bluuebunny/crossref_metadata_2025_split huggingface dataset:
Metabolic studies of [75Se]selenomethionine and [75Se]selenite in the rat
Authors: Thomson Christine D. , Stewart R. D. H. 
Published: September 2005

1. Information was sought concerning the long-term fate of orally and intravenously administered [75Se]selenomethionine and [75Se]selenite in rats.2. Urinary and faecal radioactivity was assayed during the 1st week and whole-body radio-activity was determined weekly for 16 weeks. Rats were killed at intervals for analysis of 75Se tissue distribution.3. Intestinal absorption after oral administration was estimated to be 91–93% for selenite and 95–97% for selenomethionine.4. Urinary excretion of absorbed [75Se]selenite was greater than that of [75Se]selenomethionine during the 1st week.5. After the 1st week, whole-body retention diminished exponentially at a similar rate in rats given either selenomethionine or selenite. Except for the erythrocytes, 75Se content of individual tissues also decreased exponentially.6. It appears that, after an initial period, 75Se from either selenomethionine or selenite is metabolized similarly, suggesting that Se from both potential dietary sources is ultimately incorporated into the same metabolic pool.
The measurement of total body water in living pigs by deuterium oxide dilution and its relation to body composition
Authors: Houseman R. A. , Mcdonald I. , Pennie K. 
Published: September 2005

1. Deuterium oxide was used to estimate body water in twenty-four pigs of widely differing body composition and of average weight 83·9 kg.2. After infusion of the isotope, blood samples were collected every 30 min for 4 h. The resulting plasma was purified by a heat-distillation procedure, after which it was analysed for D2O by infrared spectroscopy.3. Approximately 24 h after infusion of the D2O each pig was killed, and its composition determined both by chemical analysis and physical dissection.4. Equilibration of D2O in the body was found to be complete within 2 h of injection of the tracer.5. The mean D2O space was found to be 8·6% greater than the mean empty body water space, but only 2·2% greater than the total body water space.6. Empty body water and total body water were estimated from the regression lines with residual standard deviations of 2·7 and 1·9% respectively. Similarly, the residual standard deviations of the regressions involving the other fat-free components were 6·3% for dissectible lean, 3·2% for fat-free mass, and 5·6% for crude protein.7. The residual standard deviations of the regressions in which the weights of dissectible fat and total body lipid were predicted were 6·0 and 6·7% respectively.
Morphological and functional aspects of oxytetracycline administration to conventional rats
Authors: Ruitenberg E. J. , Kampelmacher E. H. , Van Noorle Jansen Lucretia M. , Cohen Ph. 
Published: September 2005

1. Studies were performed with female rats to examine the effect of various levels of orally administered oxytetracycline on body-weight, weight of various portions of the intestinal tract, weight of mesenteric lymph nodes, distribution pattern of the tissue elements in the terminal portion of the ileum, and on the susceptibility to invasion bySalmonella typhi-murium.2. There was no growth promotion resulting from any antibiotic treatment. A consistent finding was the decrease in the wet weight of mesenteric lymph nodes in the rats given antibiotic.3. In the bacteriological test, no differences between antibiotic-fed and control groups were observed in isolations from the liver, spleen or intestinal tissue. It was concluded that there were no effects of oxytetracycline administration on invasive capacity of orally administeredS. typhi-murium.
Amino acid composition of hen's egg
Authors: Lunven P. , Marcq C. Le Clement De St , Carnovale E. , Fratoni A. 
Published: September 2005

1. Pooled samples of eggs from White Leghorn and New Hampshire hens given diets containing 110 and 200 g protein/kg were analysed for their content of essential amino acids.2. The amino acid composition of the hen's egg protein was not significantly affected by variations in breed and diet.3. The estimated values for lysine, total sulphur-containing amino acids and tryptophan in egg protein were higher by 8·9, 2·0 and 8%, respectively than those adopted for hen's egg by the FAO/WHO Expert Committee (FAO, 1965).4. The isoleucine content of egg protein was found to be much lower (338 mg/g nitrogen) than that reported by other workers.
Metabolic balance of zinc, copper, cadmium, iron, molybdenum and selenium in young New Zealand women
Authors: Robinson Marion F. , McKenzie Joan M. , Thompson Christine D. , Van Rij Anita L. 
Published: September 2005

1. Metabolic balance studies of zinc, copper, cadmium, iron, molybdenum and selenium were made on four young New Zealand women, using brilliant blue and chromic oxide as faecal markers.2. Zn, Cu, Cd and Fe concentrations in foods, faeces and urine were measured by atomic absorption spectrophotometry, whereas Mo was determined spectrophotometrically with dithiol and Se fluorimetrically with diaminonaphthalene.3. The dietary intakes of Zn, Cu and Fe were similar to those reported in the USA and the UK, whereas those of Cd, Mo and Se were less. The subjects ate a diet consisting of foods normally consumed by New Zealand women.4. For each subject there was little variation in the urinary output of each element for three 6 d periods. Day-to-day variation was small for each subject. The individual variation in urinary output of each element among the subjects was smaller when expressed as a ratio of intake, except for Mo.Retentions were small for Zn, Cu and Fe, all elements which are poorly absorbed. Balances of Se, Mo and possibly Cd were in equilibrium.
Changes in lipid metabolism in genetically different types of calves during chronic hyperthermia
Authors: O'Kelly J. C. 
Published: September 2005

1. The effects of chronically raised body temperature on lipid metabolism were studied in groups of 3-month-old British (Shorthorn × Hereford) and Zebu (Africander × British) bull calves. Calves in control groups at ambient temperature were pair-fed to calves housed in a climate room.2. In control groups, concentrations of plasma cholesterol and phospholipid were significantly higher and the excretion of fatty acids 14:0, 16:0 and 18:0 was lower in the Zebu than in the British calves.3. In the climate room the constant daily environmental temperature required to maintain an increase in rectal temperature of 1·3° was 33° for British and 38° for Zebu calves. Changes in respiration rate, water metabolism and nitrogen metabolism associated with hyperthermia were similar in both breeds.4. Hyperthermia in all animals was associated with lowered plasma concentrations of cholesterol and phospholipid and increases in the ratio of free to total cholesterol. It was without effect on the circulating concentrations of non-esterified fatty acids and about twice the amount of fat was excreted without change in its fatty acid composition.5. The results showed that, when control of normal body temperature was lost, increased rectal temperature led to similar metabolic changes in animals of both breeds.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Williams V. J. 
Published: September 2005

1. Three groups of sheep receiving 400, 800 and 1200 g lucerne chaff/d in equal hourly meals were killed. The large intestines were removed and divided into segments 15 cm long to provide information on the amounts and dry-matter contents of digesta and on the rates of passage of digesta and absorption of water along the large intestine.2. With increasing intakes of food, increases were observed along the entire large intestine in the amounts of wet digesta present, in the transit rates of digesta and in the rates of absorption of water. The mean retention time of digesta in the large intestine decreased with increasing food intake, being 1737, 1056 and 692 min respectively.3. Four patterns of sodium and potassium concentrations in digesta water along the large intestine were found.
Urinary aromatic acid excretion by fed and fasted sheep in relation to protein metabolism in the rumen
Authors: Martin A. K. 
Published: September 2005

