bluuebunny/crossref_metadata_2025 huggingface dataset:
Nutrient intakes of urban dwellers in Lagos, Nigeria
Authors: Mcfie John
Published: September 2005

1. The nutrient contents of diets consumed by families in the lower income groups in Lagos are compared with published values for diets consumed by Nigerians in rural areas.

2. Qualitatively, the dietary patterns of urban dwellers tended to resemble those of the regions from which they had migrated; attention is drawn to certain exceptions.

3. Quantitatively, urban diets resembled those in rural areas in (a) providing a lower proportion, in relation to requirements, of calories rather than of protein; and (b) allowing children lower intakes of all nutrients, in relation to requirements, than adults.

4. Restriction of calorie intake resulted in diversion of dietary protein to energy production, and this in turn led to low mean body-weights of children and of adults.
Nitrogen balance studies with the milk-fed lamb
Authors: Walker D. M.
Published: September 2005

1. Five male cross-bred lambs at the age of 3 weeks were starved for a period of 4 days. The utilization of nitrogen, energy and minerals was compared with the pre-starvation and post-starvation periods, when the lambs were given reconstituted dried whole cow's milk.

2. The mean loss in weight during starvation was 253 g/24 h. The gain in weight during realimentation was significantly greater than that in the pre-starvation period, when adjusted for differences in energy intake.

3. The urinary loss of N during starvation was 478 mg N/kg live weight 24 h. During realimentation the urinary N loss was greater than during the pie-starvation period. A higher urea excretion during realimentation was responsible for the increased urinary N.

4. Excretion of ammonia, creatine, amino acid and purine base N increased during starvation. Excretion of creatinine N remained constant.

5. The increase in total sulphur excretion during starvation was due mainly to an increase in the inorganic sulphate fraction. The ratio of N to S of 27: 1 during starvation was much greater than would be expected from the katabolism of muscle tissue alone (ratio N to S = 16.2:1).

6. The titratable acidity and acetone excretion in the urine increased during starvation.

7. There was a marked reduction in the urinary excretion of chloride, potassium and sodium during starvation, an increase in the excretion of phosphorus, but little change in the excretion of calcium and magnesium. The loss of minerals was not closely related to the losses predicted from muscle tissue alone.

8. Pulse rate, respiratory rate, and rectal temperature all decreased during starvation. Heat production decreased after 1 day of starvation, but was relatively constant thereafter.

9. Blood urea concentrations did not change significantly during starvation.

10. The results for the lamb were in reasonable agreement with published results for the calf, except for the marked ketone acidosis and considerable increase in the excretion of purine N. The losses during starvation differed from those with the adult sheep in showing a relatively greater loss of body protein.
Studies of the possible transference of flavonol antioxidants from the diet to the tissue lipids of rats
Authors: Letan A.
Published: September 2005

1. The oxidative stability of lipids in the tissues (erythrocytes, liver and depot fat) from vitamin E-deficient rats was not improved by feeding these animals, for a period of 39–55 days before killing, on a vitamin E-free diet richly supplemented with the flavonoid antioxidants quercetin (3,5,7,3',4'-pentahydroxyflavone) and flavone (3,7,8,2',5'-pentahydroxy-6-tert.-butyl flavone).

2. Addition of α-tocopherol (in the form of α-tocophery1 acetate) to the diet relieved, as expected, the investigated symptoms of vitamin E deficiency and greatly improved the stability of the tissue lipids.

3. Quercetin and flavone, when added in vitro to liver homogenate or to extracted adipose tissue, strongly retarded oxidation. It was concluded that those flavonols either were not absorbed by the animals or were destroyed in the body.
The determination of lignin
Authors: Czerkawski J. W.
Published: September 2005

1. The methods for estimating lignin based on 72% sulphuric acid are lengthy and usually require large corrections for the residual nitrogenous impurities. The steps used in the initial purification of lignin, and particularly those concerned with the removal of nitrogenous impurities using proteolytic enzymes, have been investigated.

2. The conditions that remove the maximum amount of nitrogen were investigated. The nitrogenous material remaining in the lignin isolated by the adopted procedure was partly characterized, and it was shown that about half of the resistant N could be obtained in the form of amino acids which were presumably present in the lignin in the form of protein. The amino acid compositions of the resistant nitrogenous material in lignin derived from grass, and in lignin derived from faeces of sheep, when the same grass was given, were compared. They were found to be sufficiently similar to suggest a common origin.

3. A modified procedure is proposed and described in detail; it is suitable for routine work.

4. Comparisons were made between the results obtained by determining lignin in forage and faeces samples by the method now presented and those obtained by the method used previously.
Reproduction and vision in rats maintained on a retinol-free diet containing 3-dehydroretinol (vitamin A2)
Authors: Howell J. McC. , Thompson J. N. , Pitt G. A.
Published: September 2005

1. Seventeen hooded female rats were given from weaning a retinol-free diet containing methyl retinoate. When 105 days old they were mated with normal bucks.

2. Six of these rats were subsequently given dietary supplements of 100 μg retinol daily and another six were given 100 μg 3-dehydroretinol daily. All twelve rats had litters.

3. The five rats that received only methylretinoate during pregnancy resorbed their foetuses.

4. One of the litters from the female rats given 3-dehydroretinol consisted of six male pups. These young rats had never had access to retinol. They were maintained on a retinol-free diet supplemented with methyl retinoate. Two of these rats were given daily supplements of 3-dehydroretinol and another pair were given daily an equal amount of retinol.

