bluuebunny/crossref_metadata_2025 huggingface dataset:
The requirement of sheep for cobalt or for vitamin B12
Authors: Marston H. R.
Published: May 2005

1. Sheep confined topens and given a cobalt-deficient ration which supplied about 30μgCo/d required for maintenance of normal growth rate a Co supplement approaching 40 μg administered per os daily; for maintenance of what appeared, under the conditions of the experiments described, to be the maximum vitamin B12 status of a sheep, namely 3 ng vitamin B12/ml serum and 1.4 μg vitamin B12/g liver tissue, a supplement of between 0.5 and 1.0 mg Co/d per os was necessary.

2. For maintenance of normal growth rate the minimum daily requirement for vitamin B12 of sheep given the Co-deficient diet was about 11μg: about 5 μg absorbed from the gut and about 6 μg injected parenterally.

3. Extrapolation of the linear regression obtained by plotting the amount of vitamin B12injected/d against concentration of vitamin B12 in the liver tissue of a sheep indicated that to attain a concentration of 1.4 μg vitamin B12/g liver (wet weight) injection of 34 μg vitamin B12/d was necessary.

4. Comparison of the relative effects on body-weight of the administration of 100 μg vitamin B12/dper os and 3.12 μg vitamin B12/d by injection to sheep given the Co-deficient diet indicated that the efficiency of absorption of the vitamin from the gut was < 3%.

5. Loss of appetite, the first symptom of vitamin B12 deficiency to appear in the sheep, occurred when the concentration of vitamin B12 in the liver was reduced to about 0.1 μg/g wet weight.

6. In sheep given a supplement of 1 mg Co/d per os neither production in the rumen nor absorption from the gut but rather capacity for storage limited the concentration of vitamin B12 in the liver.

7. Following treatment to restore the vitamin B12 status of a sheep whose stores of the vitamin had been depleted, there was a linear negative correlation between the increase in the concentration of vitamin B12 in the liver and the concentration prior to treatment.

8. Following withdrawal of treatment from a sheep whose stores of vitamin B12 were adequate, there was a linear positive correlation between the rate of depletion of vitamin B12 from the liver and the concentration prior to cessation of treatment.

9. The concentrations of vitamin B12 in the serums of sheep given the Co-deficient diet, and given a supplement of 1 mg Co/d per os 0.5 h after feeding, remained relatively stable over the period 0–7 h after feeding; maximum concentration occurred 7–8 h after feeding.

10. Under the conditions of the experiments described a significant linear regression existed between concentration of vitamin B12 in the liver of a sheep and the logarithm of the concentration in the serum.
Effect of riboflavine deficiency on incorporation in vivo of [14C]amino acid into liver proteins of rats
Authors: Chatterjee Ajay K. , Jamdar S. C. , Ghosh B. B.
Published: May 2005

1. The effect of riboflavine deficiency on in vivo incorporation of [2–14C]glycine into proteins of liver homogenates and its subcellular fractions has been studied on rats maintained on a 16 % protein diet.

2. Riboflavine deficiency did not seem to affect the in vivo incorporation of [2–14C]g1ycine into proteins of liver homogenates. But riboflavine deficiency caused increased and reduced invivo incorporation of [14C]amino acid into mitochondrial and microsomal proteins, respectively.There was no significant change in the in vivo incorporation of [14C]amino acid into proteins ofnuclear, ribosomal and soluble fractions in riboflavine deficiency.

3. Riboflavine deficiency caused enhanced and reduced proportions of liver mitochondrial and microsomal proteins, respectively.

4. The results are discussed as suggestive of enhanced and reduced protein synthesis in the mitochondrial and microsomal fractions, respectively, of riboflavine-deficient rats.
The effect of phosphate and carbonate-bicarbonate supplements on the rumen buffering systems of sheep
Authors: Emmanuel Bijan , Lawlor M. J. , McAleese D.
Published: May 2005

1. Two wethers fitted with permanent rumen cannulas were used to study the effect of two mineral supplements, Na2HPO4 and a 1:1 mixture of Na2CO3 and NaHCO3, on the buffering system in the rumen of sheep given a pelleted roughage-concentrate diet.

2. Measurements were made of rumen pH, buffering capacity value (β), total volatile fatty acids (VFA), CO2 and inorganic phosphorus concentrations as well as rumen cellulase activity.

3. The addition of either mineral supplement to the diet significantly (P < 0.001) increased the rumen pH values during the critical post-feeding period, there was a difference of only 0.5 pH unit between the minimum and maximum pH values.

4. Both mineral supplements significantly increased the concentrations of CO2 in the rumen fluid and rumen cellulase activity. They resulted in a general reduction in total VFA concentrations. It is suggested that this may possibly arise from increased absorption of VFA associated with increased CO2 tension in the rumen fluid.

5. The Na2HPO4 supplement significantly ( P < 0.001) increased the β values in the pH range 6–8, whereas the bicarbonate supplement contributed to raising the β values in the pH range 5–6.

6. The bicarbonate supplements raised cellulose digestibility from 39.7% for the control diet to 45.6% and the addition of Na2HPO4 further raised the digestibility to 51.1%. It would appear that low rumen pH impairs rumen cellulase activity and this could be offset by the addition of mineral supplements.
Influence of starch digestion in the large intestine of sheep on caecal fermentation, caecal microflora and faecal nitrogen excretion
Authors: Ørskov E. R. , Fraser C. , Mason V. C. , Mann S. O.
Published: May 2005

1. The concentrations of volatile fatty acids (VFA) in the rumen and caecum were compared when sheep were given barley or dried grass. The molar proportions of VFA in the caecum resembled those in the rumen except that the proportions of isobutyric and isovaleric acids were higher in caecal than in rumen fluid indicating an extensive breakdown of protein during fermentation in the caecum.