1. Two adult wether sheep were maintained on a diet of hay and two on a diet of dried grass for 3 weeks before starvation for a period of 10 d. Urinary excretion of the following acids was determined when the animals were fed and when they were fasted: total diethyl ethersoluble acids of hydrolysed and unhydrolysed urine, hippuric acid, benzoic acid and phenylacetic acid. By the 5th day of fasting, urinary output of all acids had attained stable levels that did not change during the remaining starvation period. The output of all urine fractions except phenylacetic acid declined rapidly during the first 4 d of fasting: phenylacetic acid output by all sheep increased to a maximum during the first 4 d of fast and then declined to stable values (0·42–0·73 g/24 h) which were greater than those observed when the sheep were fed. It is concluded that prolonged retention of food and microbial residues in the digestive tract is responsible for the large output of phenylacetic acid in the urine of fasted sheep.2. Solutions of casein which supplied between 6·3. and 26·5 g nitrogen/24 h were infused into the rumens (fifteen experiments) or abomasums (sixteen experiments) of eight adult wether sheep. Ruminal infusions of casein caused increments in the urinary excretion of diethyl ethersoluble acids and phenylacetic acid. Both these increments were described by linear regression equations (P< 0·001), the coefficients of which showed that 284 ± 44 and 220 ± 21 mg benzoic acid equivalent were excreted as diethyl ether-soluble acids and phenylacetic acid respectively per g casein N infused. The phenylacetic acid excreted was equivalent to 95% of the phenylalanine of the infused casein. No increments in urinary benzoic acid were observed. One sheep scoured when it was given an abomasal infusion of casein. This was the only animal to show any increment in urinary aromatic acids when casein was infused into the abomasum.3. When four sheep were given two rations containing an excess of carbohydrate as sugarbeet pulp or rolled barley, 11 and 16% respectively of their phenylalanine intakes were excreted in the urine as phenylacetic acid. When the same sheep were given two rations containing an excess of N as linseed meal or field beans, 51 and 59% respectively of their phenylalanine intakes appeared in the urine as phenylacetic acid.4. Methods for the determination of creatinine, and of benzoic, phenylacetic, 3-phenylpropionic, cinnamic, hippuric and phenaceturic acids are described.5. It is suggested that the amount of phenylacetic acid excreted in the urine is a measure of the equilibrium occurring in the rumen between catabolism of phenylalanine and reutilization of the products of catabolism for phenylalanine synthesis.
Comparison of the development of proteolytic activity in the abomasum of the preruminant calf with that in the stomach of the young rabbit and guinea-pig
Authors: Henschel M. J. 
Published: September 2005

1. Proteolytic activity was measured in the abomasal contents of five calves during the first 7 weeks of life and in the stomach contents of rabbits and guinea-pigs during the first 4 weeks of life.2. The pattern of protease secretion in the abomasum varied considerably among individual calves; in addition to rennin, some pepsin activity was found in most animals from the first sampling at 9 d of age.3. Only pepsin was secreted in the guinea-pig stomach from birth, at a consistently high level at all ages.4. The main peak of proteolytic activity in the rabbit stomach during the 1st weekpost partumhad an optimum at pH 3·5–4·0, corresponding to that for calf rennin. During the 3rd week of life the main pepsin peak, with an optimum at pH 1·6–2·0, developed.5. Agarose gel electrophoresis of an extract of neonatal rabbit stomach mucosa showed the activity peak at pH 3·5–4·0 to be due to two slow-moving components of mobilities similar to that of crystalline rennin. At least one of these cross-reacted with antiserum to crystalline rennin.6. At 10 d and 3 weeks of age, activity at pH 1·6–2·0 was due to two faster-moving proteases, one being the main pepsin of the adult rabbit, which moved at the same speed as crystalline porcine pepsin, with the antiserum of which it cross-reacted.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Williams V. J. 
Published: September 2005

1. The rates of passage of markers of fluid and particulate digesta through the sheep alimentary tract have been described mathematically in single-injection experiments by analysing the concentration curves of marker excretion in faecal dry matter and then predicting these concentrations by means of an equation containing two exponential terms. Three components related to this equation are a transit time for digesta in the intestines, a half-time of marker in the reticulo-rumen and a half-time tentatively associated with the passage of marker through the caecum and proximal colon. With this approach no surgical interference with an animal is required to obtain meaningful information about gut function.2. Abomasal cannulation did not affect the rate of passage of 51Cr EDTA through the gut.3. The mean half-times (T1/2) for 51Cr EDTA in the reticulo-rumen and hind-gut, respectively, were 646 and 236 min for a roughage diet and 890 and 607 min for a diet consisting mainly of wheat grain, both diets providing approximately the same amounts of digestible dry matter. These results indicated that the changes in half-times were proportionately much greater in the caecum and proximal colon than in the reticulo-rumen. The mean transit time of marker through the digestive tract also increased from 721 to 1345 min when the concentrate diet was given.4. The complex of chromium-51 with EDTA was excreted faster in faeces than cerium-144–praseodymium-144 when both were given together as a single injection into the reticulorumen. This was caused mainly by differential rates of elimination of water and particulate matter from the reticulo-rumen.
Proteolytic enzyme activity in the gut of doe-suckled and hand-reared rabbits
Authors: Henschel M. J. 
Published: September 2005

