bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of dietary protein level on in vivo and in vitro vitamin A esterase activity in the chick
Authors: Nir I. , Bruckental I. , Ascarelli I. , Bondi A.
Published: September 2005

1. The efficiency of absorption of and liver storage from a single oral dose of 10000 i.u. vitamin A palmitate decreased in chicks reared on a diet containing 10% protein as compared to the efficiency in chicks reared on a diet in which the protein level was adequate. When the chicks were given orally an equivalent dose of vitamin A alcohol, the absorption was equally efficient at both dietary protein levels.

2. The vitamin A alcohol content of this intestine, plasma and liver of chicks dosed with vitamin A palmitate was decreased by protein restriction. The physiological change responsible for this decrease seems to be the lowering of the hydrolysing activity for vitamin A palmitate in pancreas and in the duodenal mucosa.

3. The importance of the enzymic step in the absorption of an oral dose of vitamin A palmitate is shown by the finding that protein malnutrition reduced only slightly the final liver stores when vitamin A in its different forms (palmitate, acetate or alcohol) was injected directly into the blood stream.

4. The uptake of injected vitamin A from the blood was much delayed when the vitamin was injected as palmitate, i.e. the ester of a long-chain fatty acid, instead of the acetate ester of the free alcohol.

5. When vitamin A was injected, the liver content did not rise continuously with time, but showed a temporary decrease after a certain period. The phenomenon was apparently due to changes in the rate of the two inverse processes of uptake of the vitamin by the liver and liberation from it.
Nutritive value of groundnut (Arachis hypogaea)
Authors: Chopra A. K. , Sidhu G. S.
Published: September 2005

1. The nutritive values of nine varieties of groundnut were determined by the nitrogen balance method in diets containing 10% protein. The results indicated that the varietal differences did not affect the biological values significantly.

2. Three varieties showing small but significant differences of approximately 5% in methionine content were further assayed for protein efficiency ration at the 10% level of protein for a period of 4 weeks. No significant differences in per were obtained, but the least significant difference that could have been detected under these conditions was approximately 8%.
The influence of dietary molybdenum on the xanthine oxidase activity of the milk of ruminants
Authors: Hart L. I. , Owen E. C. , Proudfoot R.
Published: September 2005

1.The oral administration of sodium molybdate caused a rapid rise of molybdenum in the milk of cows and goats fed on a low-molybdenum diet, but did not affect the xanthine oxidase activities of the milk of either species.

2.In the milks of cows not dosed with sodium molybdate, the regression of the xanthin oxidase activity (y) on the molybdenum content (x) was found to be y = 170.7x+43.86 (r = +0.9386; P < 0.0001), suggesting that all the molybdenum of such milk is bound to enzymically active xanthine oxidase.

3.The molybdenum contents of the milk of goats not does with sodium molybdate varied from animal to anumal and the xanthine oxidase activites were much lower than those of cow' milk. there was no correlation between xanthine oxidase activity and the molybdenum contend of the milks of the goats.

4. These results are discussed in relation to previous work of the authors and others.
Studies on magnesium in ruminant nutrition
Authors: Field A. C.
Published: September 2005

1. The excretions of magnesium, calcium, potassium and faecal dry matter (DM) by sheep grazing the same pasture have been determined at intervals throughout two grazing seasons. Two groups of four wethers, 2 and 7 years old, were used. Collections of faeces were total and of urine only partial; creatinine was used as an indicator of urine volume.

2.The overall mean outputs of DM in the faeces of the young and old sheep were 509 and 387 g/day respectively.

3. The values for the percentage digestibility of herbage DM ranges from 81.1 in spring to 63.2 in winter. The overall means for the estimated intake of DM by the young and old sheep were 1859 and 1405 g/day respectively and the difference was highly significant (P < 0.001).

4. The mean values for overall excretion of Mg by the young and old sheep were respectively 0.452 and 0.292 g/day in the urine and 2.70 and 2.21 g/day in the faeces. For all sheep there was a highly significant rectilinear relationship between the amount in urine and in faeces, but there were significant differences between the regression coefficients for the individual sheep.

5. The values for the excretion of Ca in urine and faeces were significantly higher for the young than for the old sheep; the respective means were 0.385 and 0.306 g/day for urinary Ca and 13.02 and 10.8 g/day for faecal Ca.

6.The mean values for the excretion of K by the young and old sheep were respectively 28.2 and 29.1 g/day in the urine and 7.1 and 3.9 g/day in the faeces, the latter differences being highly significant.

7.High values for the total excretion of Mg, Ca and K occurred in June and low values in winter.

8. Intakes of Mg, Ca and K by the sheep have been calculated from the information on intake of DM and chemical composition of the cut herbage and compared with total excretion in urine and faeces. Good agreement between the two sets of values was obtained for Mg, but not for either Ca or K. The possible causes of these findings have been discussed and it was concluded that the sheep selected herbage with concentrations of Ca and K different from those in the samples of cut herbage.
Protein reserves and muscle constituents of protein-depleted and repleted cocks
Authors: Ashley John H. , Fisher Hans
Published: September 2005

1. Body-weight changes and nitrogen balance were studied, together with the concentration of various nitrogenous muscle components, in adult cocks before and after a 6-day period on a N-free diet and again after a 16-day repletion period on diets supplying various amounts and types of dietary N.