2. The capacity for starch digestion in the large intestine was studied in two sheep receiving dried grass. Starch was infused into the caecum, the amount given increasing by daily increments of 20 g until 300 g daily were infused. Infused starch in excess of 138 g daily largely appeared in the faeces, indicating a limited but substantial capacity for starch fermentation in the large intestine. The infusion caused a marked increase in the molar proportion of butyric acid.

3. Determinations made with a single sheep showed that the infusion of starch into the caecum caused large changes in the microflora, and species similar to Butyrivibrio became prevalent. The viable count on a starch medium was increased by 83 % by starch infusion.

4. The infusions of starch increased the excretion of nitrogen in the faeces from 5.8 to 9.0 g daily. Using a fractionation procedure it was shown that when 100 g of starch were fermented in the large intestine the 'bacterial and endogenous debris' nitrogen increased by about 1.0 g. When starch was given orally to two sheep the increase in this fraction was about 0.4g nitrogen/100 g starch digested.

5. It is suggested that dietary factors that cause changes in the site of fermentation from the rumen to the caecum will render less microbial nitrogen available to the host animal per unit of carbohydrate fermented and decrease the apparent digestibility of nitrogen.
The effect of diet on the haemoglobin and haematocrit values of some Nigerian village children
Authors: Osifo 'Bola O. A.
Published: May 2005

1. Eighty-eight Nigerian village children aged 1–12 years were involved in this study.

2. A food consumption survey on each child was carried out for 7 consecutive d; iron, folic acid and calorie intakes were calculated from food composition tables.

3. Samples of the children's diets (cooked) were collected and analysed for moisture, total nitrogen and ascorbic acid content.

4. Blood samples were assessed for haemoglobin and haematocrit values.

5. Calorie, protein and folic acid intakes were low for all age groups; iron and ascorbic acid intakes were adequate.

6. There was no incidence of severe anaemia. Only 10% of all the eighty-eight children had a haemoglobin concentration below acceptable levels and only about 8 % of all the eighty-eight children had haematocrit values below acceptable level.
The effect of folic acid and iron in the prevention of nutritional anaemias in pregnancy in Nigeria
Authors: Osifo 'Bola O.A.
Published: May 2005

1. Fifty-two pregnant women in a village were divided into three groups, A, B and C, and were given the following supplements: A, iron in the form of 200 mg ferrous sulphate daily; B, Fe(as group A) and 5 mg of folic acid daily; C, Fe and folic acid (as group B) plus an antimalarial drug.

2. Blood samples were collected each week and assessed for haemoglobin and haematocrit values.

3. Dietary intakes of Fe and folic acid were calculated for both pregnant and non-pregnant women. Results revealed that Fe intake was adequate and Fe deficiency not common. The supplement of Fe increased the haemoglobin levels.

4. Folic acid intake was low and intake probably fluctuated during the year because of seasonal changes in the dietary folic acid.

5. About 28% of patients, during their first attendance, had haematocrit values below normal. Folic acid supplements increased these values.
The metabolism of glucose, acetate, palmitate, stearate and oleate in pigs
Authors: Freeman C. P. , Noakes D. E. , Annison E. F.
Published: May 2005

1. Isotope dilution techniques were used to measure the rates of entry and oxidation of glucose, acetate, palmitate, stearate and oleate in fed and fasted (16 h) pigs.

2. Glucose entry rates measured in eight fed and five fasted (16 h) pigs were 20.6 and 8.0 mg/min per kg0.75(mean values) respectively. The entry rates in fed pigs were lower than the calculated rates of glucose uptake from the alimentary tract, and the validity of glucose entry rates determined under these conditions is discussed.

3. Acetate entry rates were unrelated to the fibre content of the diet, and acetate produced from endogenous metabolism was the main contributor to total acetate production.

4. Increased rates of entry and oxidation of palmitate, stearate and oleate were observed in fasted pigs.

5. Glucose production in fasted pigs was inhibited by raising the concentration of blood glucose. Infusion of insulin in the fed pig caused a decrease in glucose production and a simultaneous reduction in the mobilization of free fatty acids. When blood glucose concentrations fell below about 55 mg/100 ml the release of free fatty acid into the circulation was restored.
The preparation of nutritious protein from wool
Authors: Shorland F. B. , Gray Judith M.
Published: May 2005

1. The nutritive value of solubilized wool protein prepared by dissolving finely ground wool in sodium sulphide-sodium sulphite solution followed by precipitation with 40 % acetic acid has been tested by incorporating it into protein-free diets containing the amounts of vitamins and minerals required by weanling rats.

2. At the level of 10 % (w/w) of the diet, solubilized wool protein failed to support growth in weanling rats, but when the diet was fortified with histidine, methionine and lysine a protein efficiency ratio of up to 1.8 was obtained. The effect of the addition of lysine was marginal. Similar results were obtained with solubilized wool protein prepared from dyed wool suiting material.