5. The six rats were killed when 195 days old. The testes and the retina of the rats given either 3-dehydroretinol or retinol were normal. The testes and the retina of the rats given methylretinoate only were degenerate.
The digestion of heat-damaged protein
Authors: Nesheim M. C. , Carpenter K. J.
Published: September 2005

1. The apparent digestibilities for chicks, operated on so as to allow separate collection of urine and faeces, of the nitrogen in a heat-damaged cod flour (C35) and of a control, freezedried cod muscle (C23) were 77 and 90% respectively.

2. The differences are similar to those found for rats in earlier work and considerably smaller than the differences found in nutritional value of the materials as sources of either lysine or methionine for chicks.

3. Chicks killed 3 h after a test meal containing C23showed little more N in their small intestine than did those on a N-free diet; other chicks receiving C35showed much more N remaining in the gut.

4. It is hypothesized that significant quantities of heat-damaged protein may remain undigested in the small intestine, but may then be de-aminated by fermentation in the caecum so that values for the digestibility of N and of individual amino acids may be misleadingly high.

5. This hypothesis is supported by the finding that in caecectomized chicks the apparent digestibility of the N of C35was only 68%, whereas the digestibility of C23remained the same as in intact chicks.
Interrelations of calcium, fluorine and vitamin D in bone metabolism
Authors: Gaster Deborah , Havivi E. , Guggenheim K.
Published: September 2005

1. The interrelationships between dietary calcium, fluorine and vitamin D were studied in young rats.

2. Rats maintained on a low-Ca diet gained less weight and had less ash in their bones. Their femurs incorporated more radioactive Ca than those of rats kept on a control diet. Supplementation of the diet with F slightly decreased growth and the content of bone ash without any effect on the content of Ca and phosphorus in the bone ash. The F supplement decreased uptake of radioactive Ca by bone. Addition of vitamin D to a low-Ca diet improved growth and, when added alone, increased uptake of radioactive Ca by bone without affecting the content in femurs of ash, Ca or P. Addition of F to a low-Ca diet supplemented with vitamin D diminished the uptake of radioactive Ca.

3. Decrease of bone ash in rats fed the low-Ca diet was accompanied by an increase in bone nitrogen. The bones of the unsupplemented rats contained less citric acid per unit of dry, fat-free mass. Addition of F decreased citric acid, whereas addition of vitamin D increased it.

4. The results are discussed and it is concluded that vitamin D added to a low-Ca diet does not exert a calcifying effect on bone, but rather increases Ca turnover. F, on the other hand, reduces the exchangeability of bone mineral.
Distribution of carotene and vitamin A in liver, pancreas and body fat of Ghanaians
Authors: Dagadu J. Maud
Published: September 2005

I. The carotene and vitamin A levels of liver, pancreas and body fat were determined in seventeen Ghanaians coming from areas where carotene-rich foods were freely available.

2. The liver was confirmed as the main storehouse of vitamin A, and vitamin A values for it were exceptionally high. Values for the other tissues were not higher than average.

3. In the study the carotene and vitamin A concentrations in the liver were higher in the females than in the males.

4. Under the conditions of high intake of carotene-rich foods, carotene was found to be distributed more evenly in various tissues than vitamin A.
The effect of a low-protein diet and a cold environment on calorie intake and body composition in the rat
Authors: Schmida P. , Widdowson Elise M.
Published: September 2005

1. Rats 10 weeks old were fed for 9 weeks either on a stock diet containing 17% protein, or on a low-protein diet prepared from the stock diet with added glucose, minerals and vitamins. Half the animals on each diet were kept at room temperature (21°) and half in a cold environment (5°).

2. The calorie intake of the animals kept at 5° on both diets was 60–70% higher than that of the corresponding group at 21°. The animals on the stock diet and kept at 5° gained weight but not so much as those on the same diet at 21°. The animals kept on the low-protein diet at 21° lost weight, while those on the same diet at 5° lost only a little weight initially and none thereafter.

3. On both types of diet the liver, kidneys and gastro-intestinal tract weighed more per 100 g body-weight in animals kept in the colder of the two environments; the small intestine was conspicuous in this respect.

4. The weight of the fur was greater, and the weight of the skin less per 100 g body-weight at 5° than at 21°.

5. The animals on the stock diet at 21° had most fat in their bodies, both in absolute terms and per 100 g body-weight. There were no significant differences between the other three groups.

6. The skin of the animals kept at 5° had a significantly higher collagen to N ratio than the skin of those having the same diet at 21°.
Chemical and biological evaluation of the effects of fermentation on the nutritive value of foods prepared from rice and grams
Authors: Rajalakshmi R. , Vanaja K.
Published: September 2005

1. Studies were made of the effects of fermentation on the chemical composition and nutritive value of Idli, a product prepared from milled rice and dehusked black gram, and also of Khaman, a product prepared from dehusked and milled bengal gram.

2. Fermentation brought about an increase in thiamine and riboflavine contents and a decrease in phytate content in both materials.

