bluuebunny/crossref_metadata_2025 huggingface dataset:
The metabolism of [75Se]selenomethionine in four women
Authors: Griffiths Nora M. , Stewart R. D. H. , Robinson Marion F.
Published: May 2005

1. The long-term fate of an oral dose of [75Se]selenomethionine was studied in four women.

2. Urinary and faecal excretion, respiratory losses and whole-body retention of 75Se were measured, and also 75Se turnover in whole body, plasma and erythrocytes during a period of 33–44 weeks.

3. Intestinal absorption of [75Se]selenomethionine by the four subjects was 95.5–97.3% of the administered dose.

4. Urinary excretion accounted for 6–9% of absorbed 75Se in the first 2 weeks. No radioactivity was detected in expired air.

5. After the initial 8 weeks during which radioactivity decreased more rapidly, whole-body retention of 75Se decreased exponentially with a half-time of 207–290 d.

6. Plasma 75Se concentration reached a maximum level 3–4 h after the dose. Transient initial uptake of 75Se in erythrocytes during the first hour was followed by a gradual increase to a maximum concentration at 8–12 weeks.

7. These results are compared with the results of an earlier study of the metabolism of [75Se]selenite in two of the same women. 75Se from [75Se]selenomethionine was found to be more completely absorbed, had a greater retention and smaller endogenous urinary and faecal losses than 75Se from [75Se]selenite, and these differences persisted throughout the experimental period. These findings differed from those obtained in rats in which, after an initial period, 75Se from selenite was metabolized similarly to that from selenomethionine.
Mechanisms of heat damage in proteins
Authors: Hurrell R. F. , Carpenter K. J. , Sinclair W. J. , Otterburn M. S. , Asquith R. S.
Published: May 2005

1. Studies have been made with solvent-extracted chicken muscle, bovine plasma albumin (BPA) and other proteins, all severely heated in the absence of carbohydrates so as to cause a large decrease in their fluorodinitrobenzene (FDNB)-reactive lysine contents.

2. ɛ-N-(β-L-aspartyl)-L-lysine and ɛ-N-(γ-L-glutamyl)-L-lysine isopeptides were determined after enzymic digestion of heated chicken muscle, and their content was found to increase as the material was subjected to more heat treatment. Heated chicken muscle was not found to contain lanthionine. Heated BPA, on the other hand, was found to contain lanthionine but not the isopeptides. Both lanthionine and isopeptide cross-linkages were detected in most of the other heated proteins. There was some difficulty in quantifying the amounts of isopeptides formed on heat treatment, because the enzymic digestion procedure used in their isolation appeared to be incomplete. Neither lysinoalanine nor ornithinoalanine was detected in any of the test materials.

3. The severely heated chicken muscle was fed to rats, and ileal and faecal digestibilities were studied. Protein digestibility was found to be greatly reduced after heat treatment, although the isopeptides themselves appeared to be at least as digestible as the total N component, total lysine, or FDNB-reactive lysine. However, the reduction in ileal N digestibility only partly accounted for the much larger reduction in nutritive value, as measured by net protein ratio ((weight loss of N-free animals + weight gain of test animals) ÷ weight of crude protein (N × 6.25) consumed by test animals). Possible reasons for this are discussed.
The effect of feeding on the motility of the stomach and small intestine in the pig
Authors: Ruckebusch Y. , Bueno L.
Published: May 2005

1. Electromyographical studies were made on the motility of the stomach and small intestine of five pigs when given a standard diet eitherad lib., or as one or two meals/d. Recordings were made from electrodes placed chronically on the antrum, the duodenum and the jejuno-ileum, and a continuous 24 h recording was made every 2 d for a period of 4 weeks. A simple ‘T’-shaped cannula was positioned in the proximal duodenum in two of the pigs.

2. The basic pattern of activity of the small intestine was grouped in phases of irregular and regular activity characteristic of the myoelectric complex. This pattern recurred about eighteen times/d in fasting pigs, or in animals fedad lib.and so eating frequent but small meals. When a myoelectric complex on the duodenum reached its regular ‘spiking’ phase, antral activity and passage of digesta ceased completely for a period (5–15 min) which varied according to the time elasped since the last meal.

3. In animals receiving one meal/d a postprandial pattern of activity lasted about 6 h. The proximal part of the intestine showed continuous activity with vigorous isolated or peristaltic spike bursts. The average number of myoelectric complexes was thirteen/d. When receiving two meals/d the postprandial pattern lasted for only 2–3 h, and approximately sixteen myoelectric complexes/d were recorded.

4. It is concluded that the extent of disruption of the basic intestinal motility pattern depends on the amount of food consumed per meal and subsequent release of nutrients.
The effects of grass and concentrate diets on the specific activities of some enzymes of hepatic carbohydrate metabolism in sheep
Authors: Pearce J. , Unsworth E. F.
Published: May 2005

1. Feeding sheep a concentrate diet compared with grass diets increased the hepatic specific activities of the three glycolytic enzymes studied, and that of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), and reduced the specific activity of D-fructose-1,6-diphosphate 1-phosphohydrolase (EC 3.1.3.11). The specific activities of phosphogluconate dehydrogenase (EC 1.1.1.43) and malate dehydrogenase (decarboxylating) (NADP) (EC 1.1.1.40) were unaffected by diet.
Utilization of dietary energy for maintenance, milk production and lipogenesis by lactating crossbred cows during their midstage of lactation
Authors: Patle B. R. , Mudgal V. D.
Published: May 2005

1. Twenty-four energy and nitrogen balances were determined using twenty-four crossbred cows (Brown Swiss × Sahiwal) during their midstage of lactation. Energy balances were estimated by subtracting milk energy and heat production from the metabolizable energy (me) intake. Heat production was estimated by indirect calorimetry, by collection and analysis of respiratory gases. The cows were given amounts corresponding to 90, 110 and 130 % of the me and 90 and 110% of the digestible crude protein (DCP) standards of the (US) National Research Council (1966).

2. Energy requirements were estimated by partitioning the me intake for maintenance, milk production and energy gain or loss by multiple regression of energy balance values. Heat production (and thus energy balance) was corrected for excess N intake.

3. Energy requirements for maintenance were 585.18, 580.17 and 574.41 kJ me/kg body-weight0.75 per d for cows in negative balance, cows in positive balance and for all cows, respectively.

4. The efficiency of utilization of me for milk production was 68.52, 65.48 and 66.12% respectively, for cows in negative balance, for cows in positive balance and all cows. Energy required per kg fat-corrected milk production was 4.580, 4.791 and 4.746 MJ me for the respective groups of cows.

5. The efficiency of utilization of me for tissue gain was 67.67 and 64.86 % for cows in positive balance and for all cows respectively.
The effect of feeding magnesium-enriched diets on the quality of the albumen of stored eggs
Authors: Monsey J. B. , Robinson D. S. , Miller W. S. , Ellis Margaret
Published: May 2005

1. Pullets were given from 1-d-old diets containing 1.6, 4.1, 8.1 and 12.0 g Mg/kg. Only small effects of these diets on live weight, food consumption, egg number, egg weights or egg-shell thickness were observed except at the highest level (12.0 g Mg/kg) which caused diarrhoea and an appreciable lowering of the live weight of growing pullets. A further group was given from point-of-lay a diet containing 9.3 g Mg/kg.

2. Eggs laid on 3 consecutive days from each of eighteen hens were collected at intervals of 3 weeks until the birds were 68.5 weeks old. Eggs laid on the 3rd day were used to determine the initial proportion of thick egg-white present and also the concentration of Mg, Ca, Na and K in the thick egg-white. Eggs laid on the 1st and 2nd days were stored at 20° for 20 d to establish the proportion of thick egg-white remaining after storage.

3. With the unsupplemented diet the proportion of residual thick egg-white after storage of eggs for 20 d at 20° was 306, 161 and 305 mg/g total egg-white when the hens were 26.5, 53.5 and 68.5 weeks of age respectively. When the diet containing 9.3 g Mg/kg was given, the proportion of thick egg-white after storage remained approximately 400 mg/g throughout the period of the trial.

4. The mean Mg concentration in the thick egg-white of eggs laid by hens given unsupplemented diets was 5.77 mm. The addition of extra Mg to the diet increased the content of Mg in the thick egg-white, for example when the diet contained 9.3 g Mg/kg the mean concentration rose to 7.69 mm.
Intravenous infusion of glucose and insulin in relation to milk secretion in the sow
Authors: Reynolds L. , Rook J. A. F.
Published: May 2005

1. A comparison was made of the composition of milk from front and rear teats in four sows. There were small and not significant differences in fat, protein and lactose contents, and in the fatty-acid composition of the milk fat with the exception of the 18:3 acid where the difference was also small but significant.

2. The effects of intravenous infusions of glucose and insulin in lactating sows on milk secretion and blood composition were investigated in two sows.

3. Intravenous infusion of glucose had no effect on blood plasma glucose concentration but increased the yields of lactose, protein and water.

4. Intravenous infusion of insulin depressed plasma glucose concentration and the yields of lactose and water. The yield of protein was unaffected.

5. It is concluded that differences between the non-ruminant (the sow) and the ruminant in the responses in milk secretion to glucose infusion may be related to differences in the sensitivity to insulin of mammary tissue.
Some effects of variation in carbohydrate and nitrogen intakes on the chemical composition of mixed rumen bacteria from young steers
Authors: McAllan A. B. , Smith R. H.
Published: May 2005

1. Samples of rumen digesta were taken at different times after giving calves various dried forage or hay and cereal diets and mixed bacteria were separated.

2. For calves receiving dried forage only, the carbohydrate content of mixed bacteria varied with time after feeding, reaching a maximum of approximately 140 g/kg dry matter (DM) after 0.5-1 h, decreasing to about 60 g/kg DM after 4 h.

3. Replacement of part of the dried forage with glucose to give a similar metabolizable energy intake but approximately half as much nitrogen, produced a similar pattern of change with time after feeding but resulted in a markedly increased maximum bacterial carbohydrate content (approximately 230 g/kg DM). Addition of urea to this diet reduced the bacterial accumulation of carbohydrate to approximately the same level as was found in samples from calves receiving forage only diets. For the forage diets the carbohydrate content fell to 60-100 g/kg DM 4 h after feeding. For the hay and cereal diet the value was 170 g/kg DM at this time.

4. Changes in bacterial carbohydrate content were largely a result of changes in storage polysaccharide (α-dextran) content.