3. Apart from the methionine content, which varied from 0.49 to 0.66 g/100 g protein, the contents of the essential amino acids in the solubilized wool protein generally met the requirement of the FA0 (1957) provisional pattern, although in many of the preparations the levels of isoleucine and lysine were marginal. The tryptophan content was not determined. Supplementation of the solubilized wool protein with lysine to the level of 6–10 g/100 g protein slightly enhanced the nutritive value.
The uptake of radioactive copper by the brain and other tissues of the developing rat
Authors: Ryan Deirdre , Warren P. J.
Published: May 2005

1.64Cu as copper chloride in aqueous solution was given by intraperitoneal injection to rats varying in age from a few hours to 14 weeks. The isotope was allowed to circulate in the body for 24 h.

2. The amount of gamma radioactivity present in the brain and blood was measured and the percentage of the initial dose present was calculated. It was shown that the brain64Cu activity reached a maximum around the 16th day of life and that the blood showed a steady decrease in the64Cu activity per g from birth to maturity. Measurements were also made on the liver and kidney.

3. The excretion of64Cu in the urine and faeces in 24 h was also studied. Approximately 30% of the isotope was excreted in that time, mostly in the faeces.

4. A limited number of experiments in three different age groups were carried out to discover whether changes in specific activity of the isotope given to rats had a significant effect on the percentage of64Cu taken up by the brain and blood. No such effect was seen.
Changes in the metabolism of vitamin B12and methionine in rats fed unheated soya-bean flour
Authors: Edelstein S. , Guggenheim K.
Published: May 2005

1. Young rats were fed on diets containing heated or unheated soya-bean flour.

2. Feeding unheated soya-bean flour decreased concentrations of vitamin B12in liver, kidneys and blood serum, urinary excretion of sulphate and concentration of reduced glutathione in liver. Blood glutathione level and urinary excretion of methylmalonic acid and formimino-glutamic acid following loads of propionate and histidine, respectively, were increased.

3. Supplementing a diet of unheated soya-bean flour with vitamin B12, had no effect on the level of reduced glutathione in the liver. Adding methionine to this diet decreased excretion of methylmalonic acid and the level of glutathione in blood.

4. The activity of liver methyl-tetrahydrofolate: L-homocysteine S-methyltransferase was not affected by the nature of dietary soya-bean flour nor by supplementation with vitamin B12

5. It is concluded that heat-labile substances present in soya-bean flour induce metabolic changes which can bring about an increased requirement for vitamin B12, and a deficiency of sulphur-containing amino acids.
The effect of dilution of milk proteins with non-essential amino acids (L-alanine and L-glutamic acid) on nitrogen retention and biological value of the proteins in children
Authors: Daniel V.A. , Doraiswamy T.R. , Swaminathan M. , Rajalakshmi D.
Published: May 2005

1. The effect of addition of a mixture of two non-essential amino acids (NEA), namely alanine and glutamic acid, to milk proteins on nitrogen retention and the biological value of the proteins was determined in a group of six girls aged 10–11 years.

2. The mean daily intakes of milk protein by the children on three diets (1, 3 and 5 ) were 1.41, 1.10 and 0.70 g/kg body-weight. The quantities of NEA added daily to the three diets were 0.97, 0.49 and 0.97 g/kg body-weight respectively.

3. Addition of NEA did not bring about any significant increase in N retention in the children. The addition of NEA to milk proteins significantly decreased the biological value of the proteins.
The influence of the amount and nature of dietary fat on milk fat composition in the sow
Authors: Witter R.C. , Rook J.A.F.
Published: May 2005

1. The effects of the introduction into the diet of natural fats rich in individual fatty acids or of simple triglycerides on the composition of blood lipids and of milk fat in the sow were investigated.

2. Replacement in the diet of a mixture of animal, vegetable and marine oils by a single natural fat had varying effects on the concentrations of plasma lipid fractions, whereas replacement of tallow by simple triglycerides, with few exceptions, increased the concentrations of all fractions.

3. When butyric or caprylic acids were present in the diet there was no detectable transfer of those acids to plasma triglycerides, and there was only a limited transfer of dietary erucic acid. An increase in the dietary concentration of other acids (ranging from capric to linolenic) was associated with an increase in the content of the acids in the plasma triglycerides. For saturated fatty acids the response to dietary changes was at a maximum for myristic acid.

4. The effects on the composition of milk fat reflected the changes in the composition of the plasma triglycerides, except during the feeding of cottonseed oil when there were marked decreases in milk fat of palmitoleic and oleic acids and corresponding increases in palmitic and stearic acids which were not observed in the plasma triglycerides. Also, during the feeding of coconut oil, capric acid was present in the plasma triglycerides but not in milk fat, and the increases in the plasma triglycerides of lauric and myristic acids were much more marked than the corresponding increases in milk fat.
The protein quality of cassava leaves
Authors: Eggum B.O.
Published: May 2005

1. A chemical and biological evaluation of the protein content of some leaves and leaf extracts from the eastern region of Nigeria (Biafra) has been made: most were from cassava (Munihot utilissima).

2. The protein content of the leaves was from 3 0 to 40% (expressed as percentage of leaf dry matter). The concentrations of essential amino acids were adequate, except for methionine. The biological criteria, true digestibility (TD) and biological value (BV), showed that the digestibility was from 70 to 80%, whereas BV varied from 44 to 57%, depending on the methionine content.