2. In the first experiment a comparison was made during the repletion period between a fish-protein supplement and a supplement of glycine + glutamic acid added to an essential amino acid mixture.

3. During the depletion period the muscle concentration of RNA, DNA and of two transaminase enzymes decreased significantly; during the repletion period these components increased again significantly, and usually to levels greater than the pre-depletion concentration. There were no differences in these responses obtained during repletion with the two N supplements, although the cocks given the glycine–glutamic acid supplement differed from those receiving fish protein in being in Negative N balance and in losing body-weight during the repletion period.

4. In the second experiment one group of depleted cocks was given an essential amino acid mixture alone as the dietary N source and a second group this mixture supplemented by aspartic acid.

5. A decrease in RNA and in the transaminase enzymes during depletion was followed by a significant increase during repletion, but the increase was greater for the group receiving the aspartic acid than for that receiving only the essential amino acid mixture.

6. It was concluded that adding non-essential amino acids to a maintenance mixture of essential amino acids will permit greater repletion in mature cocks.

7. The fluctuations in concentration of RNA and of certain enzymes with dietary protein supply may well be controlling factor in the regulation of N losses and accretions during protein deficiency and sufficiency.

5. The relative constancy of muscle DNA in contrast to the fluctuations in other nitrogenous muscle constituents provides additional support for the concept of protein reserves.
Vitamin E and stress
Authors: Cawthorne M. A. , Diplock A. T. , Muthy I. R. , Bunyan J. , Murrell Elspeth A. , Green J.
Published: September 2005

1. Vitamin E-deficient rats were found to be more susceptible than vitamin E-supplemented controls to the toxic effects of hyperbaric oxygen (60 lb/in.2 for 20 min). This agrees with the findings of other workers.

2. Hyperbaric O2 treatment did not increase the metabolic destruction of a small amount (46.65 μg) of [14C-5-Me]D-α-tocopherol given to adult vitamin E-deficient rats 24 h previously. The O2 treatment also did not affect the soluble sulphydryl compounds and ascorbic acid of rat liver, nor the percentag haemolysis in vivo of rat blood.

3. Hyperbaric O2 treatment did not increase the true lipid peroxide content of rat brain, compared to control rats treated with hyperbaric air, which has no toxic effects. Increases in ‘lipid peroxidation’ reported by previous workers are considered to have been due to the use of inadequate controls (untreated rats) and of in vitro techniques that are open to criticism.

4. The toxic effects of hyperbaric O2 in the vitamin E-deficient rat cannot be attributed to peroxidation in vivo.

5. Vitamin E was not found to protect rats against the effects of reduced O2 tension (anoxic anoxia). This finding contrasts with some reports by earlier workers. Reduced O2 tension had no effect on the metabolism of radioactive tocopherol, on blood haemolysis in vivo, or on the soluble sulphydryl compounds and ascorbic acid of liver.
Vitamin E and stress
Authors: Diplock A. T. , Green J. , Bunyan J. , Cawthorne M. A. , Dawson Jean
Published: September 2005

1. The effects of iron overloading and unsaturation of dietary lipid on the metabolism of α-tocopherol in the rat were studies.

2. Young adult male vitamin E-deficient rats were given 1000 i.u. of vitamin A and 100 μg of [14C-5-Me]D-α-tocopherol and then given diets containing 5% methyl oleate or 5% cod-liver oil fatty-acid methyl esters. Rats from each group were given intramuscular injections of iron-dextran (50 mg Fe/kg rat) at 48 h intervals for 15 days, and compared with controls given dextran. After this time, liver, kidney and the remainder of the carcass were analysed for [14C]α-tocopherol, and liver and kidney were also analysed for vitamin A.

3. There was no evidence that Fe overloading caused any increase in the destruction of either tocopherol or vitamin A in vivo, whether or not the diet contained polyunsaturated fatty acids. Indeed, treatment with Fe significantly decreased the metabolism of the radioactive tocopherol dose in all three tissues studied.

4. These experiments show that the stress effect of Fe in the vitamin E-deficient animal is unrelated to an increase in oxidative reactions. They provide further evidence that ‘lipid peroxidation’ is not causally concerned in ‘anti-vitamin E’ stress conditions and that α-tocopherol does not function, in vivo, as an antioxidant.
Experimental resection of the intestine in newborn pigs
Authors: McCance R. A. , Wilkinson A. W.
Published: September 2005

1. The whole of the lower half of the small intestine, with the exception of the last few cm of the ileum, has been removed from sixteen suckling pigs, 3–4 kg in weight.

2. The operation is technically easy, but the exposure and handling of the intestines may produce crippling adhesions.

3. The postoperative management presents no serious nutritional difficulties.

4. If the operation is successful the animals become functionally normal, if slightly small, adults.
Zinc deficiency and the zinc requirements of calves and lambs
Authors: Mills C. F. , Dalgarno A. C. , Williams R. B. , Quarterman J.
Published: September 2005

1. The effects of changes in zinc intake on weight gain, plasma Zn concentration and the development of clinical lesions of Zn deficiency have been studies in Zn depletion and repletion studies with calves and lambs.

2. A basal diet, the principal components of which are urea, dried egg white, starch, glucose, cellulose and arachis oil has been developed for trace element deficiency studies with ruminants.

