bluuebunny/crossref_metadata_2025 huggingface dataset:
Serum ferritin as an index of iron nutrition in rural and urban South African children
Authors: Derman D. P. , Lynch S. R. , Bothwell T. H. , Charlton R. W. , Torrance J. D. , Brink B. A. , Margo G. M. , Metz J.
Published: May 2005

1. Serum ferritin concentrations were measured in 378 Zulu children aged 1–4 years living in Nqutu, KwaZulu and in 342 children of mixed race (Cape coloureds) aged between 1 and 16 years living near Johannesburg.

2. The pattern of serum ferritin concentrations encountered in the children at different ages tended to parallel the changes in iron stores which are known to occur during development.

3. Serum ferritin concentrations showed a significant direct correlation with age, haemoglobin, serum Fe and percentage saturation of transferrin values.

4. Anaemia was most prevalent in the younger children. Of the rural and urban children aged 13–24 months 60 and 53% respectively were anaemic while only 11% of those over 24 months had haemoglobin concentrations that were below normal.

5. The prevalence of anaemia among children who had serum ferritin values below 12 μg/l was only slightly higher than that for the groups as a whole (38.8 %v.24.3%), while the prevalence in those with values of 12 μg/l or more was only slightly less (18.2%). However, when a ferritin concentration of less than 12μg/l was associated with a percentage saturation of transferrin of less than 16%, the prevalence of anaemia was 70.0%, and only 10.2% of children in whom both values were within the normal range were anaemic.

6. Since 67% of children had either a normal serum ferritin and a normal percentage saturation of transferrin or both values below the normal range, the two measurements taken together provided a useful means of separating the children who had significant Fe deficiency from those whose Fe stores were sufficient to make the appearance of anaemia unlikely.
Trace nutrients. Selenium in British food
Authors: Thorn Janet , Robertson Jean , Buss D. H. , Bunton N. G.
Published: May 2005

1. The amount of selenium in nationally representative samples of prepared and cooked groups of foods, and in a variety of raw individual foods, was determined fluorimetrically.

2. The average British diet was calculated to provide approximately 60 μg Se/d, of which half was derived from cereals and cereal products and another 40% from meat and fish. Milk, table fats, fruit and vegetables provided little or no Se.

3. Individual foods which were particularly rich in Se (>0.2 mg/kg) included ‘bread-making’ and wholemeal flours, kidney, fatty fish, brazil nuts (Bertholletia excelsa) and several other varieties of nut. In contrast, breast milk and other foods for babies (except some cereal products) contained little Se.

4. The total intake, and the amounts of Se in major foods, were lower than in most other studies. This is probably the result of the comparatively low levels of this element in British soil.
The development of obesity in preweanling obob mice
Authors: Thurlby P. L. , Trayhurn P.
Published: May 2005

1. The body compositions of obob and lean (ob+ and + +) mice at 10, 12, 17 and 28 d of age were investigated using a ‘cold stress’ test to identify the two groups.

2. At each of these ages the obob mice were found to contain significantly more fat than the lean. At 10 d 20 % more fat was present and by 17 d the increase was 72 %. The obob mice at 28 d contained nearly three times as much fat as the lean.

3. Carcass energy was significantly higher in obob mice at all ages investigated.

4. Other changes in body composition found in the 28 d obob mice, i.e. a reduction in total carcass nitrogen and water content, were already established in the 17-d-old mice but differences at 10 and 12 d were not apparent.

5. The livers of obob mice were significantly heavier than those from lean control mice at 28 d but no differences were detected at the earlier ages.

6. The results are discussed with reference to the early origin of obesity in obob mice.
A comparison of the effects of dietary calcium and phosphorus deficiency on the in vitro and in vivo metabolism of 25-hydroxycholecalciferol in the chick
Authors: Sommerville Barbara A. , Swaminathan R. , Care A. D.
Published: May 2005

1. Young chicks fed a diet deficient in calcium showed an eightfold increase in the in vitro renal production of 1,25-dihydroxycholecalciferol (1,25-DHCC) and those fed a diet deficient in phosphorus showed a threefold increase when compared to chicks on a normal diet.

2. The in vivo accumulation of 1,25-DHCC in the gut mucosa was doubled in both low-Ca and low-P groups as was the rate of Ca absorption from the duodenum and the Ca-binding protein activity. The accumulation of 1,25-DHCC in bone increased threefold in the low-Ca group but showed no change in the low-P group.

3. It was concluded that the increased rate of Ca absorption found in dietary P deficiency depends rather upon the capacity of the gut mucosa to accumulate larger amounts of 1,25-DHCC than upon an increased renal production of this metabolite. The mechanism by which this is achieved is unknown, but it unlikely to be a general increase in availability of 1,25-DHCC since no rise occurred in bone 1,25-DHCC levels.
Total body water in malnutrition: the possible role of energy intake
Authors: Patrick J. , Reeds P. J. , Jackson A. A. , Seakins Anne , Picou D. I. M.
Published: May 2005

1. Total body water (TBW) was measured using tritiated water in sixty-five children. The measurements were distributed throughout rehabilitation in order to define the effect of changing energy intakes.

2. Oedematous children had a high TBW which decreased to the normal range during loss of oedema providing they were not receiving more than maintenance amounts of energy during this period.

