bluuebunny/crossref_metadata_2025 huggingface dataset:
On the calculation of heat production from open-circuit calorimetric measurements
Authors: McLean J. A.
Published: September 2005

1. The equation used for calculating heat production of ruminant animals is expressed in a new form, convenient for application to open-circuit calorimetry.

2. It is shown that in open-circuit calorimetry the possible error involved in making the assumption that respiratory quotient is equal to unity is small compared with the possible error involved in neglecting methane production.

3. In open-circuit calorimetry heat production can be predicted with accuracy to within ± 2% solely from the measurement of oxygen concentration and ventilation rate.
The effects of environmental temperature and plane of nutrition on heat loss, energy retention and deposition of protein and fat in groups of growing pigs
Authors: Verstegen M. W. A. , Close W. H. , Start I. B. , Mount L. E.
Published: September 2005

1. Eight groups each of four castrated male pigs, 25–30 kg initial body-weight, were kept for periods of 3 weeks in a calorimeter equipped as a pig pen and maintained at either 8° or 20°. At each temperature two feeding levels (g food/kg body-weight per d) were used, 45 and 52 at 8°, and 39 and 45 at 20°. Metabolizable energy, heat loss and nitrogen balance were measured.

2. Heat loss was higher at 8° than at 20° and was independent of plane of nutrition, whereas at 20° the higher heat loss occurred at the higher plane of nutrition. Energy retention depended on both temperature and feeding level, and was highest at the 52 g feeding level at 8°.

3. N retention was not influenced by environmental temperature but varied with plane of nutrition (correlation coefficient = 0·94), the increase being 9·98 (± 0·8) mg N per g food increase. The correlation coefficient between N retention and body-weight gain was also 0·94; body-weight gain was correlated with N retention rather than with fat deposition. Fat gain was reduced at the lower feeding levels and at the lower environmental temperature at the feeding level of 45 g/kg.

4. The partial efficiency of energy retention at 20° was 66·5%. From this efficiency the maintenance requirement (at zero energy retention) at 20° was calculated to be 418 kJ/kg0·75. At 8° the partial efficiency of energy retention was 99·4%.
Influence of meal-feeding on some of the effects of dietary carbohydrate deficiency in rats
Authors: Akrabawi S. S. , Salji J. P.
Published: September 2005

1. Experiments were conducted to investigate the effects of feeding rats on a diet based on a mixture of maize oil fatty acids as the only source of non-protein energy (fatty acid diet) and the influence on these effects of giving such a diet in a single daily meal lasting 2 h.

2. In comparison with a triglyceride diet in which the non-protein energy was in the form of maize oil, feedingad lib.with the fatty acid diet produced no significant changes in body-weight gain, plasma glucose and plasma ketones concentrations, liver glycogen concentration and protein efficiency ratio.

3. In comparison with the triglyceride diet, meal-feeding with the fatty acid diet produced significantly lower body-weight gain and protein efficiency ratio; moreover, it significantly lowered plasma glucose and liver glycogen concentrations.

4. Rats meal-fed on the fatty acid diet synthesized glucose from protein, as evidenced by the significantly higher liver glycogen concentration detected 6 h after the meal had been eaten, but the increase was significantly lower than in the animals fed on the triglyceride diet. Also, 6 h after the meal had been eaten, the amount of meal remaining in the stomach of rats meal-fed on the fatty acid diet was significantly higher than in those fed on the triglyceride diet.
Iron Metabolism in the veal calf
Authors: Bremner I. , Dalgarno A. C.
Published: September 2005

1. The iron requirements of eighteen Ayrshire bull calves reared on fat-supplemented skim milk for 14 weeks fromc.16 d of age have been studied. There was a highly significant relationship between dietary Fe intake (10, 40 and 100 mg/kg dry diet) and blood haemoglobin concentration, packed cell volume and plasma Fe concentration.

2. A microcytic normochromic anaemia developed in the calves given a diet containing 10 mg Fe/kg diet, but not in the other calves.

3. Plasma Fe concentrations increased to > 5 μg Fe/ml in calves receiving 100 mg Fe/kg diet but there were no effects of Fe treatment on plasma Fe-binding capacity, which rose from 4·9 to 8·4 μg Fe/ml during the experiment. Saturation of plasma transferrin was only 3% in the Fe-deficient calves.

4. There were some significant effects of Fe treatment on tissue concentrations of Fe and cytochromec.

5. Dietary supplementation with 5 mg copper/kg dry diet had little effect on the growth or haematological status of the calves, although there were significant Cu × Fe interactions for mean corpuscular haemoglobin and mean corpuscular volume. There was no evidence of Cu deficiency in the calves, as measured by blood and liver Cu concentrations and by ceruloplasmin and cytochrome oxidase activities.
The effects of supplements varying in carotene and calcium content on the physical, biochemical and skeletal status of preschool children
Authors: Rajalakshmi R. , Sail S. S. , Shah D. G. , Ambady S. K.
Published: September 2005

1. Studies were made of the effects of food supplements varying in carotene and calcium content on the nutritional status of children aged 2–6 years. Three groups of children who were given a dietary supplement for 6 months and a fourth group of controls were investigated. The supplement was the fermented food dhokla, made of wheat and Bengal gram (Cicer arietinumL.) (group 1) or dhokla with added greens (group 2) or dhokla with added greens (fenugreek) and lime powder (a mixture of CaO, Ca(OH)2and CaCO3) (group 3).

