bluuebunny/crossref_metadata_2025 huggingface dataset:
The quality of protein in various lines of peas
Authors: Bajaj Satinder , Mickelsen Olaf , Baker L. R. , Markarian Deran
Published: September 2005

1. The protein quality as evaluated by nitrogen incorporation efficiency (NIE) and protein efficiency ratio (PER) was determined for twenty-eight breeding lines of peas (Pisum sativum L.) which had been grown under similar field conditions.

2. Different lines of peas, when given as the sole source of protein to weanling rats at a 10 % level in an otherwise adequate diet, varied from 18 to 78% of that of casein in their ability to support growth and nitrogen retention. There was close correlation between PER and NIE values.

3. From analysis of rat growth curves, the pea lines were separated into those that produced fairly good growth and those that barely maintained the initial body-weight. However, growth rate alone did not rank pea lines in the same order as PER or NIE.

4. Carcass protein, as a percentage of body-weight, was higher in pea-fed (20.4%) than in casein-fed rats (18.8%).This was probably associated with a difference in body fat content.

5. There was no correlation between protein quality and the protein content of the different pea lines.
Digestion of concentrates in sheep
Authors: Ørskov E. R. , Fraser C. , McDonald I.
Published: September 2005

1. Four sheep were given four diets containing proportions of rolled barley and soya-bean meal varied to provide 10.3, 13.3, 16.1 and 19.9% crude protein in the dietary dry matter; the treatments were given according to a 4 x 4 Latin square design. The mean daily intake was 989 g dry matter. The apparent disappearance of protein, ash, ether extractives and carbohydrate before the abomasum, between the abomasum and terminal ileum and between the terminal ileum and rectum was measured.

2. The amount of non-ammonia crude protein (Y1, g/d) disappearing from the small intestine increased with protein intake (X, g/d) according to the equation Y1 = 2.12X – 0.0057X2–83, reaching a maximum when there was about 19% crude protein in the dry matter of the diet.

3. The treatments had no significant effects on the disappearance of starch, ether extractives or ash. About 93% of starch disappeared in the rumen and 6% in the small intestine. The total mean daily intake of ether extractives was 21 g; 9 g were added in the rumen, 24 g disappeared from the small intestine and 6 g were excreted in the faeces. The total mean daily intake of ash was 67 g; 26 g were added in the rumen, 37 g disappeared from the small intestine, 9 g from the large intestine and 47 g were excreted in the faeces.
Digestion of concentrates in sheep
Authors: Ørskov E. R. , Fraser C. , McDonald I.
Published: September 2005

1. Diets of rolled barley supplemented with urea or fish meal at four different levels were given in a change-over experiment to four sheep with cannulas in the abomasum and in the terminal ileum.

2. Estimates were made of the disappearance of protein, ether extractives, starch, and ash in the various segments of the alimentary canal, and of the production of volatile fatty acids when the urea supplements were given.

3. The disappearance (Y, g/d) of non-ammonia crude protein from the small intestine increased with increasing protein intake (X, g/d) on the fish-meal diets according to the equation Y = 0.37X+44. There was no increase in the disappearance with the urea supplements.

4. In agreement with earlier work, it was shown that faecal nitrogen excretion was influenced to a much greater extent by fermentation in the large intestine than by that in the rumen. There was an apparent synthesis of ether-extractable lipid in the rumen at rates of 21and 18 g/d with the urea and the fish-meal diets respectively.

5. The energy of the volatile fatty acids produced when the urea diets were given was estimated to be 59% of the digestible energy consumed.
The value of hydrocarbon-grown yeast as a source of protein for growing pigs
Authors: Barber R. S. , Braude R. , Mitchell K. G. , Myres A. W.
Published: September 2005

1. The yeast grown on normal paraffins (British Petroleum Proteins Ltd, London) contained 62% crude protein and, except for lower content of methionine, its amino acid composition was similar to that of white fish meal.

2. The value to growing pigs of yeast + methionine as a protein supplement to diets based on barley and fine wheat offal was compared with that of white fish meal. The two protein supplements supplied the same amount of total nitrogen and were compared at a ‘standard’ level, commonly used in practice, and at a ‘low’ level. Two experiments were conducted: a feeding trial covering the live-weight range from 20 to 90 kg, and a metabolic trial (20–60 kg live weight) in which N retention and digestibility were measured.

3. There was a small but significant difference in favour of the yeast treatment for growth rate and feed conversion ratio, but there were no consistent differences in the linear measurements of the carcasses due to protein source.

4. In the metabolic trial there was no significant difference in performance, N retention, apparent N digestibility or linear carcass measurements and no consistent difference in tissue components, between the diets supplemented with yeast or fish meal.

5. In pigs given the ‘low’-protein diets, performance and most of the other variables measured were significantly poorer than in those given the ‘standard’ protein diets, irrespective of whether yeast or fish meal was the source of supplementary protein.

6. It is concluded that yeast (+ methionine) may be closely equated with high-quality fish meal as a protein supplement in diets for growing pigs. The small differences found are discussed in relation to possible differences in availability of amino acids and energy values in the diets.
The course of digestion of different food proteins in the rat
Authors: Buraczewski S. , Porter J. W. G. , Rolls B. A. , Zebrowska Teresa
Published: September 2005

1. Single meals of protein (24.3 mg nitrogen/100 g body-weight) were fed with and without carbohydrate (167 mg/100 g body-weight) to groups of rats kept in anticoprophagy cages after an 18 h fast. The contents of the gastro-intestinal tract were collected and analysed and the rises in plasma amino acid concentrations were also determined.