3. Marasmic children who had not received greater than maintenance amounts of energy had a normal TBW.

4. Treatment with a high-energy diet was associated with an initial increase in TBW.

5. The possible mechanisms for this phenomenon are discussed.
The use of a Thiry-Vella loop of jejunum to study the intestinal absorption of calcium and inorganic phosphate in the conscious pig
Authors: Fox J. , Care A. D. , Swaminathan R.
Published: May 2005

1. Pigs, each surgically prepared with a Thiry-Vella jejunal loop were used to study the absorption of calcium and inorganic phosphate from the intestine.

2. The loops were perfused daily for 6–8 h with a nutrient solution and absorption from the perfusate was measured.

3. The technique employed minimized atrophy of the jejunal mucosa and enabled the measurement of hourly or daily changes in absorption rate of components of the luminal fluid.

4. No differences were observed when polyethylene glycol (PEG; molecular weight 4000), [14C]PEG or 51Cr-EDTA were used as markers of net water movement.

5. Increasing the concentration of Ca in the perfusate resulted in the demonstration of a two-component relationship between net absorption rate of Ca and intraluminal Ca concentration. An initial rapid absorption rate from 0 to 4 mm was found, then a slower rate from approximately 5 mm upwards which did not saturate at the highest concentration tested (25 mm).

6. Increasing the concentration of phosphate in the perfusion solution increased the net absorption of phosphate from that solution. Although a two-component system, similar to that for Ca, was not evident, net absorption of phosphate was not saturated at the highest concentration tested (50 mm).

7. The absorption of Ca was unaffected by the presence of phosphate in the solution but Ca (2.5 mm) enhanced the absorption of phosphate.
Tissue enzyme levels as indices of protein status in sheep
Authors: Payne E. , Laws L.
Published: May 2005

1. An investigation was made to determine the value of tissue enzymes as indices of protein nutrition.

2. Sheep were given a reduced protein intake for 6 weeks, whereupon some were given a protein supplement for 1 week and then the sheep were refed their initial diet. In the first experiment sheep were taken from pasture and given a reduced protein intake for 6 weeks whereupon some were given a protein supplement for 1 week and then all the sheep were grazed on pasture. In the second experiment sheep were fed on lucerne (Medicago sativa) chaffad lib.in place of grazing before and after the period of reduced protein intake during which one group was also fed on molasses. Again, another group was given a protein supplement for 1 week after 6 weeks on the reduced protein intake.

3. As a result of reduced protein intake there were significant (P< 0.01) changes in the liver in the content of DNA, protein: DNA, arginine synthetase (combined activity of argininosuccinate synthetase (EC6.3.4.5) and argininosuccinate lyase (EC4.3.2.1)), aspartic aminotransferase (EC2.6.1.1), glutamic dehydrogenase (EC1.4.1.2), arginase (EC6.5.3.1) and tyrosine aminotransferase (EC2.6.1.5).

4. There were few consistent changes in muscle in the levels of DNA, protein:DNA, creatine kinase (EC2.7.3.2) and aspartic aminotransferase.

5. The feeding of molasses to one group tended to reduce the change in DNA level but still resulted in significant changes in the enzymes.

6. It is suggested that the levels of arginine synthetase, aspartic aminotransferase and DNA in liver could be useful indices of protein status.
A model for the estimation of volatile fatty acid production in the rumen in non-steady-state conditions
Authors: Morant S. V. , Ridley J. L. , Sutton J. D.
Published: May 2005

A method of estimating volatile fatty acid (VFA) production in the rumen in non-steady-state conditions was proposed. Laboratory models indicated that good estimates of total production over a complete feeding cycle could be obtained even when a wide range of production rates and volume changes occurred during the experiment. But estimates of instantaneous production rates might have contained large errors unless some attempt was made to match the infusion rate of labelled VFA to the rate at which VFA was produced in the rumen.
Amino acid requirements of the breeding sow: the dietary lysine requirement during pregnancy
Authors: Sohail M. A. , Cole D. J. A. , Lewis D.
Published: May 2005

1. Four pregnant sows were used to study lysine requirements by means of the interpretation of values for plasma amino acid and blood urea. Diets containing graded levels of dietary lysine were fed at the rate of 1.82 kg/d.

2. Plasma lysine remained at a low level up to 6.4 g dietary lysine/kg (dry matter basis) and then increased sharply with further increases in lysine intake.

3. Blood urea levels decreased when the dietary lysine content was increased to 6.4 g/kg and then increased at higher dietary lysine concentrations.

4. Both criteria of response indicated that the lysine requirement of the pregnant sow given 1.82 kg diet/d during the later stages of pregnancy does not exceed 10.00 g/d.
Effects of liquid feeding of concentrate from a pail on growth and on the digestibility of the diet in young calves
Authors: Abe M. , Shibui H. , Iriki T. , Kondoh K. , Kawai T.
Published: May 2005

1. Studies were done on the effects of giving calves two types of concentrate diet, both in a liquid form from an open pail or in a dry pelleted form, on the closure of oesophageal groove, body-weight gains and the digestibility of rations.

2. Twenty-four Holstein calves were used in an experiment by dividing into two groups of twelve calves each. The ‘dry-fed’ group (DFG) was given a pelleted concentrate, F1, from 25 to 42 d of age, and then given another type of pelleted concentrate, F2, from 43 to 87 d of age, and again given F1 from 88 to 112 d of age. The ‘liquid-fed’ group (LFG) was given from a pail a liquid suspension of the equivalent amount of the same concentrates as those fed to DFG calves, for the same periods. F1 contained skim milk and glucose with lower levels of maize and soya-bean meal than F2 which did not contain skim milk or glucose; F1 and F2 were both supplemented with 10 g methionine/kg and also supplemented with lysine at 5 and 10 g/kg respectively. All calves were allowed free access to roughage, and digestibilities were measured at 12 and 16 weeks of age.

