bluuebunny/crossref_metadata_2025_split huggingface dataset:
Digestion of concentrates in sheep
Authors: Orskov E. R. , Fraser C. , McDonald I. , Smart R. I. 
Published: May 2005

1. In one experiment according to a latin square design five sheep with fistulas in the abomasum and terminal ileum were given diets based on barley. Five diets were compared, one without protein supplementation, two with different levels of fish meal and two with combinations of fish meal and urea.2. The amount of non-ammonia crude protein passing through the abomasum and removed from the small intestine increased linearly with fish-meal supplementation but the only effect of supplementation with urea was to increase the crude protein removed before the abomasum. It was concluded that urea did not appear to have a sparing effect on the degradation of dietary protein.3. Seventy-eight lambs were used in a second experiment. They were given thirteen diets made up from a basal barley diet and different combinations of fish meal and urea.4. Digestibility of organic matter and efficiency of food conversion increased with each level of fish-meal supplementation. The effects of urea supplementation on organic matter digestibility and efficiency of food conversion depended upon the level of fish meal in the diet and at the highest level of fish-meal supplementation there were no effects.5. The maximum digestibility of organic matter (about 820 g/kg) could be achieved both with urea alone and fish meal alone and was attained at a lower level of nitrogen in the diet with urea. In contrast, the maximum food conversion efficiency that could be achieved with a fish-meal supplement was much greater than could be obtained with a supplement of urea alone.
Ad lib. feeding during recovery from malnutrition
Authors: Ashworth Ann 
Published: May 2005

1. Ten severely malnourished children were studied.2. During recovery the mean energy intake was 916 kJ (219 kcal)/kg per d when the children were fed ad lib. on a high-energy milk preparation.3. When a lower-energy milk preparation was given ad lib. the children voluntarily increased the volume consumed but the mean energy intake fell to 703 kJ (168 kcal)/kg per d.4. After recovery the children no longer consumed an increased volume when the lower-energy milk preparation was offered.5. The results provide further evidence of the importance of feeding with a high-energy preparation for the treatment of malnutrition, and demonstrate that additional benefits can be obtained by offering such mixtures ad lib.
The rejection of a diet which has been associated with a single administration of an histidine -free amino acid mixture
Authors: Simson P. C. , Booth D. A. 
Published: May 2005

1. A protein-free diet, to which an odour had been added, was offered to rats immediately after giving a gastric load of an histidine-free, but otherwise balanced, amino acid mixture. The same diet with a different odour was offered to the rats on another day, after administration of a control load of saline or a balanced amino acid mixture. After access to stock diet for 6 h of 1 d, the rats were offered two samples of protein-free diet, each with one of the two odours.2. The rate of consumption of odorized protein-free diet was depressed 2–4 h after administration of the histidine-free load. In the later preference test, the dietary sample with odour which had been offered after the deficient load was rejected in favour of the sample with the odour which had been offered after the control load.3. Rejection of the deficiency-paired odour in the final preference test did not occur when the histidine-free load had been given 2 h before the rats were first offered odorized diet. Also, there was in these instances no depression of rate of food consumption 2–4 h after loading. This indicated that aversive reactions to the odour were established by association of the odour with some effect of the histidine-free load which had occurred within 2 h of its administration, and that the early depression of intake and the much later rejection during choice were both expressions of these acquired reactions.4. This rapid conditioning of selective rejection did not depend on previous prolonged protein deprivation or on the use of immature rats but did depend upon an intermittent supply of amino acids during 3 d before conditioning. Subcutaneous injection of deficient amino acid mixture did not establish rejection, suggesting that conditioning depended on rapid delivery of the deficient mixture into the circulation.5. It is concluded that the critical biochemical events which lead to the rejection of diets that are imbalanced or deficient in essential amino acids occur soon after ingestion of the diet, and may have been effective in producing a conditioned aversion before any suppression of food intake appears. It is suggested that the depression of food consumption, which is the normal response to an imbalanced diet, is in this instance the result of conditioned response to sensory qualities of the diet rather than to the direct effect of biochemical stimuli.
Studies on the nutrition of marine flatfish. Utilization of various dietary proteins by plaice (Pleuronectes platessa)
Authors: Cowey C. B. , Adron J. , Blair A. , Shanks Aileen M. 
Published: May 2005

1. Five proteins, freeze-dried cod muscle, a white fish meal, a yeast-protein concentrate, a soya protein and a fish-protein concentrate (a solvent-extracted fish meal) were given separately, as single sources of protein in diets containing 500g crude protein/kg, to small plaice (Pleuronectes platessa) of mean initial weight 12–15g. Weight gain and net protein utilization (NPU) were examined.2. Even at these high protein intakes, significant differences in growth rate between fish given the different proteins were evident. These findings were reflected in different NPU values between the proteins. This position contrasts with that in the rat where proteins which differ markedly in NPU at low protein intakes have similar NPU values when given at high dietary levels.3. Coefficients of apparent digestibility measured on larger plaice (150–200g) were high for all the proteins used except soya-bean meal, which had a digestibility coefficient of 0.68.4. At high protein intakes there was no clear relationship between NPU values and essential amino acid content (as measured chemically) of the proteins tested.5. The preparation of protein concentrates from fatty fish by the use of detergents is described. One of the preparations obtained gave weight gains and NPU values similar to those obtained with commercially available feedstuff proteins.
The utilization of protein and excretion of uric acid in germ-free and conventional chicks
Authors: Salter D. N. , Coates Marie E. , Hewitt D. 
Published: May 2005

1. The influence of the gut microflora on protein utilization has been investigated with a series of good- and poor-quality protein diets in germ-free (GF) and conventional (CV) chicks by the measurement of net protein utilization (NPU) and uric acid excretion.2. The diets used were: 280 g protein per kg diet containing unheated or heat-damaged albumen (100 g/kg), casein (80 g/kg) and gelatin (100 g/kg); sesame protein (220 g/kg); sesame protein (220 g/kg) supplemented with lysine (5 g/kg); freeze-dried cod muscle (160 g/kg); heat-damaged cod muscle (160 g/kg); mildly-steamed egg albumen (100g/kg); heat-damaged egg albumen (100 g/kg).3. No significant differences in NPU values for the proteins measured in GF and CV chicks were found, with the exception of unsupplemented sesame protein, for which the NPU value was slightly higher in GF chicks.4. The replacement of unheated egg albumen by heat-damaged egg albumen in the 280 g protein/kg diet resulted in a decrease in uric acid excretion. With the cod-muscle diets, heat-damaging the protein caused an increase in uric acid excretion. Supplementing the sesame protein with lysine resulted in a decrease in uric acid excretion.5. Excretion of uric acid tended to be higher in CV chicks than in GF chicks with all proteins except sesame protein, with which uric acid excretion was a little higher in GF chicks.6. Endogenous nitrogen excretion was higher in GF than in CV chicks.7. It is concluded that the gut microflora has little influence on the utilization of dietary protein by chicks, although it may modify the route of excretion of the N which survives digestion and reaches the lower gut.
The determinatio of tryptophan in purified proteins and in feeding-stuffs
Authors: Matheson N. A. 
Published: May 2005

1. A method was developed for the estimation of tryptophan in purified proteins or in feeding-stuffs. Samples were hydrolysed by autoclaving them with barium hydroxide in polypropylene flasks or tubes. Excess Ba was precipitated as the hydroxide by cooling, and hydrogen sulphide formed during hydrolysis was removed under reduced pressure. Tryptophan was assayed colorimetrically with dimethylaminobenzaldehyde by comparison with tryptophan standards carried through the complete procedure.2. The method was applied to purified proteins, to analysed materials and to a wide range of samples. Results agreed fairly well with published values for purified proteins, though rather less well for the samples analysed by other workers. Reasons are discussed. The samples examined gave results in the expected range.
Effects of organic and inorganic sulphur on the availability of dietary copper to sheep
Authors: Suttle N. F. 
Published: May 2005

1. The effects of dietary sulphur on the availability of dietary copper were estimated by means of a repletion technique. The responses of initially hypocupraemic ewes to repletion with Cu-supplemented diets containing supplements of organic S, as methionine, and of inorganic S, as Na2SO4, were compared with those obtained with a diet low in S.2. The two forms of S had similar effects. Responses in plasma Cu were reduced by 39–56 % when S was increased from 1.0 to 3.0 or 4.0 g/kg diet and the availability of dietary Cu was estimated to have decreased from 0.062 to 0.041. Both S supplements produced marked increases in rumen sulphide concentrations.3. Dietary S had no effect on plasma Cu when added to the low-Cu diet of hypocupraemic ewes being repleted by a continuous intravenous infusion of Cu.4. The addition of CuS, providing 5 mg Cu/kg, to the diet of hypocupraemic ewes produced no response in plasma Cu or haemoglobin. The same amount of Cu, given as CuSO4, increased plasma Cu by 0.46±0.15 mg/l and haemoglobin by 33±3.8 g/l after 36 d: the subsequent replacement of CuSO4by CuS induced hypocupraemia again but had no effect on haemoglobin.5. It was concluded that variations in dietary S within the normal range for herbage exert an independent effect on Cu metabolism, possibly through the formation of insoluble CuS at sites beyond the rumen.
The influence of the gut microflora on the digestion of dietary and endogenous proteins: studies of the amino acid composition of the excreta of germ-free and conventional chicks
Authors: Salter D. N. , Fulford Rosemary J. 
Published: May 2005

1. To assess the part played by the microflora in the digestion of proteins, the amino acid composition of the excreta and the apparent and true digestibilities of individual amino acids were measured in germ-free (GF) and conventional (CV) chicks.2. Three diets were used: diet 1, nitrogen-free; diet 2,280 g protein/kg as (g/kg): casein 80, gelatin 100 and freeze-dried egg albumen 100 and diet 3,280 g protein/kg as diet 2 but with heat-damaged instead of freeze-dried egg albumen. Half of the GF and half of the CV chicks received the N-free diet in the first 7 d of test and the other half of each group received either diet 2 or diet 3. In the second 7 d test period those chicks which had been given the N-free diet received either diet 2 or diet 3 while those which had been given protein diets received the N-free diet. Total amino acids were measured in hydrolysates of the soluble and insoluble fractions of the excreta collected in the last 3 d of each test period.3. The amino acid composition of the soluble fraction of the excreta of chicks given either diet 2 or diet 3 differed markedly from that of chicks given the N-free diet. The amino acid composition of the insoluble fraction of the excreta of chicks given diet 2 was similar to that of chicks given the N-free diet, whereas that of chicks given diet 3 was markedly different and resembled egg albumen in composition.4. In the soluble fraction of excreta from CV chicks given diets 1 and 2 the proportions of threonine, serine and glucosamine were lower and those of methionine, leucine, isoleucine and phenylalanine were higher than in those from GF chicks, particularly on diet 1. In the insoluble fraction of excreta from CV chicks given these two diets, compared with GF chicks, there were lower proportions of serine and proline and higher proportions of cysteic acid and lysine, the latter particularly with diet 1.5. Lower proportions of threonine, serine and glucosamine were also observed in the soluble fractions of excreta from the CV chicks given diets 1 and 3, compared with GF chicks, whereas the proportion of glutamic acid was higher. With these two diets the insoluble fraction from CV chicks contained a higher proportion of alanine. In each instance the environmental effect was greater with diet 1.6. No effect of environment on either apparent or true digestibility of individual dietary protein amino acids was demonstrated, with the exception of threonine in diet 2, the true digestibility of which was higher in GF than in CV chicks.7. It was concluded that the gut microflora of the chick had little influence on the digestion of the proteins in the diets tested, but may serve an important role in the degradation of endogenous proteins and the recycling of N.
The effect of pregnancy and lactation on food intake, gastrointestinal anatomy and the absorptive capacity of the small intestine in the albino rat
Authors: Cripps A. W. , Williams V. J. 
Published: May 2005

1. Food consumption, live weight, anatomical measurements on the gut organs and the absorptive capacity of the small intestine for L-leucine and D(+)-glucose were made on virgin (control), pregnant and lactating albino rats.2. Food intake increased by approximately 60% during pregnancy and a further 250% during lactation.3. Pregnancy did not markedly influence the gross anatomy of the gastrointestinal tract. There was evidence for increased villus height and percentage water in the small intestine and for increased length of the colon during pregnancy.4. During lactation, the alimentary canal progressively increased in weight and size. It partially regressed following weaning.5. All anatomical measurements, except the length of the small intestine, completely regressed to control values within 20 d of weaning. The increased intestinal length had not completely regressed by day 30 post-weaning.6. No significant change was observed in absolute absorption of glucose or leucine during pregnancy.7. Absolute absorption of leucine and of glucose was increased during lactation. Greatest absorption occurred on the 10th day of lactation.8. Results for absorption of leucine and glucose per unit length indicated that the ability of the mucosal cells to absorb or the number of absorptive cells/mm had changed during lactation and the post-lactation periods.
Potassium supplementation, serum immunoreactive insulin concentrations and glucose tolerance in protein-energy malnutrition
Authors: Mann M. D. , Becker Dorothy J. , Pimstone B. L. , Hansen J. D. L. 
Published: May 2005

