bluuebunny/crossref_metadata_2025_split huggingface dataset:
Quantitative intestinal digestion of nitrogen in sheep given formaldehyde-treated and untreated casein supplements
Authors: Macrae J. C. , Ulyatt M. J. , Pearce P. D. , Hendtlass Jane 
Published: September 2005

1. In two experiments, sheep prepared with a rumen cannula and with re-entrant cannulas in the duodenum and ileum were continuously fed on diets of dried grass, dried grass plus formalin-treated casein, or dried grass plus untreated casein. Paper impregnated with chromic oxide was given once daily via the rumen fistula.2. In ten 24 h collections of digesta entering the duodenum and eleven 24 h collections of digesta reaching the ileum of sheep given dried grass, there were highly significant correlations between the 24 h flows of Cr marker and the corresponding flows of dry matter, organic matter, nitrogen, gross energy, hemicellulose and cellulose (P < 0.01) at both sites.3. Daily amounts of non-ammonia N and of individual amino acids entering and leaving the small intestine and of total N excreted in faeces and urine are given.4. Net retention of supplementary N was 36% when the supplement was administered as formalin-treated casein, but only 17% when it was administered as untreated casein.5. Formalin treatment of casein significantly increased the daily amounts of non-ammonia N entering the small intestine (P < 0.01) and the amounts of non-ammonia N apparently absorbed therein (P < 0.05).6. Apparent absorption of amino acids from the small intestine was significantly greater (P < 0.05) with treated casein than with untreated casein. There were relative increases in the small amounts of several free amino acids measured, including taurine, in the ileal digesta of sheep receiving the treated casein supplement.
Influence of feeding regimen and protein supplementation on the sites of net absorption of magnesium in sheep
Authors: Grace N. D. , Macrae J. C. 
Published: September 2005

1. Sheep prepared with a rumen cannula and with re-entrant cannulas at the proximal duodenum and terminal ileum were given diets of dried grass, and dried grass supplemented with formalin-treated or untreated casein. They were fed either continuously or once daily. Paper impregnated with chromic oxide was given once daily via the rumen fistula.2. The observed daily flows of magnesium at the duodenum and ileum were highly correlated with the corresponding flows of Cr.3. There was a net absorption of Mg from the stomach as well as the intestinal region of all sheep.4. Protein supplementation had no effect on the extent or sites of Mg absorption, but altering the feeding regimen changed the proportions of the net absorption of Mg occurring in the stomach and intestinal regions.
The influence of activity and size of meals on caloric response in women
Authors: Swindells Yola E. 
Published: September 2005

1. The oxygen utilization of ten women was measured after consuming meals supplying 230–1200 kcal (0.96–5.02 MJ) in three experiments.2. In the first experiment four subjects consumed one-ninth, one-third or one-half of the daily allowance and the oxygen consumption was measured for 3 h after the meal. The response was unrelated to the size of the meal.3. Resting conditions were rigidly controlled in the second experiment. Each woman reclined on a bed for 5–7 h while the effect of a meal providing 600 or 900 kcal (2.51 or 3.77 MJ) for the two lighter subjects and 800 or 1200 kcal (3.35 or 5.02 MJ) for two heavier subjects was measured. A greater increment in energy expenditure was obtained after the larger meal for each subject. The effect of two 30 min walks before and after the large meal was negligible.4. In a third experiment the effect of exercise was measured with five women consuming 900 kcal (3.77 MJ) (a) followed by 5 h rest and (b) preceded and followed by exercise (two 30 min walks on a treadmill). The energy increment during 90 min after the meal was equivalent in (a) to 15 kcal (63 kJ) per h and in (b) to 16 kcal (67 kJ) per h, whereas the response following exercise but without food was insignificant.
The influence of the intestinal microflora on disaccharidase activities in the chick
Authors: Siddons R. C. , Coates Marie E. 
Published: September 2005