5. Crude protein (N × 6.25) and ash contents of mixed bacteria decreased after feeding with all-forage diets, but returned to approximately fasting levels within 4 h. At this time samples from calves receiving dried forage and glucose diets contained less CP and more ash (approximately 450 and 220 g/kg DM respectively) than those from calves given diets of dried forage only (approximately 525 and 180 g/kg DM respectively).

6. CP, total carbohydrate and ash content of mixed rumen bacteria contributed approximately 0.80 g/g DM.

7. Sodium, potassium, calcium, magnesium and phosphate accounted for approximately 0.50 g/g bacterial ash.
Responses to postruminal infusions of graded levels of casein in lactating goats
Authors: Ranawana S. S. E. , Kellaway R. C.
Published: May 2005

1. A study was made in goats of the response in terms of milk production, nitrogen utilization, plasma amino acids and amino acid uptake by the mammary gland, to postruminal infusion of casein. Goats in early lactation, housed in metabolism cages, were fed on 2.5 kg basal ration/d (containing 111 g crude protein (N × 6.25)/kg) and were given, by infusion into the abomasum, 0, 15, 30 or 45 g casein/d.

2. Milk production increased from 2.41 kg/d on the basal ration to 2.52, 2.80 and 2.94 kg/d in response to infusions of 15, 30 and 45 g casein/d respectively. Milk composition was unaffected except for milk fat, which was slightly decreased during infusions of the higher levels of casein.

3. The goats were found to be in positive N balance on the basal ration. Milk N output increased with casein infusion; the increase was equivalent to a maximum of 49% of the infused N.

4. The concentration of glucose in arterial blood plasma was decreased at the highest level of casein infusion, but that of plasma urea N was unaffected by treatments.

5. Casein infusions increased the concentrations of total indispensable amino acids and the ratio, indispensable: dispensable amino acids in arterial plasma. Arterial concentrations and mammary extractions of most indispensable amino acids were increased, but only a few increases were statistically significant (P< 0.05).

6. Comparison of individual indispensable amino acids absorbed from the intestine with output in milk indicated that methionine was probably the first limiting amino acid.

7. The results of the experiment were compared to those of similar experiments with cows that have been reported by other workers. The possible ways in which the infused casein may have caused the responses were discussed. However, no firm conclusions regarding the mechanism involved could be drawn from the results of the present study.
Balance study of twenty trace elements during total parenteral nutrition in man
Authors: Jacobson S. , Wester P.-O.
Published: May 2005

1. Balances of twenty trace elements (silver, arsenic, gold, bromine, cadmium, cobalt, chromium, caesium, copper, iron, mercury, lanthanum, molybdenum, rubidium, antimony, scandium, selenium, samarium, tungsten and zinc) have been determined in four male patients during total parenteral nutrition including fat emulsion and a special solution for addition of Fe, Zn, manganese, Cu, fluorine and iodine, besides calcium and magnesium, to the infusion solutions.

2. The analyses for trace elements were made with the aid of an ion-exchange technique based on neutron activation, and combined with subsequent gamma spectrometry.

3. The intended intravenous supply of trace elements corresponded approximately to the analysed supply. However, all the other trace elements determined were found to be unintentionally administered in small amounts.

4. There was a substantial retention of Fe. Other elements retained were Ag, Co, Cr, Cu, Sb, Sc and W.

5. Particularly Br and Rb were lost by the patients, but negative balances were also found for As, Au, Cd, Cs, Mo, Se and Zn. However, Zn was retained by one patient with short bowel syndrome.

6. The serum concentrations of thirteen (Ag, Br, Co, Cs, Cu, Fe, Hg, Mo, Rb, Sc, Se, W and Zn) of the trace elements were found to have some decrease during the period of total parenteral nutrition, mostly in accordance with the corresponding balance values. Fe, in particular, was found to have the directional change in concentration.

7. The administration of trace elements is recommended in long-term total parenteral nutrition.
Whole-body albumin mass and distribution in rats fed on low-protein diets
Authors: Coward W. A. , Sawyer M. B.
Published: May 2005

1. From 5 weeks of age, control and experimental rats were given diets containing 210 and 31 g protein/kg respectively, and killed for analysis at 0, 2, 5, 8, 12 and 20 d after the start of the experiment. At these times estimates were made of plasma albumin concentration, plasma volume and total vascular and extravascular albumin mass.

2. Plasma albumin concentrations were significantly lower in the experimental animals when compared to controls at 8, 12 and 20 d but plasma volumes (ml/kg body-weight) tended to be greater in the former animals. Total vascular albumin mass (g/kg body-weight) was significantly less in experimental animals compared to controls at 8 and 20 d, but was significantly reduced below values at 0 d only at 20 d.

3. Extravascular albumin mass (g/kg body-weight) was significantly lower in experimental animals in comparison with controls at 2, 5, 8, 12 and 20 d and significantly reduced below values at 0 d at 5, 8, 12 and 20 d.

4. Whole-body albumin mass was significantly reduced at 5, 8, 12 and 20 d when compared both with controls killed at the same time and animals killed at 0 d. Measurement of the ratio, extravascular albumin mass: vascular albumin mass indicated a significant redistribution of whole-body albumin mass at 5 and 20 d and mean values for this ratio were always lower in experimental animals than in controls.

