bluuebunny/crossref_metadata_2025 huggingface dataset:
Artificial rearing of pigs
Authors: Newport M. J.
Published: September 2005

1. Pigs (twenty-one/diet) were weaned at 2 d of age and given liquid diets (200 g dry matter/l) at hourly intervals during a 26 d experiment. The pigs were fed on a scale based on live weight. The diets contained (g/kg DM): dried skim-milk 730 (diet A), dried whey 508·5, isolated soya-bean protein 218, DL-methionine 3·5 (diet S), and soya-bean oil 270 (diets A and S). Diet T contained equal proportions of diets A and S. Soya-bean supplied 0, 370 and 740 g crude protein (nitrogen × 6·25)/kg total crude protein in diets A, T and S respectively.

2. Performance was similar for both diets A and T (P > 0·05). Pigs given diet S scoured severely, and fourteen died. The survivors grew very poorly. Nitrogen retention (g/d per kg live weight) was greater for diet A compared with diet T (P < 0·0r), and decreased with age (P < 0·01).

3. Protein digestion was examined in the pigs killed at 28 d of age. The amount of soya-bean protein in the diet did not affect the amount of digesta in the stomach, but soya-bean protein decreased the pH, DM and total N content of the digesta (P < 0.01), and increased, though not significantly (P < 0·05), pepsin activity in the digesta and stomach tissue. Acid secretion into the stomach appeared to be enhanced in pigs given a diet containing soya-bean protein.

4. Amounts of trypsin, chymotrypsin, total N and proportion of non-protein-N in the digesta from the small intestine were similar for both diets A and T. The amounts for both diets were greater in the distal compared with the proximal region of the small intestine (P < 0·05). Chymotrypsin activity in the pancreas was reduced (P < 0·05) in pigs given diet T, although this reduction did not seem to impair digestion in 28-d-old pigs. Trypsin activity in the pancreas was similar for both diets A and T.

5. It seems likely that the neonatal pig does not have the digestive capacity to tolerate the large daily intakes of soya-bean protein when dried skim-milk was totally replaced in the diet (diet S). When half the dried skim-milk was replaced, protein digestion was not impaired in 28-d-old pigs.
Effect of neonatal undernutrition on serum follicle-stimulating hormone levels and ovarian development in the female rat
Authors: Schenck P. E. , Slob A. Koos , Uilenbroek J. TH. J. , Van Der Werff Ten Bosch J. J.
Published: September 2005

1. Female rats were undernourished from birth through replacement for 12 h/d of the lactating mother by a nipple-ligated mother. This resulted in slow growth so that at 22 d of age the body-weights equalled those of well-nourished animals at 14 d.

2. At 14, 17, 20 and 22 d groups of eight to ten animals each of undernourished and well-nourished rats were autopsied, serum follicle-stimulating hormone (FSH) concentration was determined by radioimmunoassay, utersuses were weighed and ovaries examined by light microscopy.

3. Undernutrition caused a 3–4 d delay in the third-week drop in serum FSH and in ovarian development as indicated by the number of antral follicles and by the maximal diameter of the ovaries and of the largest follicles.

4. It is postulated that the effect of undernutrition on serum FSH may be due to delayed increase in ovarian feedback effectiveness, which may be the result of either the retardation in ovarian development or a continued high level of serum oestrogen-binding protein. It remains uncertain through which mechanism(s) undernutrition brings about delayed onset of puberty.
The effect of dose rate of 1-α-hydroxycholecalciferol on calcium and phosphorus metabolism in sheep
Authors: Braithwaite G. D.
Published: September 2005

1. A combination of a mineral balance and a radioisotope technique has been used to study the relationship between dose rate of 1-α-hydroxycholecalciferol (1α-OH-D3) and the magnitude and duration of its effect on the various processes of calcium and phosphorous metabolism in adult wether sheep.

2. The rate of absorption of Ca was markedly increased by treatment and maximum response occurred at the lowest dose rate.

3. Although sheep were already Ca-replete, the extra Ca absorbed was all retained and increased retention was brought about by a combination of an increase in bone accretion and a decrease in bone resorption. This finding conflicts with the generally-held belief that bone resorption is increased by cholecalciferol treatment.

4. The rates of absorption and retention of P were increased by 1α-OH-D3treatment and maximum response occurred at the lowest dose rate.

5. That P absorption could be increased by treatment suggests that not all the available dietary P was absorbed in the control period.

6. Although the loss of endogenous P in the faeces was unaltered by treatment, the secretion of P into the gut was increased, and the increase was directly related to increased serum inorganic P concentration.

7. Nearly all the extra P absorbed was retained and increased retention was achieved by a combination of an increased incorporation into and a decreased loss from the non-exchangeable pools of bone and soft tissues.

8. The time interval taken for absorption rates of Ca and P to return to normal after the end of each treatment was related to the dose rate of 1α-OH-D3. Although higher dose rates had little effect on the magnitude of response, they did prolong slightly the duration of response.
Total body glucose metabolism in the conscious, unrestrained piglet and its relation to body- and organ weight
Authors: Flecknell P. A. , Wootton R. , John Muriel
Published: September 2005

1. Neonatal hypoglycaemia is a relatively common clinical problem in children but ethical constraints limit the investigations that may be made in the newborn.

2. As a preliminary step to assess the suitability of the piglet as a model for glucose metabolism in man, whole-body glucose turnover and glucose pool size were measured using [2-3H]glucose in forty piglets from ten litters.

3. Glucose pool size was linearly related to brain weight. However, multiple regression showed that the most useful predictors of pool size were body-weight and resting plasma glucose concentration.