2. After ingestion of different proteins with sucrose, the passage of protein from the stomach was delayed compared with that when the meal was of protein alone: the initial stomach emptying was little affected by the nature of the protein in the diet, but subsequently the relative rates of evacuation of different proteins were similar to those when the proteins were given alone.

3. When proteins were given with different carbohydrates the subsequent digestion and absorption of the meal was modified in a way which could be explained by the observed properties of the carbohydrates given alone, particularly with regard to solubilization in the stomach.

4. The rises in concentration of plasma free amino acid were lower after ingestion of proteins with carbohydrate than when the proteins were eaten alone, and different carbohydrates affected these rises to different degrees.
Protein quality of feeding-stuffs
Authors: Carpenter K. J. , McDonald I. , Miller W. S.
Published: September 2005

1. The reproducibility of an assay for methionine based on live-weight gains in young chicks has been tested in a collaborative study in six laboratories.

2. Results were analysed by the slope-ratio procedure and, in general, the assays were statistically valid. The variability between laboratories was similar to that found in previous studies of variablity within a single assay in one laboratory.

3. With the combined estimates from five or six laboratories the standard error of the estimates was apporoximately 10% of the mean. Expressing response as‘g gain/g food eaten’ gave no more precision than using ‘weight gain’ alone, but is nevertheless thought to be less open to error due to apetite effects.

4. The experiments have shown that materials can be ranked consistently, but that the absolute estimates of potency varied between assays and further improvements are desirable if potency estimates are to be used for the calibration of in vitro procedures of protein evaluation.
On the existence of lipid peroxides in rat tissue
Authors: Glavind J.
Published: September 2005

1. The colorimetric micro-adaption of the iodometric method and the colorimetric thiocyanate method for the determination of lipoperoxides were compared. Similar results were obtained when methyl linoleate hydroperoxide was tested, but when lipid from rat liver, muscle, kindney and testes was examined, substantial amounts were found by the iodometric, but almost nothing by the thiocyanate method.

2. The main reason for the discrepancy between the methods seems to be that the iodometric micromethod also estimates substances other than true lipoperoxides. The presence of ubiquinone and vitamin A in the organ extracts was shown to interfere in this way in the method.

3. The yellow colour which develops when retinol and its esters are tested by the iodometric micromethod is due not to liberated iodine but to conversion products of retinol.

4. It is concluded that the occurrence of substantial amounts of lipoperoxides in vivo has so far been demonstarted only in the adipose tissue, and not in the parenchymatous organs of the rat.
Diurnal variations in the concentrations of volatile fatty acids in the alimentary tracts of wild rabbits
Authors: Henning Susan J. , Hird F. J. R.
Published: September 2005

1. Wild rabbits were caught during both phases of the excretory cycle and their gut contents were analysed for volatile fatty acids (VFA).

2. All rabbits were found to have high concentrations of VFA in the caecum and in the proximal colon. Acetic was the most abundant acid followed by n-butyric, then propionic.

3. VFA concentrations in the caecum and in the proximal colon of rabbits caught during the day and during the night were similar. Hard pellets from the distal colon and rectum of rabbits caught during the night had considerably less VFA than did the soft pellets from rabbits caught during the day.

4. Owing to the ingestion of soft faeces, the VFA content of stomach material was greater in rabbits caught during the day than in those caught at night.

5. The results are discussed in terms of the mechanism of the diurnal excretion pattern and the role of coprophagy in the rabbit.
The effect of protein deficiency and calorie deficiency on the reproduction of rats
Authors: Widdowson Elsie M. , Cowen Jean
Published: September 2005

1. Groups of twelve female rats were fed from 4 weeks of age on four different experimental dietary regimens, and on a stock diet containing 18% protein givenad lib.as a control (group 1). The rats in two of the experimental groups were malnourished either by being given a low-protein (9%) dietad lib.(group 2), or the stock diet containing 18% protein in limited amounts to maintain weight as in group 2. These animals were designated calorie-deficient (group 3). Two other groups of twelve rats were more severely malnourished from 4 to 13 weeks of age by being given a low-protein (6%) dietad lib.(group 4) or the stock diet in limited amounts to maintain weight as in group 4 (group 5). From 13 weeks all the rats in groups 4 and 5 were rehabilitated on stock dietad lib.

2. Well-nourished males were introduced into the cages 1 week after the vaginas opened, and again immediately after the females had suckled successive litters. This was repeated until the females were 60 weeks old and had reared up to six litters.

3. Chronic deprivation of protein or of calories delayed puberty, reduced fertility and gave rise to smaller numbers in the litters. It also interfered with lactation.

4. More severe malnutrition for 9 weeks further delayed puberty, but when these animals were rehabilitated they produced as many young as those that had been well-nourished throughout. They lactated well and there was no carry-over of the effects of the early deficiencies.
Plasma zinc as an indicator of zinc status in rats
Authors: Wilkins P. J. , Grey P. C. , Dreosti I. E.
Published: September 2005

1. Standard zinc solutions for the atomic absorption analysis of rat plasma were prepared to contain 14% (w/v) of sucrose. In this way the problems of sample nebulization were overcome with a minimum of manipulation before assay.