5. It was concluded that measurement of plasma albumin concentration does not indicate the true extent of whole-body albumin losses in protein deficiency since total vascular albumin mass is, to some extent, maintained at the expense of extravascular albumin mass.
The enhancement by dietary zinc deficiency of the susceptibility of the rat duodenum to colchicine
Authors: Dinsdale D. , Williams R. B.
Published: May 2005

1. The incidence of colchicine-induced lesions in the germinal epithelium of the rat duodenum was studied in young rats in an early stage of zinc deficiency and in their pair-fed controls. At both dose levels of colchicine used, a marked increase in the amount of cell damage was observed in the duodenum of Zn-deficient rats as compared with the pair-fed, control (Zn-supplemented) rats.

2. No statistical interaction between Zn and colchicine was demonstrable, and no lesions were found in the duodenum of animals that had not been treated with colchicine.

3. The results are discussed in relation to the effects of Zn deficiency in animals and the possible involvement of Zn in the maintenance of the integrity of microtubular structures.
Nutritive value of mixed proteins
Authors: Woodham A. A. , Deans P. S.
Published: May 2005

1. Two series of protein feeding-stuffs each consisting of a fish meal, meat-and-bone meal, soya-bean meal, groundnut meal and sunflower-seed meal were analysed for total amino acid composition and evaluated, both individually and combined in all possible pairs, as supplements to cereal-based diets for growing chicks by the total protein efficiency (g weight gain/g protein consumed; TPE) procedure. Each pair of feeding-stuffs provided 120 g supplementary protein/kg diet and the diet was made up so that the relative amounts of protein provided by each of the pair of constituents were (w/w): 120:0, 100:20, 80:40, 60:60, 40:80, 20:100 and 0:120 respectively, in addition to 60 g protein/kg provided by cereals.

2. In all but one of the twenty pairs of feeding-stuffs studied the mixtures exhibited a marked synergistic effect in that the TPE value was higher than the appropriately weighted mean of the TPE values obtained with the individual components.

3. Neither chemical score ([amount of limiting amino acid/the chick's requirement for the same amino acid] × 100) nor essential amino acid index; geometric mean for the ratio, amount of essential amino acid: the chick's requirement for that amino acid, for all ten essential amino acids) calculated from the amino acid composition of the dietary constituents could be used routinely to predict the results of the chick growth test, although chemical score did parallel the TPE values in some instances. In a number of instances, mixtures containing an apparently less favourable amino acid composition than one of the components of the mixture gave a higher TPE value.

4. It seems likely that the relative proportions of a number of amino acids determine the optimum combination of a mixture of proteins. The removal of amino acid deficiencies alone is not sufficient to ensure that a given mixture of proteins produces optimum performance in growing chickens.
Nutritive value of mixed proteins
Authors: Woodham A. A. , Clarke Eileen M. W.
Published: May 2005

1. A fish meal, meat meal, soya-bean meal, groundnut meal and sunflower-seed meal of known amino acid composition were evaluated individually, and combined in all possible pairs, by the estimation of net protein utilization (NPU) and protein efficiency ratio (body-weight gain:crude protein intake; per) using rats. Each pair provided a total of 100 g protein/ kg diet made up so that the amounts of the constituents were (w/w) 100:0, 80:20, 60:40, 20:80 and 0:100.

2. Marked synergistic effects were noted only for mixtures of sunflower-seed meal with soya-bean, fish and meat meals.

3. Chemical score ([amount of limiting amino acid/the rat's requirement for the same amino acid] × 100; CS), but not essential amino acid index; geometric mean for the ratio, amount of essential amino acid: the rat's requirement for that amino acid, for all ten essential amino acids; EAAI), successfully predicted the rankings of all mixtures except groundnut meal-meat meal and groundnut meal-soya-bean meal, by both per and NPU tests.

4. Although there is broad agreement linking results of per and NPU tests with results obtained by a more practical feeding trial in which the mixtures were evaluated as supplements to cereals, neither of these two standard tests is capable of predicting in every instance the advantages to be gained by mixing protein concentrates.
Measurement of the rate of flow of dry matter in digesta passing through the duodenum of sheep
Authors: Oldham J. D. , Ling J. R.
Published: May 2005

1. A total of seven sheep fitted with re-entrant cannulas in the proximal duodenum were used in three experiments to measure the passage of dry matter (DM) in duodenal digesta.

2. Fifty-three 24 h measurements and ten 48 h measurements of DM flow were made in Expt 1. Coefficient of variation (CV) of these measurements was 22.1 % which was similar to variability reported for chromic oxide ‘corrected’ flows and for an estimate of day-to-day variation. DM flow on day 1 was 103.2 % (SE = 8.94) of flow on day 2 in 48 h measurements.

3. In two 3 × 3 Latin-square design experiments, duodenal DM flow was measured continuously over 72 h and on days 1, 2 and 3 DM flow was 100.4, 102.6 and 96.9 % (SE = 5.82) of mean flow (Expt 2) and 95.8, 101.2 and 103.0% (SE = 6.70) of mean flow (Expt 3) respectively.

4. It was concluded that no depression in duodenal DM flow occurred during the first 24 h of collection in these experiments and that the variability of repeated 24 h measurements of flow was within day-to-day variation.
The energy cost of fat and protein deposition in the rat
Authors: Pullar J. D. , Webster A. J. F.
Published: May 2005

1. Measurements were made of energy balance by direct calorimetry, and of nitrogen balance in groups of lean and congenitally obese (‘fatty’) Zucker rats at body-weights of 200 and 350 g given a highly digestible semisynthetic diet at 14.0 or 18.4 g/rat per 24 h.

