bluuebunny/crossref_metadata_2025 huggingface dataset:
An estimate of the nutrients utilized for pregnancy by Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M.
Published: June 2005

1. Fifty-one pregnant fine-wool Merino ewes were slaughtered at intervals during pregnancy. The gravid uteri were dissected and were separated into uterus, membrane and fluid, and foetus fractions, which were analysed separately for water, nitrogen, ash, fat, calcium, phosphorus, sodium and potassium content.

2. Uteri from twenty-one similar non-pregnant ewes were also analysed for these constituents.

3. A number of relationships between the composition of the gravid uterus minus the composition of the uterus taken from non-pregnant sheep, and time from conception were calculated.

4. The rate of nutrient deposition was calculated from these relationships and estimates were made of the nutrients utilized for pregnancy.
The absorption of [58Co]cyanocobalamin by unweaned rats
Authors: Williams D. L. , Spray G. H.
Published: June 2005

1. ‘58Co’cyanocobalamin was given by stomach tube to Wistar albino rats aged between 6 h and 24 days. The fraction of the dose absorbed was assessed by measuring the amount retained by the animals after 7 days, by total body counting.

2. Rats up to 4 days old absorbed about 90% of the test dose, compared with a mean of 83% at the age of 8 days, 66% at 16 days and 47% at 24 days.

3. The proportion of the test dose absorbed did not appear to be affected by starvation for up to 24 h, by increasing the dose from 0·05 ng to 0·25 ng/g body-weight, or by giving the ‘58Co’cyanocobalamin mixed with rat's milk.

4. The results support earlier suggestions that newborn rats absorb vitamin B12 by a different mechanism from that in adults.
Serum enzyme changes, muscular dystrophy and erythrocyte abnormalities in lambs fed on diets containing cod-liver oil and maize oil, and the therapeutic effect of vitamin E
Authors: Boyd J. W.
Published: June 2005

1. Lambs fed on skim milk containing either maize oil or cod-liver oil or both were observed for signs of muscular dystrophy, changes in serum enzymes and increases in the susceptibility of red cells to haemolysis by peroxide (peroxide haemolysis).

2. Four lambs fed on the milk containing cod-liver oil, and not receiving α-tocopheryl acetate injections, developed acute muscular dystrophy, but no abnormal changes occurred in peroxide haemolysis, packed cell volume or haemoglobin concentration in the blood. Marked increases occurred in the aspartate transaminase, alanine transaminase and glutamate dehydrogenase, and in lactate dehydrogenase isoenzyme activities of the serum, presumably due to leakage from the degenerating tissues. One lamb given weekly injections of 100 mg α-tocopheryl acetate remained clinically normal and maintained normal serum enzyme levels. Treatment of dystrophic animals with 200 mg α-tocopheryl acetate by injection produced prompt clinical recovery and an exponential decline in the raised serum enzyme activities.

3. In the five lambs fed on the skim-milk containing maize oil, muscular dystrophy did not occur. Small but significant increases occurred, however, in serum aspartate transaminase and glutamate dehydrogenase activities. In all five animals peroxide haemolysis was greatly increased, but in only two did packed cell volume and haemoglobin values fall slightly below the lower limit of normal (mean − 2 × SD). Injections of 100–200 mg α-tocopheryl acetate neither prevented nor cured the abnormally high levels of serum enzymes and peroxide haemolysis, although a change in the diet was followed by a gradual return to normal. In one lamb given massive doses of α-tocopherol by mouth, peroxide haemolysis was not reduced. Large amounts of α-tocopherol added in vitro to erythrocytes from the lamb did, however, prevent peroxide haemolysis.

4. Peroxide haemolysis did not increase in any of three lambs fed on skim milk containing both maize oil and cod-liver oil, although two of them, which were given much larger amounts of cod-liver oil than the third, developed muscular dystrophy with elevated serum enzyme levels.

5. Peroxide haemolysis in lambs is evidently not a measure of vitamin E deficiency. It is suggested that increased peroxide haemolysis in lambs, like encephalomalacia in chicks, depends on the fatty acid composition of the unsaturated lipids in the diet.
Absorption of sugars by the piglet
Authors: Kidder D. E. , Manners M. J. , McCrea M. R. , Osborne A. D.
Published: June 2005

1. Diets containing various sugar mixtures together with polyethylene glycol of high molecular weight as a marker were fed to pigs 1, 2 and 3 weeks old. The piglets were slaughtered 2.5 h later, and the ratio of sugar to marker was determined in the contents of the alimentary tract as far as the caecum.

2. The greatest fall was found in the first part of the small intestine.

3. Glucose had always disappeared by the third quarter of the small intestine.

4. Xylose and fructose disappeared more slowly, especially in the younger pigs, but were usually absent from the contents of the last quarter of the small intestine.

5. Sucrose was removed far less completely, and the ratio of sucrose to marker frequently did not decrease along the second half of the small intestine. Sucrose was removed much less efficiently when it formed 15% of the diet than when it formed only 5%, and much less efficiently by the younger than by the older pigs.
The variability of vitamin C in our diet
Authors: Allen R. J. L. , Brook M. , Broadbent S. R.
Published: June 2005

1. The variability in the purchase and consumption of vitamin C in the diet of people living in the United Kingdom has been studied using the Annual Reports of the National Food Survey Committee and new observations gathered independently.

2. The sources of variability examined have been family household composition, social class, seasonal and week-to-week sampling variation.