4. Glucose turnover was related to both brain weight and body-weight alone, but multiple regression showed that better predictors of turnover were liver weight, spleen weight and pancreas weight.

5. Similarities between our own results in piglets and those obtained in human neonates by Bieret al.(1977) extend not only to glucose turnover, but also to its relationship with body-and brain weight. These findings suggest that the piglet may be a useful model for the study of glucose metabolism in babies.
Factors affecting the absorption of iron from Fe(III)EDTA
Authors: MacPhail A. P. , Bothwell T. H. , Torrance J. D. , Derman D. P. , Bezwoda W. R. , Charlton R. W. , Mayet Fatima
Published: September 2005

1. The modification of iron absorption from Fe(III)EDTA by agents known to promote or inhibit absorption was examined in 101 volunteer multiparous Indian women. Fe absorption from Fe(III)EDTA was compared with absorption of intrinsic food Fe in a further twenty-eight subjects. Finally the urinary excretion of radio-Fe after oral administration of59Fe(III)EDTA was studied in twenty-four subjects and evidence of intraluminal exchange of Fe was examined.

2. Fe absorption from maize porridge fortified with Fe(III)EDTA was more than twice that from porridge fortified with FeSO4. 7H2O.

3. Although bran decreased Fe absorption from FeSO4. 7H2O approximately 11-fold, it had no significant effect on Fe absorption from Fe(III)EDTA. Nevertheless tea, which is a more potent inhibitor of Fe absorption, decreased absorption from Fe(III)EDTA 7-fold.

4. Fe absorption from Fe(III)EDTA given in water was only increased 40% by addition of 3 mol ascorbic acid/mol Fe but by 7-fold when the relative proportions were increased to 6:1. This enhancing effect was blunted when the Fe(III)EDTA was given with maize porridge. In these circumstances, an ascorbate:iron value of 3:1 (which doubles absorption from FeSO4. 7H2O) produced no significant increase in Fe absorption, while a value of 6:1 produced only a 2.5-fold increase.

5. Fe absorption from Fe(III)EDTA was not altered by addition of maize porridge unless ascorbic acid was present.

6. Less than 1% of59Fe administered as59Fe(III)EDTA was excreted in the urine and there was an inverse relationship between Fe absorption and the amounts excreted (r0.58,P> 0.05).

7. Isotope exchange between55Fe(III)EDTA and59FeSO4. 7H2O was demonstrated by finding a similar relative value for the two isotopes in urine and erythrocytes when the two labelled compounds were given together orally. This finding was confirmed by in vitro studies, which showed enhanced59Fe solubilization from59FeSO4. 7H2O in maize porridge when unlabelled Fe(III)EDTA was added.

8. Although Fe absorption from Fe(III)EDTA was marginally higher it appeared to form a common pool with intrinsic food iron in most studies. It is postulated that the mechanism whereby Fe(III)EDTA forms a common pool with intrinsic food Fe differs from that occurring with simple Fe salts. When Fe is present in the chelated form it remains in solution and is relatively well absorbed because it is protected from inhibitory ligands. Simple Fe salts, however, are not similarly protected and are absorbed as poorly as the intrinsic food Fe.

9. It is concluded that Fe(III)EDTA may be a useful compound for food fortification of cereals because the Fe is well absorbed and utilized for haemoglobin synthesis. The substances in cereals which inhibit absorption of simple Fe salts do not appear to inhibit absorption of Fe from Fe(III)EDTA.
Effect of intramuscular vitamin A injection on plasma levels of vitamin A and retinol-binding protein in malnourished children
Authors: Reddy Vinodini , Mohanram M.
Published: September 2005

1. Serum levels of retinol-binding protein (RBP), total vitamin A and retinyl ester were measured in twenty-four malnourished children with corneal lesions and nine normal children.

2. Initially, the RBP and vitamin A levels were significantly lower in malnourished children than in normal children.

3. After intramuscular injection of 30000 μg of aqueous vitamin A, serum levels of total vitamin A were increased significantly at 24 h and tended to fall within 5 d of treatment in both groups.

4. Before treatment, retinyl ester accounted for less than 10% of the vitamin in circulation. After vitamin A injection, it increased to 30%, a level much lower than that reported in patients with hypervitaminosis A.

5. There was no significant difference between the two groups of children and none of them showed clinical signs of toxicity. These observations indicate that administration of massive doses of vitamin A over a short period will not produce toxic effects even in malnourished children.
Reproductive performance in rats with different histories of malnutrition
Authors: Galler Janina R. , Zartarian Gary
Published: September 2005

1. Reproductive competence, as measured by weight gain during pregnancy, duration of pregnancy and foetal outcome, was assessed in primiparous rats (4–6 months of age) with various histories of malnutrition.

2. Although weight gain during pregnancy was reduced in rats with intergenerational malnutrition, the duration of pregnancy and number of live births did not differ from well-fed controls, suggesting adaptation of these measures to long-term dietary deprivation.

3. Rats malnourished from birth through pregnancy (one generation of malnutrition) had fewer live births than did rats with chronic, intergenerational malnutrition or well-fed control rats.

4. Gestation was prolonged and weight gain accelerated among female rats with histories of intergenerational malnutrition, who had been provided with an adequate diet from birth through pregnancy.
Influence of mild cold on 24 h energy expenditure, resting metabolism and diet-induced thermogenesis
Authors: Dauncey M. J.
Published: September 2005

1. It has been suggested previously that people in developed countries do not expose themselves to cold severe enough to induce a metabolic response. The energy expenditure, as both heat production and total heat loss, of nine women was therefore measured continuously while each lived for 30 h in a whole-body calorimeter on two occasions, one at 28° and the other at 22°. All subjects followed a predetermined pattern of activity and food intake. The environmental conditions were judged by the subjects to be within those encountered in everyday life. In the standard clothing worn, 28° was considered to be comfortably warm but not too hot, while 22° was judged to be cool but not too cold.