2. Studies were made of the effects of the above supplements on height, weight, skeletal status as judged by increments in bone age and cortical thickness of the second metacarpal bone and femur, and biochemical status as judged by the composition of blood (haemoglobin), serum (protein, albumin and vitamin A) and urine (creatinine, nitrogen, thiamin, riboflavin and vitamin C).

3. All the groups given the supplement were found to be superior to the controls as judged by these criteria. The size of the increment generally increased from group 1 to group 3 and the differences were most marked for bone age and cortical thickness.

4. The results suggested that (a) calcium deficiency is a crucial factor in the aetiology of skeletal retardation in young children and (b) that at the levels of calcium (560 mg) and phosphorus (980 mg) consumed, and with liberal exposure to sunlight, a dietary supply of vitamin D may not be a crucial factor for skeletal development in young children.
The effect of frequency of feeding on the flow and composition of duodenal digesta in sheep given straw-based diets
Authors: Thompson F.
Published: September 2005

1. The effect of feeding sheep at two different frequencies (once hourly and once daily) on the flow of digesta, dry matter, and starch to the duodenum was assessed by fitting sheep with re-entrant cannulas in the proximal duodenum and giving them, at each feeding frequency, rations differing in the particle size of the roughage component.

2. Frequent feeding resulted in a less variable daily pattern of flow of digesta and a significant increase (P < 0·01) in the total daily volume flowing to the duodenum. Altering the particle size of the ration did not affect the flow of digesta at either feeding frequency.

3. The pattern of flow of dry matter followed very closely that of the flow of digesta, but there was a significant (P < 0·001) interaction between feeding frequency and particle size of the ration which affected the flow of starch to the duodenum. As a result, more starch entered the duodenum when both the frequency of feeding and the particle size of the ration were increased.
Importance of palatability in determining the feed intake of sheep offered chopped and pelleted hay
Authors: Van Niekerk A. I. , Greenhalgh J. F. D. , Reid G. W.
Published: September 2005

1. In the first of three experiments four sheep received chopped (C) and pelleted (P) hay by mouth (m) or rumen fistula (f) in the four combinations shown below. Feed eaten by mouth was offered ad lib. from 09·15 to 16·00 hours; feed was given by fistula at 09·00 hours in amounts equal to half of total intake (i.e. by mouth and by fistula) on the previous day. Daily dry-matter intake (g/kg metabolic live weight, W0·75) was as follows: treatment CmCf, 51·5; CmPf, 74·5; PmCf, 57·8; PmPf, 85·7. The corresponding dry-matter digestibility coefficients were 0·59, 0·56, 0·57 and 0·53.

2. The intention was that the difference in intake between CmPf and PmCf should provide a measure of palatability, since the animals digested the same composite diet but ate different components of it. For the comparison to be valid the two treatments had to promote equal rates of digestion, but measurements of rumen fill and of rate of passage of digesta suggested that Cf was digested more slowly than Cm.

3. In Expt 2, each form of hay was given entirely by mouth or partly by fistula. Daily dry-matter intake (g/kg W0·75) was as follows: Cm, 45·5; CmCf, 42·4; Pm, 80·4; PmPf, 79·2. In this experiment there was less evidence of Cf being digested more slowly and hence depressing intake.

4. The conclusion drawn from these two experiments is that fistula feeding in its present form is not a suitable technique for measuring the relative palatability of feeds differing considerably in physical structure. However, the technique might be improved if food given by rumen fistula to one animal was previously masticated by, and collected from the oesophageal fistula of, a second animal.

5. In Expt 3, the effects of sudden changes from a composite diet to either C or P, or from C to P or vice versa were measured in sheep receiving food by mouth only. The patterns of intake suggested that total intake might be partially determined by feed palatability.
Allantoin excretion in the rat
Authors: Pak Nelly , Donoso G. , Tagle Marfa A.
Published: September 2005

1. Allantoin excretion was determined in forty-four rats; twenty-four rats were 21 d old and twenty were 90 d old. The animals receivedad lib.for 11 d diets that contained varying amounts of protein from casein and from gluten. Urinary allantoin excretion was determined during the last 3 d of the period.

2. The amount of allantoin excreted in both young and adult animals was independent of the diet consumed and was related to metabolic weight (W in kg0·73) and rate of gain in body-weight (ΔW in g/d), also to body nitrogen content (N in g0·73) and rate of gain in body N (ΔN in mg/d), according to the equations allantoin (mg/d) = 60·54 W0·73+ 2·12ΔW, and allantoin (mg/d) = 5·45 N0·73+ 0·071ΔN.
Experimental protein-energy malnutrition in baby baboons
Authors: Patrick R. S. , Mackay A. M. , Coward Dorothy G. , Whitehead R. G.
Published: September 2005

1. Liver biopsies were performed through laparotomy wounds in six baby baboons during the development of a kwashiorkor-like illness induced by low-protein, high-carbohydrate diets similar to those consumed by many East African children. Up to six biopsies have been performed successfully in one animal within a period of 1 year. This material has been studied by light and electron microscopy.

2. A similar study was carried out in two healthy animals fed on an adequate diet. A description is given of liver ultrastructure in normal baby baboons, based on examination of these biopsies.