1. The serum immunoreactive insulin (IRI) concentrations, and glucose disappearance rate-constants after intravenous glucose administration were measured on admission and during recovery in children suffering from protein-energy malnutrition (PEM).2. A high potassium intake resulted in a considerable increase in the serum IRI levels early in the treatment period. There was a definite relationship between potassium depletion and many measurements of insulin secretion.3. The results are consistent with the hypothesis that impaired insulin release in children suffering from PEM is partly the result of potassium depletion.
Solubility and net exchange of calcium, magnesium and phosphorus in digesta flowing along the gut of the sheep
Authors: Ben-Ghedalia D. , Tagari H. , Zamwel S. , Bondi A. 
Published: May 2005

1. The changes in the solubility of calcium, magnesium and phosphorus in digesta flowing along the intestinal tract and the net movement across the intestinal wall of these elements were determined in six rams, each equipped with three T-shaped cannulas; cannulas were placed in a total of six different sites of the small intestine. Cr2O3 was used as a marker substance to measure the rate of flow of the digesta.2. The concentrations of soluble Ca, Mg and P decreased as digesta moved along the intestine. The greatest fall in soluble Ca occurred after the first 3 m of the intestine, while a significant decrease in soluble Mg was found only at 15 and 25 m from the pylorus. The concentration of soluble P in digesta decreased until the 7 m site and then remained stable. In the faeces, the level of soluble Mg was approximately 4 times higher than, and that of Ca equal to, the levels of Mg and Ca found in digesta flowing through the upper intestine. Unlike Ca and Mg, a very low concentration of soluble P was found in the faeces.3. In the duodenum, 84, 78 and 62% of the total Ca, Mg and P respectively were soluble, whereas in the digesta flowing through the terminal ileum the corresponding values were 3·2, 7·2 and 19% for Ca, Mg and P respectively.4. The forestomachs and the colon were found to be the main sites of Mg net absorption; 1·12 mmol/h was apparently absorbed from the stomach and 1·05 mmol/h from the colon. The upper small intestine (1–3 m from the pylorus) appeared to be the major site of Ca and P absorption.5. In the last 10 m of the small intestine, considerable amounts of minerals were secreted; 4·70, 0·96 and 1·85 mmol Ca, Mg and P/h respectively were added to the digesta flowing between 15 and 25 m from the pylorus. The effect of the increase in the pH of digesta along the small intestine on the solubility of these minerals is discussed.
Jejunal absorption of an amino acid mixture simulating casein and an enzymic hydrolysate of casein prepared for oral administration to normal adults
Authors: Silk D. B. A. , Clark M. L. , Marrs T. C. , Addison Jill M. , Burston D. , Matthews D. M. , Clegg K. Mary 
Published: May 2005

1. An intestinal perfusion technique was used in six normal human subjects to study absorption of sixteen individual amino acids from an amino acid mixture simulating casein and from an enzymic hydrolysate of casein, prepared for oral administration to these subjects, which consisted of a mixture of oligopeptides and free amino acids.2. Total absorption of α-amino nitrogen was greater from the casein hydrolysate than from the amino acid mixture, and the considerable variation in percentage absorption of individual amino acids from the amino acid mixture was much reduced when the enzymic hydrolysate solution was perfused, as a number of amino acids which were poorly absorbed from the amino acid mixture were absorbed to a greater extent from the casein hydrolysate.3. These findings indicate that after extensive intestinal resections or in malabsorption there might be significant nutritional advantages in the administration of protein hydrolysates rather than amino acid mixtures.
Maintenance requirements for energy in cross-bred cattle
Authors: Patle B. R. , Mudgal V. D. 
Published: May 2005