3. The distribution of mean household daily intakes of vitamin C approximates closely to a log-normal distribution. Assuming this to be so, it may be calculated that about one-quarter of households have vitamin C intakes averaging less than the 30 mg/person per day recommended by the British Medical Association Committee on Nutrition to provide a good margin of safety. Households with intakes below 20 mg/person per day may average 5% of the total. These percentages fall during the late summer and rise correspondingly in the remainder of the year.

4. Allowing for the many uncertainties involved, it is suggested that up to 10% of households and an even greater proportion of individuals may have a vitamin C intake that is permanently below 30 mg/person per day.
The nutritive value of groundnut protein
Authors: Woodham A. A. , Dawson R.
Published: June 2005

1. A laboratory-prepared groundnut flour defatted at room temperature (DGF) was subjected to dry heat or to pressure steaming under varying conditions of time and temperature, and its amino acid composition and nutritive value, the latter assessed by a chick growth test—the gross protein value (GPV) test, were compared with those of some commercial groundnut meals. Trypsin inhibitor activity, available lysine value (ALV) and ‘arachin’ and ‘conarachin’ content and, in some instances, GPV were estimated in the heated samples.

2. The amino acid composition of the DGF and of commercial meals of high, medium and low GPV did not differ markedly, and the GPV of the DGF fell within the range of the three commercial samples.

3. Both dry and moist heat under specified conditions lowered ALV in the DGF and in the ‘arachin’ fractions, but had little effect on the ALV of the ‘conarachin’ fraction.

4. Moist, but not dry, heat rapidly removed trypsin inhibitor activity, and dry, but not moist, heat lowered GPV.

5. Neither ‘conarachin’ content nor trypsin inhibitor activity correlated with GPV in a range of commercial groundnut meals.

6. Dry heat (125. for 5 h) lowered nutritive value and ‘conarachin’ content but did not reduce the amount of total nitrogen soluble in sodium chloride solution.

7. No trypsin-inhibiting activity was found in the testa (skins) but these did exhibit growth-depressant properties for chicks. This property was removed by mild moist heat treatment.

8. ‘Arachin’ isolated from a commercial groundnut meal was valueless as a protein supplement for a cereal ration for chicks; ‘conarachin’ by itself, and mixed with arachin (1:3) was equivalent in GPV to the parent meal.

9. A factor other than those considered here, and possibly unassociated with processing, is primarily responsible for the differences in growth-promoting qualities of the commercial groundnut meals used in this work.
Manganese in the nutrition and metabolism of the pullet
Authors: Hill R. , Mathers J. W.
Published: June 2005

1. The first two experiments were similar; pullets were given either a low-manganese diet, 6–7 μg/g, or a high-Mn diet containing an additional 50 μgMn/g; shell thickness as measured by weight per unit area was obtained for the first four and the last four eggs produced during a short laying period and the Mn contents of the first two and last two eggs were determined.

2. Shell thickness was significantly reduced by the low-Mn diet in Expt 1, but not in Expt 2. In both experiments there was an increase in thickness from the first four to the last four shells produced.

3. The Mn content of eggs from birds given the low-Mn diet was significantly lower in both experiments than that from birds given the high-Mn diet. In Expt 1 there was an increase in Mn content from the first to the last eggs laid, but no corresponding change occurred in Expt 2.

4. The differences between the results of the two experiments are discussed; they were probably due to differences in the time for which the experimental diets were given before laying began.

5. In Expt 3 pullets were given the high-Mn or low-Mn diet from about 4 weeks before laying began or the high-Mn diet to the point-of-lay and then the low-Mn diet. Shell thickness was determined in batches of six eggs from each bird at intervals during a 6- to 7-month laying period.

6. Shell thickness was depressed by the low-Mn diet in birds given this diet 4 weeks before laying but not in those given the low-Mn diet from the point-of-lay.

7. In Expt 4 shell thickness was determined on the first thirty eggs laid by four pullets given the high-Mn diet and four given the low-Mn diet from about 4 weeks before starting to lay. The difference between shells from birds given the high-Mn and low-Mn diets just failed to reach significance and there was no significant increase or decrease in the series of thirty shells from each bird, studied in successive groups of six shells.
Beneficial and ineffective levels of selenium for growth and muscular dystrophy
Authors: Desai I. D.
Published: June 2005

1. The effectiveness of supplementing a vitamin E-deficient basal diet with levels from 0 to 20 ppm of selenium as sodium selenite, alone and in combination with graded levels of L-cystine, sodium sulphate, L-serine and vitamine E, has been studied in chicks from 1 day of age to 4 weeks. Supplementation with Se at levels up to 1 ppm had maximum beneficial effects on growth and prevention of muscular dystrophy. Levels of Se above 1 ppm were progressively less effective, and, in chicks given supplements of 20 ppm Se, growth and muscular dystrophy were depressed to that found with chicks given the basal diet.

2. Supplementation with L-cystine (0.08% and 0.16%) in combination with Se up to 1 ppm was beneficial, but this effect was progressively suppressed as the amount of Se was increased beyond this level. Supplementation with sodium sulphate (0.08% and 0.16%) or L-serine (0.08% and 0.16%) instead of L-cystine had no influence on the effectiveness of Se at any level of the latter tested.

3. The effectiveness of dietary D-α-tocopheryl acetate, up to 20 mg/kg, for growth and in the prevention of muscular dystrophy was improved by Se at levels up to 1 ppm. Its effectiveness was then progressively reduced as the amount of Se was increased above 1 ppm.