2. Plasma Zn concentrations in rats were found to fall by approximately 40% (from 1.2 to 0.7 μg/ml) after 1 d on a Zn-deficient (< 0.25 ppm) diet. Thereafter, the fall became less marked and after 5 d the concentrations usually varied between 0.4 and 0.6 μg/ml.

3. A single oral dose (20–200 μg) of Zn was reflected in high plasma Zn concentrations in the depleted rats 1.75 h after dosing, but to a much lesser extent in animals receiving 10–60 ppm Zn in their diet before dosing.

4. It is suggested that the plasma Zn response to a single oral dose of zinc sulphate may provide a useful method for the detection of a subnormal Zn status in individual farm animals without the necessity of determining breed norms.
Fermentation of various glycolytic intermediates and other compounds by rumen micro-organisms, with particular reference to methane production
Authors: Czerkawski J. W. , Breckenridge Grace
Published: September 2005

Experiments with a small-scale artificial rumen have shown that of forty-two compounds tested the majority were fermented, as judged by the production of volatile fatty acids, but methane production was associated only with the fermentation of formate, certain hydroxy-acids, pyruvic acid, primary alcohols (methanol, ethanol, propanol and butanol), glycerol and methyl compounds. With primary alcohols there was a stoichiometric relationship between methane production and the oxidation of the alcohols to the corresponding acids.

The fermentation of rhamnose and 1,2-propanediol was studied in detail. With both compounds there was a temporary accumulation of lactic acid and a continuous net production of propionic acid. The initial rate of acetate production was rapid with rhamnose but decreased subsequently, whereas propionate continued to increase. With propanediol the net rate of production of acetate was slow at first and then increased. There was no increase in the production of butyric acid with either rhamnose or propanediol, and the endogenous methane production was inhibited by 20–40%. There was evidence for the formation of an unidentified compound during fermentation of rhamnose and propanediol.
Effect of dietary changes on intestinal absorption of L-methionine and L-methionyl-L-methionine in the rat
Authors: Lis Maria T. , Crampton R. F. , Matthews D. M.
Published: September 2005

1. The absorption rates of L-methionine and L-methionyl-L-methionine (dimethionine) from the upper jejunum and lower ileum of the rat were studied in vivo after different dietary treatments. Rates were expressed per unit gut length and per unit gut weight; the former was considered to be the more satisfactory under the different dietary conditions.

2. The dietary treatments were either short-term (10 d) or long-term (40–84 d).

3. The rate of absorption of methionine increased in the jejunum after a restricted dietary intake, a high-protein diet or a high-methionine diet, but decreased after long-term protein deprivation. Short-term dietary restriction had a similar effect on methionine absorption in jejunum and ileum, though less pronounced in the latter. The rate of absorption of dimethionine was less influenced by dietary changes than that of methionine.

4. Under all conditions studied, the absorption rate of methionine was greater when presented as the dipeptide than when presented as the equivalent amount of free amino acid. This confirms that dimethionine is taken up intact from the intestinal lumen, and it seems likely that there are different mechanisms of mucosal uptake for methionine and its dipeptide.
The role of amino acid oxidation in causing ‘specific dynamic action’ in man
Authors: Garrow J. S. , Hawes Susan F.
Published: September 2005

1. The increase in metabolic rate which occurs after ingestion of protein (the so-called ‘specific dynamic action’) has been attributed to the energy requirements for urea synthesis and amino acid degradation.

2. We have tested, in normal adult subjects, the effect of meals which increase or decrease the rate of urea production, and our results do not substantiate this hypothesis.

3. The difficulties of accurate measurement of resting metabolic rate are discussed.

4. The term ‘specific dynamic action’ is inappropriate since the effect is not specific. We believe that it may prove to be a reflection of protein synthesis rather than of protein catabolism.
Metabolic balance of manganese in young women
Authors: McLeod Barbara E. , Robinson Marion F.
Published: September 2005

1. Metabolic balance studies of manganese were made on four young women, using brilliant blue and chromic oxide as faecal markers.

2. Mn concentrations in food, faeces and urine were measured by atomic absorption spectrophotometry.

3. No difference in Mn concentrations was obtained between dry-ashing and wet-digestion for removal of organic matter from food or from faeces.

4. Retentions of 0.05–0.46 mg Mn/d were obtained. Dermal and menstrual losses were not measured or allowed for.

5. Unlike most other Mn balance studies reported, the retentions obtained were consistent with the accepted size and stability of the body pool of Mn in healthy adult subjects.
Nutritional aspects of amino acid metabolism
Authors: Bloxam D. L.
Published: September 2005

1. Concentrations of the amino acids in the plasma of blood from the portal vein and hepatic vein and in the liver of fed rats and rats starved for 1 d or 3 d were measured. The 1 d values were compared with the equilibrium concentrations of the amino acids found in the perfusion medium during perfusion of livers from rats starved for 1 d.

2. The measurements of portal–venous differences in amino acid concentrations confirmed the idea that postprandially and during starvation most of the amino acids flow from extrahepatic tissues to the liver but also showed that during starvation tryptophan, cystine, ornithine, valine, leucinc and isoleucine flow in the opposite direction, from liver to extrahepatic tissues.

3. The blood levels of the non-essential amino acids fell markedly during starvation while those of the essential ones tended to be maintained. This contrasts with the pattern of changes known to take place in rats and man given low-protein diets. In the liver, changes in amino acid concentrations were generally related to those in the blood but not strictly parallel. The relative changes in amino acid concentrations in blood and liver indicate that as starvation progresses the concentrative ability of the liver is enhanced for most of the amino acids which are taken up and that the increased output of those which are released is also due to changed membrane transport.

4. The changes in plasma amino acid concentrations in the blood passing through livers of rats starved for 1 d were, except for tryptophan and perhaps cystine, consistent with the extracellular changes found during perfusion of livers form rats straved for 1 d, indicating that the perfused liver influences concentrations of extracellular amino acids substantially as it does in vivo.

5. The results suggest of mechanism wherby the liver may control the maintenance of the essential amino acids during starvation.
Nutritional aspects of amino acid metabolism
Authors: Bloxam D. L.
Published: September 2005

1. Measurements of the concentrations of amino acids in the plasma of blood from the portal vein and hepatic vein in the livers of rats made diabetic with streptozotocin or alloxan and starved for 1 d were compared with similar measurements from normal rats starved for 1 d.

2. The concentrations of many of the amino acids in the blood plasma were lower in the streptozotocin diabetic rats than in the normal animal while the liver concentrations tended to be increased. This suggests that there is enhanced concentration of these amino acids by the liver in diabetics, as is also found in starvation, which is probably due to factors other than the direct absence of insulin.

3. The direction of flow of the groups of amino acids into and out of the liver was unchanged in the diabetic compared with the normal rat except that the output of tryptophan was abolished, and that of the branched-chain group was abolished in alloxan diabetes though apparently enhanced in streptozotocin diabetes. The rates of movement of amino acids in both directions appeared to be increased in the streptozotocin diabetic animals.

4. The changed amino acid pattern in the alloxan diabetic rats was to some extent similar to that of the streptozotocin diabetic rats but the changes were more difficult to interpret, perhaps because of side-effects of alloxan on tissues including liver.
Quantitative studies on nitrogen metabolism in the bovine rumen
Authors: Mangan J. L.
Published: September 2005

1. Monozygous twin cattle with permanent rumen fistulas were used to measure the rate of degradation of casein and ovalbumin. One twin was used as a control and the other had protein administered by fistula about 4.75 h after eating a standard ration.

2. Casein was rapidly degraded with a half-life in the range 5.6–21.5 min, with the formation of peptides, free amino acids and finally ammonia. Up to 43% of the casein nitrogen was found as ammonia in the rumen fluid. Most of the amino acids present in casein were found in the free state in the rumen fluid to an extent of less than 7%, but valine, leucine, isoleucine and lysine were present as 25, 27, 21 and 38% respectively of the amounts present in the casein administered.

3. When acid-hydrolysed casein was given, ammonia was rapidly formed, the maximum amount found in the rumen being equivalent to 39% of the casein N. The individual amino acids were rapidly broken down except for valine, leucine, isoleucine and lysine of which synthesis in addition to degradation may occur.

4. Ovalbumin was degraded slowly with a half-life of 175 min, which was reduced to 132 min by feeding the cattle with ovalbumin for 5 d. Ammonia was produced slowly.

5. When added together the two proteins were degraded in the rumen independently at their own rates.

6. δ-Amino-n-valeric acid was produced in large quantity when casein or casein hydrolysate was degraded in the rumen.
Absorption of labelled vitamin A in children during infection
Authors: Sivakumar B. , Reddy Vinodini
Published: September 2005

1. The intestinal absorption of [11,123H2] retinyl acetate was studied in five apparently normal children, eight children with respiratory infection and three with gastroenteritis.

2. The absorption of vitamin A was significantly lower in children with respiratory infection or gastroenteritis than in normal children.

3. In the light of these observations, it is suggested that repeated attacks of infections may significantly contribute to the prevalence of vitamin A deficiency in children of poor communities.
The effect of methionine supplementation on the levels of pancreatopeptidase E, trypsin, chymotrypsin and amylase in the pancreas of chicks receiving raw and heated soya-bean diets
Authors: Nitsan Zafrira , Gertler A.
Published: September 2005

1. The effect of methionine supplementation upon pancreatic trypsin, chymotrypsin, pancreatopeptidase E and amylase of chicks given raw and heated soya-bean diets (RSD and HSD) was studied before and after fasting.

2. Statistical analysis of the ratios of amylase to pancreatopeptidase E, trypsin and chymotrypsin in each individual chick revealed that methionine supplementation consistently increased the ratio of amylolytic to proteolytic enzymes. This phenomenon was most marked in the fasted RSD group, less in the fed RSD and fasted HSD groups and least in the fed HSD group.

