bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of catabolic doses of corticosterone on heat production in the growing rat
Authors: Coyer Penny , Cox M. , Rivers J. P. W. , Millward D. J. 
Published: May 2005

1. The effect of corticosterone treatment on energy balance and heat production was investigated in growing rats. Animals were treated with daily subcutaneous injections of a vehicle containing 0, 50 or 100 mg corticosterone/kg for 5 d.2. Measurements of digestible energy intake and urinary energy losses showed that corticosterone treatment resulted in a depression of metabolizable energy intake due to elevated urinary energy losses resulting from massive glucosuria.3. Measurements of the metabolizable energy intake and the change in carcass energy indicated that at 50 mg/kg energy deposition and heat production were reduced, whilst at 100 mg/kg energy deposition was completely abolished with heat production increased. Postprandial oxygen consumption was unchanged at 50 mg/kg and increased at 100 mg/kg.4. Factorial analysis of these results based on reported values for the energy cost of protein and fat deposition indicated that (a) the depression of total heat production at 50 mg/kg could be entirely accounted for by the concomitant suppression of growth, and (b) the elevation of total and postprandial heat production at 100 mg/kg reflected a specific influence of corticosterone on thermogenesis.5. The significance of these findings is discussed in the light of reports that corticosterone in low doses suppresses heat production.
The nitrogen requirement of the weanling kitten
Authors: Smalley Katherine A. , Rogers Quinton R. , Morris James G. , