-fold increases in radiocalcium absorption 48 h after oral treatment with 1,25- dihydroxycholecalciferol or leaves ofSolanum malacoxylonshowed the usefulness of the method in situations of rapidly changing Ca absorption.4. Endogenous adaptations in intestinal radiocalcium absorption from 20 to 43% were observed in lactating goats when Ca intakes decreased from 12 to 4 g/d.5. It is concluded that the double-isotope technique is a suitable method for studies of Ca absorption in ruminants when tracer is introduced into the abomasum. The test is completed in 3–4 h and may therefore be used in situations where the absorption of Ca undergoes rapid changes.
Influence of dietary phosphorus and sulphaguanidine levels on P utilization in rats
Authors: Moore Robert J. , Reeves Philip G. , Veum Trygve L. 
Published: May 2005

1. The effects of dietary phosphorus and sulphaguanidine levels, and sex differences on: (a) phytate digestibility, (b) calcium and P utilization, (c) the activities of alkaline phosphatase (EC3.1.3.1), alkaline phytase (EC3.1.3.8) and acid phosphatase (EC3.1.3.2) in the intestinal mucosa of male and female rats were investigated.2. There was a linear increase in femur ash, Ca and P contents and the maximum force withstood by the fresh femurs as dietary P level was increased from 1.5 to 3.0 to 4.5 g/kg diet.3. The apparent digestibilities of Ca, P and phytate-P decreased as the level of P in the diet increased. Rats given the diets with 1.5 or 3.0 g P/kg were hypercalciuric and hypophosphaturic compared with rats receiving 4.5 g P/kg diet.4. The level of Ca retained was similar for all treatments. The level of P retained increased as the dietary P level increased. This suggests that P deprivation was a result of inadequate amounts of P retained and not due to the absorption of inositol phosphates formed during the enzymic hydrolysis of phytate.5. The addition of sulphaguanidine increased phytate digestibility without changing the activities of acid and alkaline phosphatase or alkaline phytase of the intestinal mucosa. This suggests that these enzymes did not play a role in the increase in phytate digestibility. However, dietary sulphaguanidine enhanced phytate digestibility, suggesting that alterations in the diet which modify either the composition or metabolism of the gastrointestinal microflora may be beneficial in enhancing the in vivo hydrolysis of phytate.6. Differences between males and females are reported and discussed.
The zinc requirements of broiler chicks and turkey poults fed on purified diets
Authors: Dewar W. A. , Downie J. N. 
Published: May 2005

1. Chicks and turkey poults were fed for 3 weeks on low-zinc diets, prepared from purified ingredients, supplemented with zinc oxide at graded levels.2. Birds of both species given the unsupplemented basal diets grew poorly, with high mortality rates. All had severe hyperkeratosis but bone development was normal. Only when birds received diets with low concentrations of added Zn were leg abnormalities observed.3. Zn requirements were assessed visually from dose-response graphs. The chick required 18 mg Zn/kg diet for maximal live weight and 24 mg Zn/kg for maximal Zn concentration in blood serum. The responses of tibial Zn and net retention of Zn did not reach plateaux within the range of dietary Zn concentrations studied. The turkey poult's Zn requirement for maximal live weight was 25 and 28–29 mg/kg for net retention of Zn and for maximal concentration of Zn in blood plasma and in the tibia; 41 mg Zn/kg diet was required for maximal Zn in blood serum.4. Liver Zn was not correlated with dietary Zn in either species.
The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep
Authors: Barry T. N. , Manley T. R. 
Published: May 2005

1. Primary growth vegetativeLotus pedunculatuscontaining 46 and 106 g/kg dry matter (DM) of total condensed tannin and 3 and 14 g/kg DM of free condensed tannin, was cut and fed fresh at hourly intervals (750 g DM/d) to sheep fitted with permanent cannulas into the rumen and duodenum. Low- and high-tannin lotus contained respectively 41.3 and 31.6 g total nitrogen/kg DM and 132 and 152 g lignin/kg DM. The two forms of lotus were similar in carbohydrate composition.2. Nutrient intake was recorded and faecal output measured by direct collection. Digesta flow to the duodenum was estimated by measuring dilution at the duodenum of inert ruthenium phenanthroline (Ru-P) and chromium-EDTA markers continuously infused into the rumen.3. Effects attributable to condensed tannins were assessed by comparing the digestion of the two diets, and by comparing the digestion of each with predicted values for non-tannin-containing fresh forages fed at similar intakes.4. Apparent digestibility of all nutrients measured was less for high- than for low-tannin lotus (P< 0.01). The levels of cellulose digested ruminally and post-ruminally in both forms of lotus were similar to predicted values. However, less hemicellulose and readily fermentable carbohydrate (RFC; soluble carbohydrate + pectin) was digested in the rumen in sheep given both forms of lotus than would be predicted for non-tannin-containing fresh forage diets, but this was compensated for by greater post-ruminal absorption of both nutrients.5. Total N gains across the rumen (duodenal N flow – total N intake) were 1.8 and 10.5 g/d for low- and high-tannin lotusv.predicted losses of 3.7 and 2.1 g/d for non-tannin-containing fresh forages given at the same total N intakes. Post-ruminal digestion of non-amonia-N (NAN; proportion NAN flowing at duodenum) was 0.71 and 0.67 for low- and high-tannin lotus respectivelyv.0.76 for comparable non-tannin-containing fresh forages. Energy absorbed as amino acids from the small intestine was calculated to be 0.29 of metabolizable energy for both forms of lotus, compared with 0.17 and 0.21 for perennial ryegrass and white clover.6. It was concluded that the presence of condensed tannins in lotus markedly increased post-ruminal NAN absorption compared with non-tannin-containing fresh forage diets, but depressed ruminal digestion of RFC and hemicellulose.
Protein utilization in the young steer: digestion and nitrogen retention of 15N-labelled rumen bacterial protein
Authors: Salter D. N. , Smith R. H. 
Published: May 2005

1. 15N-labelled mixed rumen bacteria, obtained from a steer that had received [15N]urea in its diet, were disrupted ultrasonically and freed from nucleic acids and their degradation products. Samples were subjected to a simulated abomasal digestion with pepsin.2. The digests were infused with a non-absorbable marker (polyethylene glycol) into the duodenum of four steers equipped with simple duodenal and re-entrant ileal cannulas and adapted to a diet of barley straw, flaked maize and urea. The outflow from the ileum was collected for 6–7 h. The mean value for the digestibility of 15N bacterial proteins in the small intestine was estimated to be 0.74.3. [14C]urea was administered intravenously during the infusion of the 15N-labelled protein into the duodenum. Urine and faeces were collected for the next 48 h and the proportion of urea-N produced, that was excreted in the urine, estimated from urine 14C excretion. Total urea 15N production was estimated from this value and the amount of 15N excreted in the urine. The mean proportion of 15N absorbed that was deposited in body protein, 0.70, was calculated by difference. The over-all efficiency of utilization of 15N in the infused rumen bacterial protein was 0.52.4. An approximate estimate of the mean rate of protein synthesis calculated from the data was 24 g/kg body-weight (W)0.75 per d and compared with an estimated net deposition of protein of 1.67 g/kg W0.75 per d.5. The importance of these values in factorial schemes for estimating ruminant N requirements is discussed.
Stability of tryptophan during food processing and storage
Authors: Nielsen Henrik K. , Klein A. , Hurrell R. F. 
Published: May 2005

1. Tryptophan losses in stored milk powders and in different model systems representing the major reactions of food proteins during processing and storage were determined using four different chemical methods and in a rat assay.2. Similar tryptophan values were obtained by the three chemical methods which included high pressure liquid chromatography (HPLC) after sodium hydroxide hydrolysis. colorimetric reaction withp-dimethylamino- benzaldehyde (p-DAB) after barium hydroxide hydrolysis, and fluorescence of the Norharman derivative after NaOH hydrolysis.3. Tryptophan losses in the treated proteins as measured by the alkaline-hydrolysis methods were generally smaller than those determined by the rat assay. Good agreement however was obtained when the chemical value was multiplied by the true nitrogen digestibility.4. Determination of tryptophan by reaction withp-DAB after papain (EC 3.4.22.2) digestion gave lower values in the processed proteins than the other chemical methods or the rat assay.5. A method using alkaline-hydrolysis is recommended, preferably combined with HPLC-measurement of the liberated tryptophan.