3. Adding methionine to a diet of cassava leaves raised BV from 49 for the leaves alone to 80 for the mixture. This relationship clearly shows that cassava leaves contain too little available methionine. An investigation into the true availability of the amino acids showed that this is somewhat variable, and only 60% of the methionine is available.

4. The BV of cassava leaves combined with Norwegian dried cod showed a mutual supplementation effect.
The effects of feeding procedure on closure of the oesophageal groove in young sheep
Authors: Ørskov E. R. , Benzie D. , Kay R. N. B.
Published: May 2005

1. Barium sulphate suspensions were given to young sheep by mouth or by injection via an oesophageal catheter. Closure of the oesophageal groove was assessed by observing radiographically whether the suspension passed to the ruminoreticulum or to the abomasum.

2. Complete closure of the groove took place in lambs that were trained to drink small meals from a trough after being weaned from their dams, a finding similar to that for lambs weaned on to a teat-bottle.

3. When barium was injected into the oesophagus of lambs that were excited by being offered their bottle or trough beyond their reach, the barium passed direct to the abomasum if the normal feeding routine was closely imitated. When the lambs were able to discriminate between this teasing procedure and the normal routine, the barium frequently passed to the ruminoreticulum. If the lambs were not teased the barium passed invariably to the ruminoreticulum.

4. It is concluded that the reflex closure of the groove can be conditioned by the feeding procedure adopted at weaning so that it no longer depends on the stimuli associated with sucking and swallowing.
The effect on protein utilization of feeding different protein supplements via the rumen or via the abomasum in young growing sheep
Authors: Ørskov E. R. , Fraser C. , Corse Elizabeth L.
Published: May 2005

1. Sixteen lambs were used to compare two methods of administering various protein supplements to weaned lambs. In one method the protein supplement was mixed with the dry feed, consisting mainly of rolled barley, so that it passed to the rumen. In the second method the supplement was suspended in water which the lambs were trained to suck from a bottle; the suspension then passed directly to the abomasum by way of the oesophageal groove and so escaped rumen fermentation.

2. When the protein supplements were given in amounts that provided less than the estimated protein requirement of the animals, giving the liquid suspension led to significantly lower urinary nitrogen excretion (P < 0.001), greater nitrogen retention (P<0.05) and greater live-weight gain (0.05<P<0.1) than giving the feed in the dry form.

3. The body-weight gain was greater with white fish meal than with casein (P<0.05) and soya-bean meal (P<0.001), whichever method of feeding was adopted. There was no significant interaction between method of feeding and protein source, but the faecal nitrogen excretion was highest when soya-bean meal was given in liquid suspension.

4. From a regression of nitrogen retention on nitrogen intake with lambs receiving the basal ration only, it was calculated that the improvement in retention of the protein supplement effected by giving it in liquid suspension was 31 % for casein, 27 % for fish meal and 24 % for soya-bean meal.
Salt intake in Ceylon
Authors: Mahadeva K. , Karunanayake E.
Published: May 2005

1. Salt is a convenient household commodity which is generally used as a vehicle for iodine in the prophylactic treatment of endemic goitre.

2. Iodization of salt depends on the normal requirements for iodine, the intensity of the environmental iodine deficiency, the presence of goitrogenic factors and the daily salt consumption per head of the population.

3. Although the intake of most nutrients has been worked out during the normal course of dietary surveys in the past, the daily salt consumption per head of the population has not been estimated.

4. In this survey a simple method has been described for evaluating salt consumption and this finding will be the basis for planning the iodization programme in Ceylon.
Artificial rearing of pigs
Authors: Braude R. , Newport M.J. , Porter J.W.
Published: May 2005

1. The time course of digestion of milk protein was studied in the 28-d-old pig given a test meal of homogenized cow's milk after a preliminary starvation period.

2. The milk was found to clot in the stomach 15–30 min after the meal. The soluble or ‘whey’ fraction of the stomach contents rapidly passed into the small intestine. Most of the clotted digesta had also left the stomach z h after the meal.

3. The distribution of digesta was studied in six equal segments of the small intestine. In general, there were no significant increases in the amount of intestinal contents at any time after the meal when compared with those in starved pigs, suggesting that digestion of milk at this age is a very efficient process.

4. Fractionation of the soluble digesta from the stomach and small intestine in Sephadex G-25 indicated that relatively little proteolysis occurred in the stomach, but in the small intestine digestion proceeded rapidly, producing a considerable increase in free amino acids in the mid-region.

5. The level of proteolytic enzyme activity in the stomach wall was elevated at 15 min after the meal, but thereafter returned rapidly to the prefeeding levels. Increasing the level of feeding increased the enzyme activity of the digesta and stomach wall. The enzyme activity appeared to be mainly adsorbed by the stomach clot.

6. The proteolytic enzyme activity in the pancreas was unaffected by the meal. However, the activity in the contents of the small intestine increased after the meal, reaching a maximum value at 45 min. Some accumulation of enzymes was found in the lower part of the small intestine, except in the region of the distal ileum where a marked decline in enzyme activity occurred. Increasing the level of feeding increased the proteolytic enzyme activity in the contents of the small intestine.