3. The results are discussed in relation to methionine metabolism in chicks given RSD and HSD supplemented with trypsin inhibitors.
Effects of diets low in fat or essential fatty acids on the fatty acid composition of blood lipids of calves
Authors: Sklan D. , Volcani R. , Budowski P.
Published: September 2005

1. Groups of newborn calves were fed on liquid diets which had fat contents ranging from 0.2 to 17% (dry- weight basis) and which provided linoleic acid in amounts ranging from 0.01 to 0.7% of the calorie intake. Two commercial milk replacers, high in fat (17–18%) and linoleic acid (3.4 and 5.0% of calories) were also given. All diets were given for at least 65 d.

2. Except for reduced feed utilization associated with the two diets lowest in fat (0.2 and 0.4%), the calves developed normally, without signs of essential fatty acid deficiency.

3. The polyunsaturated fatty acid content of erthrocytes and plasma phospholipids and cholesteryl esters rose rapidly during the first few days on all diets. At 65 d, these concentrations were higher than at birth and appeared generally to be related to the linoleic acid intake. However, in the low dietary linoleic acid range, the fat content of the diet also seemed to exert some influnce. In no instance was there any indication of the appearance of 20:3ω9, which is observed in other species under conditions of essential fatty acid deficiency.

4. Some of the experimental diets were given to weanling rats. There was a rapid fall in the polyunsaturated fatty acid content of erythrocyte lipids and plasma phospholipids and cholesteryl esters, accompanied by the appearance of 20:3ω9.

5. These results suggest that calves on liquid diets have apparently a very low requirement for essential fatty acids.
Some effects of rumen ciliate protozoa in cattle given restricted amounts of a barley diet
Authors: Whitelaw F. G. , Eadie J. Margaret , Mann S. O. , Reid R. S.
Published: September 2005

1. Two pairs of Friesian steers were changed fromad lib.to restricted intake of a pelleted barley diet and were maintained on this latter intake for periods of 18 or 25 weeks. The restricted level of intake was 70 g/kg0.73and was adjusted weekly according to individual live weights. The daily allowance was given in three equal feeds during day-time.

2. After an initial period of 9 weeks on the restricted diet, during which all four animals were kept free of rumen ciliate protozoa, one member of each pair was given an inoculum of rumen ciliates. Eight weeks later, the ciliate-free member of the younger pair of steers was similarly inoculated. Observations were made on the rumen bacterial and protozoal populations and on changes in rumen pH and volatile fatty acids (VFA) throughout each treatment period. The concentrations of urea and haemoglobin in blood and of glucose and amino acids in plasma were examined on one occasion in each animal.

3. In the absence of ciliates, restriction of intake resulted in rumen pH values and molar proportions of VFA similar to those normally encountered on anad lib.intake of a barley diet. A decrease in bacterial numbers and certain minor changes in bacterial types were observed on changing fromad lib.to restricted intake but the resultant population under ciliate-free conditions was basically the same as that found later in the faunated animals. In culture, organisms of the genusBacteroideswere predominant.

4. Large populations of rumen ciliates were established in each animal inoculated. Relative to the ciliate-free periods, the presence of ciliates resulted in an increase in rumen pH, a reduction in total VFA concentration and a decrease in the ratio of propionic to butyric acid in rumen fluid. It is concluded that these changes are a direct effect of ciliate activity.

5. Conditions within the rumen remained more stable from day to day when large ciliate populations were present than when ciliates were absent. In one animal, spontaneous fluctuations in ciliate number were accompanied by corresponding changes in rumen pH and VFA proportions.

6. Significant differences were observed between faunated and ciliate-free animals in the concentration urea in blood and of glucose in plasma; only minor differences were noted in blood haemoglobin and plasma amino acid concentrations.
The sugar intake of businessmen and its inverse relationship with relative weight
Authors: Richardson J. F.
Published: September 2005

1. Yudkin's (1967) questionnaire on the dietary intake of sugar was given to 415 businessmen for self-administration.

1. The results showed an inverse relationship between sugar intake and relative weight (actual weight as a percentage of expected weight for height and age) and additional evidence suggests a direct relationship between sugar intake and adequate exercise.

2. The statement that ‘sugar was restricted’ was shown to be a factor of considerable importance affecting the reported level of sugar intake and should be taken into account when comparing different series.

3. The positive association between cigarette smoking and mean sugar consumption in this series was due to the low-sugar intake of ex-smokers.

4. In future studies on the role of sucrose in the aetiology of ischaemic disease, both smoking habits and levels of activity should be recorded.
The influence of the nutritive value of proteins on the level of protein synthesis in vitro in rat skeletal muscle
Authors: Omstedt P. T. , Von Der Decken Alexandra
Published: September 2005

1. The amino acid incorporating activity of skeletal muscle ribosomes was studied in rats under various nutritional conditions using labelled amino acids.

2. Ribosomes were obtained from rats that were given a protein-free diet for 5 d followed by a high-protein diet containing casein, gelatin or wheat gluten for 16.5 h and from others that were given one of these protein-containing diets or one containing protein from polished rice for 6 d.

3. The level of isotope incorporation relative to RNA was somewhat higher when the protein source given for 16.5 h was a good-quality protein such as casein than with gelatin or wheat gluten, but fine discrimination between proteins was not considered to be feasible with this system.