3. Wet weights of reticulo-rumen and abomasal tissues (% whole stomach weight) were respectively 69.8 and 17.6 in DFG, and 59.0 and 26.4 in LFG at 42 d of age; at 87 d of age, the corresponding values were 68.0 and 16.3 in DFG, and 52.8 and 36.6 in LFG, and further, LFG had significantly more developed caecums and large intestines as well as significantly less developed reticulo-rumens and omasums than DFG.

4. Free amino acid patterns in plasma did not vary in DFG, but varied in LFG in response to the change in diet from F1 to F2 and to the difference between diets in lysine supplementation.

5. Feeding F1 in a liquid form and F2 in a dry form significantly improved calf gains. The intake of roughage in DFG exceeded that in LFG especially when F2 was fed.

6. The digestibility of diethyl ether extracts did not vary with feeding procedures, but that of crude protein (nitrogen × 6.25) was significantly higher in DFG independent of the type of diet. Digestibilities of dry matter and N-free extracts were significantly higher in LFG for F1, while higher in DFG for F2. The digestibility of acid-detergent fibre did not differ significantly between groups at 12 weeks of age, but was significantly higher in LFG at 16 weeks of age, suggesting a possible compensatory contribution of the large intestine to the digestion of fibre in LFG.

7. The efficiency of liquid feeding of a concentrate diet to ruminants compared with that of dry feeding is discussed.
Sex, body composition and regulation of food intake during growth in the Zucker rat
Authors: Radcliffe J. D. , Webster A. J. F.
Published: May 2005

1. Food intake and rates of protein, lipid and energy deposition during growth were measured for lean and congenitally obese (fatty) Zucker rats offered from 34 d of age to slaughter at 66 d of age, one of six semi-synthetic diets containing casein (C) in the following amounts (g C/kg): 40C, 100C, 150C, 300C, 500C and 700C.

2. In Expt 1, groups of four male rats were offered each diet to appetite. The digestibility of dietary protein and metabolizability of dietary energy were determined. Total carcasses were analysed for protein, energy and lipid at 34 and 66 d of age. The results showed that, given diets containing 300C or above, both fatty and lean males regulate food intake so as to sustain a maximal rate of protein deposition. This maximal rate was greater in males than in females, and the sex difference was more marked in lean rats. Diets containing less than 300C did not permit maximal protein deposition and, in this instance, both sexes and phenotypes showed a similar reduction in food intake and protein deposition. The rate of deposition of body lipid did not appear to be controlled in either phenotype.

3. In Expt 2, fatty and lean rats were pair-fed diets 100C and 500C. Carcass composition at 66 d of age confirmed that obesity in the fatty rat was not due to hyperphagia but to an abnormal pattern of energy utilization between fat deposition (too much), and protein deposition and heat production (too little).

4. In Expt 3, fatty and lean, male and female rats were given diets 100C and 500C to slaughter at 66 d of age. The carcasses were analysed into different parts by weight, and according to protein and lipid contents of viscera, pelt and subcutaneous fat, and empty carcass. Fatty rats stored approximately 0.53 of their protein in the empty carcass, lean rats approximately 0.65.

5. The results confirm that food intake in the Zucker rat is intimately related to the capacity of the animals for protein deposition, but this capacity differs between sexes and between phenotypes, and the distribution of body protein in the fatty rat eatingad lib.is not that of a normal rat.
Studies in iron supplementation of preschool children
Authors: Pereira Sheila M. , Begum Almas , Baker S. J.
Published: May 2005

1. The effect of daily supplements of 20–30 mg inorganic iron as ferrous sulphate on the growth, activity and haematological status of preschool children was studied for 3.5, 7 and 12 months and compared to that of children who served as controls. All children were given their daily requirements of energy and protein. In addition, they received 5 μg cyanocobalamin and 200 μg folic acid.

2. Fe supplementation increased the haemoglobin, serum Fe and percentage saturation of transferrin and reduced the unsaturated Fe-binding capacity significantly compared to corresponding values for the controls.

3. Height and activity were unaffected by Fe supplements.

4. Of the children 45% had haemoglobin values below 110 g/l at the end of 7–12 months of Fe supplementation.
Effects of vitamin B12deficiency on lipid metabolism of the rat liver and nervous system
Authors: Fehling C. , JÄgerstad Margaretha , Åkesson B. , Axelsson J. , Brun A.
Published: May 2005

1. Rats bred from vitamin B12-depleted dams were fed on a vitamin B12-deficient diet for 12–15 months and developed a severe vitamin B12deficiency, as judged from methylmalonic acid excretion and tissue vitamin B12levels at slaughter. Control rats were supplemented with vitamin B12in the drinking-water.

2. Neurological signs were recorded after 7 months but the motor nerve conduction velocities remained normal. Neuropathological examination revealed mild changes in the peripheral nerves but no changes in the central nervous system.

3. The amounts of total lipids and phospholipids were normal, but in all examined tissues the proportions of pentadecanoate (C15fatty acid) and heptadecanoate (C17fatty acid) were considerably increased in vitamin B12deficiency.

4.3H2O was incorporated to the same extent into the fatty acids of nervous tissue from vitamin B12-deficient and control rats after 48 h. Less3H was found in the liver fatty acids of the vitamin B12-deficient rats.