2. Heat production for 24 h was significantly greater at the lower temperature, by (mean ± SE) 7.0 ± 1.1%. The range was between 2 and 12%. Total heat loss was also significantly greater, by 6%, and there was a large change in the partition of heat loss. At the lower temperature sensible heat loss increased by 29% while evaporative heat loss decreased by 39%.

3. Resting metabolism measured in the morning 12–13 h after the last meal was significantly greater at 22° than at 28°, whereas there was no difference when the resting measurement was made for 2.5 h following a meal.

4. In conclusion: (a)environmental temperature may play a more important role than was previously recognized in the energy balance of those living in this country, and (b) there is an indication of at least a partial replacement of cold-induced by diet-induced thermogenesis in man.
Inhibition of kynureninase (L-kynurenine hydrolase,EC3.7.1.3) by oestrone sulphate: an alternative explanation for abnormal results of tryptophan load tests in women receiving oestrogenic steroids
Authors: Bender David A. , Wynick David
Published: September 2005

1. A partial purification of kynureninase (L-kynurenine hydrolase,EC3.7.1.3) from rat liver and a total resolution of the apoenzyme have been achieved. The hypothesis that conjugates of oestrogenic steroids compete with pyridoxal phosphate for the cofactor binding site of the enzyme, and so disturb tryptophan metabolism, leading to apparent vitamin B6deficiency, has been tested.

2. Kynureninase from rat liver was partially purified, and the cofactor-free apoenzyme was prepared. Oestrone sulphate inhibited the enzyme uncompetitively with respect to pyridoxal phosphate, and competitively with respect to kynurenine, with a mean (±SE) inhibitor constant (Ki) of 82 ± 6 μM.

3. The addition of a saturating concentration of pyridoxal phosphate to unfractionated liver homogenates led to an approximately fivefold increase in kynureninase activity, indicating the presence of a relatively large amount of apo-kynureninase in the tissue.

4. It is suggested that the abnormal results of tryptophan load tests in women receiving oestrogens are the result of inhibition of kynureninase by oestrogen conjugates, and that there is no evidence for oestrogen-induced vitamin B6deficiency in such cases.
A trial of the effects of soya-bean flour and soya-bean saponins on plasma lipids, faecal bile acids and neutral sterols in hypercholesterolaemic men
Authors: Calvert G. D. , Blight Lesley , Illman R. J. , Topping D. L. , Potter J. D.
Published: September 2005

1. The hypothesis that soya-bean saponins, by binding bile salts in the gastrointestinal lumen, are responsible for some of the plasma-cholesterol-lowering effect of soya-bean preparations, was tested. In a double-blind crossover study 50 g soya-bean flour/d, containing either 22 or 4 g saponins/kg (adjusted by ethanol extraction) was incorporated in biscuits as a substitute for biscuits or bread into the diet of ten outpatient hypercholesterolaemic men over two consecutive 4-week study periods. The diet was monitored to ensure constancy, saponin-rich foods excluded, faeces collected for bile acid and neutral sterol analysis, and blood taken for plasma lipoprotein lipid analysis.

2. Neither diet had any effect on cholesterol in any plasma lipoprotein fraction, on fasting plasma triglyceride, or on faecal bile acids and neutral sterols.

3. These results suggested that soya-bean saponins are not responsible for the hypocholesterolaemic effect of soya-bean products.
The non-random distribution of copper within the liver of rats
Authors: Haywood S.
Published: September 2005

1. Two groups of weanling male rats were fed on a powdered proprietary diet for up to 6 weeks. The diet of one group was supplemented with 2 g Cu/kg and the other group received the unsupplemented diet.

2. The livers in the supplemented group accumulated more Cu within the right vascular compartment than the left. This difference was observed in the unsupplemented group after 6 weeks but not at 4 weeks.

3. The distribution of Cu between the different lobes of the livers of the supplemented groups displayed a characteristic pattern, the median lobe containing the most Cu and the omental lobe the least.

4. The distribution of Cu within the liver is thought to reflect the site of its absorption from the gastointestinal tract and a consequence of portal streaming.
Digestion in the pig between 7 and 35 d of age
Authors: Wilson R. H. , Leibholz Jane
Published: September 2005

1. One hundred and fourteen pigs between 7 and 35 d of age were given diets containing milk or soya-bean proteins in four separate experiments.

2. The substitution of milk protein by soya-bean meal (SBM) to 75% of the total dietary protein reduced the weight gains and food conversion efficiencies of the pigs by 85% between 7 and 14 d of age and 31% between 21 and 28 d of age.

3. The treatment of soya-bean protein with alkali did not improve the performance of the pigs.

4. The substitution of milk protein by two different isolated soya-bean proteins (ISP) resulted in weight gains of 34 and 60% of the gains of pigs given milk protein diets.

5. Supplementation of the soya-bean-protein diets with methionine to 13.7 g/kg (5 g/16 g nitrogen) resulted in reduced food intakes and weight gains of the pigs and a 20-fold increase in the concentration of methionine in the blood plasma.

6. Supplementation of soya-bean-protein diets with lysine to 22 g/kg (8g/16 g N) in addition to methionine doubled the concentration of lysine in the blood plasma.