4. It appears that Se at low levels spares L-cystine and vitamin E in the chick, whereas at high levels it increases their requirement for growth and prevention of muscular dystrophy.
Effects of dietary excesses of vitamins A and D on some constituents of the blood of chicks
Authors: Taylor T. G. , Morris K. M. L. , Kirkley Jean
Published: June 2005

1. Groups of chicks were given diets containing four levels of vitamins A and D, 1, 10, 100 and 1000 times the basal level, in all sixteen combinations, with the object of investigating a possible antagonism between the two vitamins.

2. Only diets containing 1000 times the basal level (approx. 1700 times the dietary requirements) of one or both vitamins depressed growth and induced changes in the blood.

3. The packed cell volume was substantially reduced from 4 weeks of age in the chicks given the highest level of vitamin A. It is suggested that this was due to an effect of the vitamin on the fragility of the red cells and thus on their life span.

4. Chicks given the toxic level of vitamin D showed an increase in plasma calcium and a decrease in plasma inorganic phosphorus. The highest level of vitamin A depressed plasma Ca without influencing plasma inorganic P. Increasing amounts of vitamin A given in combination with the highest level of vitamin D caused a progressive increase in the plasma inorganic P.

5. The highest level of dietary vitamin A significantly increased the activity in the plasma of three lysosomal enzymes: acid phosphatase, β-glucuronidase and arylsulphatase. Excess vitamin D given in conjunction with the basal level of vitamin A significantly depressed the plasma acid phosphatase and the activity of this enzyme increased with increasing amounts of vitamin A. Excess vitamin D had no influence on the other hydrolases studied.

6. A marked antagonism between the effects of excessive amounts of the two vitamins occurred only in respect of their actions on the plasma levels of Ca, inorganic P and acid phosphatase, all of which are involved in bone metabolism.
Quantitative aspects of intestinal fat absorption in young pigs
Authors: Freeman C. P. , Noakes D. E. , Annison E. F. , Hill K. J.
Published: June 2005

1. The uptake of lipid by the small intestine of the pig was examined by the perfusion of a segment of the jejunum with radioactively labelled lipid in vivo. The rate at which lipid was presented to the small intestine under specific dietary regimes was also examined by means of re-entrant fistulas in the duodenum and jejunum.

2. The capacity of the small intestine to absorb micellar lipid, prepared in vitro or isolated from intestinal contents, was much in excess of the normal rate of flow of fat into the small intestine.

3. There was little uptake of lipid when emulsions of oleic acid were examined, suggesting that the absorption of particulate fat is probably of little importance in pigs.

4.No specificity in the removal of fatty acids from their mixed micellar solutions was observed.
Absorption of vitamin C from the human buccal cavity
Authors: Sadoogh-Abasian F. , Evered D. F.
Published: June 2005

1. Ascorbic acid was absorbed across the mucosa of the human mounth.

2. Omission of sodium ions from the medium decreased the absorption of ascorbic acid.

3. The presence of D-glucose, or 3-O-methyl-D-glucose, incrased the absorption of ascorbic acid but D-fructose had little effect and D-mannitol had no effect.

4. Calcium ions also increased ascorbic acid absorption probably by a secondary effect on Na+fluxes.

5. Buccal mucosa was also premeable to dehydroascorbic acid and D-isoascorbic. acid
Long-term vitamin status and dietary intake of healthy elderly subjects
Authors: Bates C. J. , Rutishauser Ingrid H. E. , Black Alison E. , Paul Alison A. , Mandal A. R. , Patnaik B. K.
Published: June 2005

1. Long-term clinical and biochemical vitamin C (ascorbic acid and dehydroascorbic acid) status and dietary intake of vitamin C were monitored for 18 months in twenty-three relatively-healthy elderly subjects living at home in the north of England.

2. Plasma vitamin C showed a strong positive correlation with buffy-coat vitamin C both cross-sectionally between subjects and longitudinally within subjects; plasma levels, therefore, were almost as good an index of long-term status as buffy-coat levels.

3. Vitamin C intake was strongly correlated with plasma and with buffy-coat levels both between subjects and within subjects. This contrasts with the poor correlation observed between riboflavin intake and biochemical riboflavin status in the same subjects.

4. Subjects with relatively high average intakes showed considerable seasonal variation, and several widely-spaced measurements would be needed to characterize their long-term status accurately. Those with low average intakes and blood levels showed little variation during the study.

5. The strongest within-subject correlation was obtained by relating the biochemical values to the 7 d dietary intake directly preceding the biochemical analysis. Blood and tissue levels therefore appear to be strongly related to the current dietary intake.

6. Although some subjects had blood vitamin C levels consistently within the region associated with biochemical deficiency, none showed clinical evidence of specific deficiency symptoms.

7. After the main study, fifteen of the subjects received supplementary vitamin C for 2 months. Plasma and buffy-coat levels rose sharphy, but fell to presupplementation levels within 1 month of withdrawal, emphasizing the transitory nature of increased tissue levels. No significant changes were detected in the following collagen-related urinary ratios: hydroxyproline: creatinine, proline: creatinine, proline: total amino-nitrogen and proline: hydroxyproline in hydrolysates either of whole urine or of various fractions. These variables thus appear to be insensitive to short-term changes in vitamin C status over the ranges encountered in this study.
Copper, iron, manganese and zinc concentrations in the carcases of lambs and calves and the relationship to trace element requirements for growth
Authors: Suttle N. F.
Published: June 2005

1. The minced carcases of twenty-seven lambs, ranging from 18 to 69 kg in live weight, and twenty-five calves (30–90 kg) were analysed for copper, iron, manganese and zinc. The lambs were weaned whereas the calves were reared exclusively on milk.