3. Weanling rats fed on fermented Idli and Khaman were found to be superior to those fed on the corresponding unfermented product with regard to weight gain, nitrogen retention, thiamine and riboflavine contents of the liver and the activities of liver xanthine oxidase and succinic dehydrogenase and haemoglobin content of blood.
Factors influencing the retention of an oral dose of radioactive manganese by the chick
Authors: Mathers J. W. , Hill R.
Published: September 2005

1. In two experiments, involving 110 chicks up to 5 weeks of age, retention of an oral dose of 54Mn was always low; less than 5%.

2. There were no significant differences in retention by hybrid broiler cocks, hybrid layer cocks, and hybrid layer pullets, nor was retention affected by the period of fasting, i.e. 1 ½ or 24 h, before dosing.

3. Two-weeks-old birds retained 58% more radioactive manganese than 5-week-old birds, and retention in birds killed 24 h after the dose was only 64% of that in birds killed 4 h after the dose.

4. With the addition to a fixed dose of 54Mn of increasing quantities of non-radioactive Mn retention decreased only from 2.52% with no Mn added to 1.02% with 5000 μg Mn added, representing a very large increase in total retention of Mn.
Pathogenesis of endemic goitre in Eastern Nigeria
Authors: Ekpechi O. L.
Published: September 2005

1. A survey in Eastern Nigeria revealed an area of endemic goitre with a marked variation in incidence form village to village not accounted for by iodine deficiency alone.

2. As dried unfermented cassava was consumed in large quantities in the highly goitrous areas, experiments with rats were undertaken to assess the significance of this factor.

3. Groups of rats were fed (a) cassava, (b) equal parts cassava and standard diet, (c) cassava with added iodine and (d) standard diet, and each rat received and intraperitioneal injection of 20 μc iodine 24 h before being killed.

4. The iodine content and hardness of the water in the various areas were estimated and the chemical and bacteriological indices of pollution determined.

5. The following effects were observed: thyroid weight, iodine uptake and plasma-protein-bound iodine were all increased in the cassava-fed animals, the last markedly so. the thyroid's precursor and hormone iodine stores were severely depleted in these animals, which also showed an impaired transfer of iodine from monoiodotyrosine to diiodotyrosine and a high proportion the iodine present as iodothyronine. The giving of iodine with the cassava did not prevent these changes from taking place.

6. Many of the observed effects suggest that cassava was acting like the thionamide group of an antithyroid drug.

7. These findings are discussed.
The voluntary intake and digestibility, in sheep, of chopped and pelleted Digitaria decumbens (pangola grass) following a late application of fertilizer nitrogen
Authors: Minson D. J.
Published: September 2005

1. Experiments were conducted with wether sheep in 1964 and 1965 fed pelleted or chopped mature Digitaria decubemes Stent (pangola grass) bay containing different crude protein contents. The voluntary intake of food, digestibility of dry matter and nitrogen, nitrogen retention and apparent time of retention of feed organic matter in the reticulo-rumen were measured. The different crude protein contents of the grass were obtained by applications of urea to the sward 14 and 28 days before cutting for hay in 1964 and 1965 respectively. This treatment increased the crude protein content of the dry matter from 4.9% to 8.7% in 1964 and from 3.7% to 7.2% in 1965. The size of the particles of the ground hay before pelleting is given.

2. The mean voluntary intake of chopped fertilized grass was 10% and 54% greater than that of the unfertilized; the voluntary intake of pellets made from fertilized grass was 35% and 75% greater than of those made from the unfertilized grass in 1964 and 1965 respectively.

3. The voluntary intake of pellets of unfertilized grass was 7% and 14% greater than that 30% greater than that of chopped fertilized grass in 1964 and 1965 respectively.

4. The digestibility of the pellets was less than that of the chopped grass.

5. The apparent digestibility of the feed nitrogen was increased by the fertilizer nitrogen, but grinding and pelleting had no consistent effect. Sheep eating chopped or pelleted fertilized hay were in positive nitrogen balance.

6. The apparent retention time of organic matter in the reticulo-rumen was longer when the sheep were eating chopped hay than when they were eating pellets. In 1964 the apparent retention time of organic matter in the reticulo-rumen was shorter for chopped and pelleted unfertilized grass than for chopped and pelleted fertilized grass, but in 1965 the order was reversed.

7. The relationship between voluntary intake, apparent retention time of organic matter in the rumen and the protein content of the food is discussed.
Effect of storage on the fatty acids of dried ryegrass
Authors: Czerkawski J. W.
Published: September 2005

1. The compositions of the fatty acids in ryegrass were determined in fresh samples, and in samples dried at room temperature for 26 h, at 50° and for 18 h or at 100° for 12 h. The drying of grass resulted in a small increase in palmitic acid and a decrease in linolenic acid in the total fatty acids.

2. Samples of grass dried at 50° and 100° were stored at three relative humidities (rh < 3%, 47% and 80%) for 13 months.

3. There were marked changes in the samples stored at 80% rh, with an onset of mould growth and a loss of dry matter. The samples stored at lower humidities had no mould.

4. There were two types of change in the fatty acids during storage. The deterioration brought about and mould was accompanied by a decrease in the concentration of linolenic acid and an increase in the concentrations of oleic and linoleic acids. The other type of change observed at the lower humidities resulted in a decrease in the content of linolenic and an increase in the content of palmitic, and did not affect the amounts of oleic and linoleic cells.