3. Weight gain ceased abruptly in both calves and lambs when either the unsupplemented basal diet was given or when Zn supplements provided only 0.05 mg Zn/kg live weight per day. Mean plasma Zn concentrations in these animals fell from pre-experiment values of between 0.8 and 1.2 μg Zn/ml to below 0.4 μg Zn/ml after 1 week on these treatments.

4. Supplements providing 0.2 mg Zn/kg live weight per day were sufficient to maintain a good rate of growth but insufficient to prevent a fall in plasma Zn.

5. Growth arrest occurring within 2 weeks and a rapid fall in plasma Zn occurring within 1 week after Zn supplements were withheld from calves and lambs that had previously received 0.7 mg Zn/kg live weight per day for 6 and 14 weeks respectively indicated that these species have only a limited capacity to store Zn in a form that can be utilized during periods of inadequate Zn intake.

6. Tentative estimates are presented of the Zn requirements of calves maintained on this type of basal diet and the influence of ration composition of Zn availability is discussed.

7. The possible value and the limitations of plasma Zn determination as an aid to the field diagnosis of Zn deficiency are considered.
Continuous measurement of heart rate as an indicator of the energy expenditure of sheep
Authors: Webster A. J. F.
Published: September 2005

1. The relationship between the heart rate and the energy expenditure of four sheep, S6, S7, S8 and S1, was studies under conditions known to increase energy metabolism.

2. A close relationship between heart rate and energy expenditure was shown to exist in three of the four sheep tested when energy expenditure was increased by cold exposure and by increased levels of food intake.

3. The source and magnitude of the errors associated with this relationship were studied by analysis of the variation occurring in the O2 pulse (ml O2/heart beat) of the sheep in response to factors other than those directly related to changes in heart rate. In two sheep, S8 and S6, variations in O2 pulse were random. The errors associated with the estimation, from heart rate measurements, of the energy expenditure of these sheep were ±6.8% and ±8.1% respectively. In the other two sheep, S7 and S1, O2 pulse tended to vary significantly during the experiments, in a way that was not directly related to changes in heart rate. The errors of the relationship in these sheep were ±8.6% and ±13.8% respectively.

4. Indirect evidence was obtained to suggest that continuous measurements of heart rate continued to reflect with reasonable accuracy the energy expenditure of the three sheep, S6, S7 and S8 when they were standing and lying and when they were eating.

5. Direct measurements were made of the O2 consumption and heart rate of sheep S7 and S1 during the act of eating. The energy expenditure of sheep S7 estimated from its O2 consumption was close to that estimated from measurements of its heart rate. Large errors were noted between these two estimates in sheep S1.

6. It was concluded that sheep S8 and S6 would be suitable for long-term experiments designed to predict energy expenditure from heart rate measurements made in the field. Sheep S7 was considered to be of limited value for short-term experiments. Sheep S1 was considered to be unsuitable.
Blood copper as an indicator of copper status with a note on serum proteins and leucocyte counts in copper-deficient rats
Authors: Dreosti I. E. , Quicke G. V.
Published: September 2005

1. Albumin, α1-, α2-, β- and γ-globulin fractions were demonstrated in serum from control and copper-depleted rats, but no quantitative difference was found in the distribution of the proteins between the two groups of animals. Both the total number of leucocytes and the number of polymorphonuclear leucocytes increased during copper depletion.

2. Plasma copper content was found to be superior to whole blood copper content as an index of the copper status of rats at intermediate stages of depletion. The copper content of erythrocytes was found to be unaffected even in the severely depleted animals; this explains, in part, the poor response of whole blood copper content to intermediate stages of depletion.

3. A single dose of orally administered copper was reflected in the plasma copper content of depleted rats about 12 h after dosing. No similar rise was observed in control animals, and the extent of the response was not increased by increasing the dose of copper.

4. It is suggested that plasma copper response to a single oral dose of copper sulphate may provide a useful method for the detection of subnormal copper status in individual farm animals without the necessity of determining breed norms.
Studies on the composition of food
Authors: Harries J. M. , Hubbard A. W. , Alder F. E. , Kay M. , Williams D. R.
Published: September 2005

1. An attempt has been made to compare the nutritive value of beef from intensively reared animals with that from more extensively reared stock.

2. The difficulties of such a comparison are described and the consequent limitations of this experiment specified.

3. It was found that samples of longissimus dorsi and superficial digital flexor muscles showed no significant differences between intensively reared and extensively reared animals in their content of moisture, intramuscular fat, protein, non-protein nitrogen, iron, thiamine, riboflavine, or nicotinic acid.

4. The longissimus dorsi muscles had more non-protein nitrogen and more nicotinic acid, but less iron and less riboflavine, than the superficial digital flexor muscles.

5. There was less vitamin A and less carotene in samples of liver from intensively reared animals than in comparable samples from extensively reared animals.
Rates of production of volatile fatty acids in the rumen of grazing sheep and their relation to ruminal concentrations
Authors: Leng R. A. , Corbett J. L. , Brett D. J.
Published: September 2005

1. The rates of production, or entry rates, of acetic, propionic and butyric acids in the rumen of grazing sheep have been measured by a radioisotope technique previously used on penned animals.

2. Regression equations were derived relating entry rates to ruminal concentrations. The equations from penned and grazing sheep did not differ significantly.