2. Losses of food energy and N in faeces were very small. The fatty rats lost much more N in urine than did lean rats. Despite this the proportion of gross energy that was metabolized was 0.92 for both fatty and lean rats.

3. In all trials, fatty rats lost a smaller proportion of metabolizable energy (ME) as heat and deposited less as protein than thin rats but deposited much more as fat.

4. The amounts of ME required to deposit 1 kJ of protein and 1 kJ of fat respectively were shown by regression analysis to be 2.25 (±0.16) and 1.36 (±0.06) kJ respectively. These values agree extremely closely with recent, more tentative, estimates based on assumptions as to maintenance requirement which the present experiments were able to circumvent. It may be concluded with confidence that the energy costs of depositing 1 g of protein or fat are almost identical at 53 kJ ME/g.
Absorption of ‘fortification’ iron
Authors: Björn-Rasmussen E. , Hallberg L. , Rossander L.
Published: May 2005

1. The first part of this study was designed to determine the increase in the amount of iron absorbed by hypothetical groups of subjects on the border-line of Fe deficiency when they were given meals fortified with ferrous sulphate. Two levels of Fe fortification were used (1.6 and 8.9 mg/meal) and the increase in the amount of Fe absorbed by the ‘border-line’ groups was 0.13 and 0.7 mg respectively.

2. Subjects which are on the border-line of Fe deficiency may be considered the target group of an Fe-fortification programme. Therefore the experimental model used can provide valuable information on the effects on the prevalence of Fe deficiency which can be expected when such a programme is introduced.

3. In the second part of the study, the bioavailability in man of reduced Fe with different physico-chemical properties was measured. Special emphasis was given to the relationship between the values obtained in vitro and in vivo.

4. The bioavailability was expressed as absorbability relative to that of ferrous sulphate. In four samples of hydrogen-reduced Fe the bioavailability ranged from 90 to 13%. The reduced-Fe products differed considerably with respect to solubility in hydrochloric acid (8–94% dissolved after 30 min), particle size distribution (91–1% < 7 μm) and reactive surface area (< 0.1–2.7 m2/g).

5. The relationships found between physico-chemical information and bioavailability indicated that reactive surface area and dissolution rate were better predictors of the bioavailability than the particle size.
Degradation of the nucleic acids in mixed rumen bacteria on incubation with different media
Authors: Smith R. C. , Smith R. H.
Published: May 2005

1. Mixed rumen bacteria were grown in vitro in a medium containing [U-14C]adenine. Radioactivity was incorporated into the purine bases of the nucleic acids.

2. Labelled bacteria were incubated with a nitrogen-deficient cell-free medium (medium A), a protozoa-free supernatant suspension from a slow-speed centrifuging of a steer's rumen contents (medium B) and whole rumen contents of a steer (medium C). Mean (six experiments) proportional rates of release of radioactivity(/h) were significantly greater for medium A (0.140) than for media B or C (0.055 and 0.043 respectively). Some of the radioactivity accumulated in the cell-free media; some was lost, partially as carbon dioxide.

3. Calculation from this and other information indicated that about 30% of bacterial nucleic acids may turn over in the rumen even in the absence of protozoa.
Responses to postruminal infusions of glucose and casein in lactating goats
Authors: Ranawana S. S. E. , Kellaway R. C.
Published: May 2005

1. A study was made in goats of the response in terms of milk production, nitrogen utilization, plasma amino acids and glucose kinetics to postruminal infusions of glucose and casein. Goats in mid-lactation, housed in metabolism cages, were fed on 2 kg basal ration (containing 112 g crude protein (N × 6.25)/kg)/d alone (control) and with daily infusions into the abomasum of 45 g casein or 45 g glucose.

2. Milk production increased with casein infusion (P < 0.01), but not with glucose infusion, being 1.59, 1.86 and 1.62 kg/d with the control, casein and glucose infusions respectively. Milk composition was unaffected except for milk fat, which was decreased by the glucose infusion.

3. The goats were in positive N balance on the basal ration. Milk N output increased with casein infusion, by an amount equivalent to 27% of the infused N.

4. The concentration of dispensable amino acids in arterial plasma was decreased with casein infusion and increased with glucose infusion.

5. Glucose kinetic measurements with control, casein and glucose infusions indicated that pool sizes were 247, 279 and 302 mg/kg live weight0.75, and irreversible losses were 5.5, 6.7 and 7.0 mg/kg live weight0.75 per min respectively. The differences between the results obtained from the glucose and casein infusions were not significant (P < 0.05).

6. The results of the experiment indicate that the increased milk production obtained when casein was infused was not due to enhanced gluconeogenesis.
Studies on lipid digestion in the preruminant calf
Authors: Edwards-Webb J. D. , Thompson S. Y.
Published: May 2005

1. A comparison has been made of the products of lipolysis of the fat in cow's milk by salivary and pancreatic lipases (EC3.1.1.3) from a preruminant calf.

2. It was confirmed that salivary lipase releases short-chain acids preferentially, particularly butyric and caproic acids. This was not only true initially but also as the course of lipolysis progressed. Even after 60 min incubation the longer-chain acids were only released to about one-twentieth of the extent of butyric acid.