1. Maltase sucrase, palatinase (the enzyme that hydrolyses palatinose, i.e. 6-o-α-D-gluco-pyranosyl-D-fructose) and lactase activities were measured in the small and large intestines of germ-free and conventional chicks given either a diet of purified ingredients or a practical chick mash.2. With the purified diet there were no differences in body-weight or small intestinal disaccharidase activities between germ-free and conventional chicks. With the chick mash the germ-free birds were heavier and had higher total amounts of maltase, sucrase and palatinase activities in the small intestine than did their conventional controls. When disaccharidase activities were expressed in terms of body-weight there were no differences between birds in the two environments. Enzyme activities were consistently higher in the birds given chick mash.3. Inclusion of milled fibre in the purified diet did not increase the weight or disaccharidase activities of the small intestine in either environment.4. Lactase was virtually absent from the small intestine of birds in both environments and from the large intestine of germ-free birds. There was appreciable lactase activity in the large intestinal contents of conventional chicks, and it was increased by inclusion of lactose in the diet.5. When lactose was the sole source of carbohydrate the birds grew poorly but mortality rate was less among conventional compared with germ-free chicks.6. It was concluded that the presence of micro-organisms has no direct effect on disaccharidase production in the small intestine of the chick. Microbial lactase is present in the large intestine, and at least some of the products of its action can be utilized by the bird.
Intestinal alkaline phosphatase and inorganic pyrophosphatase activities in the zinc-deficient rat
Authors: Williams R. B. 
Published: September 2005

1. The effect of zinc deficiency on the activities of rat duodenal alkaline phosphatase and inorganic pyrophosphatase has been investigated.2. Zn deficiency adversely affected the activity of these enzymes before growth rate and food intake were reduced.3. The level of food intake was without effect on the activity of alkaline phosphatase but markedly influenced that of inorganic pyrophosphatase.4. The relevance of changes in the activities of Zn-dependent intestinal enzymes to the food intake of Zn-deficient rats is discussed.
Production within the rumen and removal from the blood-stream of volatile fatty acids in sheep given a diet deficient in cobalt
Authors: Marston Hedeey R. , Allex Shirley H. , SMITH R. M. 
Published: September 2005

1. The production and metabolism of volatile fatty acids were studied in sheep offered a cobalt-deficient diet.2. The molar proportions of acetic (60%), propionic (26%) and butyric (14%) acids in the rumen fluids of sheep given the Co-deficient diet, but whose stores of vitamin B12were adequate, were similar before and after administration of an oral supplement of Co.3. In pair-fed sheep, one member of which was vitamin B12-deficient and the other (control) treated with vitamin B12parenterally, the concentrations after feeding of both total and individual volatile fatty acids in the blood tended to be higher in deficient than in control sheep.4. Following injection of the respective salts of individual volatile fatty acids into the blood-stream, formate clearance was apparently not affected, whereas that of acetate was slightly, and that of propionate very significantly, delayed in vitamin B12-deficient sheep compared with pair-fed control animals.5. Acetate metabolism was retarded in the presence of propionate; the effect was greater in deficient than in pair-fed control sheep.6. The hypothesis is advanced that it is the failure to metabolize propionate at the normal rate that leads to the progressive loss of appetite in vitamin B12-deficient sheep.
The replacement of protein concentrates by synthetic lysine in the diet of growing pigs
Authors: Braude R. , Mitchell K. G. , Myres A. W. , Newport M. J. , Cuthbertson A. 
Published: September 2005

1. Pigs from 20 to 60 kg live weight were fed on cereal diets, supplemented only with vitamins and minerals, with and without supplementary lysine.2. Growth rate, feed:gain ratio and carcass quality of pigs given a high-barley diet (75% barley meal, 23% wheat offal) were inferior to those of pigs given a high-wheat offal diet (75% wheat offal, 23% barley meal).3. On both diets, but particularly on the high-barley diet, performance was improved by the addition of L-lysine (to give a total lysine content of 5.2 g/16 g nitrogen, approximating to that present in a standard barley meal–wheat offal diet supplemented with 7% white fish meal).4. Percentage N retention was improved on both diets by supplementation with lysine.5. Results for carcass composition showed that the carcasses of pigs fed on the unsupplemented high-wheat offal diet contained more lean tissue than those of pigs given the unsupplemented high-barley diet. Lysine supplementation resulted in an increased content of lean tissue on both diets, the percentage increase due to lysine being greater (but not significantly so) on the high-barley diet. The increased lean content was reflected in the carcass measurements but not in the total N retention values, which did not differ significantly between treatments.6. The results are discussed in relation to the shortage and high cost of animal protein concentrates and the possible replacement of these concentrates with synthetic amino acids.
Dynamic aspects of ammonia and urea metabolism in sheep
Authors: Nolan J. V. , Leng R. A. 
Published: September 2005