1. Proteolytic activity in the stomachs and pancreases of infant doe- and hand-reared rabbits was studied to the age of 3–4 weeks.2. In the stomachs of both the doe- and hand-fed animals total proteolytic activity at birth was low, rising slowly during the first 2 weeks and then rapidly, until at 3 weeks of age the level was similar to that of the adult.3. In the pancreases of the doe-suckled pups the level of proteolytic activity was highest during the 1st week of life, falling steadily after that to a minimum at 3 weeks of age. In contrast in the hand-reared rabbits, it fell sharply during the 1st week and then rose, reaching at 2 weeks of age a level slightly higher than that found in the doe-suckled pups.4. Growth and survival of hand-reared rabbits during the first 12 d of life were improved by predigestion of the diet with trypsin and α-chymotrypsin.
The effect of bypassing the rumen with supplements of protein and energy on intake of concentrates by sheep
Authors: Ørskov E. R. , Fraser C. , Pirie R. 
Published: September 2005

1. Two experiments were conducted with young early-weaned lambs to measure the voluntary intake of dry concentrates when additional protein or lactose was given as a fluid preparation from a bottle.2. The voluntary intake of a barley–urea diet (130 g crude protein/kg) was increased by 10–15% as a result of giving 2·3 g nitrogen/d as a fish-protein concentrate in fluid suspension. Amounts greater than 2·3 g N/d did not further increase voluntary intake but increased growth rate and food conversion ratio. Urea given as a solution in water in the same way in amounts equivalent to 4·6 N/d had no effect on voluntary intake.3. The voluntary intake of a high-protein barley–fish-meal diet was decreased by giving 10 or 20% of the estimated intake as lactose by bottle. The results indicated that maximum energy intake was achieved with the basal diet, since the decrease in energy intake was about equal to the amount given in the solution bypassing the rumen.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Phillips G. D. 
Published: September 2005

1. Sheep were given 800 g lucerne chaff/d and the mean half-times of cerium-144 – praseodymium-144 and the complex of chromium-51 with EDTA were 811 and 604 min in the reticulo-rumen, 37 and 17 min in the abomasum and 413 and 406 min in the caecum and proximal colon respectively. The average time available for digestion and absorption in the abomasum was therefore very short relative to that in the other two organs.2. The half-times of the markers also indicated that particulate matter and water had different rates of turn over in the reticulo-rumen and abomasum but not in the caecum and proximal colon.3. Evidence is presented which suggests imperfect mixing of the digesta in the caecum and proximal colon.
Sulphur as a nutrient for Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M. 
Published: September 2005

1. Faecal and urinary sulphur excretions of Merino sheep given fifty-one forage diets were measured in 205 balance experiments to derive estimates of the dietary requirements of Merino sheep for S.2. Faecal S excretion varied with the S, organic matter and digestible organic matter intakes. Non-dietary faecal S excretion was estimated by regression analysis and was approximately 0·7 g S/kg organic-matter intake. Apparent S digestibility declined linearly with the reciprocal of dietary S content, and was predicted to be zero when the dietary S content was 0·81 g S/kg organic matter.3. Both urinary S excretion and S retention varied with the digestible S and digestible organic-matter intakes. Endogenous urinary S excretion was taken to be the urinary S excretion when digestible S intake was zero, and the sheep was at zero energy balance. It was estimated by regression analysis to be 38 mg S/d.4. The S and digestible S intakes necessary to maintain the fleece-free tissues in S equilibrium can be calculated from the equations derived in this study. An example is presented.
Sulphur as a nutrient for Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M. , Playne M. J. 
Published: September 2005