7. The soluble marker polyethylene glycol was not entirely satisfactory as an indicator of the rate of passage of digesta. The concentration of the marker was found to be greater in the soluble stomach fraction than in the clot shortly after the milk had been ingested. The transit time of the marker from ingestion to the terminal ileum was 2–3 h.
Digestion and nitrogen metabolism in sheep and red deer given large or small amounts of water and protein
Authors: Maloiy G. M. O. , Kay R. N. B. , Goodall E. D. , Topps J. H.
Published: May 2005

1. The interaction between nitrogen and water intake was studied in two ewes and two red deer hinds. They were given pelleted diets, at maintenance level, containing equal amounts of roughage but either rich or poor in nitrogen. The deer received 50 % more food than the sheep. Water was given either in large amounts (sheep 5.01, deer 7.0 1 daily) or in small amounts (sheep 1.1 l, deer 2.4 l daily).

2. Nearly three-quarters of the nitrogen of the high-nitrogen rations but less than half of that of the low-nitrogen rations was excreted in the urine. Restriction of water intake reduced urinary nitrogen excretion by only about 1 g daily, mainly as a result of decreases in the excretion of urea and ammonia, but did not affect the excretion of nitrogen in the faeces.

3. The urinary excretions of creatinine, creatine, hippuric acid, uric acid and allantoin were also examined. The excretion of creatinine was not related to either nitrogen or water intake. The excretion of uric acid and of allantoin was greater in the sheep than in the deer.

4. The concentrations of urea in the plasma and of ammonia in the rumen fluid were measured before and after feeding. The plasma urea value was related to dietary nitrogen intake and was higher on the low- than on the high-water regime. The rumen ammonia value also was related to the nitrogen intake but, while it generally increased after feeding when the high-nitrogen diet was given, it fell almost to zero 2 h after feeding when the low-nitrogen diet was given.

5. The sheep digested dry matter, cellulose and nitrogen a little more fully than the deer. The high-water regime slightly increased the digestibility of dry matter and cellulose but did not affect the digestibility of nitrogen.
Action of growth hormone in vitro on the net uptake and incorporation into protein of amino acids in muscle from intact rabbits given protein-deficient diets
Authors: Turner M. R. , Reeds P. J. , Munday K. A.
Published: May 2005

1. Net amino acid uptake, and incorporation into protein have been measured in vitro in the presence and absence of porcine growth hormone (GH) in muscle from intact rabbits fed for 5 d on low-protein (LP), protein-free (PF) or control diets.

2. In muscle from control and LP animals GH had no effect on the net amino acid uptake but stimulated amino acid incorporation into protein, although this response was less in LP animals than in control animals.

3. In muscle from PF animals, GH stimulated both amino acid incorporation into protein and the net amino acid uptake, a type of response which also occurs in hypophysectomized animals. The magnitude of the effect of GH on the incorporation of amino acids into protein was reduced in muscle from PF animals.

4. The effect of GH on the net amino acid uptake in PF animals was completely blocked by cycloheximide; the uptake effect of GH in these animals was dependent therefore on de novo protein synthesis.

5. It is proposed that in the adult the role of growth hormone in protein metabolism is to sustain cellular protein synthesis when there is a decrease in the level of substrate amino acids, similar to that which occurs during a short-term fast or when the dietary protein intake is inadequate.
The effect of molybdenum on the conversion of sulphate to sulphide and microbial-protein-sulphur in the rumen of sheep
Authors: Gawthorne J. M. , Nader C. J.
Published: May 2005

1. [35S]sulphate was used to measure the apparent turnover of sulphate, sulphide and microbial-protein-S in the rumen contents of four sheep that were intraruminally infused with 10 g sodium sulphate/d alone, or together with 126 mg sodium molybdate (50 mg molybdenum/d).

2. Infusion of molybdate increased the concentration of sulphate in rumen fluid from 2.2 to 7.2 μg S/ml and decreased the rate of reduction of sulphate to sulphide by 50%. Although the rate of sulphide production was slower, the concentration of sulphide in rumen contents was increased. A dual role for molybdate in the metabolism of sulphide in the rumen is suggested to explain these changes.

3. In animals that were not infused with molybdate, only one-third of the S (3.0 g/d) that passed through the sulphate pool in rumen fluid was converted to sulphide, decreasing to one-sixth when molybdate was infused.

4. The turnover of S amino acids in microbial protein was not significantly affected by molybdate. Only 52–57% of the S amino acid content of microbial protein was synthesized de novo by way of the sulphide pool.
The induction of obesity in rodents by means of monosodium glutamate
Authors: Bunyan J. , Murrell Elspeth A. , Shah P. P.
Published: May 2005

1. Monosodium glutamate (MSG) was administered by various methods to mice and rats of various ages and the incidence of obesity was later measured.

2. Newborn mice were injected subcutaneously with 3 mg MSG/g body-weight at 1, 2, 3, 6, 7 and 8 d of age; 16% died before weaning. Of the survivors, 90% or more became markedly obese. Mean carcass lipid content was increased by about 120% in both sexes at 20–30 weeks of age. In male mice, MSG treatment increased body-weight and epididymal fat pad weight, and greatly decreased adrenaline-stimulated lipolysis in isolated fat cells. Body-weight of females was not increased significantly. Food intake was not increased in either sex from weeks 13 to 15. Blood glucose level was not generally increased by MSG but some of the male mice had abnormally high values.

3. Obesity was not detected in the offspring of female mice that had received 100 g MSG/kg diet, either from 3 weeks before mating until weaning, or from the 14th day of pregnancy until weaning.

4. Intraperitoneal injection of 10 mg MSG/g body-weight (in two doses) at weaning increased carcass lipid content in female mice by 34% by 23 weeks of age, but female rats were not affected.