2. Mean concentrations of Fe, Mn and Zn for groups of lamb carcases fell within the ranges 52.6–75.1, 0.7–1.2 and 20.8–25.6 mg/kg fresh carcase weight respectively. The concentrations of Fe and Mn decreased while that of Zn increased slightly with age at slaughter. The concentrations of Fe, Mn and Zn in calves were close to thosein lambs.

3. For both species, the concentration of Cu in the carcase varied erratically: variation in hepatic Cu storage was implicated. In an additional study of ten full-term foetuses from Cu-depleted or Cu-supplemented ewes, a dietary Cu supplement (10 mg/kg dry matter (DM)) increased foetal Cu status 10-fold, due largely to an increase in foetal liver Cu.

4. The mean retentions of trace elements in the lamb carcases (%intake) were approximately: Cu 2.0, Fe 1.3, Mn 0.08, Zn 4.0. The corresponding values for the milk-fed calves were all probably much higher (Cu 23, Fe 43.7, Mn 4.9, Zn 34.0) but Cu intake was not accurately measured.

5. After allowing for tissue storage of Fe and Mn, values of 55, 0.85 and 24 mg/kg carcase gain were taken to represent the approximate net growth requirements of lambs for Fe, Mn and Zn respectively: the corresponding value for Cu was probably < 1.0 mg/kg. Values for calves were similar to those for lambs.

6. It was concluded that the total net requirements of ruminants for Fe and Zn shouldbe considered in terms of daily intakes of the metans rather than dietary concentrationsbecause of the relatively large and constant contribution of the growth component to thetotal requirement.
Influence of the level of dietary phosphorus on the voluntary intake of energy and metabolic utilization of nutrients in the growing rat
Authors: Henry Y. , Gueguen L. , Rérat A.
Published: June 2005

1. An experiment was carried out on growing male rats to study the effects of a phosphorus deficiency on voluntary energy intake, estimated by the separate-feeding technique, as well as the consequences on growth and metabolic utilization of energy, protein and minerals. After a preliminary period of P deprivation, three groups of twelve animals were fed separately and simultaneously two dietary rations. A protein ration provided 1.2 g protein/d to which was added one of three levels of P in the form of monosodium phosphate: a normal level of 35.4 mg/d (treatment A), half the normal level (19.1 mg/d, treatment B) or one-quarter the normal level (9.6 mg/d, treatment C). Another protein-free ration was fedad lib.

2. It was only when the level of P represented one quarter the normal level that a significant decrease in growth rate was noticed, accompanied by a definite decrease in daily energy consumption. The food conversion ratio (g dry matter intake/g body-weight gain) increased whereas the protein efficiency ratio (g body-weight gain/g protein intake) was lower. The nitrogen and energy retentions changed in the same way: both dectreased with treatment C compared to treatment A and B. Independently of the protein supply, the voluntary energy intake was closely related to the intensity of protein retention, which depended on the dietary level of P. The daily retention of P only slightly decreased at the lowest ingestion level (9.6 mg/d in treatment C), compared to that of the higher levels. On the other hand, the amount of calcium retained regularly decreased with the decreasing supply of P. The result of this was a progressive reduction in retained Ca:P as the level of P decreased.

3. From these results it appeared that the primary effect of a P deficiency in the growing rat was a decrease in bone mineralization. At a more advanced stage, the tissue P levels were affected and the resulting metabolic alterations reduced protein deposition and consequently the voluntary energy intake. The level of energy consumption, in separate-feeding, is more generally dependent on the level of protein deposition allowed by the limiting factor for growth, either protein, minerals or vitamins.
Studies on digestion and absorption in the intestines of growing pigs
Authors: Sambrook I. E.
Published: June 2005

1. Seventeen pigs were fitted with single re-entrant cannulas in either the duodenum (posterior to the entry of the bile and pancreativ ducts), the mid-jejunum, or the terminal ileum. A further twenty-four pigs were used in a conventional digestibility trial.

2. Three diets were used: these contained barley, fine wheat offal, white fish meal, minerals and vitamins (diet BWF); starch, sucrose, maize oil, cellulose, minerals, vitamins and either groundnut meal (diet SSG) or casein (diet SSC).

3. The quantities of total carbohydrate (TC), total reducing substances (TRS) and glucose (G) passing through the re-entrant cannulas and excreted in the faeces in 24 h were measured. These were used to determine the net absorption of the carbohydrate fractions in the different regions of the intestine.

4. The small intestine was the principal site of absorption of TC, TRS and G, but there were differences between the diets in the quantities of each of these carbohydrate fractions that were absorbed in the different regions of the small intestine studied.

5. The quantities of TRS and G in solution were very low for all diets at all sites, indicating that the rate of absorption of the products of hydrolysis kept pace with their rate of formation.
The effects of breads containing similar amounts of phytate but different amounts of wheat bran on calcium, zinc and iron balance in man
Authors: Andersson H. , Nävert B. , Bingham S. A. , Englyst H. N. , Cummings J. H.
Published: June 2005

1. The capacity of wheat bran to impair mineral absorption independent of its phytate content was studied by metabolic balance studies in man.

2. Three breads were prepared, equivalent to white, brown and wholemeal, by adding bran in different quantities to white flour. Calcium, iron, zinc and sodium phytate were added to the loaves to make the amounts equal in all breads.

3. Six healthy volunteers were studied for three consecutive 24-d-periods during which they ate a controlled diet, typical of that normally consumed in the UK but with 200 g bread/d. Only the type of bread changed between each dietary period.