3. The standard errors of entry rates predicted for a single sheep from equations based on all results were calculated to be ± 0·06, 0·18 and 0·15 m-mole/min for acetic, propionic and butyric acids respectively.

4. Interconversions between acetic and butyric acids in the rumen were similar in extent to those found in penned sheep. These values were used to calculate from entry rates the net amounts of the acids becoming available to the animals.

5. An equation was derived that permits the amount of energy supplied to an animal by the acids to be predicted from concentrations with a standard error of ± 0·17 kcal/min.

6. The applicability of the prediction equations is discussed.
The contribution of propionate to glucose synthesis in sheep given diets of different grain content
Authors: Judson G. J. , Anderson Elizabeth , Luick J. R. , Leng R. A.
Published: September 2005

1. Glucose entry rates into the blood and propionate production rates in the rumen have been measured in sheep given rations containing varying proportions of starch and roughage (lucerne).

2. Glucose entry rates and propionate production rates were similar for all rations studied.

3. The proportion of the glucose entry rate arising from propionate produced in the rumen was highest on the ration containing the greatest quantity of lucerne and decreased as the proportion of starch in the ration increased. Rate of conversion of propionate into glucose was estimated and was found to decrease as the amount of starch in the ration increased.

4. Concentrations of total volatile fatty acids (VFA) in the ruminal fluid were lowest in the ration with the greatest proportion of starch, implying lower VFA production rates with the starch rations although intakes of digestible energy were approximately the same. The mean concentrations and rates of production of propionate in ruminal fluid were similar for all rations.

5. The low VFA concentrations and the reduced conversion of propionate into glucose on the high rations, despite similar propionate production rates and glucose entry rates, may have been due to starch escaping ruminal fermentation. It is suggested that this glucose absorption may have reduced gluconeogenesis from propionate.
Effects of ascorbic acid on the skeletal response of chicks to vitamin D deficiency
Authors: Thornton P. A.
Published: September 2005

1. The skeletal response of vitamin D-deficient chicks to dietary ascorbic acid was tested.

2. The epiphyseal cartilaginous plate width, which was increased by the vitamin D deficiency, was further increased when ascorbic acid was added and the effect appeared sooner.

3. Absence of vitamin D was associated with a reduction in the relative amount of cancellous to compact bone ash in the tibia. Dietary ascorbic acid intensified this effect to a significant degree.

4. Plasma ascorbic acid levels in rachitic chicks were approximately 25% less than in controls. This observation may explain the skeletal response to added vitamin C and suggests that avian bone tissue has a particularly high requirement for this vitamin.
Effect of level of dietary calcium on the skeleton of the rat
Authors: Toothill Joyce , Hosking Zena D.
Published: September 2005

1. The total body calcium (Expt 1) of litter-mate male rats given a diet adequate in phosphorus and high (0·74%) or low (0·13%) in Ca from the age of 3 weeks was determined after 21, 48 and 60 weeks on the diet. In Expt 2, the ash content of ten groups of bones from 10-week-old rats given these same diets for 7 weeks was studied to ascertain whether all groups were equally affected by the difference in dietary Ca level. Four groups of bones, i.e. skull and mandibles, vertebras, the shafts and the ends of long bones, were consequently chosen for examination in Expt 3 where their growth and composition were studied in rats given the Ca diets for 24, 48 or 60 weeks from the age of 3 weeks.

2. Total body Ca (Expt 1), expressed as g Ca or as a percentage of the net body-weight or of net dry, fat-free carcass weight, was always significantly higher in rats given the higher level of Ca. The dietary effect was greatest after 21 weeks.

3. The higher level of dietary Ca led to a highly significant increase in the weight of the dry, fat-free bone and in the percentage ash content of all ten bone groups after 7 weeks (Expt 2). The greater treatment differences in ash content occurred with the less well mineralized bones.

4. In Expt 3, irrespective of diet, the four groups of bones developed at different rates. In rats given the diets for 24 weeks or longer, the vertebras and the shafts of long bones showed the greatest proportional increase in weight of dry, fat-free bone and ash relative to the corresponding values for 3-week-old rats; the greatest change in percentage ash content occurred in the ends of the long bones.

5. Increasing the level of Ca in the diet increased the weight of the dry, fat-free bone and its ash content. The effect of diet decreased with increasing time on the diets, in general persisting most strongly in the skull and mandibles and declining most rapidly in the ends of the long bones. The percentage Ca and P content of the bone ash was only slightly affected by diet and, except for the Ca in the ash of vertebras, significant differences were only found in the composition of the ash of bones from 27-week-old rats.
On the postulated peroxidation of unsaturated lipids in the tissues of vitamin E-deficient rats
Authors: Bunyan J. , Green J. , Murrell Elspeth A. , Diplock A. T. , Cawthorne M. A.
Published: September 2005

1. The micro-iodimetric method has been used to study some factors affecting the concentration of lipid peroxides in the adipose tissue of vitamin E-deficient rats.

2. Cod-liver oil methyl esters (CLOME) or maize oil methyl esters (MOME) with peroxide values ranging from 3 to 330 μ-equiv./g were given by mouth to vitamin E-deficient rats deprived of food before and after the dose. Lipid peroxides did not accumulate in the adipose tissue of these rats.