1. To obtain a quantitative model for nitrogen pathways in sheep, a study of ammonia and urea metabolism was made by using isotope dilution techniques with [15N]ammonium sulphate and [15N]urea and [14C]urea.2. Single injection and continuous infusion techniques of isotope dilution were used for measuring ammonia and urea entry rates.3. Sheep were given 33 g of chaffed lucerne hay every hour; the mean dietary N intake was 23.4 g/d.4. It was estimated that 59% of the dietary N was digested in the reticulo-rumen; 29% of the digested N was utilized as amino acids by the micro-organisms, and 71% was degraded to ammonia.5. Of the 14.2 g N/d entering the ruminal ammonia pool, 9.9 g N/d left and did not return to the pool, the difference of 4.3 g N/d represented recycling, largely within the rumen itself (through the pathways: ruminal ammonia → microbial protein → amino acids → ammonia).6. Urea was synthesized in the body at a rate of 18.4 g N/d from 2.0 g N/d of ammonia absorbed through the rumen wall and 16.4 g N/d apparently arising from deamination of amino acids and ammonia absorbed from the lower digestive tract.7. In the 24 h after intraruminal injection of [15N]ammonium salt, 40–50% of the N entering the plasma urea pool arose from ruminal ammonia; 26% of the15N injected was excreted in urinary N.8. Although 5.1g N/d as urea was degraded apparently in the digestive tract, only 1.2g N/d appeared in ruminal ammonia; it is suggested that the remainder may have been degraded in the lower digestive tract.9. A large proportion of the urea N entering the digestive tract is apparently degraded and absorbed and the ammonia incorporated in the pools of nitrogenous compounds that turn over only slowly. This may be a mechanism for the continuous supply to the liver of ammonia for these syntheses.10. There was incorporation of15N into bacterial fractions isolated from rumen contents after intraruminal and intravenous administration of [15N]ammonium salts and [15N]urea respectively.11. A model for N pathways in sheep is proposed and, for this diet, many of the pool sizes and turn-over rates have been either deduced or estimated directly.
The effect of ammonium chloride on calcium metabolism in sheep
Authors: Braithwaite G. D. 
Published: September 2005

1. A combination of balance and isotope techniques has been used to study the effects of dietary supplements of NH4Cl, given for 1 and 10 weeks, on calcium metabolism in 1- and 2-year-old wethers.2. The main effects of the NH4C1 supplements were to decrease urinary pH, increase urinary Ca excretion and to increase Ca absorption and the percentage of dietary Ca absorbed.3. The results were different from those obtained by other workers in man and rat, and possible explanations of this difference are discussed.4. A difference was also found between 1- and 2-year-old animals in their long-term response to the NH4Cl supplement. This difference may have been due to a lack of available Ca in the diet of the younger animals, and prolonged ingestion of NH4C1 may increase the amounts of Ca absorbed and retained.
Dietary intake of manganese by New Zealand infants during the first six months of life
Authors: McLeod Barbara E. , Robinson Marion F. 
Published: September 2005

The manganese concentrations of breast-milk, liquid and dried cow's milk, and foods widely used in mixed feeding of infants in New Zealand, were measured by atomic absorption spectrophotometry.The dietary supply of Mn to infants during the first 6 months was calculated. This varied from 2.5 to 75 μg/d per kg body-weight depending upon the age of the infant, the type of milk and the quantity of solid foods consumed. Young infants in New Zealand received about as much Mn as has been reported for infants elsewhere.
The digestion of heather (Calluna vulgaris) by red grouse (Lagopus lagopus scoticus)
Authors: Moss Robert , Parkinson J. A. 
Published: September 2005