4. The phytate contents (mmol) of 200 g of each of the breads after baking were: white 2·3, brown 2·1 and wholemeal 2·2; non-starch polysaccharide contents (9) were: white 3·3, brown 10·9 and wholemeal 18·7

5 . The increased amount of bran in the breads increased stool output in the expected way but no change was seen in Ca, Zn and Fe balance. Blood levels of these minerals remained unchanged.

6. It is concluded that wheat bran and, in particular, the cell-wall polysaccharides of bran, are unlikely to exert a significant effect on mineral absorption in man, in amounts customarily eaten, independently of the effect of phytate present in the bran.
Evaluation of a mathematical model of rumen digestion and an in vitro simulation of rumen proteolysis to estimate the rumen-undegraded nitrogen content of feedstuffs
Authors: Krishnamoorthy U. , Sniffen C. J. , Stern M. D. , Van Soest P. J.
Published: June 2005

1. Twelve grain mixtures, one lucerne (Medicago sativa) hay and one maize silage which had been used in mixed diets for which dietary nitrogen undegraded in the rumen (UDN) had been estimated with duodenally-cannulated cows, were studied. Total N in the feeds was fractionated into pool A (N soluble in borate–phosphate buffer), pool B (total N–(pool A + pool C)) and pool C (acid-detergent-insoluble N or residual N after 24 h incubation in protease solution).

2. N solubilization in protease solution containing 6·6 units/ml (substrate-saturating enzyme concentration) indicated the presence of subfractions in pool B, with different rates of solubilization. Such subfractions were not detectable fromin situ, Dacron bag, estimates of N solubilization.

3. UDN was estimated using a dynamic mathematical model and rate-constants obtained from N solubilization in protease solution orin situ.For three grain mixtures tested using the protease technique the model predicted UDN values of 7, 10 and 12% compared with values of 47, 66 and 59% estimated in vivo. The full range of experimental feeds was tested using thein situtechnique and UDN values predicted by the model were used to derive UDN values for twelve mixed diets. The latter values were significantly but not closely correlated with those determined in vivo (r20·41,P< 0·05).

4. An attempt was made to simulate rumen proteolysis in vitro by choosing a protease enzyme concentration (0·066 units/ml) providing a proteolytic activity similar to that of whole rumen fluid. The experimental samples of feed were subjected to simulated rumen proteolysis for 18 or 48 h to resemble the mean retention times in the rumen for grain mixtures and roughages respectively. The residual N at the end of incubation was considered as an estimate of UDN. The UDN values estimated from simulated rumen proteolysis and those determined in vivo for twelve mixed diets were in close agreement (r20·61,P< 0·01).

5. Simulated rumen proteolysis can serve as a simple, rapid and sensitive method to estimate UDN in a variety of feedstuffs.
Neonatal role of milk folate-binding protein: studies on the course of digestion of goat's milk folate binder in the 6-d-old kid
Authors: Salter D. N. , Mowlem A.
Published: June 2005

1. Groups of kids were reared from birth to 5 d on goat's milk. On the 6th day five of the kids received by bottle a morning feed of goat's milk with [3H]folic acid added to saturate the folate-binding proteins (FBP) (Expt 1); three kids received raw goat's milk containing only the endogenous folate and hence a large surplus folate-binding capacity (FBC) (Expt 2). The contents of the stomach, duodenum, jejunum and ileum were recovered by washing out 1·5 h after feeding (Expt 1) or at 0·5, 1 and 3·5 h after feeding (Expt 2).

2. Recovery of [3H]folic acid 1·5 h after feeding (Expt 1) in all segments was 58·4%, mainly in a soluble form, most of this being in the stomach (37·0%) and ileum (14·3%). No surplus FBC was found in any gut segment. Sephadex G-75 chromatography of the soluble fractions of the contents of the various gut segments showed that [3H]folic acid remained bound to FBP throughout the stomach and small intestine. The bound [3H]folic acid exhibited a molecular weight of 81000 in stomach contents, similar to that in the milk feed, presumably representing an aggregated form of the FBP, whereas in the intestinal contents its molecular weight was 39000 indicating dissociation to monomer due to dilution in the recovery process.

3. In Expt 2, the total recovery of free FBP in all four gut segments was 67, 54 and 23% respectively at 0·5, 1 and 3·5 h after the milk feed, and the distribution of FBP along the gut at 1 h was similar to that of [3H]folic acid-labelled FBP at 1·5 h in Expt 1. In mature goat's milk the endogenous 5-methyltetrahydrofolate was shown to be associated with species of molecular weight 80000 and 38000.

4. The results indicate that goat's-milk FBP is relatively resistant to digestionby gastric and intestinal enzymes in vivo in the kid and survives along the length of thesmall intestine.

5. The implications of the findings are discussed in relation to the possible influence of FBP on uptake of folate by mucosal cells and their relevance to neonatal folate nutrition.
The influence of protein nutrition in early life on growth and development of the pig
Authors: Campbell R. G. , Dunkin A. C.
Published: June 2005

1. The effects of feeding either high-protein (HP) or low-protein (LP) diets between 1·8 and 15 kg live weight (LW) and a low-energy (LE) or high-energy (HE) intake subsequently on the cellularity of muscle and adipose tissue in pigs growing to 75 kg LW were investigated.

2. The effects of the nutritional treatments on muscle tissue were assessed from the weight and DNA content of them. adductor. For adipose tissue the total DNA content and fat cell size of the subcutaneous adipose tissue contained in the left shoulder joint were determined.

3. Feeding the LP diets in early life reduced the weight and DNA content of them. adductor (P< 0·01) and increased fat cell size (P< 0·01) at 15 kg LW.

4. Subsequent to 15 kg there was an almost linear increase in muscle DNA with increasing LW, and the difference between pigs from the initial protein treatments progressively diminished and was no longer apparent at 60 kg LW.

5. At 30 kg LW, pigs given the LP diets before 15 kg LW contained less DNA in the subcutaneous adipose tissue from the shoulder joint (P< 0·01) and had larger fat cells (P< 0·05) than pigs given the HP diets initially. However, adipose DNA and fat cell size increased with increasing LW and the differences resulting from the initial protein treatments progressively diminished. On the LE and HE treatments subsequent to 15 kg these differences were no longer evident at 45 and 60 kg respectively.

6. Pigs given the HE intake subsequent to 15 kg, contained less DNA in muscle tissue (P< 0·05) at 60 and 75 kg LW and had larger fat cells (P< 0·05) at 45, 60 and 75 kg LW, than pigs on the LE treatment.
Mammalian small intestinal phytase (EC3.1.3.8)
Authors: Cooper John R. , Gowing Helen S.
Published: June 2005

1. Phytase (EC3.1.3.8) concentration has been measured in the small intestineof rat, rabbit, guinea-pig and hamster. Levels varied from 0·12 units (μg phosphorus released/min)/mg protein in the rat to 0·03 units/mg protein in the rabbit.

2. The enzyme is localized in the brush border of the small intestine of the rat.

3. It is suggested that the levels and location of phytase are an important factor inthe uptake of metals from metal–phytate complexes. Metal ions released in the immediate vicinity of the absorptive surface of the intestine could be absorbed before being rendered insoluble by competing reactions such as hydrolysis.
A comparison of the chemical composition of mixed bacteria harvested from the liquid and solid fractions of rumen digesta
Authors: Merry R. J. , McAllan A. B.
Published: June 2005

1. Steers, equipped with simple rumen cannulas, were given diets of approximately equal parts of rolled barley and straw supplemented with urea. The diets provided sufficientestimated rumen degradable nitrogen (RDN: RDN: metabolizable energy values of 1:3) to maintain maximum microbial synthesis. In some experiments Na235SO4was introduced into the rumen to label microbial protein.

2. Rumen digesta samples were taken before feeding and mixed rumen bacteria were separated from the solid (solid-associated bacteria; SAB) and liquid (liquid-associated bacteria; LAB) fractions of digesta. The most effective method of removing SAB from the fibre was a combination of homogenizing and pummelling. This process did not affect the physical form or chemical composition of the bacteria.

3. Samples of SAB contained significantly (P≤ at least 0·05) less ash, total N, RNA and diaminopimelic acid (DAP) and significantly (P≤ 0·01) more lipid than samples of LAB. Concentrations (g/kg dry matter) of ash, total N, RNA, DAP and lipid in SAB were approximately 87, 70, 35, 2.2 and 245 respectively. Corresponding values for LAB were 157, 80, 50, 3.8 and 124 respectively.

4. RNA-N: total N and DAP-N: total N values in SAB were significantly lower than those in LAB (P≤ 0·05 and 0·02 respectively).35S: totalN values were similar in both groups of bacteria. The importance of differences in constituent: total N values in the two groups of bacteria in relation to their use as indices of microbial protein synthesis is discussed.
Winter food restriction and summer compensation in red deer stags (Cervus elaphus)
Authors: Suttie J. M. , Goodall E. D. , Pennie K. , Kaya R. N. B.
Published: June 2005

1. Twelve red deer stags (Cervus elaphus) penned individually from weaning were fed on a concentrate diet. Six stags received the diet to appetite throughout the study, and the other six were restricted to 70% of the intake of the first group during winter and then fed to appetite during summer.

2. The winter-restricted stags showed remarkable compensatory growth during summer. Compared with the unrestricted stags they showed greater food intake, greater daily live-weight gain and increased food conversion efficiency. Nonetheless, they failed to compensate fully for the previous undernutrition.

3. The hind-foot of the restricted stags failed to grow as long as that of the unrestricted stags.

4. Poor winter nutrition, particularly during the first year of life, and subsequent failure to compensate during the short periods of summer plenty, provides an explanation for the small mature size of wild stags in Scotland.

5. Although the winter-restricted stags were less fat both grossly and relative to body-weight than the unrestricted stags, both groups showed the same relationship of level of fatness to empty-body-weight. In both the groups of stags, extensive fat deposition began once they had reached about half their expected mature weight, a much later stage of development and age than in sheep and cattle.

6. The annual cycle of growth and appetite is considered to form part of a complex adaptive system to enhance survival in a harsh seasonal environment followed by a mild seasonal environment. On Scottish hills deer reach a size appropriate to their environment rather than their genetic potential size.
Physiological changes associated with the production of defective egg-shells by hens receiving sodium chloride in the drinking water
Authors: Balnave D. , Yoselewitz I. , Dixon R. J.
Published: June 2005

1. Supplementing the drinking water of laying hens with 600 or 2000 mg sodium chloride/l induced large increases in egg-shell defects without corresponding changes in egg production, egg weight or food and water intakes. A supplement of 2000 mg NaCl/l resulted in a high incidence of shell-less eggs.

2. The increased incidence of egg-shell damage in hens receiving the NaCl was associated with a decrease in egg-shell quality measured objectively. These responses persisted even after the NaCl was removed from the drinking water.