3. The hepatocytes of the malnourished animals contained excessive amounts of glycogen and showed a reduction in rough and smooth endoplasmic reticulum. Even at the height of an illness indistinguishable clinically from marasmic kwashiorkor, there was no excess of liver fat except in those animals whose diet contained sucrose. This may have been the result of stimulation of hepatic triglyceride synthesis by fructose.

4. In no specimen from the experimental group were there signs of serious progressive and irreversible liver cell damage which might have been expected if liver dysfunction were an important component of kwashiorkor.

5. Biopsies performed in one malnourished animal during recovery showed a return of liver ultrastructure to normal.
Studies on the composition of food
Authors: Knight R. A. , Christie A. A. , Orton C. R. , Robertson Jean
Published: September 2005

1. Loaves of conventional white bread and of bread made by the Chorleywood Bread Process (CBP) were bought from bakers’shops in Britain over a 10-month period and were bulked to give samples representative of each type of bread produced for consumption in the country as a whole. These were analysed for moisture, protein and amino acids, fats and fatty acids, carbohydrate (by difference), sodium, potassium, iron, thiamin, riboflavin, total and available nicotinic acid, vitamin B6, and free folic acid.

2. There were no great differences between the nutrient contents of the two types of bread. The mean moisture contents differed by only 5 g/kg but a variation was found between some selected nutrients in paired loaves of the same type. CBP bread could not be distinguished from conventional bread in its content of fat, ash, calcium, sodium, potassium, thiamin, total and available nicotinic acid and vitamin B6. The content of riboflavin was slightly higher, and of protein and carbohydrate slightly lower in CBP bread than in conventional bread. Differences in fatty acid composition of the two types of bread and in their content of total sulphur-containing amino acids were slight.
The energy cost of standing and lying in adult cattle
Authors: Vercoe J. E.
Published: September 2005

1. Gas exchanges on eleven steers with a mean weight of 273 kg, fasted for 96 h, were obtained over time intervals of 5·76 min in a confinement-type respiration chamber, when the animals were either standing of lying, or engaged in the act of standing or lying.

2. In all, 751 observations were analysed and these included twenty-four associated with the act of standing, forty-eight with the act of lying and the remainder approximately equally divided between standing and lying.

3. When lying, the heat production was 72·2 kJ (17·2 kcal)/kg fasted weight per 24 h and when standing, 85·7 kJ (20·5 kcal)/kg fasted weight per 24 h; an increase when standing of 18·7%. The double act of standing and lying was associated with an increase in heat production of 11·3 kJ (2·7 kcal)/100 kg fasted weight and while the act of standing was energetically more costly than the act of lying, the difference between the two was not significant.

4. The results are discussed in relation to earlier estimates.

5. Confinement-type respiration chambers of the type described by Turner & Thornton (1966), which have a fast response time and monitor the changes in chamber air frequently, are ideally suited to the detection of short-term changes in metabolic rate such as occur with changes in posture.
Feeding trials with lysine- and threonine-fortified rice
Authors: Pereira Sheila M. , Jones Sheila , Jesudian G. , Begum Almas
Published: September 2005

1. The effect of fortification of rice with lysine and threonine (at levels of 2 g and 1 g/kg respectively) on the growth of preschool children was assessed in feeding trials at a residential orphanage and a village day-care centre.

2. In the first trial, the children at the orphanage were offered a diet based on rice, to provide the recommended allowances of protein and energy. For the children in the experimental group, the rice was fortified with lysine and threonine for the 6 months of the trial.

3. Statistically significant differences in final height and weight were not observed between the children in the control and in the experimental groups.

4. The children in the control group grew at optimal rates.

5. In the second trial, the diet provided approximately 80% of the daily energy and protein intakes from rice and was offered ab lib. at four meals a day in the orphanage and at three meals a day in the day-care centre.

6. In the orphanage, most children are enough of this high-bulk diet to ensure an adequate energy intake. The children given the fortified rice and those who served as controls grew at very satisfactory rates.

7. At the village centre most of the children were unable to eat enough food to achieve an adequate intake of energy. The children given the fortified rice did not grow taller than those given unfortified rice.

8. Fortification of rice with lysine and threonine did not improve rates of growth of preschool children.
Carbohydrases of the bovine small intestine
Authors: Coombe N. B. , Siddons R. C.
Published: September 2005

1. Homogenates of mucosa from bovine small intestine hydrolysed isomaltose slowly.

2. The enzyme exhibited maximum activity at pH 6·0–6·2 and possessed aKmvalue of 9·1 mM.

3. Isomaltase and maltase activities showed a similar pattern of distribution along the small intestine; activity was higher in the jejunum than in the ileum, the lowest activity being in the duodenum.

4. Neither activity changed markedly with age.

5. The disaccharidase activities (maltase, isomaltase, trehalase, lactase and cellobiase) of the small intestine were found in the sediment when homogenates were centrifuged at 100000g.

6. Heat inactivation studies suggested that there was one enzyme which hydrolysed trehalose, one enzyme which hydrolysed isomaltose, one enzyme which hydrolysed lactose and cellobiose and that the hydrolysis of maltose was brought about by more than one enzyme.
A pilot study of vitamin B12 in the treatment of tiredness
Authors: Ellis F. R. , Nasser S.
Published: September 2005

1. Twenty-eight subjects complaining of tiredness completed a double-blind cross-over trial of injections of hydroxocobalamin (5 mg twice weekly for 2 weeks) followed by a rest period of 2 weeks and then a similar course of matching placebo injections. Symptoms were assessed by a daily self-rating method and included appetite, mood, energy, sleep and general feeling of well-being.