5. Neurological dysfunction can be demonstrated in the vitamin B12-deficient rat; the relation of the biochemical and neuropathological changes to the neurological signs needs further study.
Studies on digestion and absorption in the intestines of growing pigs
Authors: Low A. G. , Partridge I. G. , Sambrook I. E.
Published: May 2005

1. Digesta were collected from twenty-three pigs, initially of 30 kg live weight, and fitted with single Ash re-entrant cannulas in either the duodenum, jejunum or ileum. A further twenty-four pigs were used in a conventional digestibility trial.

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

3. The flow-rates of dry matter (dm), ash and water were measured hourly in the duodenum and jejunum, and every 6 h in the ileum during 24 h collection periods. Faeces were collected during 5 d periods.

4. Marked increases in the flow rates of each of the digesta components after feeding each diet were observed in the duodenum and jejunum, but not in the ileum. The total flow in 24 h periods was much lower in the ileum than at the other sites.

5. Values for the ratio, dm output:intake for dm outputs from the duodenal, jejunal or ileal cannulas, and in faeces, in 24 h periods were respectively 0.94, 0.81, 0.28 and 0.22 for diet BWF; 0.96, 0.76, 0.20 and 0.15 for diet SSG; 0.96, 0.73, 0.08 and 0.04 for diet SSC. The corresponding values for ash were: 1.47, 1.65, 0.74 and 0.53 for diet BWF; 1.28, 1.34, 0.59 and 0.51 for diet SSG; 1.63, 1.35, 0.50 and 0.26 for diet SSC. The corresponding values for water were: 3.49, 3.41, 0.88 and 0.18 for diet BWF, 2.75, 2.80, 0.80 and 0.08 for diet SSG and 2.61, 1.87, 0.23 and 0.01 for diet SSC.
Studies on digestion and absorption in the intestines of growing pigs
Authors: Partridge I. G.
Published: May 2005

1. Pigs growing from 20 to 60 kg live weight were given diets based on barley, weatings and fish meal, or starch, sucrose and groundnut meal or starch, sucrose and casein. Seventeen pigs were fitted with single re-entrant cannulas in the duodenum (posterior to entry of bile and pancreatic ducts), jejunum or terminal ileum and twenty-four non-cannulated pigs were used in a conventional digestibility trial.

2. The amounts of calcium, phosphorus, magnesium, sodium and potassium passing through the reentrant cannulas and amounts excreted in the faeces were measured. These values were used to calculate the direction and extent of net movements of the five elements through the walls of the four parts of the digestive tract anterior to the collection sites.

3. The small intestine was the principal site of Ca and P absorption but there were differences between the diets in the relative importance of the regions anterior and posterior to the mid-jejunum.

4. Secretion of small amounts of Mg occurred in the anterior small intestine; the ileum and large intestine were the principal sites of net absorption.

5. There was a large net secretion of Na anterior to the duodenal cannulas and further secretion into the anterior small intestine with each diet. There were marked differences between diets in the amounts secreted but the ileal Na concentration was the same in each instance. Absorption occurred in the ileum and large intestine.

6. Secretion of small amounts of K was evident anterior to the duodenal cannulas and net absorption occurred in both parts of the small intestine with each diet.
Studies on digestion and absorption in the intestines of growing pigs
Authors: Partridge I. G.
Published: May 2005

1. Seven pigs of 30 kg initial live weight were fitted with re-entrant cannulas in the terminal ileum. Each was fed, in succession, four purified diets having cellulose and sodium levels (g/kg) of 30 and 2.7, 30 and 0.9, 90 and 2.7 or 90 and 0.9, respectively. Collections of digesta (24 h) and 3 or 4 d collections of faeces were made.

2. There was a greater throughput of ileal digesta with the high-cellulose diets than with the low-cellulose diets, mainly due to increased water content, and there was a concomitant reduction in the net absorption of Na from the small intestine. The immediate response to reduced Na intake was increased secretion of Na into the gut lumen anterior to the terminal ileum; this was more pronounced with the high-cellulose diet. Na concentrations in ileal digesta were very similar for all four diets.

3. The apparent absorptions of calcium, phosphorus, magnesium, potassium and zinc were reduced by the high-cellulose diets. In each instance this was due to reduced absorption posterior to the terminal ileum.
Blood pyruvate carboxylase (EC6.4.1.1) activity as a criterion of biotin status in chickens and turkeys
Authors: Whitehead C. C. , Bannister D. W.
Published: May 2005

1. Blood pyruvate carboxylase (pyruvate-CO2ligase (ADP-forming);EC6.4.1.1; PC) activities in young chickens and turkeys given low-biotin diets supplemented with biotin at graded levels were studied in three experiments.

2. In both species PC activity was related positively to the supplemental biotin level. The relationship was sigmoid and maximum activity was attained with supplemental levels above those required to give maximal growth response.

3. Enzyme activity decreased between 2 and 4 weeks of age but remained almost constant thereafter.

4. Activity in chicks was not affected by alterations in the fat or protein content of the diet.

5. Changing poults from high to low and from low to high supplemental biotin levels resulted in reversals in the levels of enzyme activity.

6. It is concluded that blood PC activity is a promising new criterion for assessing the biotin status of young chickens and turkeys.
Metabolic changes associated with intake by cows of complete diets containing straw and concentrates in different proportions
Authors: Bines J. A. , Davey A. W. F.
Published: May 2005

1. Pelleted diets containing concentrates and 0, 200, 400 or 600 g chopped straw/kg were fed ad lib. for 5 h daily to four cows. Concentrations of various energy-yielding metabolites were measured in samples of rumen fluid and jugular blood taken before feeding and at intervals after food was offered.