3. Although pancreatic lipase also initially released proportionately more butyric acid than other fatty acids, within 30 min the longer-chain acids were released to about half the extent of butyric acid.

4. Since the over-all extent of lipolysis by salivary lipase was limited by its inability to release long-chain acids, the release of these acids (which comprise two-thirds of the total fatty acids of milk fat) in the calf is likely to be dependent on the subsequent action of pancreatic lipase.

5. The release of fatty acids by pancreatic lipase was enhanced by pre-incubating milk fat with salivary lipase.
A quantitative study into the role of infection in determining nutritional status in Gambian village children
Authors: Rowland M. G. M. , Cole T. J. , Whitehead R. G.
Published: May 2005

1. Growth in weight and height in 152 children between the ages of 0.6 and 3 years was investigated in Keneba, a rural Gambian village. By 1 year of age the average weight-for-age of the children was only 75% of the Jelliffe (1966) standard.

2. The relationship between the prevalence of nine different categories of diseases and growth was investigated to determine the quantitative contribution of the diseases to the growth faltering observed. There was a highly significant negative relationship between gastroenteritis and both weight gain and height gain. The only other disease category having a similar relationship was malaria, but in this instance only with weight gain.

3. Although over-all growth in weight and height was considerably below the standard values, multiple regression analysis indicated that after the age of 1 year, except in July and August, normal and sometimes slow ‘catch-up’ growth would be possible in the absence of gastroenteritis.

4. Attention is drawn to the limitations of the use of anthropometry in a settled village community as the only criterion by which dietary adequacy can be judged.
An animal model to study iron availability from human diets
Authors: Narasinga Rao B. S. , Prasad J. Siva , Sarathy C. Vijaya
Published: May 2005

1. The retention of ferric- and ferrous-iron was determined in guinea-pigs and monkeys using55Fe and59Fe.

2. The bioavailability of Fe from two typical Indian diets based on rice and wheat was determined in humans and monkeys using a59Fe tracer and whole-body counting.

3. The retention ratio, ferric-Fe; ferrous-Fe was 0.90 in guinea-pigs and 0.33 in monkeys, indicating that monkeys absorb ferrous-Fe preferentially.

4. In monkeys retention of Fe from the test diets, as from ferrous ascorbate was lower than that in humans.

5. When food-Fe retention was expressed in relation to inorganic-Fe retention the value for retention ratio, food Fe: inorganic Fe in monkeys was similar to that in human subjects.

6. The results indicate that the monkey can be used as a model to study Fe absorption from human diets.
Selenium concentrations and glutathione peroxidase activities in whole blood of New Zealand residents
Authors: Thomson Christine D. , Rea Heather M. , Doesburg Veronica M. , Robinson Marion F.
Published: May 2005

1. A relationship was found between selenium concentrations and glutathione peroxidase (EC 1.11.1.9) activities in whole blood of 264 New Zealand residents (r 0.71, P < 0.001).

2. New Zealand residents returning from visits overseas of 7 months to 3 years had elevated blood Se, but normal GSH-Px activities, whereas for some new settlers in New Zealand both Se and GSH-Px activities were high.
Simulation of energy metabolism in the simple-stomached animal
Authors: Schulz A. R.
Published: May 2005

1. A computer programme is described which simulates energy metabolism in the whole animal. Simulation was based on representation of the animal as a quasi-steady-state system.

2. Input for the programme consisted of the chemical composition of the diet and an estimate of either the maintenance energy requirement or an estimate of energy retention.

3. Simulation was performed by estimating the yield of adenosine triphosphate in the major metabolic pathways operative in simple-stomached animals, and on the utilization of adenosine triphosphate in major anabolic processes.

x4. Results obtained from simulation were in close agreement with experimental observations reported by McCracken (1975).
The effect of frequency of feeding on the response by growing pigs to supplements of free lysine
Authors: Batterham E. S. , O'neill G. H.
Published: May 2005

1. Six experiments, involving a total of 320 pigs, were conducted to examine the reponse of growing pigs to diets supplemented with free lysine when fed either once daily or in six equal portions at intervals of 3 h. The effect of dry or wet feeding on the response to free lysine was examined in Expt nos. 4 and 5. The assumption of linear lysine response over the range of lysine supplementation was examined in Expt no. 6.

2. A significant (P < 0.01) interaction between lysine supplementation and frequency of feeding occurred for growth rate and food conversion ratio. Growth responses to the supplements of free lysine with once daily feeding were only 67 % of that achieved with frequent feeding.

3. Wet feeding had no effect on the growth responses to free lysine supplements.

4. The lysine response was linear over the range of lysine supplementation examined.

5. The implications of these results to the interpretation of experiments examining the lysine requirements of pigs are discussed.
The utilization of proteins and amino acids in diets based on cassava (Manihot utilissima), rice or sorghum (Sorghum sativa) by young Nigerian men of low income
Authors: Nicol B. M. , Phillips P. G.
Published: May 2005

1. The net protein utilization (npu, the percentage of dietary nitrogen retained in the body, allowance being made for endogenous urinary and faecal N) of diets composed of Nigerian foodstuffs, based on rice, sorghum (Sorghum sativa) or cassava (Manihot utilissima), was compared to that of a minimal protein diet used to determine endogenous N excretion, supplemented with whole egg. The addition ofdl-methionine andl-tryptophan to the rice diet produced a small but non-significant increase innpu, whereas the addition ofdl-methionine to the cassava diet produced a very significant increase innpu.Thenpuof a diet based on home-pounded, winnowed, sorghum flour was higher than that of a diet based on milled whole-meal sorghum due to the low digestibility of the latter diet.