4. In the rats that were given the protein-containing diets for 6 d the differences were more pronounced and the amino acid incorporating activity was correlated with the biological value of the protein.
The use of hydroxyproline analyses to predict the nutritional value of the protein in different animal tissues
Authors: Dvořák Z.
Published: September 2005

1. The amounts of available cystine and tyrosine in the protein of different animal tissues showed a close correlation with the level of hydroxyproline, and may be estimated from hydroxyproline values by regression equations.

2. Estimates of ‘chemical score’ have been calculated from the content of hydroxyproline determined in a series of samples for which net protein utilization (NPU) for rats had also been determined. Chemical scores calculated as percentages of the total ‘essential+semiessential’ amino acid content of each material correlated closely with NPU, whereas scores calculated as percentages of total amino acids did not. ‘Methionine+cystine’ were calculated to be first limiting amino acids in every sample.
Energy intake and expenditure of Indian schoolboys
Authors: Banerjee B. , Saha N.
Published: September 2005

1. Sixteen Indian schoolboys, aged 12–14 years resident in Singapore, were tested for the determination of energy cost, pulmonary ventilation (PV) and oxygen consumption at rest and at various daily activities; their height, body-weight, pulse and blood pressure were also measured. An energy balance study was made by estimating from a diary of measured activities the 24 h energy intake and output.

2. PV and O2 consumption during running showed positive correlations(r = 0.4 and r =0.3 respectively) with mean post-exercise recovery pulse, O2 consumption and PV.

3. The daily mean calorie intake and output of the subjects were found to be 2108 kcal (8.85 MJ) and 1811 kcal (7.60 MJ) respectively.

4. The boys gained an average of 2.2 kg in weight and 0.7 cm in height in 2 months. They did not suffer from any mental retardation, they were physically fit, free from disease and did their daily routine work satisfactorily.
Digestion of concentrates in sheep
Authors: Ørskov E. R. , Fraser C. , McDonald I.
Published: September 2005

1. The effects of adding increasing supplements of urea to mainly barley diets for early-weaned lambs were investigated in two experiments. In the first experiment the passage of nutrients along the alimentary tract was studied by taking samples of abomasal, ileal and rectal contents and using a marker technique. In the second experiment, feed consumption and rate of gain were recorded over the growth period up to 40 kg live weight, and nitrogen balances were carried out. In the second experiment a barley-fish meal diet was also included.

2. The fermentation of organic matter in the rumen increased with the amount of urea in the diet and levelled off when the diet contained about 12% crude protein.

3. Urea supplementation had significant effects in increasing N retention and rate of live-weight gain and in decreasing feed conversion ratio, but supplementation beyond about 12% crude protein in dry matter had no further effect on these measurements. In each instance results with the barley–fish meal diet were better than the results with any of the barley-urea diets.

4. From the concentrations of diaminopimelic acid (DAPA) in abomasal fluid it was estimated that microbial protein was produced in the rumen at a rate of 15.6% g/100 g organic matter fermented. This ratio did not appear to alter significantly with urea supplementation, but the comparison depends on the assumption that the concentration of DAPA in the bacterial protein did not itself change with urea supplementation.

5. Using results from both experiments, it was calculated that the retained N on the urea-supplemented barley diets was approximately 47% of the amount of protein N absorbed in the small intestine.

6. It is suggested that barley diets for early-weaned lambs can with advantage be supplemented with non-protein N to increase the crude protein in the dry matter up to about 12%. When barley diets are given with a protein supplement the addition of non-protein N is unlikely to be beneficial unless the protein supplement is given in such a way that it is not subject to degradation to yield ammonia in the rumen.
The effect of intravenous infusions of sterculic acid on milk fat synthesis
Authors: Bickerstaffe R. , Johnson A. R.
Published: September 2005

1. The effects of intraduodenal infusions of sterculic acid, a naturally occurring inhibitor of desaturase activity, on the yield and composition of milk were examined in a lactating goat.

2. Sterculic acid administration increased the percentage of stearic acid in milk fat, reflecting inhibition of mammary desaturase activity. Milk yield was not affected, but milk fat output decreased. Possible explanations are discussed.

3. No evidence was obtained for an alternative pathway of oleic acid synthesis from acetate.
Glucose tolerance and insulin sensitivity in malnourished children
Authors: Alleyne G. A. O. , Trust P. M. , Flores H. , Robinson H.
Published: September 2005

1. In malnourished, compared with recovered children, fasting blood glucose concentrations were low and there was impaired peripheral glycolysis as shown by a failure of blood lactate to rise after glucose was injected intravenously.

2. Homogenates of muscle biopsies from malnourished and recovered children produced equal amounts of lactate when incubated anaerobically with various substrates, but when compared with homogenates of biopsies from normal children the pattern suggested an impairment of glycolysis.

3. The rate of glucose disappearance after intravenous glucose was slow in the malnourished child and there was possibly diminished sensitivity to exogenous insulin.

4. Isocaloric diets relatively high or low in fat were fed to children who had recovered from malnutrition. Glucose tolerance, insulin sensitivity, fasting plasma insulin and insulin response to intravenous glucose were all the same in children on either diet.
Conversion of lutein into dehydroretinol by the freshwater fish,Saccobranchus fossilis
Authors: Barua A. B. , Tombi Singh H. , Das R. C.
Published: September 2005

1. The vitamin A content ofSaccobranchus fossiliskept on a diet of rice and meat gradually decreased and became negligible at the end of 3–5 months.