2. Those subjects who received the placebo in the first 2-week period showed a favourable response to hydroxocobalamin in the second period in all measurements made. The response achieved statistical significance (P = 0·006) in respect of general well-being; ‘happiness’ achieved a value of P = 0·032. Subjects who received hydroxocobalamin in the first period showed no difference between responses to active and placebo treatments, which suggests that the effects of the vitamin may persist for a period of at least 4 weeks.
The chemical nature of the bound nicotinic acid of wheat bran: studies of nicotinic acid-containing macromolecules
Authors: Mason J. B. , Gibson Norah , Kodicek E.
Published: September 2005

1. Preparations of bound nicotinic acid obtained from wheat bran by an acid extraction procedure (‘niacytin preparations’) were resolved into several nicotinic acid-containing components.

2. Extraction of wheat bran under neutral conditions yielded 62% of the bound nicotinic acid in solution; of this 90% was non-diffusible. Methods were developed which gave high yields of ‘non-diffusible nicotinic acid’ preparations.

3. The bound nicotinic acid in the latter preparation was linked to macromolecules of mol. wt about 1500 to 17000 daltons, approximately 60% of which were polysaccharide and 40% peptide or glycopeptide in character.

4.o-Aminophenol, and ferulic and sinapic acids, are also contained in macromolecules in wheat bran, but are not directly associated with the bound nicotinic acid.

5. The significance of these results in explaining the nutritional unavailability of bound nicotinic acid is discussed.
Absorption of glucose and galactose and digestion and absorption of lactose by the preruminant calf
Authors: Coombe N. B. , Smith R. H.
Published: September 2005

1. Uptakes of glucose, galactose, glucose+galactose and lactose from the intestine were studied in preruminant calves fitted with cannulas in the proximal small intestine, and in slaughtered calves. Responses in concentration of blood sugar to the presence of sugar in the small intestine were also investigated.

2. Glucose and galactose were absorbed at about the same rate when present in the intestine separately. The rate for each sugar approached a maximum with increasing sugar concentration in the lumen.

3. When glucose and galactose were present in the intestine together, the rate of galactose absorption was greatly depressed; that of glucose was virtually unaffected. Consequently, when calves were fed with mixtures of glucose and galactose, absorption of galactose in the proximal intestine, where the relative concentration of glucose was high, was depressed. In the more distal intestine where the glucose concentration had fallen, absorption of galactose was rapid. Both sugars were absorbed efficiently during their passage through the whole small intestine, but at different sites.

4. Galactose appeared in the blood after galactose alone was given but conversion of some galactose into glucose always occurred. Results of experiments in which [14C]galactose, together with glucose, was infused into the duodenum of a calf suggested that under these conditions the rate of galactose absorption was depressed to such an extent that nearly all the galactose entering the blood was converted into glucose.

5. Lactose hydrolysis occurred much more rapidly than the absorption of its constituent monosaccharides. Thus, after lactose was fed to the calves, glucose and galactose accumulated in the lumen of the proximal small intestine. A similar accumulation occurred when lactose was infused into loops of small intestine. The rate-limiting step in the total absorption of lactose in the young calf was not, therefore, the hydrolysis stage, as reported for other mammals. The absorption of the released glucose and galactose occurred in a manner similar to that described above for mixtures of glucose and galactose.
Circulating ‘big’ insulin in protein-energy malnutrition
Authors: Becker Dorothy J. , Murray Penelope J. , Hansen J. D. L. , Pimstone B. L.
Published: September 2005

1. The ‘big’ insulin content of the serums from ten children with protein–energy malnutrition was estimated before, during and after 3–6 weeks of treatment. The values for immunoreactive insulin (IRI) after intravenous injections of glucose were almost normal, with one exception, although tolerance was impaired. In addition, total body potassium content (TBK) was measured for three of the children on each test day.

2. In nine of twenty-three estimations ‘big’ insulin content was slightly more than 20% of the total IRI. However, there was a wide fluctuation in the values and no change was noted after treatment.

3. The amount of ‘big’ insulin did not correlate with either the magnitude of insulin secretion, the insulin:glucose ratio or TBK. There was a barely significant negative correlation between ‘big’ insulin content and degree of glucose intolerance, with some individual exceptions.
The effect of inhibitors of methane production of fermentation pattern and stoichiometry in vitro using rumen contents from sheep given molasses
Authors: Marty* R. J. , Demeyer D. I.
Published: September 2005

1. The fermentation in the presence of four known methane inhibitors was investigated in rumen contents from sheep given molassesad lib.and showing two different fermentation patterns.

2. The average hydrogen recoveries obtained with the high butyrate and high propionate patterns were 93 ± 2 and 95 ± 2% respectively.

3. Sodium sulphite, chloral hydrate and a hemiacetal of chloral and starch (HCS) all inhibited methane production, and were associated with an accumulation of hydrogen and lactate in rumen contents showing the high butyrate fermentation pattern. Propionate production was slightly stimulated.