2. The digestibility of the rice and cassava diets were the same, although the total crude fibre content of the rice diets was lower than that of the cassava diets.

3. Nigerian men used the proteins of the egg diet and of mixed diets based on rice, sorghum and cassava more efficiently than predicted by applying methods recommended by the FAO/WHOad hocExpert Committee on Energy and Protein Requirements (FAO/WHO, 1973).

4. The recommendations of that Committee (FAO/WHO, 1973) to reduce the amounts of sulphur amino acids and tryptophan, contained in the ‘provisional pattern of amino acids’ proposed by the FAO Committee on Protein Requirements (FAO, 1957), are supported, but the increases in lysine and threonine are not supported, by the present results.
Response of lipogenic enzymes to intensity and duration of overfeeding in the adult Japanese quail (Coturnix coturnixjaponica)
Authors: Shapira Niva , Nir I. , BUDOWSKI P.
Published: May 2005

1. Adult male Japanese quail (Coturnix Coturnix Japonica) were overfed at different intensities during varying periods: (1) by gradually increasing the daily amount of food up to twice the control level in a period of 11 d and keeping this level constant during the subsequent 12 d period (prolonged overfeeding); (2) by gradually increasing the daily amount of food up to approximately twice the control level in a period of 6 d (short, low-intensity overfeeding; SL); (3) by gradually increasing the daily amount of food up to approximately 2.5-fold the control level in a period of 7 d (short, high-intensity overfeeding; SH).

2. The activities of acetyl-CoA carboxylase (EC6.4.1.2; CBX), fatty acid synthetase (FAS), ATP citrate lyase (EC4.1.3.8; CCE) and malate dehydrogenase (decarboxylating) (NADP) (EC1.1.1.40; ME) were determined in adipose tissue (AT) and liver of the overfed andad lib.- fed chicks. Size and fat content of carcass, AT and liver were also determined in order to evaluate the extent of obesity.

3. The weight of carcass, lean body mass, liver and AT and the extent of fat deposition increased with the total amount of food consumed. Obesity was particularly pronounced in quail after prolonged overfeeding.

4. Lipogenic enzymes in liver were much more active than those of AT. The specific activities of CBX, FAS and CCE in liver and AT in overfed Japanese quail increased consistently in the SL and SH groups only and the increase was related to the level of food intake in these groups. ME was the only enzyme whose specific activity increased in all overfed groups. Total AT enzyme activities were increased most strongly after prolonged overfeeding because of the pronounced tissue enlargement in that treatment. But in liver, where tissue enlargement was less and differences in size due to the three overfeeding treatments were less marked, total activities depended mainly on the enhancement of specific activities.

5. The results lead to the conclusion that the increase in hepatic lipogenic enzymes roughly reflects the current food intake and may thus be considered to represent the primary adaptation in the overfed Japanese quail. Secondary adaptation, involving tissue enlargement, occurs principally in AT of Japanese quail after prolonged overfeeding, in which situation AT contributes significantly to total lipogenic activity.
The assessment of zinc status of an animal from the uptake of65Zn by the cells of whole blood in vitro
Authors: Chesters J. K. , Will Marie
Published: May 2005

1.65Zn uptake by blood cells in vitro has been compared with plasma Zn concentration and plasma alkaline phosphatase (EC3.1.3.1) activity as indicators of an animal's Zn status.

2. Dietary Zn deficiency, low food intake, reduced dietary protein content and endotoxin administration all reduced plasma Zn concentration in the rat. In each case there was a parallel reduction in plasma alkaline phosphatase activity and an increase in65Zn uptake in vitro by cells of whole blood.

3. A similar relationship between the three measurements existed in sheep with lowered plasma Zn concentrations whether these were caused by dietary deficiency or by post-surgical stress.

4.65Zn uptake by cells of whole blood did not differentiate dietary Zn deficiency from the other factors which reduce plasma Zn under ‘field’ conditions.

5.65Zn uptake by the cells in whole blood in vitro was three to five times less rapid in blood of ruminant origin than in that from non-ruminants. This difference related to the erythrocytes rather than to the leukocytes or the plasma.
The presence of an aldehyde dehydrogenase inhibitor in animal diets and its effects on the experimental results in alcohol studies
Authors: Tottmar O. , Marchner H. , Karlsson N.
Published: May 2005

1. The effects of chronic ethanol administration on the metabolism of ethanol and acetaldehyde were studied in rats fed on a commercial diet containing an aldehyde dehydrogenase inhibitor, calcium cyanamide (calcium carbimide), as a contaminant in the calcinated bone-meal fraction of the diet.

2. Rats given an ethanol solution (150 ml/l) for 3 months and fed on a diet containing calcinated bone meal showed two times higher activity of the low-Kmacetaldehyde dehydrogenase in the liver, 26 % higher rate of ethanol elimination, and two to three times lower acetaldehyde levels in blood during ethanol elimination compared with control rats pair-fed on the same diet.