1. In the wild, red grouse live largely on heather, a high-fibre (25%), low-protein (7%) food. Digestibility trials were carried out under semi-natural conditions, with magnesium as a digestibility marker. Two trials were done, one in autumn and one in spring.2. Digestibility of the dry matter varied from 21 to 30% and metabolizable energy from 1.1 to 1.6 kcal/g. These variations were inversely related to intake and could partly be accounted for by facultative variations in holocellulose and lignin digestion.3. Digestion of soluble carbohydrates, protein (measured as α-amino-nitrogen) and holocellulose varied between trials according to the initial concentration in the food. The digestibility of soluble carbohydrate was high (78–83%) in autumn (16% in food) and low (61–66%) in spring (11% in food) and that of protein was relatively low (24–31%) in autumn (6% in food) and high (42–48%) in spring (7% in food). Digestibility of crude fat was 30–33% for four birds and 20% for one bird.4. By comparison with poultry, voluntary intake of dry matter was very high relative to body-weight and intake of energy appeared to be adequate. None the less, all birds lost weight during the trials, presumably for reasons other than energy shortage.5. Urate excretion increased in parallel with body-weight losses, but formed only 2% of the total N output at low weight losses, in which event the main nitrogenous compounds in the droppings were α-amino N (presumably largely from undigested protein), ammonium salts and ornithuric acid.6. The ornithuric acid was presumably a detoxication product of prolignins and possibly tannins and other polyphenols. Its excretion by grouse corresponds to the excretion of hippuric acid by ruminants.
Nutrient stores in human foetal livers
Authors: Iyengar Leela , Apte Sharad V. 
Published: September 2005

1. Liver composition and hepatic nutrient stores in foetuses born to mothers belonging to a low socio-economic group of the population were determined.2. The contribution by the liver to body-weight and the concentration of water and nitrogen in liver at different gestational ages were relatively constant.3. Total iron and copper contents of the liver were in the normal reported range but the ferritin content was considerably lower in the present investigation.4. Hepatic stores of vitamin A, vitamin B12and folate were lower than the values that have been reported elsewhere.5. It is suggested that inadequate stores of iron, vitamin A, vitamin B12and folate in these infants may predispose them to the early development of some deficiency diesease.
The effects of dietary protein and non-protein nitrogen on liver glutamate dehydrogenase activity in the chick
Authors: Davis K. H. , Martindale C. H. 
Published: September 2005

1. Diets containing varying levels of crude protein (CP) in the range 9.5–18.5% with and without supplements of diammonium citrate (DAC) as a source of non-protein nitrogen (NPN) were given to 160 growing chicks from 2 to 4 weeks of age, and their livers were assayed for glumate dehydrogenase (GDH) activity.2. Growth rate and total liver protein were increased by raising the protein level from 9.5 to 18.5% CP. Chicks receiving 9.5 or 12.5% CP were heavier when they had also received 1.94% DAC. At 18.5% CP the addition of 3.88% DAC depressed growth.3. GDH activity per unit liver weight and total GDH activity increased with dietary protein level but there were no consistent responses to DAC supplements. It was concluded that liver GDH activity did not provide a useful index of the utilization of NPN.
The influence of maize oil on the fatty acid composition of tissues of calves with and without vitamin E
Authors: Poukka Ritva , Oksanen Aili 
Published: September 2005

1. Fatty acid levels were studied in the tissues of 1-week-old calves receiving maize oil (in filled milk) with and without supplementary α-tocopherol. The calves that were not given vitamin E developed muscular dystrophy.2. Decreased amounts of linoleic acid and increased amounts of arachidonic acid were found in nearly all the lipid fractions of skeletal muscles, hearts, livers and kidneys of vitamin E-deficient calves. The concentration of the polyunsaturated fatty acids beyond arachidonic acid remained about the same in both groups. There was a significant decrease of 20:2Ω6 fatty acid in the phosphatidy1 choline, phosphatidy1 ethanolamine and free fatty acid fractions in the livers and kidneys of vitamin E-deficient calves.3. It is suggested that vitamin E has an inhibitory effect on the desaturating but not on the chain-elongation enzymes of microsomes in the liver and kidney.4. Maize-oil feeding had only a slight effect on erythrocyte fatty acid composition, and the erythrocyte haemolysis test was negative even in the vitamin E-deficient animals.
Effect of diet on disaccharidase activity in the chick
Authors: Siddons R. C. 
Published: September 2005