4. In rumen contents showing the high propionate fermentation pattern, linseed-oil hydrolysate depressed methane production at high levels only, increased hydrogen and lactate production but depressed all other products, and HCS depressed methane production and slightly increased propionate production.

5. Low hydrogen recoveries in the presence of the inhibitors were probably associated with the utilization of metabolic hydrogen in reactions not accounted for in the scheme under investigation.
A preliminary study on the action of cassava on thyroid iodine metabolism in rats
Authors: Van Der velden M , Kinthaert J , Orts S. , Ermans A. M
Published: September 2005

1. The ingestion of cassava (Manihot esculenta Crantz) by rats increased the plasma thiocyanate concentration and reduced the thyroid iodine content and the plasma protein-bound iodine.

2. Administration of increasing doses of thiocyanate raised the plasma thiocyanate concentration and reduced the thyroid iodine content and the plasma protein-bound iodine.

3. In producing these effects, the daily ingestion of 10 g cassava root containing 1·6 mg cyanide was approximately equivalent to a daily intake of about 1–2 mg thiocyanate.

4. These results suggest that the antithyroid action of cassava is the result of the production of thiocyanate by the rat from cyanide arising from the cyanogenic glucosides present in this food.
Lactose aborption kinetics in Zambian African subjects
Authors: Cook G. C. , Asp N.-G. , Dahlqvist A.
Published: September 2005

1. Using a double-lumen tube perfusion system, solutions of lactose (50, 125 and 250 mmol/l) were introduced into the upper jejunum of six Zambian African subjects. By reference to a non-absorbable marker, polyethylene glycol, mol. wt 4000, the rates of absorption of lactose from each solution were calculated for a 300 mm jejunal segment.

2. In three subjects total lactase activity of the jejunal mucosa and brush-border lactase and other disaccharidase activities were estimated. The jejunal total and brush-border lactase activities were low. Jejunal morphology was normal for African subjects.

3. All subjects suffered abdominal colic and diarrhoea during and after the lactose perfusions. The kinetic curves for lactose were very shallow, and with all perfused solutions, there was a net movement of water into the jejunal lumen. The limited number of subjects, and the low and narrow range of enzyme activity, did not permit correlation between lactose absorption rate and lactase activity.

4. In Zambian African subjects with adult hypolactasia, the jejunal mucosa absorbs a very small proportion of the perfused lactose.
Some factors controlling food intake by zinc-deficient rats
Authors: Chesters J. K. , Will Marie
Published: September 2005

1. Male hooded Lister rats given a diet containing 40 mg zinc/kg were described as Zn-adequate. Other rats were subsequently given diets containing less than 1 mg Zn/kg. After a period of approximately 5 d these animals ceased to grow and were described as Zn-deficient.

2. Zn-deficient rats offered ad lib. a Zn-deficient diet containing 200 g egg albumen/kg ate only 55% of the weight eaten by Zn-adequate rats given a similar diet supplemented with Zn. The intake of the deficient rats increased when the metabolizable energy content of the diet was decreased and also when the environmental temperature was lowered.

3. Zn-deficient rats offered Zn-deficient diets containing 200 g egg albumen/kg showed a high day-to-day variability of intake. When the albumen content was raised to 400 g/kg, neither the mean food intake of the rats nor the variability of food intake changed, but with diets containing only 50 g albumen/kg the quantity eaten increased and the variability of food intake decreased. Results obtained when the low-protein diet was supplemented with essential and non-essential amino acids indicated that increased variability of intake was associated with the essential amino acid content of the diet. The effect on variability of intake was greatest when the supplements contained methionine, phenylalanine, threonine and tryptophan; addition of this group of amino acids to a Zn-supplemented, low-protein diet produced the largest increase in the growth rate of Zn-adequate rats.

4. When the food intake of the rats was examined for periods of 2 h throughtout the day, the Zn-deficient rats were found to eat on fewer occasions than the control rats. However, in those periods when the Zn-deficient rats did eat, the quantities eaten in 2 h showed the same distribution of weights as did those for the Zn-adequate rats.

5. There were significant relationships between food intake and plasma Zn concentration; the most significant was the negative correlation between food intake in 24 h and plasma Zn concentration at the end of the 24 h period.

6. Zn deficiency resulted in a failure of growth in the young rat and therefore in a reduction in its rate of energy expenditure but did not appear to cause directly a loss of appetite. It is suggested that cyclical patterns of food intake associated with Zn deficiency in young rats resulted from the slow but effective control of food intake by the energy balance of the animals.
Dental caries and plaque formation from diets containing sucrose or glucose in gnotobiotic rats infected with Streptococcus strain IB-1600
Authors: Grenby T. H. , Paterson Frances M. , Cawson R. A.
Published: September 2005

1. Techniques were devised for the operation of a new small-scale gnotobiotic rat unit.

2. The unit was then used to compare the cariogenicity of sucrose and glucose under carefully controlled conditions in the presence of a single strain of a streptococcus, as gnotobiotic experiments by other workers had given conflicting results.

3. Streptococcus IB-1600 was implanted into thirty-four rats, which were then fed on high-sugar diets under gnotobiotic conditions for 5 or 8 weeks from weaning. The level of caries was significantly higher on the sucrose than on the glucose diet, but there was no significant difference in the extent of soft coronal dental plaque.
Seasonal variations in glucose metabolism of reindeer (Rangifer tarandusL.) estimated with [U-14C]glucose and [3-3H]glucose
Authors: Luick J. R. , Person S. J. , Cameron R. D. , White R. G.
Published: September 2005

1. The pool size, space and rate of irreversible loss of glucose were estimated with primed infusions of [U-14C]glucose in reindeer cows within 6 h of being taken from outdoor pens or from free grazing in the field.