5. The addition of 20 g MSG/l to the drinking-water from weaning onwards did not increase carcass lipid content in female rats or mice.

6. The addition of 20 g MSG/kg diet from weaning onwards did not alter body-weight or carcass lipid content in male and female rats by 14 weeks of age.

7. The obesity induced in mice by MSG was not associated with hyperphagia, unlike genetic obesity and obesity induced by gold thioglucose (GTG).

8. All types of mouse studied, obese and lean, had essentially the same linear relationship between carcass water content and carcass lipid content.

9. Although MSG-obese mice could not readily be differentiated from normal mice by the increase in body-weight, which was only about 10% compared to 50–120% for genetic and GTG-induced obesity, the proposed schedule of injections in the newborn was almost 100% reliable in inducing a high extent of adiposity.
Resistance to ketosis during prolonged fasting by rats fed on a diet containing undecanoic acid, an odd-carbon-number fatty acid
Authors: Pi-Sunyer F. X.
Published: May 2005

1. Sixty-four male rats were fed on a nutritionally complete diet containing 30% of the dietary energy as fat. For thirty-two rats (control) the fat source was maize oil; for the remaining thirty-two rats (experimental) the fat source was triundecanoin–maize oil (7:3, w/w).

2. After 6 weeks, groups of control and experimental rats were fasted and killed on days 0, 1, 2 and 4 of the fasting period. In the experimental group, adipose-tissue fatty acids contained, on average, 246 mmol undecanoic acid/mol total fatty acids. In contrast, the adipose tissue of the control group did not contain odd-carbon-number fatty acids.

3. Plasma glucose levels were significantly higher for all fasted experimental groups and blood ketone levels were significantly lower for these groups.

4. Thus, during prolonged starvation, animals which accumulated odd-C-number fatty acids resisted the development of ketosis. It appeared that odd-C-number fatty acids mobilized from fat depots during fasting may provide their terminal three-C residues for gluconeogenesis rather than for acetyl-CoA production, thereby allowing for better maintenance of blood glucose and insulin levels than in control animals.

5. It is concluded that the lower acetyl-CoA production and higher blood insulin levels reduce ketogenesis.
Protein absorption and ammonia production: the effects of dietary protein and removal of the colon
Authors: Gibson J. A. , Sladen G. E. , Dawson A. M.
Published: May 2005

1. The effect of increasing dietary protein content on the amount of faecal nitrogen was measured in six normal subjects and five subjects without functioning colons (three with ileostomy and two with ileo-rectal anastomosis).

2. There was a significant increase in the amount of faecal N with increased dietary protein content in the subjects without functioning colons.

3. In normal subjects with intact colons, faecal N content was found to be lower than that in subjects without colons, and furthermore there was no significant variation with diet.

4. The source of the increase in faecal N with increased dietary protein content in subjects without functioning colons is discussed and the significance of these findings in relation to the efficiency of protein absorption is considered.
Micellar solubilization of fatty acids in aqueous media containing bile salts and phospholipids
Authors: Smith A. , Lough A. K.
Published: May 2005

1. The solubility of fatty acids in aqueous media containing bile salts alone and in admixture with either lecithin (phosphatidylcholine) or phosphatidylethanolamine was determined.

2. Over the pH range 2.0–7.4, the order of fatty acid solubility in aqueous solutions containing bile salts was linoleic > oleic > elaidic > palmitic > stearic. The solubility of each fatty acid increased as the pH of the micellar solution increased.

3. Addition of lecithin to aqueous solutions of bile salts greatly increased the solubility of palmitic acid and stearic acid.

4. In the presence of bile salts and lecithin, the solubility of oleic acid and elaidic acid decreased with increasing pH of the micellar solution, indicating a competitive effect between the fatty acid anions and lecithin. The solubility of linoleic acid increased linearly with lecithin concentration.

5. Phosphatidylethanolamine as an additive to bile salts increased the solubility of both saturated and unsaturated fatty acids in the pH range 2.0–7.4. The effectiveness of phosphatidylethanolamine as an amphiphile was similar to that of lecithin, although at pH 3.0 fatty acid solubility was greater in the presence of phosphatidylethanolamine.

6. The significance of these findings is discussed in relation to the intestinal absorption of fatty acids in sheep.
Influence of the products of phospholipolysis of phosphatidylcholine on micellar solubilization of fatty acids in the presence of bile salts
Authors: Lough A. K. , Smith A.
Published: May 2005

1. The solubility of fatty acids in aqueous solutions containing bile salts and lysolecithin at pH values between 2.0 and 7.4 was studied. Both the 1-acyl and 2-acyl isomers of lysolecithin increased the solubility of fatty acids to the same extent, the order of solubility being linoleic > oleic > elaidic > palmitic > stearic.

2. The influence of the products of phospholipolysis of lecithin on palmitic acid solubility was determined. On a molar basis, lysolecithin was more effective than were bile salts in promoting the solubilization of the fatty acid.

3. In bile salt solutions in which the phospholipid concentration was constant on a molar basis, the solubility of palmitic acid decreased linearly with the progressive replacement of lecithin by lysolecithin. Palmitic acid was solubilized to the same extent on replacing lecithin with lysolecithin on a constant weight basis.

4. In bile salt solution containing lysolecithin and oleic acid in equimolar amounts, the solubility of palmitic acid was similar to that in bile salt solutions containing lecithin in equivalent proportion.