1. The influence of diets, particularly dietary carbohydrate, on the development of the intestinal disaccharidases of the chick was studied.2. The maltase activity in the small intestine was similar in groups of 25-d-old chicks that had been fed, from hatching, on diets containing either starch, glucose, maltose, sucrose, or a mixture of 50% glucose + 50% lactose, as the source of carbohydrate. The sucrase activity in the small intestine was also similar in the different groups, as was the palatinase (the enzyme that hydrolyses palatinose, i.e. 6-o-α-D-glucopyranosyl-D-fructose) activity. The maltase activity in the large intestine of the group receiving the starch-containing diet was significantly increased. The lactase activity in the large intestine was significantly higher in the group receiving the 50% glucose + 50% lactose and in the group receiving glucose than in the other groups. Body- weights were similar with all the diets.3. The fasting of chicks for a period of 3 d caused a marked decrease in the activity of the disaccharidases and in the protein content of the homogenates of the small intestine.4. The maltase activity was similar in the small intestine of chicks that had been fasted for 3 d and subsequently given diets containing either starch, glucose, maltose, sucrose or fructose for 5 d. The sucrase activity, the isomaltase activity and the palatinase activity were also similar in the small intestine of the chicks given the different diets. Feeding with a fat-free or protein-free diet did not affect the development of disaccharidases in the small intestine, but feeding with a carbohydrate-free diet resulted in reduced disaccharidase activity.5. The results suggest that, in the chick, dietary carbohydrate is necessary for the development of the disaccharidases but the form of the carbohydrate is not important. None of the sugars tested had a specific effect on a particular disaccharidase.
Effects of cyclamate and food restriction on various metabolites in the rat
Authors: Prosky L. , O'Dell R. G. 
Published: September 2005

1. Rats were given stock chow diets containing several levels of calcium cyclamate to study the effects on growth and on some metabolites in liver and blood.2. Levels up to 1% in the diet produced diarrhoea without affecting body-weight. At a level of 3% in the diet, body-weight was decreased by 12% in 8 weeks.3. No changes were noted in liver protein, lipid and RNA-P and serum protein and lipid.14CO2excretion during the 1st hour after [14C]glucose administration also remained unchanged.4. Adult rats weighing 500 g were given, at a restricted intake, a diet with variations in its fat and cyclamate contents.5. During 15 weeks, the animals given the fat-supplemented diet plus cyclamate lost twice as much weight as controls without cyclamate and also excreted 20% more14CO2. When the food intake was further restricted for 15 weeks weight losses in all groups were the same.6. Serum lipid and free cholesterol concentrations were lowered in the cyclamate group.14CO2excretion for this group was 35% higher than for controls, indicating increased metabolic activity.7. Concentrations of aspartate, glutamate, lactate, succinate, malate and glycerol-I-phosphate in liver were within normal limits. There were indications of decreased levels of lactate and succinate in cyclamate-fed rats which could be associated with aerobiosis and increased metabolic activity.
Energy expenditure of soldiers in a warm humid climate
Authors: Haisman M. F. 
Published: September 2005

1. Energy expenditure determinations have been made on thirty-two soldiers newly arrived in the warm humid climate of southern Malaya. Ergometer cycling was investigated as well as everyday activities such as lying, sitting, riding in a trunck, abultions, buildings a jungle camp and walking with loads over four different routes.2. The inter-individual variation in the gross energy expenditure (kcal/min and kJ/min) of each activity has been compared with the variation in energy expenditure standardized for body-weight, surface area and lean body mass. Standardization for body size did not consistently or effectively reduce the coefficients of variation of energy expenditure.3. The gross energy expenditure of most activities was significantly correlated with bodyweight, surface area or lean body mass but the correlation coefficients were not of a high order, suggesting that less than 41% of the inter-individual variation in energy expenditure was accounted for by variation in body size.4. The energy expenditure of walking at various speeds over both firm and uneven terrain was related to the square of the walking speed and the total weight of the man and his equipment (correlation coefficients 0.89–0.92, P < 0.001).