3. Experiments with dietary CLOME and MOME of varying peroxide values (2–230 μ-equiv./g) showed that exogenous lipid peroxide accumulates in the adipose tissue when the rats received these lipids at 10% in the diet for 4 weeks, but not if the dietary concentration was only 4% or if the diet with 10% lipid was given for 5 days only.

4. Rats were given dietary CLOME for 4 weeks. Their adipose tissue was then found to contain about 50 μ-equiv. lipid peroxide/g. They were divided into three groups. One group was given a fat-free diet and, after 10 days, the adipose tissue concentration of lipid peroxide had decreased to about 10 μ-equiv./g. The other groups were given the fat-free basal diet supplemented with vitamin E or DPPD (N,N′-diphenyl-p-phenylenediamine). Neither supplement significantly affected the rate of disappearance of the peroxides from the adipose tissue.

5. It was shown that neither α-tocopherol nor DPPD reacted with the lipid peroxides of CLOME or MOME in vitro, at room temperature or even after 65 h at 37°.

6. It was concluded that unsaturated lipids do not become peroxidized after incorporation into the adipose tissue of vitamin E-deficient rats. Lipid peroxides taken up from the diet into the adipose tissue are not of fleeting existence, having a half-life of about 6 days. Dietary vitamin E probably prevents the accumulation of exogenous lipid peroxides in the adipose tissue by reinforcing the barrier to their absorption in the gut.

7. These studies provide further evidence that current concepts of lipid peroxidation in vitamin E-deficient animals are incorrect. In fact, vitamin E-deficient animals have low concentrations of peroxide in their adipose tissue, unless they have received large amounts of unsaturated lipid for long periods, and the role of vitamin E in controlling this concentration is not due to any effect on peroxidation in vivo.
On the relationship between vitamin A and vitamin E in the rat
Authors: Cawthorne M. A. , Bunyan J. , Diplock A. T. , Murrell Elspeth A. , Green J.
Published: September 2005

1. The effect of vitamin E on the metabolism, utilization and storage of vitamin A has been studied in the rat.

2. Male weanling rats were given a vitamin A-deficient, vitamin E-deficient diet until growth had ceased for 3 days, and each rat was then given 50 i.u. vitamin A palmitate. The rats were divided into four groups and given the diet with the addition of 10% methyl oleate or 10% cod-liver oil methyl esters, or either of these diets supplemented with 100 ppm D-α-tocopheryl acetate. There was no increase in maximum weight-gain response in the two groups given vitamin E. There was a significantly lower weight-gain response in the groups given cod-liver oil methyl esters. This effect was not influenced by the presence of vitamin E in the diet.

3. Weanling rats of both sexes were made deficient in vitamins A and E and then divided into two groups. One group received, every other day, 1·75 i.u. vitamin A palmitate and 0·6 mg D-α-tocopherol given together; the second group received the two vitamins, in the same amounts, on alternate days. After 28 days there was no difference in the growth of the two groups of rats, irrespective of sex.

4. Vitamin A-depleted, vitamin E-deficient rats were given 17·51 μg‘14C-carbinol’retinyl acetate and then a vitamin A-deficient, vitamin E-deficient diet or that diet supplemented with 100 ppm D-α-tocopheryl acetate. After 6 days, the total remaining ‘14C’retinol and its lipidsoluble metabolites were measured in the carcasses of the rats. Vitamin E administration did not affect the metabolism of the vitamin A dose or its effect on growth.

5. Vitamin E-deficient rats were given vitamin A until their liver reserves exceeded 30000 i.u. and were then divided into two groups. One group received a diet deficient in vitamins A and E and the other received, in addition to this diet, a weekly oral supplement of 1 mg D-α-tocopheryl acetate. The vitamin E supplement significantly decreased the rate of vitamin A depletion from the liver during the next 6 weeks. This effect, which was not found to occur when the initial liver reserves were only 3000 i.u., suggests a role for vitamin E in connexion with the capacity of the liver to bind vitamin A.

6. The relationship between vitamin A and vitamin E in vivo cannot, in the light of these results, be regarded as that between an antioxidant and a peroxidizable substrate.
A new biological method for estimating food protein nutritive value
Authors: Mokady Shoshana , Vila S. , Zimmermann G.
Published: September 2005

1. A new method has been devised for the nutritional evaluation of food protein quality. The method is analogous to the classical determination of net protein utilization (NPU). The suggested new criterion, the protein utilization by the liver (LPU), expresses the amount of food nitrogen ‘retained’ in the liver as a percentage of the food nitrogen intake.

2. Five different foods, casein, soya-bean protein isolate, maize gluten, wheat gluten, cottonseed meal alone or with supplements of amino acids, a total of thirteen samples, were tested for LPU and NPU in groups of six rats. The correlation coefficient between values for LPU and NPU for all seventy-eight rats was +0.85 and was highly significant.
Growth inhibitory action of saccharin and cyclamate on rats receiving a poor rice diet
Authors: Sabri M. I. , Sharma S. K. , Krishna Murti C. R.
Published: September 2005

1. The effect of saccharin and cyclamate on growth of young rats fed on a poor rice diet or a balanced diet was investigated.

2. Saccharin and cyclamate retarded the growth of rats on the multi-deficient diet but not of those on the well-balanced diet during an 8-week feeding period.