7. The apparent digestibility (AD) of dry matter (DM) and N of the diets containing soya-bean protein increased with increasing age of the pigs, but the AD of the milk-protein diet was not affected by the age of the pigs. The retention of N as a percentage of the N intake increased from 57–67% for soya-bean protein over the duration of the experiments while the average value for the milk-fed pigs was 85% at all ages.

8. At 35 d of age, the fat content of the carcasses of the pigs given the ISP diet was 249 g/kg DM compared to 164 g/kg DM for the pigs given the milk diets.
Digestion in the pig between 7 and 35 d of age
Authors: Wilson R. H. , Leibholz Jane
Published: September 2005

1. In two separate experiments, forty-four pigs weaned at 4–5 d of age were fed on diets containing milk or soya-bean protein until slaughtered at 14, 28 or 35 d of age.

2. Daily amounts of nitrogen flowing through the stomach and proximal small intestine of pigs were similar with both sources of protein fed.

3. Endogenous N flows in the duodenum, jejunum and ileum of pigs given an N-free diet were 22.9, 7.4 and 4.6 g N/kg dry matter (DM) intake. Endogenous N in faeces was 0.970 g N/kg DM intake.

4. The apparent and true digestibility of N to the ileum of 28-d-old pigs was 0.86 and 0.92 for the pigs given the milk-protein diets, 0.80 and 0.86 for the pigs given the isolated soya-bean protein (ISP; Promine D) diets and 0.51 and 0.62 for pigs given the soya-bean meal (SBM)-protein diet. These values over the entire gastro-intestinal tract were 0.98 and 1.00 for milk, 0.92 and 0.95 for ISP and 0.82 and 0.85 for SBM.

5. The apparent and true digestibility of N to the ileum of 14-d-old pigs given a liquid milk diet was 0.92 and 0.94, while the values for the pigs given a pelleted milk diet were 0.86 and 0.87. At 35 d of age there were no differences in the apparent digestibility of the N in the liquid and pelleted milk diets.

6. The apparent digestibility of N to the ileum and over the entire gastro-intestinal tract of pigs given ISP (Supro 610) increased with increasing age of pigs from 0.83 at 14 d of age to 0.88 at 35 d of age.

7. Of the N in the stomach 14–32% could not be precipitated by trichloroacetic acid (TCA; 30 g/l).

8. In the jejunal and ileal contents an average of 46 and 24% of the N was precipitated by TCA in pigs given soya-bean proteins and milk proteins respectively.
Metabolism of zinc and copper in the neonate: accumulation and function of (Zn, Cu)-metallothionein in the liver of the newborn rat
Authors: Mason R. , Bakka A. , Samarawickrama G. P. , Webb M.
Published: September 2005

1. Measurements were made of the hepatic concentrations and contents of total and thionein-bound zinc and copper in late foetal and newborn rats and of the distribution of these metals between the particulate and soluble components of the liver.

2. The decrease in the hepatic concentration of thionein-bound Zn, which occurred with age after birth, was proportional to the increase in liver weight until the 16th day post partum; thereafter it was greater.

3. Throughout the period from birth to 25 d of age the Zn concentration remained constant in the cytosolic non-thionein fraction (i.e. total cytoplasmic Zn – thionein-bound Zn). but decreased in other compartments of the liver.

4. The same constant concentration of cytoplasmic non-thionein-bound Zn also was observed in animals with reduced total hepatic Zn contents, but normal body-weights, and in 20-d-old Zn-deficient pups.

5. The concentration of thionein-bound Cu exhibited two maxima, one at 2 d of age and the second at 14 d.

6. The total hepatic content of Cu increased significantly only between the 6th and 14th day post partum. The age-related variations in Cu contents of the particulate components closely paralleled those in the whole liver, whereas the Cu contents of the cytosolic thionein and non-thionein fractions did not increase appreciably until after the 10th day.

7. It is concluded that the cytosolic non-thionein fraction of newborn rat liver may contain particularly important metabolic sites that require Zn and a major function of Zn-thionein is to regulate is to regulate the supply of the metal to these sites. As, from birth to 26 d of age, the sum of the concentrations of thionein-bound Zn and Cu was correlated with whole liver Zn, the accumulation of Cu as a soluble metallothionein seems to be a secondary event, dependent on the hepatic Zn concentration.
Metabolism of zinc and copper in the neonate: accumulation of Cu in the gastrointestinal tract of the newborn rat
Authors: Mason R. , Brady F. O. , Webb M.
Published: September 2005

1. The concentration of copper in the rat intestine was found to increase rapidly after birth to a maximum greater than 140 μg/g wet weight at 2 d of age and then to decline, at first slowly to 90 μg/g wet weight on day thirteen and then rapidly to 40 μg/g and 3.4 μg/g wet weight on the 15th and 19th day respectively. The intestinal concentration of Zn, which doubled between 1 d prepartum and 2 d post partum, also fell slowly until 10 d of age, but thereafter remained constant.

2. From the 2nd to the 15th day post partum approximately 60% of the total Cu and 50% of the total zinc in the intestine was located in the soluble fraction of the tissue. Most of the Zn in this fraction was bound by proteins of molecular weights greater than 13700 daltons, whereas most of the Cu was present as an extremely polydisperse complex of lower molecular weight. This complex in the intestine of the 5-d-old rat, in contrast with the soluble proteins of higher molecular weight. This complex in the intestine of the 5-d-old rat, in contrast with the soluble proteins of higher molecular weight, did not incorporate either 3H or 35S within 4 h of the administration of L-[4,5-3]leucine and L-[35S]cystine.