3. The NaCl treatment had little effect on blood acid-base balance and electrolytes, but significant reductions were observed in the carbon dioxide tension, and bicarbonate and calcium concentrations in the fluid surrounding the egg in the shell gland.

4. The poor shell quality appeared to be associated with a reduced supply of bicarbonate, rather than with an effect on Ca, in the lumen of the shell gland, although a reduced residence time of eggs in the shell gland may also have contributed to the problem.
The role of propionate and acetate in the control of food intake in sheep
Authors: Farningham D. A. H. , Whyte C. C.
Published: June 2005

Sheep fed ad lib. on a good-quality pelleted diet (g/kg; hay 500, barley 300, molasses, fish meal and minerals) were infused via the hepatic portal vein with mixtures of the sodium salts of volatile fatty acids, acetate and propionate, and a variety of equivalent osmotic loads. Propionate infused at rates between 0·6 and 2·5 mmol/min consistently reduced food intake in a linear, dose-related manner. Propionate infusions resulted in consistent dose-related increases in peripheral venous plasma glucose concentration but variable changes in insulin concentration. Infusion of osmotically balanced mixtures of propionate, acetate, mannitol or saline (9 g NaCI/I) indicated that at constant osmotic loading propionate caused a greater reduction in intake than other infusions. Acetate infusions only depressed food intake when administered as a 1 M solution. Lower concentrations had little effect, similar to that of equivalent osmotic loads of mannitol or saline. It is concluded that portal propionate flow has a potential role in the control of food intake in ruminants which is independent of osmotic effects or changes in plasma insulin concentration.
Relationship between hepatic fatty acid oxidation and gluconeogenesis in the fasting neonatal pig
Authors: Lepine Allan J. , Watford Malcolm , BOYD R. Dean , Ross Deborah A. , Whitehead Dana M.
Published: June 2005

Hepatocytes were isolated from sixteen fasting neonatal pigs and used in two experiments: (1) to determine the effect of various factors on the ability for hepatic oxidation of fatty acids and (2) to clarify the relationship between fatty acid oxidation and glucose synthesis. In Expt 1, newborn pigs were either fasted from birth for 24 h or allowed to suckad lib. for 3 d followed by a 24 h fast. In the presence of pyruvate, oxidation of octanoate (2 mM) was about 30-fold greater than oleate (1 mM) regardless of age, but glucose synthesis was not enhanced beyond that observed for pyruvate alone. Inclusion of carnitine (1 mM), glucagon (100 nM) or dibutryl cAMP (50 μM) in the incubation media did not stimulate either fatty acid oxidation (octanoate or oleate) or glucose synthesis. Extending the period of fasting to 48 h (Expt 2) failed to enhance the fatty acid oxidative capacity or glucose synthesis rate. Likewise, the redox potential of the giuconeogenic substrate (lactatev. pyruvate) did not influence glucose synthesis regardless of the oxidative capacity exhibited for fatty acids. These data indicate that fatty acid oxidative capacity is not the first limiting factor to full expression of gluconeogenesis in hepatocytes isolated from fasted newborn pigs.
Sugar composition of dietary fibre and short-chain fatty acid production during in vitro fermentation by human bacteria
Authors: Salvador Valérie , Cherbut Christine , Barry Jean-Luc , Bertrand Dominique , Bonnet Christian , Delort-Laval Jean
Published: June 2005

The aim of the present study was to assess the relationship between the disappearance of dietary fibre sugars and the production of individual short-chain fatty acids (SCFA). The bacterial degradation of five dietary fibres whose sugars were quantified was investigated in vitro using a human faecal inoculum. Involvement of the main fibre sugars in SCFA production was evaluated by a stepwise multiple linear regression. The results show first that the nature and chiefly the associations between the fibre sugars were key variables in the fermentability. Second, the nature and the amounts of SCFA produced were closely related to the in vitro fermentation of the main sugars available: uronic acids seemed to be principally involved in the production of acetic acid whereas the production of propionic acid could be promoted by the fermentation of glucose and, to a lesser extent, by that of xylose and arabinose. Xylose tended to have a greater impact than uronic acids and glucose on the production of butyric acid. Thus, it would be possible to predict which SCFA could be specifically produced during the fermentation of a fibre, as far as the chemical composition and structure of this fibre are known.
Effects of chronic dietary fructose with and without copper supplementation on glycaemic control, adiposity, insulin binding to adipocytes and glomerular basement membrane thickness in normal rats
Authors: Rizkalla Salwa W. , Boillot Josette , Tricottet Vivianne , Fontvieille Anne-Marie , Luo Jing , Salzman Jean-Loup , Camilleri Jean-Pierre , Slama Gérard
Published: June 2005