3. The sweeteners did not produce any macroscopic or microscopic changes in the liver, kidneys, intestines, spleen or lungs of the animals receiving the poor rice diet other than the changes resulting from the nutritional deficiency of the diet.

4. The sweeteners did not inhibit the liver xanthine oxidase activity of rats receiving the poor rice diet to an extent greater than the inhibition brought about by the deficiency of protein in the diet.

5. When given by intubation to healthy rats, the sweeteners inhibited the induction of liver tryptophan oxygenase; given in vitro, they inhibited the succinate dehydrogenase activity of rat liver mitochondria.
A study on the effect of vitamin D in rats maintained on diets with different calcium and phosphorus content but with the same high ratio of calcium to phosphorus
Authors: Harrand R. B. , Hartles R. L.
Published: September 2005

1. Eight groups of ten weanling rats were maintained for 60 days on diets containing calcium and phosphorus in the ratio 10:1 at four different levels of mineral, namely 0.8, 1.19, 2.29 and 3.33% Ca.

2. At the two lower levels of mineral intake the provision of vitamin D reduced final body-weight. Increasing the mineral intake increased final body-weight except at the highest level.

3. Increasing the dietary mineral content had no effect on serum Ca, but serum P was higher in the groups receiving the two higher levels of dietary mineral. Vitamin D raised the serum Ca level in the rats receiving the two lower levels of mineral, and serum P was raised by the vitamin at all levels of mineral intake.

4. Provision of vitamin D at the two lower levels of mineral intake decreased the fresh weight, dry weight and volume of the humerus but had no significant effect on the absolute amount of mineral ash in the bone. Consequentially there was an increase in percentage of ash, overall density and the ratio of weight of ash to organic matter in dry fat-free bone (A:R value). With increasing mineral intake there was an increase in all the bone measurements except volume.

5. The presence of vitamin D had no effect on tooth mass or ash content. Increasing the mineral intake caused an increase in tooth mass and ash except at the highest level of intake.

6. The ratio of tooth ash to bone ash was very much greater at the lower levels of mineral intake than at the higher levels.

7. In the animals on the two lower levels of mineral intake the bones were frankly rachitic, and the presence of vitamin D ameliorated the condition. With increase in mineral intake histological signs of rickets were reduced, but even at the highest level of dietary mineral the epiphyseal discs appeared slightly wider than normal.

8. The incisor teeth of animals on the two lower levels of dietary mineral had wide predentine, and the presence of vitamin D reduced the amount of predentine. At the two higher levels of mineral intake the dentine appeared normal when vitamin D was present in the diet.

9. Quantitatively, the bones were much more affected than the teeth by a low intake of mineral at a Ca to P ratio of 10:1.
In vivo and in vitro methods of measuring nutritive value of leaf-protein preparations
Authors: Buchanan R. A.
Published: September 2005

1. Several in vitro methods were compared with in vivo methods for estimating the nutritive value of leaf-protein concentrates (LPC), using a freeze-dried preparation from wheat (A) fresh, (B) after heating moist, (C) after heating moist and then extraction with chloroform, and (D) after extraction with an acidified solvent.

2. The treatments had little effect on the biological value (BV) of the samples for rats.

3. Heating moist decreased true digestibility (TD), net protein utilization (NPU) and protein efficiency ratio (PER), but the original values were almost restored by lipid extraction. Acidified solvent extraction decreased TD, NPU and PER of LPC perhaps by making it brittle and difficult to wet.

4. Papain solubility and TD were well correlated. Pepsin-pancreatin solubility and TD were less well correlated.

5. Microbiological estimations of available amino acids, involving predigestion with pepsin, correlated poorly with TD determinations.

6. Unsaturated fatty acids, particularly linolenic, formed complexes during heating of LPC. The effect of this on enzyme solubilization procedures and on digestion in vivo is discussed.

7. Some comparisons are made between the effect of heat and of extraction with solvents on LPC and on fish meal.
Dietary linoleic acid and the plasma phospholipids of the rabbit
Authors: Moore J. H. , Noble R. C.
Published: September 2005

1. Groups of rabbits were given diets containing different proportions of butterfat and maize oil. After the animals had been given the experimental diets for 40 weeks the plasma phospho- lipids were fractionated and the fatty acid composition of each fraction was determined.

2. Phosphatidyl choline and lysophosphatidyl choline accounted for about 75 and 12% respectively of the total plasma phospholipids: phosphatidyl ethanolamine, sphingomyelin and phosphatidyl serine accounted for only about 5.3, 5.0 and 2.6% respectively. Changes in the linoleic acid content of the diet had little effect on the relative proportions of the individual plasma phospholipids, but there was an over-all decrease in the concentration of total phospholipids in the plasma as the linoleic acid content of the diet was increased from 0.25 to 10.6%.

3. When the diet contained 0.25 % linoleic acid, the linoleic acid:oleic acid ratio in the phosphatidyl choline (1.3) was similar to that in the phosphatidyl ethanolamine (1.2), but as the linoleic acid content of the diet was increased to 10.6% the linoleic acid:oleic acid ratio in the phosphatidyl choline increased to 48, whereas that in the phosphatidyl ethanolamine increased only to 2.2. Increases in the linoleic acid content of the diet resulted also in increases in the linoleic acid:oleic acid ratios in the phosphatidyl serine, lysophosphatidyl choline and sp hingomyelin.