3. The loss of Cu from the intestine between the 13th and 15th day of post-natal age occurred mainly from this complex and was accompanied by the transient appearance of Cu in a fraction of low molecular weight.

4. At 21 d of age the soluble fraction of the intestine contained only a small amount of Cu. This was distributed between two protein fractions, one of which contained Zn and appeared to be a metallothionein.

5. The results are discussed in relation to the control of Zn and Cu absorption.
Availability of lysine in vegetable protein concentrates as determined by the slope-ratio assay with growing pigs and rats and by chemical techniques
Authors: Batterham E. S. , Murison R. D. , Lowe R. F.
Published: September 2005

1. The availability of lysine in seven vegetable protein concentrates was determined using the slope-ratio assay with growing pigs and rats and with two chemical techniques.

2. With pigs, estimates of availability were lower using carcass compared to live-weight values, but there was no consistent effect of including food intake in the criterion of response. Availability estimates, using food conversion efficiency on a carcass basis were (proportion of total) linseed meal − 0·23, lupin-seed meal 0.74, rapeseed meal no. 1 0.97, no. 2 0.77, sunflower meal no. 1 0.59, no. 2 0.66, no. 3 0.54.

3. Availability estimates for lysine with rats were also lower using carcass compared to live-weight values. Estimates based on food conversion efficiency were higher than those based on weight gain. Availability estimates in lupin-seed meal and sunflower meals were in general agreement with the pig estimates, whilst that with linseed meal was considerably higher (0·82). Assays were not conducted with rapessed meal due to problems of food rejection with this meal.

4. The differences in available lysine were not detected by the chemical Silcock available-lysine test (Roach et al. 1967) nor by the direct fluoro-dinitrobenzene procedure (Carpenter, 1960).
The urinary excretion of N-methyl histidine by cattle: validation as an index of muscle protein breakdown
Authors: Harris C. I. , Milne G.
Published: September 2005

1. The recoveries of radioactivity in cattle urine following the intravenous administration of Nτ-[14CH3]methyl histidine were essentially quantitative in 5–7 d in non-lactating cows, bulls and steers and did not change with age.

2. The Nτ-methyl histidine was excreted unchanged in urine.

3. Nτ-methyl histidine occurred in muscle extracts both in the free form and as a perchloric acid-soluble, acid-labile form which accounted for approximately 85% of the total non-protein-bound Nτ-methyl histidine in muscle and appeared identical to a similar component identified in muscle extracts of sheep and pigs.

4. There was probably an age-related decrease in the concentration of the acid-labile component in muscle but which did not produce a measurable change in recovery of radioactivity in urine.

5. The daily excretion of Nτ-methyl histidine (E, μmol) by male cattle was highly correlated with live weight (W, kg) by the equation: E=50⋅4+3⋅536(±0⋅044)W(r0⋅997). The excretions progressively decreased from 4.04 μmol/d per kg at 100 kg weight to 3.62 μmol/d per kg at 600 kg.

6. By the criterion of the rate of clearance of labelled Nτ-methyl histidine from the body, the excretion of Nτ-methyl histidine in urine appears to be a valid index of muscle protein breakdown in cattle.
The inadequacy of urinary Nτ-methyl histidine excretion in the pig as a measure of muscle protein breakdown
Authors: Harris C. I. , Milne G.
Published: September 2005

1. The validity of the urinary excretion of Nτ-methyl histidine (Nτ-MH) by pigs as an index of muscle protein breakdown in vivo was tested using the criterion of the rate of recovery of radioactivity in urine following an intravenous dose of Nτ-[14CH3]methyl histidine.

2. Urinary recoveries of radioactivity from five animals were less than 21% of dose in 7 d after which the daily recovery was less than 0.3% per day.

3. The incomplete recoveries of radioactivity were associated with the presence in muscle of a large. pool of non-protein-bound Nτ-MH, the concentration of which increased with age.

4. The Nτ-MH in this pool was present as free Nτ-MH and in a dipeptide which constituted more than 90% of the total non-protein-bound Nτ-MH. The contribution of the peptide increased with age, reaching 99.8% in older animals.

5. The pool of non-protein-bound Nτ-MH was maintained and increased in both established and newly accreted tissue by retention of some of the Nτ-MH released by muscle protein breakdown, only a proportion of which was therefore available for excretion. Hence, the urinary excretion of Nτ-MH is not a valid index of muscle protein breakdown in pig.
The effects of high dietary supplements of copper sulphate on pantothenic acid metabolism in the chick
Authors: Latymer Eva A. , Coates Marie E.
Published: September 2005

1. The effects of incorporation of copper sulphate supplying 250 mg copper/kg semi-purified diet with graded amounts of calcium pantothenate (CaPa) were studied in chicks.

2. When the doses of CaPa were marginally adequate or less the Cu supplementation induced severe signs of pantothenic acid (PaA) deficiency.

3. Livers of the Cu-treated birds given low doses of PaA had lower concentrations of total and bound PaA than those of the corresponding control birds. The bound:total PaA value was also reduced.

4. The amount and concentration of coenzyme A (CoA) were significantly less in the livers of Cu-treated chicks. Fatty acid synthetase activity was not reduced.