5. There was little difference between the changes that occurred in the composition of the total fatty acids of the grass dried at 50° and of that dried at 100°. The changes that were at all significant appeared to occur less rapidly, particularly in the early months of storage, in the grass dried at the higher temperature for the shorter time.
The N:H2O ratio in the Sprague–Dawley rat and its variation with diet under the conditions of determination of net protein utilization
Authors: Pellett P. L.
Published: September 2005

1. Analytical values are presented for body nitrogen, both on a fresh and dry carcass basis, body water and N to body water ratios for rats, of various ages, of the Sprague–Dawley Strain.

2. For 33- and 40-day-old animals, there were significant differences in body composition, including N:H2O ratio, between animals given a protein-free diet and those given protein at the 10% dietary level. For all age groups the N and water percentages were higher in the carcasses of animals given the non-protein diet.

3. For all age groups there were significant negative correlations between the percentage of N in the dry carcass and the net dietary protein value (NDpv) of the diet. For 33-, 37- and 40-day old animals there were significant negative correlations between the N content of the fresh carcass and the NDpv of the diet. For 33-day-old animals only, the correlation between N:H2O ratio and NDpv was also highly significant.

4. Body N values calculated from N:H2O ratio and from N:body-weight ratio were compared. At all ages, an equally good prediction was obtained from the N:body-weight ration as from the N:H2O ratio provided that the correct factors were used for animals given the non-protein and test diets.
Repeated alcoholic intoxication compared with continued consumption of dilute ethanol in experiments with rats on a marginal diet
Authors: Wallgren Henrik , Ahlqvist Johan , Åhman Kurt , Suomalainen Heikki
Published: September 2005

1. The effects have been compared of log-term administration of similar amount of ethanol given either diluted in drinking water or spaced out in the form of intoxicating doses.

2. The effect of ethanol on the development of liver lesions produced by a marginal diet was examined. The measurements of growth rate, water balance, plasma glucose and electrolytes, rate of ethanol elimination, and some behavioural tests for the detection of tolerance and possible signs of neurological disturbance were also included.

3. Isocalorically pair-fed growing male rats were subjected to three different regimens for 6 months: (A) ethanol solution as the sole drinking fluid with 2 days' intake adjusted to approximately 5 mg/g body-weight; (B) a similar quantity of ethanol give as a single intoxicating dose per os on alternate days; (C) oleic acid isocaloric with the ethanolper oson alternate days.

4. All the regimens caused fatty liver. Hepatic fibrosis, as judged macro- and micro- scopically, was equally severe after treatments A and C, but milder after treatment B.

5. Growth was retarded by intoxication, which also brought about a large increase in water consumption, without exerting other clear effects on water balance or on plasma electrolytes. The rate of ethanol elimination was increased by repeated intoxication. Behavioural tolerance of the effects of ethanol was also found in the animals subjected to intoxication.
The assessment of the amount of fat in the human body from measurements of skinfold thickness
Authors: Durnin J. V. G. A. , Rahaman M. M.
Published: September 2005

1. Skinfold thickness and body density were measured on 105 young adult men and women and 86 adolescent boys and girls.

2. The correlation coefficients between the skinfold thicknesses, either single or multiple, and density were in the region of −0.80.

3. Regression equations were calculated to predict body fat from skinfolds with an error of about ±3.5%.

4. A table gives the percentage of the body-weight as fat from the measurement of skin-fold thickness.
Effects of dietary polyunsaturated fatty acids on the composition of the individual lipids of turkey breast and leg muscle
Authors: Neudoerffer T. S. , Lea C. H.
Published: September 2005

1. Groups of turkeys were given, to 10 weeks of age: diets E, basal, containing 2.3% mainly cereal lipid; A, basal plus 2.5% beef fat; B, basal plus 2.5% anchovy oil; C, as B, plus 0.02% ethoxyquin; D, basal plus 5% anchovy oil. Lipids from breast and leg muscle of all five groups were fractionated by thin-layer chromatography into five ‘neutral’ and six phospholipid fractions and the fatty-acid composition of each was determined by gas–liquid chromatography.

2. Individual lipid fractions differed widely in fatty-acid composition and in the degree to which they could be influenced by dietary fat supplements. Small but usually consistent differences were observed between corresponding fractions from breast and leg. Sphingomyelin (SP) and lysophosphatidylcholine contained largely saturated acids (76–80%); the other phospholipids were 44–48% and the ‘neutral’ lipids 38–50% saturated. Phosphatidylserine (PS), phosphatidylinositol(PI) and, in less degree, phosphatidylethanolamine (PE) were rich in stearic acid, though palmitic was much more abundant in the diets and in the other muscle lipids. SP contained no acid more unsaturatedthan linoleic (1–2%). PE and PI were richest in arachidonic and PE and PI in other polyene acids.

3. The effects of beef fat on the muscle lipids were small and mainly on the ‘neutral’ fractions.

4. The polyunsaturated fatty acids of the fish oil extensively displaced linoleic (and oleic) acids from all fractions (except SP); arachidonic acid was displaced from PE but not from PI.

5. The degree to which the fish-oil polyunsaturated acids of the three series entered the muscle lipids varied with the acid and with the fraction. Docosahexaenoic acid (22:6) reached a concentration of 20–25% in PE, nearly five times as great as its concentration in the dietary lipid.

6. Hydrolysis with phospholipase A showed that most of the unsaturated fatty acids were present in the 2-position of PC and PE, but the positional specificity was not complete, particularly for the less highly unsaturated acids.

7. The antioxidant ethoxyquin had no effect on the fatty-acid composition of any of the muscle lipid fractions.
Comparison of the lipid compositions of the aortic lesions in rabbits given different atherogenic diets
Authors: Moore J. H.
Published: September 2005

1. The compositions of the lipids in the atheromatous lesions of rabbits have been studied in an experiment in which two groups of rabbits (twelve/group) were given different atherogenic diets for a period of 38 weeks. One group of rabbits was given a diet in which 35% of the total calories was derived from butterfat and the other group was given a diet in which 48% of the total calories was derived from starch.

2. At the end of the feeding period the rabbits were killed and the atheromatous plaques were dissected out from the aortic intima of each rabbit. The lipid compositions of the aortic lesions were determined and the results compared with the compositions of the plasma lipids.

3. In the lipids of the aortic lesions in the rabbits given the high-butterfat diet, the proportions of cholesterol and cholesterol esters were higher and the proportion of triglycerides was lower than in the lipids of the aortic lesions in the rabbits given the high-starch diet. Irrespective of dietary treatment, free cholesterol constituted a higher proportion of the lesion lipids than it did of the plasma lipids.

4. In the rabbits on either dietary treatment, the lesion cholesterol esters contained higher concentrations of oleic acid and lower concentrations of linoleic acid than did the plasma cholesterol esters. In the lesion phospholipids there were higher concentrations of palmitic, palmitoleic, stearic and oleic acids and lower concentrations of linoleic and arachidonic acids than in the plasma phospholipids.

5. In both groups of rabbits the phospholipids of the aortic lesions contained higher proportions of cephalin and sphingomyelin and lower proportions of lecithin than did the plasma phospholipids.

6. The results of this investigation are discussed in relation to the possible origins of the lipids in the aortic lesions of the experimental rabbits.
Lesions associated with the development of ataxia in vitamin A-deficient chicks
Authors: Howell J. McC. , Thompson J. N.
Published: September 2005

1. An investigation was made of the sequence of changes that occurred during the development of vitamin A deficiency in the chick. Particular attention was given to changes in the central nervous system (CNS) and in bone.

2. Groups of birds were killed after being fed the diet for 14, 17, 20, 22, 24 and 28 days. The tissues of five deficient and five control birds were examined unfixed for gross changes and photographed. Groups of five deficient and five control chicks were perfused through the heart with Heidenhainαs Susa solution and, after decalcification, the tissues were examined for gross and histological changes. The bones of other groups of five deficient and five control chicks were examined for tetracycline-induced fluorescence.

3. The first lesion seen was metaplasia of the nasal respiratory epithelium to a stratified squamous form. This was rapidly followed be decreased weight gain, the development of ataxia, compression of the CNS and Wallerian degeneration in the ventral and lateral columns of the cervical spinal cord.

4. Changes in bone were first seen in chicks killed 6 days after metaplasia of nasal respiratory epithelium and 3 days after ataxia and brain compression had been seen.

5. Changes were present in the epiphyseal cartilage zone of the femur and in the periosteum of the vertebrae, but not in the epiphyseal cartilage of the vertebrae. the changes in the femur were thought not to have a direct relationship to vitamin A deficiency and may have been produced by inanition.

6. An increase in osteoblast activity and cartilage formation was seen in the vertebral periosteum of the vitamin A-deficient chicks and the relationship of these changes to lesions in the CNS is discussed.
Endogenous nitrogen metabolism and plasma free amino acids in young adults given a ‘protein-free’ diet
Authors: Young V. R. , Scrimshaw N. S.
Published: September 2005

1. Variation in endogenous nitrogen metabolism was determined by giving eleven healthy men, aged 17–22, a diet supplying daily only 6 mg N/kg body-weight. Eight subjects were given the diet for 7–10 days and three other subjects were given it for 16 days.

2. Body cell mass (BCM) was calculated from whole-body40K in ten subjects and basal metabolism was determined in seven subjects during the ‘protein-free’ period. Urine was analysed daily for N and creatinine, and faecal N was measured in pooled samples. Plasma free amino acids, serum albumin and protein were measured in preprandial morning blood samples at the beginning and end of the study.

3. BCM did not change during the ‘protein-free’ period and accounted for 48% of the total body-weight. Basal calorie expenditure amounted to 48 ± 5 kcal/kg BCM per day.

4. Mean daily endogenous urinary N excretion in the eight subjects given the ‘protein-free’ diet for 7–10 days was 36·6 ± 3·0 mg N/kg body-weight, 79·4 ± 4·4 mg N/kg BCM and 1·6 ± 0·2 mg N/basal kcal. Endogenous faecal N excretion was 9·9 ± 1·1 mg N/kg body-weight and accounted for 20% of the total endogenous loss. Results obtained with three other subjects given the diet for 16 days were similar.

5. Plasma essential amino acids were reduced, glutamic acid, alanine and glycine increased, and the ratio of essential to non-essential amino acids decreased after 7 or 10 days of ‘protein-free’ diet.