2. After feeding, the pH of rumen fluid decreased rapidly and the total concentration of volatile fatty acids (VFA) increased; the changes were greatest in the diet containing no roughage. The changes were essentially complete by 135 min at approximately the time feeding stopped. Rumen lactate concentrations were always low and increased significantly only in cows given no roughage.

3. There were highly significant relationships between the peak rumen acetate concentration after a meal and the apparent digestibility of the dry matter of that meal, and the amount of material in the rumen at the end of a meal. The latter relationship resulted in there being no difference between treatments in the total amount of acetate present in the rumen after feeding.

4. In the blood, concentrations of acetate, propionate, β-hydroxybutyrate (BHB) and lactate all increased after feeding. The increase was prolonged and maximum values were rarely reached before 4–5 h. The highest concentrations of acetate and BHB were found in cows given 200 g roughage/kg and were twice as great as those in cows given no roughage; lower concentrations were found in cows given 400 or 600 g roughage/kg. This information, together with the rumen concentrations of acetate and butyrate, was interpreted as indicating an inhibition of VFA absorption from the rumen of cows given no roughage.

5. Plasma glucose concentrations decreased rapidly for 4 h after feeding, the decrease being greatest in cows given 200 g roughage/kg. Non-esterified fatty acid concentrations also decreased after feeding 200 and 0 g roughage/kg rations, but concentrations were not high at any time.

6. It is concluded that chemical changes in the rumen correspond to feeding behaviour much more closely than changes in blood and therefore any chemostatic regulation of food intake probably occurs at the former site, with acetate playing a major role. Monitoring energy balance at tissue level is likely to be mediated hormonally, with insulin an important factor.
On supplementing the selenium intake of New Zealanders
Authors: Thomson Christine D. , Burton Catherine E. , Robinson Marion F.
Published: May 2005

1. Urinary and faecal excretion of single oral doses of 1 mg selenium or 0.1 mg Se as selenomethionine (Semet-Se) in solution were studied in two women. Most of the Se was absorbed and little was eliminated in the urine (0.05–0.22 dose).

2. The results have been compared with those from an earlier study (Thomson, 1974) on the same two women after similarly sized doses of sodium selenite (selenite-Se) in solution. Although selenite-Se was almost as well absorbed as Semet-Se more was excreted in the urine (0.41–0.85 dose).

3. Repeated dosing with 1 mg selenite-Se on five consecutive days in one of the women indicated that 1.1 mg had been retained.

4. Twenty patients with muscular complaints from Tapanui (South Otago, New Zealand), a low-Se soil area, ingested 0.5 mg selenite-Se daily for 20 d. Blood Se increased rapidly to almost twice the initial concentration but reached a plateau well below most values reported for residents outside New Zealand. No difference in blood Se concentration was found between those who did or did not report improvement.

5. Spasmodic medication with selenite-Se by some residents near Lincoln (Christchurch, New Zealand) for periods of up to 10 years or more had increased the blood Se somewhat.
On supplementing the selenium intake of New Zealanders
Authors: Robinson Marion F. , Rea Heather M. , Friend Gaylene M. , Stewart R. D. H. , Snow P. C. , Thomson Christine D.
Published: May 2005

1. The daily intake of selenium by three subjects was supplemented with 100 μg Se as selenomethionine (Semet-Se) or sodium selenite (selenite-Se)/d for 10–11 weeks, or with 65 μg Se as in mackerel (Scomber japonicus) (fish-Se)/d for 4 weeks.

2. Urinary and faecal excretion of Se was measured and also Se concentration in whole blood, plasma and erythrocytes. Measurements on blood were made at intervals after supplementation had ceased.

3. Selenite-Se was not as well absorbed (0.46 of the intake) during the first 4 weeks as Semet-Se (0.75 of the intake) and fish Se (0.66 of the intake).

4. Blood Se increased steadily with Semet-Se, from 0.08 to 0.18 μg Se/ml, but more slowly with selenite-Se, reaching a plateau in 7–8 weeks at 0.11 μg Se/ml. Plasma Se increased more rapidly with Semet-Se than with selenite-Se, so that initially with Semet-Se plasma Se was greater than erythrocyte Se.

5. Daily urinary excretion increased with all forms of supplement, with initially a greater proportion of absorbed selenite-Se being excreted than Semet-Se or fish-Se. A close relationship was found between plasma Se and 24 h urinary excretion. The findings suggested that there was a rapid initial excretion of presumably unbound Se then a slower excretion of residual unbound, loosely bound or bound Se.

6. Total retentions of 3.5 mg selenite-Se and 4.5 mg Semet-Se were large when compared with an estimate of body content of 6 mg Se, derived in another paper (Stewart, Griffiths, Thomson & Robinson, 1978). Retentions of Semet-Se and fish-Se appeared to be reflected in blood Se, whereas for selenite-Se, blood Se reflected retention for only a short period after which Se appeared to be retained without altering the blood Se. This suggested that Semet-Se and selenite-Se were metabolized differently.

7. A double blind-dosing trial with 100 μg Semet-Se was carried out for 12 weeks on twenty-four patients with muscular complaints in Tapanui, a low-Se-soil area. Blood Se increased in the experimental group (from 0.067 to 0.143 μg Se/ml); clinical findings were not conclusive and will be presented elsewhere.