1. Estimates of sulphur retention by Merino sheep during growth, pregnancy and wool production, and of S excretion during lactation were obtained to derive estimates of the S requirements of Merino sheep.2. The S content of fifty Merino sheep was related by weighted regression analysis to age, live weight and (age × live weight). The quantity of S stored was calculated for varying rates of live-weight gain in sheep differing in age and live weight.3. The S contents of twenty-five samples of foetus, foetal membranes and uteruses were determined. Relationships between S content and days from mating were calculated, and differentiated to give daily net changes in S content during pregnancy.4. Milk production of twenty-seven Merino ewes was estimated on eight to ten occasions at approximately weekly intervals to the 84th day of lactation. The average S content was 472 mg/l; it increased on average by 1·0 mg/l per d of lactation. The mean S content of ninety-seven samples of wool averaged 34 g S/kg clean dry wool.5. It was concluded that wool represented the major demand for S by the Merino since approximately 70 g S were secreted in producing 2 kg clean wool, 50 g S in a lactation yielding 100 l milk and 8 g S in giving birth to a single lamb.
The metabolism of palmitic, stearic, oleic and linoleic acids in broiler chickens
Authors: Infield Jennifer M. , Annison E. F. 
Published: September 2005

1. Interrelationships between the level of dietary fat and the metabolism of palmitate, stearate, oleate and linoleate in the broiler chicken have been studied by means of isotope dilution techniques.2. The composition of the free fatty acid (FFA) and triglyceride fractions of plasma lipids was influenced by the level of dietary fat, but the only effect of diet on plasma concentration was the higher FFA levels after feeding in birds given the high-fat diet.3. The rates of entry and oxidation of the individual fatty acids were correlated with their concentrations in plasma, but were unrelated to the level of dietary fat. Slight differences in the metabolism of the individual fatty acids were observed.4. Acetyl-CoA carboxylase (EC6.4.1.2) and desaturase activities were higher in the livers of birds given the low-fat diet.
Kwashiorkor in western Nigeria: a study of traditional weaning foods, with particular reference to energy and linoleic acid
Authors: Naismith D. J. 
Published: September 2005

1. The fatty-acid composition of the plasma total lipids of children with kwashiorkor and of healthy infants was determined by gas–liquid chromatography. Breast milk from Yoruba mothers, and traditional weaning foods, were also analysed for fatty acids, and for protein, fat and carbohydrate.2. Evidence of essential fatty acid (EFA) deficiency was obtained in the children with kwashiorkor. The proportions of linoleic and arachidonic acids were reduced in the plasma lipids, whereas the endogenous eicosatrienoic acid showed a marked increase. The triene:tetraene ratio had the abnormally high value of 1·08. These changes were consistent with the prolonged ingestion of suboptimal amounts of linoleic acid.3. Breast milk was of good quality, with a particularly high concentration of retinol. The milk was also rich in linoleic acid, and was thus discounted as a factor in the development of EFA deficiency, but the weaning foods were found to provide substantially less than the minimum recommended intake of 1% of the total energy as linoleic acid.4. The maize pap with which the children with kwashiorkor had been fed for several months before the appearance of acute symptoms provided almost 7% of the energy as protein, but only 1·21 MJ (290 kcal)/kg. To satisfy energy requirements, it would have been necessary to consume 3–4 kg of the pap each day.5. It is concluded that the protein deficiency which leads to the development of kwashiorkor in the Yoruba community arises from a very severe restriction in energy intake rather than from the consumption of foods very low in protein at adequate or excessive levels of energy intake.
Iron fortification of dried skim milk and maize–soya-bean–milk mixture (CSM): availability of iron in Jamaican infants
Authors: Ashworth Ann , March Yvette 
Published: September 2005

1. The availability of iron added to dried skim milk and to maize–soya-bean–milk mixture (CSM) was measured by whole-body counting in thirty clinically healthy children and compared with the availability of Fe from ferrous ascorbate alone.2. The mean absorption of Fe added as ferrous sulphate to a test meal of dried skim milk was 9·5% when the test meal was given as a sweetened drink. When maize meal was added to the dried skim milk to produce a porridge the mean absorption of the supplementary Fe was reduced to 6·3%. The mean absorption of Fe given as ferrous ascorbate alone was 59·6%.3. These results differed from those reported for indirect tests done with animals in which the absorption of inorganic Fe added to milk-based feed preparations for infants was substantially greater than that of dietary Fe.4. The mean absorption of Fe added as ferrous fumarate to a test meal of maize–soya-bean–milk mixture was 6·0%, whereas that of Fe given as ferrous ascorbate alone was 63·5%.5. The amount of supplementary Fe added to maize–soya-bean–milk mixture (USA Department of Agriculture specification) was considered to be adequate.