6. The loss of endogenous N per basal kcal and of faecal N per kg body-weight was lower than the values assumed in the factorial approach to protein requirements by the FAO/WHO (1965) Expert Group on Protein Requirements.
A study of the effect of vitamin D in rats maintained on diets with different mineral content but with the same low ratio of calcium to phosphorus
Authors: Harrand R. B. , Hartles R. L.
Published: September 2005

1.Eight groups of weanling rats were maintained for 60 days on diets containing calcium and phosphorus in the ratio 0·1 at four different levels of mineral, namely 0·08, 0·12, 0·23 and 0·32% Ca, and in the presence and absence of added ergocalciferol.

2. Provision of vitamin D increased final body-weight, whereas at the highest mineral intake body-weight was reduced.

3. At each level of dietary mineral the serum Ca concentration was raised by vitamin D, whilst the serum P concentration was lowered except when the mineral intake was lowest.

4. With increasing mineral intake the serum Ca increased until at the highest intake it declined. Serum P was increased only at the highest mineral intake.

5. Measurements were made of bone weights, ash content and volume. Provision of vitamin D increased the fresh weight of bone at all levels of dietary mineral, and the dry weight and ash content were increased except at the lowest level of mineral intake. In general, the higher the dietary mineral the greater was the bone weight and its ash content.

6. The presence of vitamin D resulted in an increase in tooth mass and ash content at each level of mineral intake. Tooth mass and ash increased with increasing dietary mineral except at the highest level when there was a decline.

7. At the lower levels of mineral intake the ratio of tooth mass to bone mass was greater than at the higher levels of intake.

8. Histological examination of the bones revealed no increase in the width of the epiphyseal cartilage in any group. In the group with the lowest levels of Ca and P without vitamin D (0·08% Ca, 0·8% P) the shafts of the femurs appeared thinner and porotic, and the trabeculae were thin; in the group fed the same diets supplemented with vitamin D the shafts were even thinner but less porotic; in all other groups the histological appearance of the bone was within normal limits.

9. Changes in the appearance of the dentine were demonstrated in all groups.
The effect of acid peptic digestion on free and tissue-bound cobalamins
Authors: Adams J. F. , Kennedy Elizabeth H. , Thomson J. , Williamson J.
Published: September 2005

1. The extent of liberation of radioactive cobalamin in rabbit tissues incubated with acid and pepsin was evaluated by bag dialysis.

2. Between a half and two-thirds of the cobalamin—probably hydroxocobalamin—was dialysable after acid pepsin treatment and this process may be a factor in the absorption of cobalamins from foods.

3. Studies of pure cobalamin solutions at different concentrations gave apparently anomalous results, which may have been due to the adherence of cobalamin to the dialysis membrane. Measurement of the amount adherent to the membrane is an important factor in dialysis studies with cobalamins.
The protein quality of meat meals as assayed with the rat and with Streptococcus zymogenes
Authors: Ferrando R. , Henry Nicole , Larvor P.
Published: September 2005

1. Seven samples of meat meal have been assayed with rats by the protein efficiency ratio (PER) test and with Streptococcus zymogenes by Ford's (1960) ‘relative nutritive value’ (RNV) test.

2. A correlation coefficient of r = + 0·895 was obtained for the results from the two series of tests.
The biological activity of retinoic acid in the domestic fowl and the effects of vitamin A deficiency on the chick embryo
Authors: Thampson J. N. , Howell J. McC. , Pitt G. A. J. , McLaughlin Catherine I.
Published: September 2005

1. Male and female chickens were reared from hatching on vitamin A-free diets, either unsupplemented or containing retinoic acid (vitamin A acid), methyl retinoate or retinyl acetate (vitamin A acetate). The birds given retinyl acetate grew well and had a normal appearance, but those given the unsupplemented diet died before 4 weeks of age after developing typical signs of avitaminosis A. The birds given retinoic acid or methyl retinoate did not show overt signs of vitamin A deficiency or other abnormalities except for a progressive failure of vision. Minimal histological changes were found in their retinas, and their vision was rapidly restored after feeding with retinyl acetate.

2. The cocks maintained with retinoic acid or methyl retinoate had normal testes and the hens laid eggs at a normal rate, but although their eggs could be obtained fertile the development of the embryo became abnormal after 2 days incubation and it always died. The development of the embryos could be stimulated and sometimes restored to normal by injection of various forms of vitamin A into the eggs before incubation, or by previous administration of retinyl acetate to the hens.

3. It is concluded that feeding retinoic acid as the sole source of vitamin A enables the hen to produce eggs that lack vitamin A but are otherwise normal, thus permitting the demonstration of a hitherto undescribed requirement of the early chick embryo for vitamin A.

4. The toxicity of vitamin A derivatives to chick embryos was investigated; injected retinoic acid was found to be extremely toxic.
The effect of protein deficiency upon peritoneal healing and peritoneal wound contraction in the rat
Authors: Mott T. J. , Ashby E. C. , Flannery B. P. , Ellis H.
Published: September 2005

1. Adult rats were maintained on a protein-deficient diet for 6 weeks following which laparotomy was performed and peritoneal wounds of standard size were constructed,

2. The diet resulted in a progressive weight loss and a fall in plasma protein. Tissue protein, expressed as percentage protein in dried voluntary muscle, did not fall significantly.

3. Following laparotomy the rats were killed in groups on successive days and the peritoneal wounds were removed for measurement of area and for histological examination.