2.S. fossilisinitially contained more dehydroretinol than retinol; administration of β-carotene or zeaxanthin to the vitamin A-depleted fish did not result in an accumulation of dehydroretinol in the liver. On the other hand, when lutein was administered by mouth or subcutaneous injection, it was converted into dehydroretinol.
Independent jejunal mechanisms for glycine and glycylglycine transfer in man in vivo
Authors: Cook G. C.
Published: September 2005

1. Rates of absorption of glycine and glycylglycine from a 300 mm jejunal segment were compared in vivo when those compounds were given alone or together to six Zambian African subjects who had no clinical evidence of malnutrition or of gastro-intestinal disease. Solutions containing (A) glycine (100 mmol/1), (B) glycine (100 mmol/l)+glycylglycine (50 mmol/l), and (C) glycylglycine (50 mmol/l) were infused into the upper jejunum by means of a double-lumen tube perfusion system.

2. Rate of absorption of glycine was significantly higher from the glycylglycine solution (C) than from the glycine solution (A). Glycine absorption rate from solution B (glycine+glycylglycine) was very similar to the sum of absorption rates of glycine from solutions A and C in each subject. Luminal disappearance rate of glycylglycine from solutions C and B were very similar; however, the rate was significantly greater than the total glycine absorption rate from solution C and indicates back-diffusion of glycine into the lumen after glycylglycine hydrolysis.

3. The results are interpreted as indicating that the transport mechanisms for glycine and glycylglycine in man are partly, and possibly wholly, separate.
Protein requirements of growing lambs
Authors: Black J. L. , Pearce G. R. , Tribe D. E.
Published: September 2005

1. The protein requirements of lambs were established by measuring nitrogen balance in seventy-four animals given liquid diets which passed direct to the abomasum. Four groups of lambs weighing approximately 8 kg (group 1), 13 kg (group 2), 21 kg (group 3) and 30 kg (group 4) received diets in which 0·10, 0·15, 0·20, 0·25, 0·30, 0·35 or 0·40 of the digestible energy was provided as protein (DPE:DE ratio) and a gross energy intake of from 1·30 to 1·42 MJ/kg0·73per d.

2. When the protein requirements were taken to correspond to the protein intake at the point of intersection of the line describing the increase in N balance with increase in protein intake and the line representing the maximum N balance, values of 0·25, 0·23, 0·17 and 0·12 DPE:DE ratio were obtained for groups 1–4 respectively. The requirements expressed in these terms can be applied only to lambs fed on liquid diets which contain milk proteins and escape fermentation in the rumen. To enable the results to be applied to lambs given other diets, the requirements were expressed as g reference-protein (defined as a theoretical protein with the ideal pattern of amino acids) per MJ net energy and were 11·6, 10·4, 8·0 and 6·2 for groups 1–4 respectively. The relationship between protein requirement (Y, g reference protein/MJ net energy) and live weight (X, kg) was:Y= 13·4–0·242X.

3. The influence of energy intake on protein requirements in lambs is discussed and it is concluded that the results obtained are applicable to lambs given a metabolizable energy intake of more than about 1·75 times their maintenance requirement.

4. Application of the estimated requirements to ruminant lambs and methods of formulating diets to supply the required quantity of reference protein/MJ net energy are discussed.
The protein requirement of the ruminant calf
Authors: Stobo I. J. F. , Roy J. H. B.
Published: September 2005

1. Twelve Friesian bull calves were weaned at 5 weeks and reared to approximately 18 weeks of age on diets consisting mainly of concentrates containing 209 (HP), 169 (MP) or 130 (LP) g crude protein/kg dry matter. Hay was removed from the diet when the calves reached 10 weeks of age.

2. In relation to metabolic body size, daily dry-matter intake rose rapidly until the calves were about 9 weeks old and then tended to level off at between 80 and 100 g dry matter/kg0·73.

3. After adjustment for treatment differences in concentrate intake, the live-weight gains of calves given diets HP or MP were significantly greater, both from 1 to 12 weeks and from 1 to 16 weeks of age, than those of calves given diet LP.

4. Digestibility trials made twice on each calf, when given solely the concentrate diet and when live-weight gain was about 1 kg/d, showed no differences in dry-matter digestibility, but the apparent digestibility of crude protein increased with the protein content of the concentrate mixture. The true digestibility coefficient of dietary protein was estimated to be 0·880, with no difference between diets. Metabolic faecal nitrogen excretion was estimated to be 3·43 g N/kg dry matter ingested.

5. At the mean intake of digestible energy/kg0·73, N balance was significantly greater with diets HP and MP than with diet LP. Endogenous urinary N excretion was estimated to be 220 mg/kg0·73 and the apparent biological value of protein was 0·851 when diet LP was given.