5. The results are discussed in relation to the action of phospholipolytic activity on the intestinal absorption of fatty acids in sheep.
The effect of feeding frequency on the growth and composition of individual organs in the rat
Authors: Pocknee R. C. , Heaton F. W.
Published: May 2005

1. The effect of consuming the same total amount of food in either one large meal or several small meals per d was studied using weanling male rats.

2. The increase in total body-weight was the same in both instances, but the weights of the liver, kidneys, femur, small intestine and stomach were greater, and those of the spleen and residual carcass were smaller, in meal-eating rats than in continuously fed control animals. These differences persisted into the adult state.

3. No differences in gross chemical composition were found between the corresponding organs of the two groups of rats, and the differences in weight appeared to be the result of changes in the general growth rate of individual organs.

4. The hypertrophy of the kidneys in meal-eaters was due to an increase in mean cell size, but the increased weight of the liver and reduced weight of the spleen appeared to be largely the result of changes in the number of cells present.
Biotin deficiency and fatty liver and kidney syndrome in chicks given purified diets containing different fat and protein levels
Authors: Whitehead C. C. , Bannister D. W. , Evans A. J. , Siller W. G. , Wight P. A. L.
Published: May 2005

1. The occurrence of biotin deficiency and fatty liver and kidney syndrome (FLKS) in chicks was studied using a 2 × 2 × 2 × 2 factorial-design experiment in which the variables were dietary biotin, fat and protein, and starvation.

2. The severity of biotin deficiency, using growth retardation and severity of dermal lesions as criteria, was least when the low-biotin diet also contained low levels of fat and protein. Addition of fat or protein increased the severity of the deficiency. Tissue fatty acid composition was affected by biotin deficiency only in those birds given the low-protein, low-fat diet. The main change was an increase in the ratio, 16:1 fatty acids:18:0 fatty acids. Plasma glucose and free fatty acid levels in non-fasted birds were unaffected by the dietary variables.

3. Mortality from FLKS with the diet containing low biotin, fat and protein levels was 52% at 28 d, but was reduced or eliminated when the dietary level of any of these ingredients was increased.

4. Starvation considerably increased the incidence of FLKS in the period immediately after fasting, and also affected plasma glucose and free fatty acid concentrations. Liver fatty acid composition indicated an increase in the proportion of 18:0 at the expense of 16:1 and 18:1, irrespective of diet, except when the bird developed FLKS, when 16:1 and 18:1 concentrations increased in proportion, at the expense of 18:0.

5. The relationship between biotin deficiency and FLKS, and a possible mechanism for the induction of FLKS by starvation are discussed.
Further studies of the dynamics of nitrogen metabolism in sheep
Authors: Nolan J. V. , Norton B. W. , Leng R. A.
Published: May 2005

1. A study of ammonia and urea metabolism in sheep was made using isotope dilution techniques with (15NH4)2SO4, [15N]urea and [14C]urea in order to determine quantitatively the movements of urea-N and NH3-N throughout the body of normal, feeding sheep.

2. Single injections of15N-labelled compounds were made into the rumen fluid NH3, caecal fluid NH3and the blood urea pools, in order to estimate the rates of flux through, and the transfer of N between, these and other nitrogenous pools in the body.51Cr EDTA was injected into the rumen and caecum with (15NH4)2SO4to allow estimation of fluid volumes and to provide an indication of mixing, and of times of transit of isotopes between different sampling sites in the digestive tract.

3. The sheep ate approximately 22 g lucerne chaff/h and the mean dietary N intake was 16.3 g/d.

4. The rate of flux of NH3through the rumen NH3pool was 15.0 g/d (i.e. 90% of the dietary N ingested; however, this amount also included N from plasma urea (1.1 g/d) and other endogenous sources including NH3derived from caecal NH3(0.4 g/d).

5. Only 40% of the N in isolated rumen bacteria was derived from NH3, indicating that a considerable proportion of their N requirements were obtained from compounds other than NH3(e.g. peptides and amino acids).

6. There was evidence of recycling of N between nitrogenous pools in the rumen, probably through rumen NH3→ microbial N → NH3.

7. It was estimated that 5.3 g blood urea-N/d entered the digestive tract: 20% of this urea was degraded in the rumen, 25% in the caecum and the remainder was apparently degraded elsewhere; there was evidence of urea degradation in the large intestine posterior to the caecum and it is suggested that urea degradation and absorption of the resultant NH3may occur in the ileum.

8. Of the 4.8 g N/d entering the caecal NH3pool, 4.2 g N/d left and did not return and the difference (0.6 g N/d) was recycled, possibly through caecal NH3→ microbial N → NH3.

9. A large proportion of the NH3entering the caecal NH3pool (70% or 3.2 g N/d) was apparently derived from degradation of nitrogenous products, other than urea, including rumen microbial N (1.0 g N/d) passing undigested from the small intestine.

10. Less than half the NH3-N of caecal origin entering the rumen passed through the blood urea pool; the remainder was apparently transported as other nitrogenous compounds in the blood or body fluids.

11. The results of the three experiments were combined in a general three-pool, opencompartment model which formally recognizes an unlimited number of other unspecified, interconnected pools together comprising the whole-animal system. Rates of flux through, and transfer of N between these and other nitrogenous pools in the body were calculated by solving this model and the information derived has been applied to whole-animal models with a view to subsequently using these models in computer simulation studies.
Utilization of14C-labelledEscherichia coliby rats
Authors: Tong A. , Fishert R. F.
Published: May 2005

1.Escherichia coliwas grown on14C-labelled glucose and fractions representing ‘whole cells’, ‘cell contents’ and ‘cell walls’ were administered orally to rats.