5. It is suggested that high dietary supplements of CuSO4, induce PaA deficiency through interference in the biosynthesis of CoA.
Proteinase inhibitors and other biochemical criteria in infants and primary schoolchildren from urban and rural environments
Authors: Schelp F. P. , Pongpaew Praneet , Sutjahjo Rahayuningsih , Supawan Venus , Saovakontha S. , Migasena P. , Poshakrishana Prakong
Published: September 2005

1. Preschool children and schoolchildren from a rural area in the northeast of Thailand were compared with children from urban areas for prealbumin, albumin, transferrin, α1B-glycoprotein, the acute-phase reactants α1-acid glycoprotein, α1-antichymotrypsin. haptoglobin and the proteinase inhibitors α1-protease inhibitor (AlPI) as well as α1-macroglobulin (α2M). Urinary urea nitrogen: creatinine (U-C) as well as haemoglobin were also determined. Village preschool children were grouped according to their SD score for weight-for-height based on the (US) National Center for Health Statistics (1976) standard into a normal group with SD scores of ≥ −1.99 and an undernourished group with SD scores of ≤ −2.00.

2. There was no significant difference between the normal and the undernourished groups of preschool children for any of the factors measured.

3. Haemoglobin and prealbumin concentrations of preschool children were lower in the rural children than in the urban preschool children from Bangkok.

4. In rural schoolchildren haemoglobin was lower but albumin, transfemn, α1B-glycoprotein and haptoglobin were higher than in urban schoolchildren from the provincial town of Khon Kaen.

5. Serum concentrations of the proteinase inhibitors AlPI and α2M were significantly higher in the rural children than in the urban children.

6. U-C values were lower in rural schoolchildren compared with urban schoolchildren.
Nutrition–fertility interaction in lactating women of low income groups
Authors: Prema K. , Nadamuni Naidu A. , Neelakumari S. , Ramalakshmi B. A.
Published: September 2005

1. Duration of lactational amenorrhoea and interpreganancy interval were related to maternal body-weight in an urban low-income group population of 2250 women.

2. Breast-feeding practices were similar in all the women, none of whom had received any nutritional intervention.

3. In the study group the mean duration of lactation, lactational amenorrhoea and interpregnancy interval (months) were 20.7, 11.2 and 24.2 respectively.

4. Mean duration of lactation was significantly shorter in women whose body-weights were over 55 kg. Duration of lactational amenorrhoea increased with increasing duration of lactation (r 0.5164).

5. The duration of lactational amenorrhoea showed a progressive fall with increasing body-weight (r − 0.8139) even when duration of lactation was kept constant.

6. The mean duration of post-partum amenorrhoea in women who did not lactate remained unaltered irrespective of body-weight.

7. The findings suggest that maternal nutritional status modifies return of menstruation only in lactating women.
The effect of acute dietary restriction on muscle fibre number in weanling rats
Authors: Layman Donald K. , Swan Patricia B. , Hegarty P. V. J.
Published: September 2005

1. Male Sprague-Dawley rats were allocated at 100 g into either anad lib.-fed control group or a food-restricted group. The restricted group was fed for 9 d at 25% ofad lib.intake. Controls were killed at a body-weight of 100 g and 29 d of age and the restricted animlas were killed at 70 g and 38 d of age.

2. The effects of food restriction on muscle weight, fibre number, fibre diameter, DNA, and protein were examined in three skeletal muscles, the soleus, plantaris and extensor digitorum longus (EDL).

3. Acute dietary restriction caused body- and muscle-weight loss and a decrease in both the number and cross-sectional area of muscle fibres in each of the muscles.

4. The restriction halted growth-related increases in DNA in all muscles and decreased the protein: DNA value in the plantaris and EDL.

5. These results indicate that present theories describing cellular development are not adequate to define growth potential or growth retardation of skeletal muscle.
Metabolism of the nucleic acids of rumen bacteria by preruminant and ruminant lambs
Authors: Razzaque M. A. , Topps J. H. , Kay R. N. B. , Brockway J. M.
Published: September 2005

1. A rumen bacterial culture containing specifically labelled nucleic acids was prepared using [8-14C]adenine.

2. The labelled preparation was given in a liquid diet to two preruminant lambs and via a rumen tube to two ruminant lambs. The radioactivity excreted in exhaled gases, faeces and urine and that incorporated into tissues was determined.

3 The preruminant lambs absorbed 58.3% of the total radioactivity measured after 24 h and the ruminant lambs 66.6% of the total activity measured after 48 h.

4. Of the total radioactivity absorbed the preruminant lambs exhaled 38%, excreted 34% in urine and retained 29% in tissues. The corresponding values for the ruminant lambs were 12,41 and 47% respectively.

5. There was a close relationship between total nucleic acid content and radioactivity per g of tissues of both preruminant and ruminant lambs.

6. Of the radioactivity in the urine, the ruminant and one preruminant lamb excreted most in the fraction containing allantoin, while the other lamb excreted most activity in the uric acid fraction.

7. The salvaging of the breakdown products of bacterial nucleic acids to make tissue nucleic acids appears to be an important synthesis in preruminant and ruminant lambs and of the likely precursors the purine base may be more important than the nucleoside.
The role of dietary protein in hepatic lipogenesis in the young rat
Authors: Herzberg G. R. , Rogerson Minda
Published: September 2005

1. The effect of varying dietary levels of casein (40–140 g/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.40; ME), citrate cleavage enzyme (EC 4.1.3.8;CCE), acetyl CoA carboxylase (EC 6.4.1.2; AcCx), glucokinase (EC 2.7.1.2; GK), and pyruvate dehydrogenase (PDH) was examined in young, growing rats.

2. The activities of AcCx, FAS, G6PD and in vivo fatty acid synthesis were generally found to increase with increased dietary protein.