4. There was no apparent difference between control and protein-deficient animals in the rate or extent of peritoneal wound contraction although there was histological evidence of delay of collagen formation in the protein-deficient animals. This supports the theory that collagen formation is not a function of wound contraction.
The effect of change from low-roughage to high-roughage diets on rumen fermentation, blood composition and milk fat secretion in the cow
Authors: Storry J. E. , Sutton J. D.
Published: September 2005

1. Changing cows from a diet with low hay and high flaked maize content, which depressed milk fat secretion, to a high-roughage diet resulted in increased milk fat secretion and in changes in the pattern of rumen fermentation and in the composition of the blood plasma.

2. During the 1st week following the change in diet the proportions of propionic and valeric acids in the rumen decreased and the proportion of acetic acid increased. These changes in rumen volatile fatty acids were associated with decreases in the concentration of lactic acid, increases in pH and increases in the rate of breakdown of cotton threads in the ventral sac of the rumen. After 1 week, only minor fluctuations in the proportions of volatile fatty acids occurred from day to day.

3. The percentage of fat in the milk increased over a period of 3 weeks following the change in diet and, with the exception of linoleic acid which decreased, the yields of all fatty acids in milk progressively increased over this period. The increase in yield of oleic acid was relatively much smaller than the increases in yield of saturated acids.

4. The concentrations in blood plasma of acetic acid and β-hydroxybutyric acid increased in two cows and, in all cows, saturated triglyceride fatty acids increased, whereas the concentrations of the unsaturated triglyceride fatty acids decreased, during the 1st week after change to the high-roughage diet. The recovery in milk fat secretion is discussed in relation to the observed changes in rumen fermentation and blood composition.
Distribution of polyethylene glycol in suspensions of food particles, especially sugar-beet pulp and dried grass pellets
Authors: Czerkawski J. W. , Breckenridge Grace
Published: September 2005

1. It was shown that when polyethylene glycol (PEG) was added to suspensions of food particles in aqueous buffer solutions, its distribution in the total water of the food mass was not uniform. The marker was excluded from a large proportion of the water contained in the swollen food particles. This effect was independent of temperature, pH, and, within limits, the time of contact.

2. It was shown that the theoretical concentration (C0), assuming a uniform distribution of marker, could be calculated from the observed concentration (C), weight of food in suspension (W) and the total volume of water (V), using the equation C = C0(I + b[W/V]) where b is constant for any given food. The addition of PEG solution to dry food particles gave a smaller effect.

3. The distribution of PEG was usually, but not invariably, more uniform in a suspension of roughages than in a suspension of concentrates.

4. Possible implications of these findings with respect to marker experiments with PEG are discussed.
The effect of diet composition and level of feeding on digestion in the stomach and intestines of sheep
Authors: NICHOLSON J. W. G. , SUTTON J. D.
Published: September 2005

1. Four wether sheep, each fitted with re-entrant duodenal cannulas and a rumen cannula, were used to determine the relative quantitative importance of digestion in the stomach compared with that in the intestines when diets of low (HM1) and high starch (CM1) content were fed at 0.9 times maintenance and when the high-starch diet was fed at 1.7 (CM2) and 2.3 (CM3) times maintenance. Paper, impregnated with chromic oxide, and polyethylene glycol (PEG) were administered.

2. An apparatus is described which allowed one operator to collect, record, sample and return the duodenal digesta from two sheep simultaneously.

3. Total digestion was determined by faeces collections over 7–10 day periods, and digestion in the stomach by measuring the total flow of digesta from the abomasum to the duodenum over two 24 h periods with two or three sheep on each ration. Flow values were adjusted to give 100% recovery of chromic oxide.

4. The recoveries of chromic oxide and PEG were similar and it was concluded that either marker was satisfactory for adjusting 24 h flow values. Disadvantages of using PEG are discussed.

5. There was relatively little difference between rations HM1 and CM1 in the proportion of digestible organic matter and energy digested in the stomach. Only 57.1% of the total dry-matter digestion occurred in the stomach for ration HM1 compared with 65.0% for ration CM1 reflecting a smaller net gain in ash for ration CM1. Doubling the level of intake (ration CM2) resulted in a decrease in the proportion of digestible dry matter, organic matter and energy digested in the stomach. When the level was increased still further with ration CM3, the proportion continued to decrease with one sheep but increased with the other.

6. All but 5–11% of the digestible starch (measured as α-linked glucose polymer) was fermented in the stomach, the lowest proportion being with ration HM1.

7. The amount of nitrogen reaching the duodenum was approximately equal to the amount ingested with rations HM1 and CM1 but considerably greater with the other two rations. All rations contained approximately 2% nitrogen.

8. Calculation of the estimated loss of energy as methane and heat of fermentation suggested that 50–54% of the digestible energy was absorbed as volatile fatty acids.
An estimate of the nutrients utilized for live-weight gain by Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M.
Published: September 2005

1. One hundred and seven fine-wool Merino wethers and non-pregnant ewes varying in age from newly born to 110 months and in live weight from 1.7 to 55.1 kg were slaughtered and minced.

2. The nitrogen, fat, ash, calcium, phosphorus, sodium and potassium contents of the mince were determined. Energy content was estimated from the contents of fat and fat-free organic matter.

3. Weighted regression relationships were calculated between the energy, N, Ca, P, Na and K contents of the sheep, and age, live weight and (age x live weight). The relationships were differentiated with respect to age and live weight, and the rates of nutrient deposition at different rates of live-weight gain, and for sheep differing in age and live weight were calculated.