2. In conjunction with primed infusions of [U-14C]glucose, single injections of [3-3H]glucose were also used to estimate pool size, space, transfer rate, and turnover time of glucose.

3. Except in a period of severe undernutrition, the concentration of glucose in plasma was higher (range 0·76–1·40 mg/ml) than that recorded for other ruminants.

4. The size of the glucose pool (range 8–35 g) varied in parallel with plasma glucose concentration and was generally distributed in a space in excess of the extracellular fluid volume.

5. The lowest rates of irreversible loss of glucose (approximately 1·7 mg/min per kg0·75) were measured when cows were in mid pregnancy and when available food was scarce; the highest rate (5·5 mg/min per kg0·75) was found in cows during mid summer.

6. Changes in irreversible loss and transfer rate of glucose are interpreted in relation to changes in body composition (estimated in a parallel study), subjective assessment of available food and factors known to control glucose metabolism in other ruminants.

7. The difference between glucose transfer rate and rate of irreversible loss of glucose was used as an index of the rate of resynthesis of glucose from products of glucose catabolism. The rates of glucose resynthesis were highest during a period of rapid growth (4·52 mg/min per kg0·75or 45% of the glucose transfer rate) and in mid and late pregnancy (respectively 4·14 and 4·28 mg/min per kg0·75or 71 and 59% of the transfer rate).
Phospholipids in artificially induced muscular dystrophy of calves
Authors: Evarts Ritva Poukka , Oksanen Aili
Published: September 2005

1. Phospholipds were studied in the heart muscles, skeletal muscles and livers of seven Ayrshire calves which received vitamin E-free maize oil (in filled milk) with and without supplementary α-tocopherol from 1 week old for 17 d. The calves that were not given vitamin E developed muscular dystrophy.

2. Decreased amounts of cardiolipin and increased amounts of sphingomyelin were found in the skeletal muscles of vitamin E-deficient calves. There was a significant decrease of phosphatidyl choline in the livers of vitamin E-deficient calves.

3. The decrease in cardiolipin concentration confirmed the electron-microscopical picture (reported elsewhere) of preferential destruction of mitochondria in muscular dystrophy of calves.
The use of a semi-synthetic liquid diet for the supply of ethanol to rats and its effect on lysosomal enzyme activities in the liver
Authors: Pilström L. , Fellenius E. , Kiessling K.-H.
Published: September 2005

1. A liquid diet is described for the supply of ethanol to rats with a constant proportion of energy equivalents from different sources. In this diet, a protein-enriched, dry, milk powder is used as the protein source.

2. The diet was used in a two-group experiment lasting for 80 d in which the rats were fedad lib.The consumption was 120 ml/d per rat in the control group, whereas in the ethanol-consuming group the consumpton was only 40 ml/d per rat at the start of the experiment and rose to and remained at 80 ml/d per rat after 20 d.

3. The control group grew normally. In the ethanol-consuming group, there was an initial loss of body-weight; after 20 d there was some increase in body-weight but growth was slower than in the control group. The smaller food intake in the ethanol group was not wholly caused by the lower body-weight.

4. The free and total activities of acid phosphatase (EC3·1·3·2) and β-glucuronidase (EC3·2·1·31) were estimated in the liver after 10, 20, 30, 40, 60 and 80 d. Neither the free nor the total activity of acid phosphatase changed significantly during the experiment. The ratio of free activity to total activity increased significantly after 20–40 d of treatment with ethanol. The free and total activities of β-glucuronidase were significantly increased after 10 d of treatment with ethanol, but this difference could not be shown after prolonged treatment.
Changes in the activity of citrate lyase, malic enzyme and acetyl-CoA synthetase in rat liver after short-term and long-term feeding with ethanol
Authors: Fellenius E. , Nisbeth U. , Pilström L. , Kiessling K.-H.
Published: September 2005

1. The effect of short-term and long-term feeding (0–80 d) with a liquid diet containing ethanol on the activity of rat hepatic enzymes related to lipogenesis has been evaluated. Carbohydrates were isoenergetically substituted for ethanol in the control animals.

2. The maximum concentration of triglycerides in the livers was reached after about 30 d, when it was almost three times as high as in the control animals. The activity of malic enzyme (EC1·1·1·40) and ATP citrate lyase (EC4·1·3·8) decreased significantly in the ethanol group, compared with the control rats, within 10 d and remained low during the rest of the experiment (80 d). After 20 d, the acetyl-CoA synthetase (EC6·2·1·1) activity increased significantly in the livers of the ethanol-fed rats but fell subsequently to values similar to those in the livers of the control rats. Thus, despite a pronounced increase in the amount of triglyceride in the livers of rats on a liquid diet containing ethanol, there was a dramatic decrease in the activity of the enzymes (malic enzyme and citrate lyase) involved in lipogenesis.