3. The levels of GK and PDH were not related to dietary protein.

4. ME decreased with increasing dietary protein.

5. The results demonstrate a dissociation between hepatic fatty acid synthesis and ME and suggest that when rats consume low-protein diets the NADPH needed for fatty acid synthesis is generated primarily by ME but that as the level of dietary protein is increased the contribution of ME is reduced while that of the phosphogluconate pathway becomes more important.
Effects of changes in the intakes of protein and non-protein energy on whole-body protein turnover in growing pigs
Authors: Reeds P. J. , Fuller M. F. , Cadenhead A. , Lobley G. E. , McDonald J. D.
Published: September 2005

1. The relationships between the intakes of protein and of non-protein energy (NPE), nitrogcn retention and body protein synthesis have been studied in female pigs weighing 30 and 35 kg.

2. Four animals were assigned to three regimens and given a conventional (basal) diet supplemented with fat, carbohydrate or protein. After 1 week, measurements of N excretion in urine and faeces (7 d collection) and gaseous exchange (3–4 d) were made. At the end of the balance period a solution of [l-14C]leucine was infused at a constant rate. Body protein synthesis was then calculated as the difference between the apparent irreversible loss of blood leucine and the loss of 14C in expired air.

The animals were then offered the basal diet without supplement for 10 d and the measurements of N retention, energy retention and protein synthesis were repeated.

3. The intakes of metabolizable energy (ME; MJ/kg body-weight (W)0.75per d) were 1.75 for fat, 1.58 for carbohydrate, 1–25for protein and 1.18 for the basal diet; corresponding intakes of apparently digestible N (ADN; g N/kgW0.75 per d) were 2.30,2.31,4.35 and 2–17. Daily N retention, which during the period of basal feeding was 13.6 g was increased by between 3.4 and 7.2 g by the supplements. Daily fat deposition was also increased in the animals that received the diets supplemented with carbohydrate and fat.

4. The rate of leucine catabolism was significantly reduced in the animals receiving the diets that were supplemented with W Eand increased by the addition of protein to the diet.

5. When based on the specfic radioactivity of blood leucine both the synthesis and breakdown of body protein (per unit metabolic body-weight) were increased by 30% in the animals receiving the high-protein diet but the increases in protein synthesis associated with the addition of carbohydrate (+14%) and fat (+12%) were much less marked. Consideration of these results together with previous observations (Reeds et al. 1980) suggested that body protein synthesis(g N/d) increased by 0.88 for each g increase in daily ADN and by 0.93 for each MJ increase in daily ME intake.

6. Comparison of the results obtained with the animals given high-carbohydrate diets and those given high-protein diets suggested an increase in heat production of 14 KJ/g of additional fat deposition. A similar comparison of animals receiving the high-protein and basal diets suggested a heat increment of 23.5KJ/g additional protein deposition. The changes in heat production and protein synthesis in the animals given the protein supplement were compatible with a heat increment of 5.3 KJ/g additional protein synthesized. Because of the large proportion of heat production associated with the deposition of fat this could not be confirmed with either of the other supplements, but it is possible that the energy cost of protein accretion varies with the relative proportions of protein and NPE in the diet.
The effects of protein degradability and food intake on milk yield and composition in cows in early lactation
Authors: Ørskov E. R. , Reid G. W. , McDonald I.
Published: September 2005

1. In two experiments measurements were made of food intake, live-weight change, milk yield and milk composition in early lactation when dairy cows were given diets containing varying proportions of protein as fish meal (low rumen degradability) or as groundnut meal (high rumen degradability). In a preliminary trial measurements were also made with cows given supplements of either fish meal or barley and fed at a restricted level of feeding.

2. When metabolizable energy (ME) intake exceeded 160 MJ/d there was no evidence of responses to changes in protein degradability, but at ME intakes below 135 MJ/d increases in the supply of undegradable protein led to increases in fat-corrected milk yield, protein content and live-weight loss.

3. The interaction between energy intake and protein degradability is unexpected because net protein:net energy requirement increases as milk yield increases, but may be explained in terms of differential effects of changing rumen outflow rates on degradabilities.
Metabolic changes in cattle due to the specific effect of the tick,Boophilus microplus
Authors: O'kelly J. C. , Kennedy P. M.
Published: September 2005

1. An experiment was designed to provide information on the alterations in body metabolism which would account for the loss of body-weight in cattle due to the specific effect (factors other than reduced food intake) of the tickBoophilus microplus.

2. Two groups of British (Shorthorn × Hereford) and Africander × British calves, each approximately 6 months old, were used: one group (treated) of each breed was tick-infested and the other (control) was tick-free. Within breeds, calves in the control group were pair-fed to calves in the treated group.

3. In both breeds, the effect of ticks: (a) depressed packed cell volume, serum alkaline phosphatase (EC3.1.3.1) and amylase (EC3.2.1.1) activities, plasma cholesterol and phospholipid levels, serum iron and albumin levels. (b) increased the plasma levels of urea-nitrogen and γ-globulin (c) increased rectal temperature, water intake, urine volume, urinary and faecal total N, urinary urea-N and α-amino acids, the excretion of water, sodium and potassium in the faeces and (d) reduced N balance, N and dry-matter digestibilities.

4. In the British breed, ticks increased the excretion of K with a corresponding decrease in the excretion of Na in the urine and inreased the plasma clearance of bromsulphthalein.