8. Blood Se was measured in New Zealand residents before travelling to Europe or to North America. On return their blood Se was increased, and depending upon the period of time spent outside New Zealand some values reached concentrations found in visitors and new settlers to New Zealand.

9. The results from these studies and the earlier studies of single and multiple dosing have been used to look at the various criteria in use for assessing Se status of subjects. It is suggested that plasma Se be used in preference to 24 h urinary excretion, and in addition to whole blood Se and glutathione peroxidase (EC 1.11.1.9) activity.
A study of the protein and amino acid requirements of the growing New Zealand White rabbit with emphasis on lysine and the sulphur-containing amino acids
Authors: Spreadbury D.
Published: May 2005

1. New Zealand White (NZW) rabbits were given, between 4 and 8 weeks of age, a range of diets, based on oats and fish meal, containing from 104 to 255 g crude protein (nitrogen × 6.25; CP)/kg to establish the level of CP below which growth was retarded.

2. In three experiments each diet was fed to four animals and food intake, growth and N balance were measured over 4 weeks. Body analysis was also carried out after two of the experiments.

3. The rates of food intake and growth of animals increased with dietary CP concentration until a CP concentration of approximately 150 g/kg diet had been reached. Beyond this there was little further improvement. N balance studies showed that once this dietary concentration of CP had been reached, there was a reduced rate of N retention.

4. Good agreement was found between N retention measured by balance methods and by body analysis: body composition showed a tendency towards an increase in fat and a decrease in N as the dietary protein concentration was reduced.

5. Microbial protein produced in the caecum and eaten during coprophagy, was found to supplement the dietary protein by approximately 2 g CP/d, or by only 0.1 of a normal dietary intake of CP.

6. In the second part of the study NZW rabbits were offered, between 5 and 8 weeks of age, diets based on oats containing 150 g CP/kg. The protein supplied by oats was supplemented with maize gluten, gelatin, groundnut meal, casein, soya-bean meal or fish meal.

7. Rabbits offered diets containing casein, soya-bean meal and fish meal gained 40–50 g/d similar, to animals given a well-balanced control diet, while those given diets containing maize gluten, gelatin or groundnut meal gained approximately 30 g/d. This indicated that amino acid balance in dietary protein was important to the growing rabbit.

8. In later experiments, diets based on cereals and groundnut meal supplemented with varying amounts of lysine and methionine were offered during a 3-week post-weaning period in order to assess requirements for those limiting amino acids.

9. The addition of both lysine and methionine improved growth rates. The minimum requirements for normal growth were found to be 6.2 g methionine+cystine and 9.4 g lysine/kg diet.
The effect of iron status of Nigerien mothers on that of their infants at birth and 6 months, and on the concentration of Fe in breast milk
Authors: Murray M. J. , Murray Anne B. , Murray N. J. , Murray Megan B.
Published: May 2005

1. Within the limits of this study, neither maternal iron deficiency nor Fe-overload as measured at term appeared to affect the complement of Fe received by the foetus.

2. Infants feeding entirely on breast milk appeared to have normal Fe status 6 months postpartum regardless of the Fe status of the mother.

3. No relationship could be demonstrated between the Fe content of breast milk and the Fe status of the mother.
Iron availability from meat
Authors: Hazell T. , Ledward D. A. , Neale R. J.
Published: May 2005

1. The distribution of radioactive iron in59Fe-labelled rat muscle extract was determined using ge filtration. This showed that most (approximately 70%) of the radioactivity was associated with the heamatin compounds; myoglobin and haemoglobin.

2. Raw beef and freeze-dried rat muscle were digested in vitro, under simulated physiological conditions, and after centrifugation the supernatants fractionated by gel filtration. The soluble products were haematin Fe complexes of molecular weight above 10 000 and non-haematin Fe compounds of molecular weight below 6000, the major products being the non-haematin Fe complexes. The soluble compounds were also separated by dialysis and, in rat muscle, it was found that the low-molecular-weight non-haematin compounds accounted for more than 80% of the total soluble iron.

3. In vivo absorption studies with rats showed the Fe in a digested muscle dialysate to be more readily absorbed than that from an aqueous muscle extract which itself was more readily absorbed than the Fe from whole blood.

4. It may not, therefore, be the haemoproteins per se which are responsible for the high availability of Fe in meat, but rather the nature of their degradation products, formed by digestion within the meat environment.
Comparison of the chemical and biochemical composition of thirteen muscles of the rat after dietary protein restriction
Authors: Spence C. A. , Hansen-Smith F. M.
Published: May 2005

1. The objective of this study was to determine whether the chemical and biochemical changes induced by muscle wasting caused by dietary protein restriction are different in various skeletal muscles.

2. Rats were fasted for 3 d and then fed on a 10 g protein/kg diet for 21 d. Thirteen muscles from the trunk, forelimb, and hind-limb regions were analysed for muscle weight, and the content of water, fat, cellular and extracellular protein, DNA and RNA. Results were compared to values for an ‘initial’ control group killed at the start of the experiment.

3. Weight loss was greatest in trunk muscles and least in the distal forelimb muscles. Water content decreased in most muscles, but increased in three forelimb muscles. A significant loss of lipid was found in the gastrocnemius, while the biceps brachii gained lipid. Changes in lipid content of the muscles did not form a distinctive pattern.