3. The results obtained from the ethanol-treated rats were similar to those obtained in experiments on control rats fed on diets not containing calcinated bone meal.

4. Experiments performed in vitro and in vivo on the inhibition of the acetaldehyde metabolism by cyanamide suggested that the apparent effects of chronic ethanol intake were really caused by calcium cyanamide in the diet.
The effect of litter size on placental blood flow and placental calcium transfer in the multifoetate guinea-pig
Authors: Symonds H. W. , Bubar R. H. , CRACKEL W. , Twardock A. R.
Published: May 2005

1. Placental blood flow rate and calcium transfer rate were measured at 61 d of pregnancy in guinea-pigs carrying between one and eight foetuses.

2. Placental blood flow rate was significantly correlated with foetal weight. Ca transfer rate was related to placental size. Irrespective of litter size the mean amount of Ca transferred across a placenta was between 0.22 and 0.34 mg/h per g placental tissue.

3. It was concluded that there was a limit to the rate of transfer which was produced by a combination of limitations in placental blood flow rate, maternal plasma Ca concentration and placental tissue transfer capacity.
Prospective comparison of modified-fat–high-carbohydrate with standard low-carbohydrate dietary advice in the treatment of diabetes: one year follow-up study
Authors: Hockaday T. D. R. , Hockaday J. M. , Mann J. I. , Turner R. C.
Published: May 2005

1. A prospective randomized study of two dietary regimens has been started in newly-diagnosed diabetics to determine their effect on circulating metabolites and on diabetic complications.

2. During the first year of treatment the fasting plasma glucose concentrations on both the low-carbohydrate diet and the high-carbohydrate, modified-fat (MF) diet showed a similar decrease.

3. Plasma cholesterol showed a sustained decrease only in patients recommended a MF diet. Transient changes in plasma triglyceride concentrations occurred in patients on both dietary regimens.

4. Increased plasma cholesterol levels are associated with atheromatous disease which is common in diabetics in Europe and North America. A MF diet may therefore have an advantage in that it lowers the plasma cholesterol as well as being effective in lowering the plasma glucose.
The hypercholesterolaemic effect of caffeine in rats fed on diets with and without supplementary cholesterol
Authors: Fears R.
Published: May 2005

1. The effect of caffeine (2.5 g/kg diet) on lipid metabolism was examined in rats fed on a stock (low-cholesterol) diet or on a cholesterol plus cholic acid-supplemented (high-cholesterol) semi-synthetic diet.

2. When caffeine was included in the stock diet fed to rats for 7 d, there was a moderate but significant increase in the concentration of serum cholesterol compared to the levels observed in the control rats. This change can be accounted for by the increase that was observed in the rate of cholesterogenesis in the liver.

3. After 25 d of caffeine in the stock diet, hepatic cholesterogenesis was still increased but the concentration of serum cholesterol was now the same as in the control rats. During the experimental period there was a progressive increase in the faecal excretion of neutral sterols in the rats receiving caffeine.

4. When caffeine was added to a cholesterol plus cholic acid-supplemented diet, there was a marked increase in the concentration of serum cholesterol but hepatic cholesterogenesis was now reduced.

5. Caffeine in the high-cholesterol diet appeared to delay, but probably did not reduce, the absorption of an oral dose of radio-labelled cholesterol. This conclusion was confirmed using rats which had not previously received either caffeine or cholesterol in the diet.

6. When the effect of caffeine in the high-cholesterol diet was investigated during a 24 h period, an exacerbation of the hypercholesterolaemia was seen only at certain times.

7. After a 4-month period of feeding rats on the caffeine-supplemented high-cholesterol diet, histological examination did not detect any damage to the heart and aorta.

8. The metabolic regulations involved in the effects of caffeine in the two diets are discussed and the relevance of the present results to observations made with human subjects is considered.
Effect of age, weight and adequacy of zinc intake on the balance between alkaline ribonuclease and ribonuclease inhibitor in various tissues of the rat
Authors: Chesters J. K. , Will Marie
Published: May 2005

1. Deficiency of zinc inhibits growth and also increases the activity of alkaline ribonuclease in certain tissues of the rat (Prasad & Oberleas, 1973). Zn could influence ribonuclease activity by direct effects on the enzyme or its natural inhibitor, or non-specifically as occurs when growth rate is affected by various other factors. These possibilities were studied.

2. Alkaline ribonuclease was shown to be inhibited by Zn in vitro, but the concentrations of Zn required were so high that the enzyme was probably not directly affected by changes in tissue Zn concentration caused by dietary deficiency.

3. At lower concentrations, Zn added in vitro increased the activity of alkaline ribonuclease in tissue homogenates probably by inactivating the inhibitor of the enzyme.

4. Age, weight and particularly food restriction caused tissue-specific alterations of ribonuclease and ribonuclease inhibitor concentrations in liver, kidney, oesophagus, testis and thymus.

5. The ribonuclease activities in liver, kidney and testis of Zn-deficient rats were unaltered in comparison with those of pair-fed rats. In thymus, which decreased in weight in the Zn-deficient animals, there was a concomitant increase in ribonuclease activity, but in oesophagus, the deficiency reduced the activity of ribonuclease.

6. The effects of Zn deficiency upon alkaline ribonuclease and its inhibitor are probably secondary consequences of reductions in food intake or growth.