1. Twenty-seven energy and protein balances were done using nine cross-bred (Brown Swiss × Sahiwal) mature bullocks in a series of three balance trials. The bullocks were fed 75, 100 and 125 % of the metabolizable energy (ME) and digestible crude protein standard values recommended by the (US) National Research Council (1966). Heat production was estimated by indirect calorimetry, by collection and analysis of respiratory gases2. Utilization of energy for maintenance and fat production was estimated by computing regression of energy balance v. digestible energy (DE) and ME separately on a metabolic body size (kg body-weight (W)0·75) basis. Maintenance energy requirements and efficiency of utilization of ME for lipogenesis were estimated using multiple regression of ME intake, also. Heat production (and thus energy balance) was corrected for excess nitrogen intake3. An attempt was made to measure basal heat production of bullocks so that the net energy requirements for maintenance could be estimated. Extrapolation of the regression line of energy balance v. ME intake below maintenance on a W0·75 basis gave a basal metabolism of 348·09 kJ/W0·75 per d4. Energy requirements for maintenance were (kJ/kg W0·75 per d): 539·43 DE, 448·81 ME and 348·09 net energy. The results of multiple regression gave a requirement of 432·15 kJ ME/kg W0·75 per d for maintenance5. The efficiency of utilization of ME for maintenance was 81·34% while for lipogenesis it was 54·5 %.
The effects of short periods of fasting on the absorption of heavy metals
Authors: Quarterman J. , Morrison Elaine 
Published: May 2005

1. Rats were deprived of food for periods of from 0 to 40 h and then given203Pb,203Hg.59Fe,64Cu.64Zn or45Ca by stomach tube. The absorption and retention of these metals in tissues was measured 1 h and 2 d after dosing.2. After 16–24 h of food deprivation between two and ten times more metal was retained than after 0–12 h.3. The effects of length of fast on metal uptake by the intestinal mucosa were greatest in the duodenum.4. Lactale production by duodenal mucosa was halved after 12 h of food deprivation but galactose absorption was little changed after a 40 h fast.
Nitrogen balance in Indian preschool children receiving the safe level of protein at varying levels of energy
Authors: Iyengar Ashok K. , Rao B. S. Narasinga , Reddy Vinodini 
Published: May 2005

1. A study was carried out to determine the effects of varying the level of energy intake on nitrogen balance in preschool children receiving the safe requirement level of protein, determined in an earlier study.2. Seven preschool children received four energy levels, i.e. 293, 334, 376 and 418kJ/kg body-weight at the safe level of protein intake of 1·75 g/kg body-weight and N balance determined.3. The N balance decreased with a decrease in energy intake. However, the N balance was positive at all levels of energy intake studied.4. Results indicated that at a protein intake of 1·75 g/kg body-weight the minimum level of energy intake for a retention of 40 mg N/kg body-weight in these children was found to be 326·2±45·5 (mean ± SD) kJ/kg body-weight. Below this energy intake the safe level of protein intake became inadequate.
Wheat bran increases high-density-lipoprotein cholesterol in the rat
Authors: Asp N.-G. , Bauer H. G. , Nilsson-Ehle P. , Nyman Margareta , Öste R. 
Published: May 2005

1. Five groups of male Sprague Dawley rats were given for 6 months a diet with high protein and fat contents but a very low dietary fibre content (group B), and this diet mixed with (g/kg) 50 low-methoxyl pectin (groupL), 50 high-methoxyl pectin (group H), 50 guar gum (group G) and 200 wheat bran (group WB, corresponding to 100 wheat fibre) respectively.2. The weight increment was significantly lower in group G than in the other groups. Assuming no energy value of the dietary fibre, the weight increment (/kJ) was the same in groups B, L and H, lower in group G and higher in group WB, indicating that a proportion of the bran fibre might in fact be available as a source of energy.3. Wheat bran increased total plasma cholesterol and high-density-lipoprotein cholesterol after 6, 12 and 26 weeks. Group G had significantly lowered plasma cholesterol after 12 weeks. Pectin on the other hand did not significantly influence total or HDL-cholesterol levels. It is therefore possible that the plasma cholesterol lowering effect of pectin previously demonstrated in the rat is dependent on the presence of significant amounts of dietary cholesterol as our diets did not contain added cholesterol. Plasma triglycerides decreased with age but were similar in all groups.