4. All muscles except the distal forelimb muscles lost a significant amount of cellular protein, while all muscles except the diaphragm gained extracellular protein.

5. DNA content was unchanged in all muscles. The value for cellular protein:DNA was significantly reduced in the rectus abdominis and the diaphragm. A significant loss of RNA was found in all muscles; the percentage change was greatest in trunk muscles and least in the distal forelimb muscles. The values for RNA:protein and RNA:DNA were significantly lower in all muscles except two distal forelimb muscles.

6. With the exception of the water and lipid content of the muscles, the directions of the changes in the experimental animals were the same for all muscles. The results suggested, however, that the magnitude of changes in certain chemical and biochemical indices of composition may depend to some extent on the anatomical location of the muscle: trunk muscles tended to show the greatest percentage change, while the distal forelimbs changed the least.
Mono ferrous acid citrate (FeC6O7H2O) as an iron fortificant
Authors: Narasinga Rao B. S. , Kathoke Soonita , Apte S. V.
Published: May 2005

1. Iron absorption from ferrous citrate (monoferrous acid citrate, FeC6H6O7H2O) was studied in normal healthy male and female volunteers using ferrous citrate labelled with radioactive Fe and whole-body counting. Ferrous citrate was either given alone or with a rice-based meal.

2. Fe absorption from ferrous citrate was satisfactory and was comparable to that from ferrous sulphate.

3. Fortification of crude cooking salt with ferrous citrate was not satisfactory due to colour development on storage. Ferrous citrate can, however, serve as an effective Fe fortificant with sugar or wheat flour.
Influence of starches from different sources on protein utilization in rats
Authors: Rao C. Nageswara , Rao B. S. Narasinga
Published: May 2005

1. The role of the starch component of cereals and legumes on the utilization of casein-protein was studied.

2. In comparison with maize starch the legume and potato starches caused a significant lowering of net protein utilization (npu). And this reduction in npu could be partially restored by cooking the diets before they were fed to the rats.

3. It is suggested that in npu studies involving rats the experimental diet should always be cooked so that the conclusions drawn may be applicable to human diets.
Adaptations in the calcium and phosphorus metabolism of sheep in response to an intravenous infusion of Ca
Authors: Braithwaite G. D.
Published: May 2005

1. The effect on calcium and phosphorus metabolism of a high rate of Ca infused directly into the blood of Ca-deficient wethers, already receiving an adequate Ca intake, has been studied by a combination of balance and radioisotope techniques.

2. The rate of Ca retention, which was already high, increased only slightly during the infusion before it reached a maximum. The surplus Ca was compensated for by a decrease in the rate of absorption and an increase in the rate of urinary Ca excretion.

3. These findings support the theory that at maximum retention the rate of Ca absorption becomes regulated according to the rate at which Ca can be stored in bone.

4. Results suggest that the decreased absorption was due to a decrease in the rate of active absorption and that the low rate remaining was due to diffusion.

5. The rate of P retention was increased by the Ca infusion, possibly as a result of the increased Ca retention.
An evaluation of total lysine as a predictor of lysine status in protein concentrates for growing pigs
Authors: Batterham E. S. , Murison R. D. , Lewis C. E.
Published: May 2005

1. Eight protein concentrates were compared on a total lysine basis in lysine-deficient diets for pigs during the 20–45 kg growth phase. Each diet was also supplemented with free lysine to verify that lysine was the first limiting amino acid.

2. With fish meal, skim-milk powder, rapeseed meal and soya-bean meal growth rates and feed conversion efficiencies were similar and superior (P < 0.05) to those produced with cottonseed meal, two meat meals and sunflower meal.

3. The response to added free lysine confirmed that lysine was the first limiting amino acid in all diets except skim milk, where the growth response was not significant (P < 0.05).

4. The growth response of the pigs indicated that the availability of lysine in cottonseed meal, the two meat meals and sunflower meal was reduced by approximately 60% compared to that in the other protein concentrates.

5. Rat bio-assay estimates of the availability of lysine in the protein concentrates were in general agreement with those calculated from the response of pigs. There was little relationship between the Silcock estimates for lysine availability for the cottonseed, meat meals or sunflower meal relative to either the rat bio-assay estimates or the response of pigs.
Differences in the proportions of branched-chain fatty acids in subcutaneous triacylglycerols of barley-fed ruminants
Authors: Duncan W. R. H. , Garton G. A.
Published: May 2005

1. The fatty acids of the triacylglycerols of subcutaneous adipose tissue of cattle, sheep, goats and red deer (Cervus elaphus) which consumed either herbage or a barley-rich diet were analysed for their content of branched-chain components.

2. Whereas the consumption of the barley-rich diet by sheep and goats was associated with the occurrence of relatively high proportions of branched-chain fatty acids, it was not in cattle and red deer.
The effect of dietary energy source on nitrogen metabolism in the rumen of sheep
Authors: Offer N. W. , Axford R. F. E. , Evans R. A.
Published: May 2005

1. Seven isonitrogenous diets were prepared containing soya-bean meal and dried grass either unsupplemented, or supplemented with wheat starch or paper or equal mixtures of both.

2. The diets were allocated according to a balanced incomplete block design to seven Clun Forest wether sheep, each fitted with a re-entrant duodenal cannula.

3. After each sheep had received a diet for 6 d, daily samples of digesta were collected automatically for the next 3 d.

4. The amounts of dry matter, gross energy and major nitrogenous components consumed in the diet, passing into the duodenum and excreted in the urine and faeces were determined.