3. The almost unchanged activity of acetyl-CoA synthetase shows that the utilization of acetate, produced when ethanol is oxidized, is not stimulated by long-term feeding with ethanol. The involvement of citrate lyase in various postulated shuttles for the transport of reducing equivalents across the mitochondrial membrane and the role of malic enzyme in the microsomal ethanol-oxidizing system are discussed.
Degradation of nucleic acids in the rumen
Authors: McAlian A. B. , Smith R. H.
Published: September 2005

1. Nucleic acids introduced into the rumens of calves, or incubated with calf, sheep or cow rumen contents in vitro, were rapidly destroyed.

2. The degradation products formed were separated and identified by means of column chromatography on Sephadex G-10 Dextran gel and thin-layer chromatography on cellulose.

3. In vitro, RNA was rapidly (within 1 h) converted into ultrafilterable oligo-and mono-nucleotides, nucleosides, purine and pyrimidine bases. After 4 h, only the bases xanthine, hypoxanthine and uracil remained, having increased at the expense of the other constituents.

4. DNA gave similar products but with a much greater proportion of ultrafilterable oligoand mono-nucleotide material which remained as a major component even after 4 h. The only bases present in appreciable amounts were thymine, hypoxanthine, uracil and xanthine.

5. The same products accumulated temporarily in vivo, after addition of RNA or DNA to the rumens of calves, and were found also, in small amounts, in corresponding samples of duodenal digesta. The products disappeared from the rumen at a greater rate than could be accounted for by transfer to the duodenum.

6. Cell-free preparations from calf rumen fluid contained enzymes which converted RNA and DNA into products which appeared to be ultrafilterable oligonucleotides.

7. When ground hay was incubated with whole rumen contents the nucleic acids in the hay were degraded to a mixture of nucleotides, nucleosides and bases, almost as readily as were pure nucleic acids.
Utilization of volatile fatty acids and glucose for protein deposition in lambs
Authors: Eskelandt B. , Pfander W. H. , Preston R. L.
Published: September 2005

1. Glucose, and acetic, propionic and butyric acids, the major energy sources available to ruminants, have been comparatively evaluated as energy sources for growth in lambs. The energy sources were administered intravenously at 2·092 and 2·510 MJ metabolizable energy per 24 h for periods of 9–12 d. Nitrogen was given in excess of requirement so that growth rate was limited by energy, as indicated by the increased N retention after intravenous administration of energy.

2. The N-balance results from the trials showed that propionic acid promoted a significantly (P < 0·01) higher N retention than acetic acid. In some of the experiments there were no significant differences between propionic and butyric acids, and in others, no significant differences between acetic and butyric acids. Compared with isoenergetic glucose infusion, all volatile fatty acids were less efficiently utilized than glucose. The mean values for N balance (g/d) were 2·31 during control infusion, 6·53, 5·71, 5·48 and 4·59 during glucose, propionate, butyrate and acetate infusions, respectively.

3. All energy sources reduced the faecal N excretion significantly. The greatest reduction was observed during butyrate treatment. The mean values for faecal N excretion (g/d) were 4·24 for control, 4·00 for acetate, 3·89 for propionate, 3·83 for glucose, and 3·76 for butyrate infusion. The reduced faecal N excretion after butyrate infusion partly accounts for the increased N retention with that treatment.
Increased glycine absorption rate associated with acute bacterial infections in man
Authors: Cook G. C.
Published: September 2005

1. Glycine absorption rate from a 300 mm jejunal segment was determined in vivo in four Zambian African subjects with acute, and four with chronic, respiratory infections. Glycine solutions (100, 150 and 250 mmol/l) were perfused, by means of a double-lumen tube technique. The results were compared with those for four relatively normal Zambian African subjects (‘reference’ group) previously studied. The group with acute-infections had a significantly higher mean absorption rate than the reference or chronic-infection group.

2. Glycine absorption results from a 100 mmol/l glycine solution in an additional twenty-four Zambian African subjects have also been analysed. When results for the thirty-six subjects were combined, those with acute bacterial infections had a significantly higher mean absorption rate than the normal subjects or those with chronic infections. For the twenty-one normal subjects there was a significant positive correlation between the individual absorption rates and serum total globulin and γ-globulin concentrations.

3. It seems likely that the rapid catabolism of protein associated with infection is counteracted by an increase in amino acid absorption rate. In subjects on a low-protein diet that mechanism would be limited. The deterioration in nutritional status during infections in developing countries could therefore be partly explained by the present observation.
Progressive changes in serum cortisol, insulin and growth hormone concentrations and their relationship to the distorted amino acid pattern during the development of kwashiorkor
Authors: Lunn P. G. , Whitehead R. G. , Hay R. W. , Barer B. A.
Published: September 2005

1. During the initial stages of the development of hypoalbuminaemia, with concentrations between 25 and 30 g/l, fasting serum cortisol and growth hormone values remained normal. Corresponding fasting serum insulin concentrations were, however, significantly above normal. During the same period, called phase B, valine concentrations were moderately low but alanine concentrations were raised.

2. In more severe hypoalbuminaemia, culminating in kwashiorkor, a marked switch in hormonal balance occurred. Insulin concentrations fell to subnormal levels whereas cortisol became raised. Eventually growth hormone concentrations also increased rapidly to values similar to those found in acromegaly. By this time, phase C, alanine concentrations as well as those of valine were falling to very low levels.

3. The possible causes of these changes in hormonal balance, their role in the development of the distorted fasting serum amino acid pattern and their consequent effect on serum albumin synthesis and the appearance of clinical kwashiorkor are discussed.