4. When the linoleic acid content of the diet was increased, the stearic acid:palmitic acid ratio in the phosphatidyl choline increased, whereas it decreased in the phosphatidyl ethanol- amine and remained relatively unaltered in the phosphatidyl serine. The stearic acid contents of the lysophosphatidyl choline and sphingomyelin were unaltered by dietary treatments, but the palmitic acid content of these two phospholipids decreased as the linoleic acid content of the diet increased.

5. The results are discussed in terms of the metabolic relationships that exist between the various phospholipids.
The retinol requirements of rats for spermatogenesis and vision
Authors: Coward W.A. , Howell J.McC. , Thompson J.N. , PITT G. A. J.
Published: September 2005

1. Hooded rats were fed from weaning on a basal retinol-deficient diet containing retinoic acid. Such a diet maintains growth and general health but does not prevent the appearance of lesions associated with vitamin A deficiency in the retina and testis. Some animals were also given supplements of retinol averaging 0.1, 0.25, 1 or 5 μg retinyl acetate per day. Rats were killed at intervals up to 28 weeks after weaning. The weights of the testes and the histological appearance of the testes and epididymides indicated that 5 μg retinyl acetate per day had maintained spermatogenesis throughout the experimental period. Doses averaging 1 μg retinyl acetate per day were only partially effective and the two smaller doses had little beneficial effect.

2. In a second similar experiment rats were given doses of retinyl acetate averaging 0.25, 0.5, 1, 2 or 100 μg per day. Measurements of the electroretinogram thresholds of the rats indicated that a dose of 1 μg retinyl acetate per day maintained mainly normal vision until the end of the experiment 29 weeks after weaning. Additional histological observations made 21 weeks after weaning showed that this dose level had not maintained spermatogenesis but that doses of 2 μg retinyl acetate per day had been effective.

3. The experiments show that the differing functions of vitamin A in spermatogenesis and vision are reflected in the hooded rat in differences in the dietary retinol levels needed to maintain these processes.
Normal folic acid metabolism in iron-deficient rats
Authors: Burns D. G. , Spray G. H.
Published: September 2005

1. Weanling rats were fed on an iron-deficient diet without added folic acid and litter-mate controls received the same diet supplemented with Fe. Groups of deficient and control animals were killed at intervals of up to 88 days and glutamate formiminotransferase activity in liver and folic acid activity in liver and serum were measured.

2. No differences were found between the results from the deficient and control animals, although the deficient diet produced marked falls in haemoglobin, packed cell volume and serum iron.

3. In a second experiment folic acid was added to the diets and twelve rats received the Fe-deficient diet and their litter-mates were fed on the Fe-supplemented diet for 91 days. No differences were found in the activity of glutamate formiminotransferase purified from the combined livers of the two groups.
The quantitative significance of long-term regulation of food intake in the cow
Authors: Bines J. A. , Suzuki S. , Balch C. C.
Published: September 2005

1. Six adult, non-pregnant, non-lactating, Friesian cows were used when fat and when thin to measure differences in the voluntary intakes of straw, hay and hay plus concentrates caused by the fatness of the animals. Measurements of digestibility, time of retention of food in the digestive tract, rate of breakdown of cotton threads in the ventral sac of the rumen and amounts of digesta in the reticule-rumen were included.

2. The mean voluntary intakes of straw were similar for fat and thin cows. In absolute terms, thin cows consumed 31 % more hay and 23 yo more hay and concentrates than fat cows; in relation to metabolic body size (W0.75), these differences were 76% and 52% respectively.

3. Small decreases in digestibility of these diets by the thin cows, reflected in slight reductions in the rate of loss of weight of cotton threads placed in the rumen, did not alter the significance of the differences in intake between fat and thin cows.

4. Small changes in time of retention of food in the digestive tract suggested that the capacity of the tract may have been greatest in the thin cows.

5. The presence of a greater amount of digesta in the reticulo-rumen of thin cows than in that of fat cows after eating hay supports the suggestion of a greater gut capacity in these animals. In both fat and thin cows, the capacity of thereticulo-rumen didnot appearto havelimited the intake of the hay and concentrate diet. In both groups the lowest levels of rumen fill were observed after straw was given.

6. The results are discussed in terms of possible mechanisms which may operate to reduce the voluntary intake of medium- and good-quality diets as cows become fatter. When poorquality roughages are given, other factors appear to conceal any differences in intake which may exist between fat and thin cows.
The incorporation of linoleic acid into the plasma lipids of sheep given intraruminal infusions of maize oil or free linoleic acid
Authors: Noble R. C. , Steele W. , Moore J. H
Published: September 2005

1. The fatty acid compositions of the plasma cholesteryl esters, phospholipids, triglycerides and unesterilied fatty acids were determined in two sheep at various times after they had been given intraruminal infusions of emulsions of maize oil or linoleic acid.

2. The concentration of linoleic acid in the plasma triglycerides began to increase 3 h after infusion began. The infusions of maize oil and linoleic acid resulted in the appearance of peak concentrations of linoleic acid in the plasma triglycerides 6 and 12h respectively after infusion began.

3. After the infusion of maize oil the plasma triglycerides showed an increasein theconcentration of stearic acid but after the infusion of linoleic acid the plasma triglycerides showed an increase in the concentration of oleic acid.