5. A second experiment showed that the specific effect of tick infestation increased the flow of organic matter (OM) from the abomasum and the fractional turnover of rumen fluid of Hereford steers. It was also shown that the decrease in OM digestibility in the gastrointestinal tract was largely due to a decrease in OM digestibility in the rumen and that the increased urinary urea excretion and plasma urea concentration was caused by higher production rates of urea despite a tendency for lowered urea degradation in the gastroinestinal tract.
Quantitative studies of food protein degradation and the energetic efficiency of microbial protein synthesis in the rumen of sheep given chopped lucerne and rolled barley
Authors: Mathers J. C. , Miller E. L.
Published: September 2005

1. In a randomized block design, four sheep were given 800 g daily of diets containing: chopped lucerne (L), chopped lucerne–rolled barley (2:1; LB), rolled barley–chopped lucerne (2:1; BL), rolled barley (B); each diet was supplemented with minerals, vitamins and urea as considered necessary. Chromic oxide was included in the diets as a flow marker.

2. Flows of organic matter (OM) and non-ammonia-nitrogen (NAN) to the small intestine (SI) were measured and microbial protein was identified by a35S-incorporation procedure.

3. OM disappearance in the rumen increased linearly with increasing inclusion of barley in the diet but there was no significant change in microbial NAN flow to the SI so that the yield of microbial NAN (g)/kg fermented OM (FOM) decreased from 29.6 (diet L) to 22.7 (diet B). Changes in the energetic efficiency of microbial protein synthesis appeared to be unrelated to alterations in rumen fluid volatile fatty acid (VFA) proportions or in rumen fluid dilution rate (D).

4. The degradability of dietary protein (non-urea-N), estimated using the35S procedure, was 0.72, 0.76, 0.86 and 0.86 for diets L, LB, BL and B respectively. Similar values were obtained from concurrent polyester-bag experiments when the fractional outflow rate of undergraded protein from the rumen (k) was assumed to be 0.046.
The maximum capacity of the bovine liver to excrete manganese in bile, and the effects of a manganese load on the rate of excretion of copper, iron and zinc in bile
Authors: Hall Eveline D. , Symonds H. W.
Published: September 2005

1. The maximum capacity of the bovine liver to excrete manganese in bile was determined in three Friesian-cross steers surgically prepared to allow bile flow-rate to be measured and samples collected. Plasma Mn concentrations were increased by infusing manganese chloride solutions into a jugular vein and the biliary excretion rates of Mn, copper, zinc and iron were measured.

2. The maximum capacity of the liver to excrete Mn in bile was exceeded at an infusion rate of approximately 4000 μg Mn/min, and at this rate there was a significant decrease in the concentration of Cu, Fe and Zn in bile. The maximum concentration (mean ± SE) of Mn in bile was 193 ± 19 μg/ml, and the maximum excretion rate (mean ± SE) was 1210 ± 130 μg/min for the three animals. There was no reduction in bile flow or evidence of liver damage as a result of the infusions.
The effect of dietary supplements of ω3 polyunsaturated fatty acids on the fatty acid composition of platelets and plasma choline phosphoglycerides
Authors: Sanders T. A. B. , Younger Katherine M.
Published: September 2005

1. The effects of dietary supplements of ω 3 polyunsaturated fatty acids on the fatty acid composition of platelets and plasma choline phosphoglycerides were studied in vegans and in omnivores.

2. A supplement of 18:3ω3 led to an increase in 20:5 ω3 but was less effective than one of 20:5ω3+22:6ω3.
The effect of wheat bran on the absorption of minerals in the small intestine
Authors: Sandberg Ann-Sofie , Hasselblad Claes , Hasselblad Kristina , Hultén Leif
Published: September 2005

1. Studies on mineral absorption were carried out in ileostomy patients using the metabolic balance technique. The effect of wheat bran on the absorption of phosphorus, calcium, magnesium, zinc and iron was studied. The extent of digestion of bran phytate in the stomach and small intestine was also investigated.

2. Eight patients with well established conventional ileostomies were studied during two periods while on a constant low-fibre diet. In the second period, 16 g wheat bran/d (American Association of Cereal Chemists) was added to the diet. The amount of phytate-P, non-phytate-P, Ca, Mg, Zn and Fe was determined in the ileostomy contents and in duplicate portions of the diet.

3. Of the added bran phytate-P 24–61% was recovered in the ileostomy contents. In the bran period a significantly decreased amount of Zn was absorbed, while the apparent absorption of Fe and phytate-P increased and that of non-phytate-P, Ca and Mg remained constant. Due to the mineral content of bran, the relative absorption differed in some respects from the absolute absorption, being decreased for Zn, Mg and phytate-P but unchanged for Ca, Fe and non-phytate-P.

4. It is concluded that phytate is partly digested in the stomach and small intestine or possibly absorbed. Addition of 16 g bran/d to the diet does not seem to impair the mineral absorption from the small intestine except that of Zn.
Serum prolactin levels in undernourished Indian lactating women
Authors: Shatrugna Veena , Raghuramulu Namala , Prema Krishnamurthy
Published: September 2005

1. Serum prolactin (PRL) levels, both basal and post-suckling peak, were estimated in fifty-seven lactating women.

2. Basal PRL levels were significantly higher in all lactating women irrespective of the duration of lactation as compared to the levels in non-pregnant, non-lactating women.

3. There was a significant positive correlation (r 0·69, P < 0·001) between the basal PRL levels and the post-suckling peak values.

4. After 8 months of lactation, peak post-suckling, PRL levels were not significantly different from basal values.

5. Basal PRL levels were significantly lower (P < 0·05) in mothers whose infants were being supplemented.

6. PRL levels were not related to the mother's nutritional status as determined by body-weight.

7. The findings suggest that high PRL levels during lactation prolong the duration of lactional amenorrhoea and hence the relative infertility.