4. Information is also presented on the differences between these components in kwashiorkor and marasmus. Attempts have been made to rationalize apparent inconsistencies in the literature.
A comparison of fractions prepared from navy (haricot) beans (Phaseolus vulgaris L.) in diets for germ-free and conventional chicks
Authors: Hewitt D. , Coates Marie E. , Kakade M. L. , Liener I. E.
Published: September 2005

1. Germ-free and conventional chicks were given diets containing raw or heated navy (haricot) (Phaseolus vulgaris L.) bean meal, or the heated meal supplemented with one of two fractions from raw navy beans: F3 was a preparation of navy bean trypsin inhibitor; F4 was a toxic factor known to depress the growth of rats. After 2 weeks, body-weights and pancreas weights were determined and proteolytic and amylolytic enzymes in the pancreas were assayed. The contents of the small intestine were collected and analysed for nitrogenous compounds.

2. In germ-free chicks final body-weights were not affected by F3 and only slightly depressed by F4. A significant depression of 12% occurred when raw meal was given. In conventional chicks depressions in final body-weights of 13·5, 26·5 and 48% were recorded with F3, F4, and raw meal respectively.

3. In birds given either raw meal of F3, there was an increase in size of the pancreas and in its concentration of trypsin, but a reduction in concentrations of chymotrypsin and amylase. The concentration of nitrogen in the insoluble fraction of the intestinal contents was increased by raw meal and F3 in both environments.

4. It was concluded that the presence of the gut microflora aggravated the growth-depressing effect on chicks of raw navy-bean meal. In the absence of the gut flora neither factor had any effect on growth. Possible explanations are discussed.
The effect of litter size upon foetal growth rate and the placental transfer of calcium and phosphorus in superovulated Scottish half-bred ewes
Authors: Twardock A. R. , Symonds H. W. , Sansom B. F. , Rowlands G. J.
Published: September 2005

1. The ovulation rate of forty-eight Scottish half-bred ewes was increased by using pregnant mare's serum gonadotrophin thus inducing litters of one to four foetuses.

2. The effects of increased litter size upon the foetal growth rate and upon the rate of transfer of calcium and phosphorus across the placenta were studied at 108–112, 122–126 and 136–140 d gestation.

3. The number of foetuses had little effect upon foetal weight at 112 d, the mean weights of a singleton, twin, triplet or quadruplet being similar. However, by 140 d mean foetal weight decreased markedly as litter size increased.

4. Failure of individual quadruplets to grow as fast as a singleton was associated with a limitation in the capacity of the placenta for transferring minerals. The maximum rates of transfer of Ca and P, whatever the number of foetuses, were approximately 2·8 and 1·4 g/d respectively. These rates were attained by 112 d when quadruplets were being carried, by 126 d for triplets, and by 140 d for twins.
Degradation of nucleic acid derivatives by rumen bacteria in vitro
Authors: Mcallan A. B. , Smith R. H.
Published: September 2005

1. Purine or pyrimidine bases, nucleosides or nucleotides were incubated, in vitro, with whole rumen contents, or with a cell-free filtrate prepared from rumen contents of calves fed on diets of flaked maize and hay.

2. During incubations with whole rumen contents, all derivatives bearing a side amino group were deaminated to varying extents.

3. All nucleotides and nucleosides were rapidly degraded to the parent base or its desamino counterpart.

4. Evidence suggests that guanosine was degraded to guanine before deamination occurred whereas deamination preceded ribosidic cleavage for adenosine.

5. Xanthine, uracil, hypoxanthine and thymine resisted further degradation to varying degrees.

6. Little or no breakdown was observed when any derivative was incubated, in vitro, with cell-free preparations.
The response of hind-limb muscles of the weanling rat to undernutrition and subsequent rehabilitation
Authors: Dickerson J. W. T. , McAnulty P. A.
Published: September 2005

1. Weanling male rats were maintained at constant body-weight for 28 d by feeding them reduced amounts of their normal diet. They were rehabilitated for 0, 3, 7, 10 or 16 d, and compared with two sets of control groups, one set of the same body-weight and the other of the same age

2. The quadriceps, gastrocnemius and anterior tibialis muscles from the left hind-limb were weighed, and DNA, RNA, extracellular protein and intracellular protein estimated in the quadriceps and gastrocnemius muscles

3. Each muscle responded differently during undernutrition and rehabilitation if compared with ‘age controls’, but if compared with ‘body-weight controls’ there was a tendency for muscle weight to remain appropriate for body-weight

4. The amount of DNA did not change in the gastrocnemius or quadriceps muscles during undernutrition, and on rehabilitation did not begin to increase until after 7 d. RNA decreased during undernutrition, but increased rapidly on rehabilitation. The rate of increase in RNA was greatest in the quadriceps during the first 3 d, but in the gastrocnemius was greatest between 3 and 7 d. The peak values for the rate of RNA increase corresponded with the initiation of intracellular protein accretion in each muscle. Extracellular protein increased during undernutrition, and on rehabilitation, responded in the same way as DNA, that is, it increased only after 7 d

5. It is concluded that the differences found between muscles of the hind-limb during rehabilitation are due mainly to differences in the rates of DNA and intracellular protein accretion. It is suggested that these differences are the result of a differential response of RNA to rehabilitation.