4. The concentration of linoleic acid in the plasma phospholipids and cholesteryl esters did not begin to increase until 6–9 h and 24–25 h respectively after the infusions had begun.

5. No evidence was found for an absorption mechanism which involved the direct incorporation of linoleic acid into the blood phospholipids or cholesteryl esters.
The urinary excretion of aromatic acids by starved sheep
Authors: Martin A. A.
Published: September 2005

1. Four wether sheep were maintained on a diet of hay for 2 weeks and then starved for a period of 4 days.

2. Immediately before and during starvation the urinary excretion in the following fractions was determined: hippuric acid, creatinine, total diethyl ether-soluble acids of hydrolysed and unhydrolysed urine, total aromatic acids in hydrolysed and unhydrolysed urine and the proportion of the former present as benzoic and phenylacetic acids.

3. A method for determining the benzoic acid content of light petroleum extracts of urine has been developed and is described.

4. Starvation had little effect on the urinary excretion of phenylacetic acid or creatinine, but during the first 2 days of starvation there were large decreases in the excretion of all the other urinary fractions studied.

5. Of the fractions examined, 43% of the diethyl ether-soluble acids of hydrolysed urine and 42% of those of unhydrolysed urine were of exogenous origin; 76% of the total urinary aromatic acids were of exogenous origin. Partition of the aromatic acids in the urine of two of the four sheep indicated that the reduction in aromatic acid excretion on starvation was completely accounted for by the decline in benzoic acid output. Almost all the hippuric acid (97%) was of exogenous origin.

6. These results have been compared with the urinary output of aromatic acids by nonruminants when fasted, and possible reasons for the relatively large amounts of phenylacetic acid found in the urine of starved sheep have been discussed.
The sodium requirements of growing steers given an all-sorghum grain ration
Authors: Morris J. G. , Gartner R. J. W.
Published: September 2005

1. Eight groups, each of five steers, were given a basal ration of sorghum grain plus urea and minerals (0.003% sodium) adlib. and demineralized water. Two groups, one given coarsely rolled and the other finely ground grain, were given the basal ration alone or the basal ration supplemented with 3.25, 6.50 or 13.0 g Na/animal daily as NaHCO3. Mean daily intakes of Na per animal for each of the four treatments were 133 mg, 3.1, 6.0 and 11.4g, respectively.

2. The mean growth rate of steers given the basal ration was 059 kg/d, which was significantly less than that of steers ingesting 3.1 g Na/d (093 kg/d). There were no significant differences in the growth rates of steers ingesting 3.1, 6.0 and 11.4g Na/d.

3. The concentration of Na in the saliva from the steers fed on the basal ration was significantly less and the concentration of potassium significantly greater than those from steers with Na intakes of 3.1 g or more per d. The mean Na:K ratio of the saliva from steers given the basal ration was less than unity, whereas the ratio in the saliva from steers ingesting 3.1g or more Na/d varied between 11 and 21.

4. The concentrations of Na in the ruminal fluid were significantly less in steers given the basal ration than in those ingesting 3.1 g or more Na/d.

5. The widths of the cortex and the zona glomerulosa as a percentage of the adrenal cortex were significantly greater in steers given the basal ration only than in those given Na intakes of 3.1 g/d. There were no significant differences in the width of the zona glomedosa of the adrenals from steers ingesting 3.1, 6.0 or 11.4g Na/d.

6. A Na and K balance conducted on two steers given the basal ration only for a further 112 d after the other steers were slaughtered indicated that faecal and urinary Na losses approximated to the Na intake, but there was a positive K balance. When these steers were subsequently given a supplement of 380 m-equiv. Na/d for 16 d they retained 370 m-equiv. Na/d and were in negative K balance.

7. It is suggested that the value given by the Agricultural Research Council (1965)for the Na requirement of steers for growth is excessive.

8. Steers given coarsely rolled grain ate significantly more feed per d than those given finely ground grain, but rate of body-weight gain was not affected by the method of grain processing.
The effects of some dietary changes upon the concentrations of serum lipids in rats
Authors: Mcgregor D.
Published: September 2005

1. The responses of serum lipids of weanling and adult male rats to different diets have been examined. Total cholesterol, phospholipids and triglycerides were measured. The proteins used in the diets were casein and wheat gluten, the carbohydrates were starch and sucrose, and the main lipid source was groundnut oil supplemented with either gluten oil or maize oil.

2. In general, the type of carbohydrate did not influence the experimental results, whereas the type of protein had a marked effect. Compared with casein, gluten caused an increase in concentration of serum triglycerides, phospholipids and cholesterol in weanling rats, but there was no change in adult animals. Much of this ‘gluten effect’ in weanlings was not ob- served when the diet was supplemented with 0.7% L-lysine hydrochloride.

3. When 1% cholesterol was added to the gluten diets, the serum cholesterol concentrations were only slightly and variably affected in weanlings. Serum triglycerides and phospholipids were not altered in adult rats by the dietary cholesterol, whereas there were reductions in these lipid components in the weanlings, whether the protein was supplemented with L-lysine hydrochloride or not.

4. Gluten oil was not shown to be responsible for any major portion of the differences observed between gluten and casein in their effects upon the lipids of rat serum.