Sucrose feeding over a long period has been reported to induce glomerular basement membrane (GBM) thickening and insulin resistance in normal rats. These effects are attributed to the fructose moiety of the sucrose molecule, to Cu deprivation or both. Consequently, our aim was to evaluate the long-term effects of fructose feeding with normal or high amounts of Cu on body weight, plasma lipids, blood glucose regulation, GBM thickening and insulin binding to adipocytes. Four groups of eight Sprague–Dawley rats were fed for 10 weeks on a diet containing 570 g carbohydrate/kg supplied either as starch (S), dextrose (D), fructose (F) or fructose–starch (1:1, w/w; FS), and an adequate amount of Cu (12 μg Cu/g diet). A fifth group was fed on diet F supplemented with 24 μg Cu/g diet (FCu). After 10 weeks the epididymal adipose tissue and kidney weights expressed per 100 g body weight (relative weight) were heaviest in the F and FCu groups (P< 0·0001, ANOVA). The GBM thickness was within the normal range in the five groups but significantly higher in group D (1·95 (SE0·04)) nm and lower in group FS (1·79 (SE0·02)) nm when compared with group S (1·85 (SE0·03) nm;P< 0·05). Insulin binding to adipocytes (expressed per cell) was lowest in the F and FCu groups, intermediate in groups D and FS and highest in group S (P< 0·05). Fasting plasma insulin level was higher in group F than in the FCu and FS groups (P< 0·05), whereas fasting plasma glucose, total cholesterol and triacylglycerol levels remained within the normal range in all groups. We conclude that in normal rats a 10-week fructose-rich diet with an adequate amount of Cu produced deleterious metabolic effects on adipose tissue, insulin binding to adipocytes, and plasma insulin, but not on GBM thickening even though kidney weight was significantly increased. However, a moderate fructose intake mixed with other sugars did not have adverse effects.
No major differences in energy metabolism between matched and unmatched groups of ‘large-eating’ and ‘small-eating’ men
Authors: Clark Dallas , Tomas Frank , Withers Robert T. , Neville Sally D. , Nolan Stephen R. , Brinkman Menno , Chandler Colin , Clark Carol , Ballard F. John , Berry Michael , Nestel Paul
Published: June 2005

Rates of energy expenditure (J/kg fat-free mass (FFM) per min) in normal weight, ‘small-eating’ men were compared with those obtained for normal weight (n8) and underweight (n5) ‘large-eating’ men. For the matched groups of ‘large-’ and ‘small-eaters’ there were no differences in resting metabolic rate (RMR) measurements but during controlled daily activities there was a small but significant increase (P< 0.05) in energy expenditure in the ‘large-eaters’. These results contrast with those obtained for the unmatched groups where energy requirements were about 10 % (P< 0.01) higher in the underweight ‘large-eaters’ at rest but were not different during the more energetic (walking) activities. However, after adjustment for differences in FFM between these two groups, the resting energy expenditures of the ‘large-eaters’ (82·54 (SE 1·51) J/kg FFM per min) were similar to those of the ‘small-eaters’ (81·87 (SE 1·51) J/kg FFM per min). Oral temperatures were significantly higher in the matched (0·35–0·65°) and unmatched (0·7–0·9°) ‘large-eaters’ both at rest and during the different activities, but the thermic effect of food (50 kJ/kg FFM) was one fifth lower (not significant) in both groups of ‘large-eaters’. These results provide little evidence for any major metabolic differences between groups of ‘large-eating’ and ‘small-eating’ men.
Adaptive changes in energy expenditure during mild and severe feed restriction in the rat
Authors: Even Patrick C. , Nicolaïdis S.
Published: June 2005

Using a new-generation open-circuit calorimeter capable of monitoring the cost of activity, and thereby both the real thermic effect of feeding (TEF) and basal metabolism in free-moving freely-feeding rats, we have reassessed the proposal that when food intake is restricted an adaptative reduction in energy expenditure participates in the achievement of energy balance. Total energy expenditure, energy expenditure due to spontaneous activity, TEF, basal energy expenditure and respiratory quotient (RQ) were computed by indirect calorimetry in rats given either a mildly restricted (MR) feed intake for 20–30 d (17 g feed/d) or a severely restricted (SR) feed intake for 1–10 d (4 g feed/d). In MR rats no significant changes in any of the measured variables were observed. In contrast, SR rats exhibited an adaptative reduction in energy expenditure due to a reduced spontaneous activity and probably also due to a reduced basal energy expenditure. On the other hand none of the animals fed on a restricted feed intake showed an adaptative TEF decrease, suggesting that TEF under ad lib. feeding is rather an obligatory process that does not include an adaptative component. Taken together, these results point out that under restricted feeding most of the decrease in energy expenditure is associated with simple passive mechanisms, such as body weight loss, and with the reduced feed intake per se. Only under severe feed restriction can some additional energetic economy be obtained from a possible reduction of basal metabolism, and to some extent from reduced activity.
Protein requirement of young adult Nigerian females on habitual Nigerian diet at the usual level of energy intake
Authors: Egun Gloria N. , Atinmo Tola
Published: June 2005

A short-term N balance study was conducted in twelve healthy female adults aged 21–32 years to determine their protein requirement. Four dietary protein levels (0·3, 0·4, 0·5 and 0·6 g protein/kg per d) were used. Energy intake of the subjects was kept constant at 0·18 MJ/kg per d. All subjects maintained their normal activity throughout the study period. N excretion was determined from the measurements of N in a total collection of urine, faeces, sweat and menstrual fluid for each dietary period. N balance during the four protein levels were −15·15 (SD 5·95), −5·53 (SD 6·71), + 6·15 (SD 4·76) and +12·05 (SD 8·63) mg N/kg per d for 0·3, 0·4, 0·5 and 0·6 g protein/kg per d respectively. The calculated average N requirements from regression analysis was 76·0 (sd 3·37) mg N/kg per d (0·48 g protein/kg per d). The estimate of allowance for individual variation to cover the 97·5 % population was 95 mg N/kg per d (0·6 g protein/kg per d). The net protein utilization (NPU) of the diet was 0·55. When compared with a similar study with men, there was a significant difference in the protein requirement between sexes. Thus, the unjustifiable sex difference in the protein allowance recommended by the Food and Agriculture Organization/World Health Organization/United Nations University (1985) Expert Consultation group must be reviewed.