6. The results confirm the importance of a balanced relationship between energy and protein intakes in the diet of the rapidly growing calf. It is concluded that the crude protein content of the diet can be reduced to below 172 g/kg dry matter, and possibly as low as 153 g/kg, for calves of 122 kg live weight to achieve weight gains of 1 kg/d, when given an all-concentrate diet. This lower protein level would be expected to result in the maximum efficiency of utilization of the dietary energy and protein.
The effect of work level and dietary intake on water balance and the excretion of sodium, potassium and iron in a hot climate
Authors: Wheeler Erica F. , El-Neil Hamad , Willson J. O. C. , Weiner J. S.
Published: September 2005

1. The dietary intake, and urinary, cutaneous and faecal loss of water, sodium, potassium and iron have been studied in young men living and performing moderate work in a hot climate. The dietary intakes of K and Fe were lowered during part of the study.

2. The subjects were already somewhat acclimatized to heat; further acclimatization was achieved when they were performing work, and this was assessed in terms of the increase in their rate of sweating.

3. The subjects tended to be in marginally negative Na balance, partly owing to lowered Na intakes. Intakes and outputs of K were in balance. Losses of K in sweat amounted to 15% of intake when the dietary level was reduced.

4. The subjects were slow in adapting to changes in Fe intake, 8 d being an insufficient period for adaptation after their intake had been halved. Losses of Fe in sweat were approximately 0·3 mg/d, or one-third of the estimated requirement for absorbed Fe.

5. It is concluded that Fe losses in sweat could be a significant factor in Fe depletion if dietary Fe was low or unavailable, as there was no evidence that a low intake and absorption affected sweat losses.
Metabolic studies of [75Se]selenomethionine and [75Se]selenite in the rat
Authors: Thomson Christine D. , Stewart R. D. H.
Published: September 2005

1. Information was sought concerning the long-term fate of orally and intravenously administered [75Se]selenomethionine and [75Se]selenite in rats.

2. Urinary and faecal radioactivity was assayed during the 1st week and whole-body radio-activity was determined weekly for 16 weeks. Rats were killed at intervals for analysis of 75Se tissue distribution.

3. Intestinal absorption after oral administration was estimated to be 91–93% for selenite and 95–97% for selenomethionine.

4. Urinary excretion of absorbed [75Se]selenite was greater than that of [75Se]selenomethionine during the 1st week.

5. After the 1st week, whole-body retention diminished exponentially at a similar rate in rats given either selenomethionine or selenite. Except for the erythrocytes, 75Se content of individual tissues also decreased exponentially.

6. It appears that, after an initial period, 75Se from either selenomethionine or selenite is metabolized similarly, suggesting that Se from both potential dietary sources is ultimately incorporated into the same metabolic pool.
The measurement of total body water in living pigs by deuterium oxide dilution and its relation to body composition
Authors: Houseman R. A. , Mcdonald I. , Pennie K.
Published: September 2005

1. Deuterium oxide was used to estimate body water in twenty-four pigs of widely differing body composition and of average weight 83·9 kg.

2. After infusion of the isotope, blood samples were collected every 30 min for 4 h. The resulting plasma was purified by a heat-distillation procedure, after which it was analysed for D2O by infrared spectroscopy.

3. Approximately 24 h after infusion of the D2O each pig was killed, and its composition determined both by chemical analysis and physical dissection.

4. Equilibration of D2O in the body was found to be complete within 2 h of injection of the tracer.

5. The mean D2O space was found to be 8·6% greater than the mean empty body water space, but only 2·2% greater than the total body water space.

6. Empty body water and total body water were estimated from the regression lines with residual standard deviations of 2·7 and 1·9% respectively. Similarly, the residual standard deviations of the regressions involving the other fat-free components were 6·3% for dissectible lean, 3·2% for fat-free mass, and 5·6% for crude protein.

7. The residual standard deviations of the regressions in which the weights of dissectible fat and total body lipid were predicted were 6·0 and 6·7% respectively.
Morphological and functional aspects of oxytetracycline administration to conventional rats
Authors: Ruitenberg E. J. , Kampelmacher E. H. , Van Noorle Jansen Lucretia M. , Cohen Ph.
Published: September 2005

1. Studies were performed with female rats to examine the effect of various levels of orally administered oxytetracycline on body-weight, weight of various portions of the intestinal tract, weight of mesenteric lymph nodes, distribution pattern of the tissue elements in the terminal portion of the ileum, and on the susceptibility to invasion bySalmonella typhi-murium.

2. There was no growth promotion resulting from any antibiotic treatment. A consistent finding was the decrease in the wet weight of mesenteric lymph nodes in the rats given antibiotic.

3. In the bacteriological test, no differences between antibiotic-fed and control groups were observed in isolations from the liver, spleen or intestinal tissue. It was concluded that there were no effects of oxytetracycline administration on invasive capacity of orally administeredS. typhi-murium.
Amino acid composition of hen's egg
Authors: Lunven P. , Marcq C. Le Clement De St , Carnovale E. , Fratoni A.
Published: September 2005

1. Pooled samples of eggs from White Leghorn and New Hampshire hens given diets containing 110 and 200 g protein/kg were analysed for their content of essential amino acids.

2. The amino acid composition of the hen's egg protein was not significantly affected by variations in breed and diet.

3. The estimated values for lysine, total sulphur-containing amino acids and tryptophan in egg protein were higher by 8·9, 2·0 and 8%, respectively than those adopted for hen's egg by the FAO/WHO Expert Committee (FAO, 1965).

4. The isoleucine content of egg protein was found to be much lower (338 mg/g nitrogen) than that reported by other workers.