2.14C appearing as14CO2in the expired air and as unidentified radioactive products in urine and faeces was measured until the cumulative recovery showed little change with time.

3. All fractions were digested. The digestibility of cell waslls was less than that of the other fractions.

4. There was considerable variation among individual rats.
The effects of dietary histidine, methionine and homocystine on vitamin B12and folate levels in rat liver
Authors: Williams D. L. , Spray G. H.
Published: May 2005

1. L-histidine (20 g/kg) added to vitamin B12-deficient and cyanocobalamin-supplemented diets based on soya-bean flour reduced the growth of rats given the vitamin B12-deficient diet but stimulated growth of rats given the cyanocobalamin-supplemented diet. Liver weight (g/kg body-weight) increased, but the protein content of the livers decreased, in rats given histidine supplements. The histidine was associated with significantly higher folate concentrations in the livers of cyanocobalamin-supplemented rats.

2. Vitamin B12-deficient and cyanocobalamin-supplemented rats were given diets based on a mixture of amino acids that was balanced apart from methionine, which was added in various amounts, and with the addition of homocystine. The only vitamin B12-deficient rats which had reasonable gains in weight were those receiving a diet containing 8 g L-methionine/kg. The remainder, particularly those given diets containing only homocystine, had little or no increase in weight. All the cyanocobalamin-supplemented rats gained weight; those given diets containing 2 and 8 g L-methionine/kg, or 8 g homocystine/kg, had the highest gains.

3. There was a tendency for a higher concentration of either methionine or homocystine in the diet to be associated with higher concentrations of both folate and vitamin B12in the livers.

4. In vitamin B12deficiency methionine appeared to increase the accumulation of folate in the liver, affecting mainly the amounts of polyglutamate derivatives.
An improved procedure for the assay of available lysine and methionine in feedstuffs using Tetrahymena pyriformis W
Authors: Shorrock C.
Published: May 2005

1. A study was made of the assay of available lysine and available methionine using Tetrahymena pyriformis W, as applied to a variety of protein-rich feedstuffs.

2. Results were strongly influenced by the conditions under which the analyses were done. With most of the test samples predigestion with papain caused a large increase in the values obtained.

3. An improved assay procedure was developed which included enzymic predigestion of the test samples, ‘all-in’ sterilization of the medium constituents, and measurement of growth from extinction values. It gave results for available lysine that were broadly similar to those obtained in growth tests with rats, and in chemical tests by the method of Carpenter (1960). Values for available methionine agreed closely with those obtained in microbiological tests with Streptococcus zymogenes.
The utilization of diets containing acetate salts by growing lambs as measured by comparative slaughter and respiration calorimetry, together with rumen fermentation
Authors: Hovell F. D. Deb. , Greenhalgh J. F. D. , Wainaman F. W.
Published: May 2005

1. In a comparative slaughter experiment, growing lambs were given concentrate diets in which 14 or 19% metabolizable energy (ME) provided by barley was replaced by sodium, calcium and potassium salts of acetic acid. As the proportion of ME as acetate was increased, energy retention decreased. ME intake was 9271, 9430 and 9217 ± 67 kJ/d and energy retention was 2698, 2422 and 2280 ± 71 kJ/d for the diets containing 0, 14 or 19% ME as acetate respectively. There were no differences in protein deposition. The efficiency of utilization of acetate for energy retention (kf) was calculated by difference to be 3 and 10 ± 13% respectively for the diets containing 14 and 19% ME as acetate.

2. In a second experiment, growing lambs were given concentrate diets in which 4 or 16% ME provided by barley was replaced by salts of acetic acid, and utilization was measured by indirect calorimetry. There were no significant differences in the utilization of the diets for maintenance (km) or energy retention (kf). The km values were 82.4 ± 2.3 and 81.2 ± 0.7%, and kf values were 67.4 ± 4.5 and 65.8 ± 2.7% respectively for the diets providing 4 and 16% ME as acetate. The kf of the additional acetate in the diet providing 16% ME as acetate was calculated by difference to be 54%.

3. The acetate and Ca concentrations of the rumen digesta were increased by including acetate salts in the diet, but Na and K concentrations were not affected.

4. It is concluded that the best explanation for the poor utilization of acetate in the comparative slaughter experiment is that acetate was poorly utilized for lipogenesis. The calorimetry experiment contained relatively large errors, but the results suggest that acetate may be utilized efficiently in some circumstances. It is suggested that these results and apparently conflicting results in the literature may be explained by the concept that the efficient utilization of acetate is dependent upon the supply of glucose or glucose precursor.
The determination of volatile fatty acids in the caecum of the conscious rabbit
Authors: Parker D. S. , Mcmillan R. T.
Published: May 2005

1. A method of obtaining dialysed samples from the caecum of the conscious rabbit is described.

2. Values for total volatile fatty acid content and for molar proportions of individual volatile fatty acids in dialysate samples were in good agreement with those obtained from caecal material.

3. The volatile fatty acid level in the caecum throughout the day was determined using two groups of animals, one group fedad lib.and the other group on a restricted food intake. These results indicated a marked diurnal fluctuation in volatile fatty acid level in the caecum of rabbits fed once/d which was not evident in those fedad lib.