5. A novel method was applied to estimate the proportion of the total amino acids passing into the duodenum which was of microbial origin.

6. The amounts of microbial total amino acids synthesized were compared with the amounts of energy disappearing in the rumen for each of the seven diets tested. For the starch- and paper-containing diets an average of 14.7 g microbial total amino acid passed into the duodenum per MJ energy disappearing in the rumen, whilst for the diets containing either paper or starch alone the mean value, 6.1 g/MJ, was significantly lower (P< 0.05).

7. The results of the experiment suggested that the energy released from a mixture of starch and paper was utilized more efficiently for microbial protein synthesis than when the energy was provided by supplements of either paper or starch alone.
Quantitative selenium metabolism in normal New Zealand women
Authors: Stewart R. D. H. , Griffiths Nora M. , Thomson Christine D. , Robinson Marion F.
Published: May 2005

1. Quantitative selenium metabolism has been studied in normal young New Zealand women by measuring total Se intake and urinary and faecal Se output, and by using values for absorption, excretion and turnover of 75Se determined after administration of [75Se]selenomethionine or [75Se]selenite.

2. In a period of 14 d when a normal ad lib. diet was being consumed, mean dietary Se for four women was 24.2 μg/d, mean urinary Se was 13.1 μg/d and mean faecal Se was 10.8 μg/d; mean Se balance during this time was +0.3 μg/d.

3. Intestinal absorption of food Se was 0.76−0.83 of intake (mean 0.79).

4. Whole-body Se was calculated in three different ways; (a) using the specific activity of urinary Se and retained whole-body 75Se; (b) using plasma Se and the occupancy of 75Se in whole-body and plasma; (c) using absorbed food Se and the occupancy of absorbed 75Se in whole-body.

5. Whole-body Se calculated from measurements obtained following the administration of [75Se]seleno-methionine was 4.7−10.0 mg (mean 6.9) using method (a), 4.1−7.2 mg (mean 5.2) using method (b) and 4.3−8.9 mg (mean 6.2) using method (c).

6. Whole-body Se calculated from results obtained after giving [75Se]selenite was 2.7−3.4 mg (mean 2.9) using method (a), 2.3−5.0 mg (mean 3.5) using method (b) and 2.1−3.0 mg (mean 2.6) using method (c).

7. The results of this study indicate that the minimum dietary requirement of Se for the maintenance of normal human health is probably not more than 20 μg/d.
Comparative feeding and nutrition in captive, non-human primates
Authors: King G. J.
Published: May 2005

1. Food intake studies were carried out on three groups of captive primates (anthropoid apes (Pongidae), lemurs (Lemuridae) and marmosets (Callitrichidae).

2. Determination and analysis of the nutrient intakes were carried out by calculations based on food tables. The results from all groups were compared.

3. Marmosets were found to have higher intakes of energy and many other nutrients than the apes and lemurs.

4. The results suggest that there is a tendency towards over use of dietary supplements and foods of higher nutrient density for captive primates.
Behaviour of solute and particle markers in the stomach of sheep given a concentrate diet
Authors: Faichney G. J. , Griffiths D. A.
Published: May 2005

1. Fistulated sheep given a concentrate diet were used to study the behaviour of solute ([51Cr]EDTA) and particle ([103Ru]phenanthroline) markers in the stomach under conditions of continuous feeding.

2. An injection of a mixed dose of [51Cr]EDTA and [103Ru]phenanthroline was given into the rumen and the time course of marker concentrations in the rumen and the abomasum was recorded. The curves were analysed on the assumption that the stomach of the sheep could be represented as two mixing compartments (reticulo-rumen and abomasum) and a time delay (omasum). This model provided a very good description of the data.

3. [103Ru]phenanthroline associated with small particles was retained in the rumen much longer than [51Cr]EDTA. Although exchange of [103Ru]phenanthroline occurred between large and small particle fractions, the results suggested that small particles may have been retained somewhat longer in the rumen than solutes. However, it was clear from the results that the mean retention times for particulate matter in the rumen could not be simply obtained using adsorbable markers.

4. Cyclical fluctuations in the concentration of [51Cr]EDTA in the rumen indicated that there were daily variations in net water flux in the rumen.

5. The presence of protozoa was associated with much shorter retention times of both solutes and particles in the rumen. Protozoa were also associated with reduced rumen volumes.
2-Aminoethylphosphonic acid as an indicator ofTetrahymena pyriformisW growth in protein-quality evaluation assay
Authors: Maciejewicz-Ryś Julita , Antoniewicz Anna M.
Published: May 2005

1. The concentration of 2-aminoethylphosphonic acid (AEP) in 96 h cultures ofTetrahymena pyriformisW was studied in order to apply it as an indicator in the assay of the relative nutritive value (RNV; protozoa population with test protein: protozoa population with whole-egg powder) of protein. Foodstuffs and food mixtures of different protein contents and qualities were used as test samples.

2. RNV values based on AEP determination (RNVAEP) were compared with corresponding values calculated from protozoa counts (RNVpc), as well as with biological value (bv) and net protein utilization (npu) of the same proteins assayed on rats.

3. Both for foodstuffs and food mixtures highly significant correlations were found between RNVAEPand RNVpc, RNVAEPand bothbvandnpu, and RNVpc, and bothbvandnpu.

4. AEP content in the protozoal suspension was preferred to cell count as a measure of growth response, since it took into account large differences in cell dimensions that were observed between cultures grown with different test proteins.