4. The rates of nutrient deposition were compared with those estimated by the Agricultural Research Council (1965) and by Mitchell (1962). and were in general lower in energy content and higher in ash constituents per unit live-weight gain.
Influence of the diet on the composition of faecal bile acids in rats
Authors: Gustafsson B. E. , Norman A.
Published: September 2005

1. [24-14C]cholic acid was given orally to rats receiving three different diets, a semi-synthetic diet (D7) with and without 20% cellulose, and a commercial, pelleted diet. The labelled metabolites excreted in the faeces in the 8 days following administration of the labelled cholic acid were chromatographically separated, and tentatively identified by means of thin-layer chromatography.

2. In all three dietary groups the faecal bile acids mainly consisted of unconjugated and 7α-dehydroxylated metabolites. In rats receiving pellets or diet D7with cellulcse, there was a higher percentage of monohydroxy-monoketo-cholanoic acids than in those receiving diet D7alone. Dihydroxy-cholanoic acids, present in approximately the same ratio as were the 3α- and 3β-hydroxy isomers, were excreted by all the rats in the three dietary groups.
Effect of antibiotics on intestinal absorption in mice
Authors: Madge David S.
Published: September 2005

1. The effects of dietary antibiotics (penicillin, neomycin or terramycin) on the absorption of D-glucose, D-galactose, L-arginine or L-histidine by the mouse were investigated by using sacs of entire everted ileum.

2. Compared with the controls, there was generally an increased absorption of all these solutes. Tissue uptake of the solutes remained unaltered. The inward movement of water into the sacs was increased but was generally independent of solute transport.

3. The body-weight decreased slightly and caecal weight increased with penicillin only. The weight of the small intestine decreased with the different antibiotics, and the gut wall became thinner. Faecal fat increased slightly, but not significantly, with neomycin only. Water intake decreased with the different antibiotics.
Production and absorption of ammonia in the sheep's stomach
Authors: Pilgrim A. F. , Gray F. V. , Belling G. B.
Published: September 2005

1. When rumen fluid together with small quantities of (15NH4)2S04[1-14C]sodium acetate and polyethylene glycol (PEG) was introduced into the emptied rumen of a sheep, no significan change occurred in the ratio15N:14C during a period of 30–60 min. The ratio15N:PEG, however, declined by 22–53%. when(15NH4)2SO4, [1-14C]sodium acetate and PEG were introduced into the normal rumen of a sheep fed on lucerne hay the ratio15N:14C in the whole rumen contents showed no appreciable change in a period of 1 h, but the ratio15N:PEG declined by 25–41%. It was therefore concluded that the rate constants for removal of ammonia nitrogen (NH2-N) and volatile fatty acid (VFA) from the rumen were very nearly equal.

2. In sheep fed at 1 h intervals on lucerne hay chaff or lucerne hay pellets VFA production, VFA and NH3-N concentration in the rumen fluid and the volume of fluid passed from the rumen to the omasum were determined. From these results and the information previously gained on the relative rates of removal of NH2-N and VFA from the rumen, the amounts of NH3-N produced in the rumen and absorbed there or at lower levels of the digestive tract were calculated to be equivalent to 23–27% of the dietary N in lucerne hay chaff and 17% of that in lucerne hay pellets; 59–66% of the NH3-N was absorbed from the rumen and the remainder passed to the omasum.
Effect of riboflavine deficiency on nucleic acid metabolism of liver in the rat
Authors: Chatterjee Ajay K. , Roy Amitabha D. , Ghosh B. B.
Published: September 2005

1. The effect of riboflavine deficiency on liver ribonuclease activity, RNA and DNA content, and32P incorporation into RNA and DNA has been studied in rats maintained on a 16% protein diet, a protein-free diet and on a protein-free diet subsequently replaced with a 40% protein diet.

2. Rats maintained on a riboflavine-deficient diet for 45 days showed decreased incorporation of32P into liver RNA but no effect on the RNA content of liver. The concentration of DNA in liver and33P incorporation into it remained unaffected. After a deficiency period of 70 days, both the RNA and DNA contents of liver were found to be decreased. When the riboflavine-deficient or control rats were given the protein diet for 30 days and then a proteinfree diet for 15 days, the RNA content of their livers decreased, while the liver DNA content was increased. Repletion with a 40% protein diet restored the RNA and DNA content in both control and riboflavine-deficient rats.

3. Liver ribonuclease activity was decreased after a deficiency period of 45 days, whereas it was increased after a deficiency period of 70 days.

4. A correlation between liver RNA level and liver ribonuclease activity in riboflavine deficiency is suggested.
Nucleic acid metabolism in the ruminant
Authors: Mcallan A. B. , Smith R. H.
Published: September 2005

1. Procedures, based on those of Schmidt & Thannhauser (1945) and Schneider (1945), for the extraction and estimation of nucleic acids in bovine digesta were examined in detail.

2. Final methods which were suitable for routine determination of RNA and DNA were essentially as follows. Digesta samples were extracted in the cold, first with a solution of trichloroacetic acid in ethanol, then with aqueous trichloroacetic acid solution and finally with lipid solvents. The dried residue was hydrolysed with alkali, purified by passage through a Dowex resin, and the RNA, in the form of mononucleotides, determined by U.V. absorption. DNA was determined separately in hot perchloric acid extracts of the original dried residue by colorimetric estimation of the deoxyribose content.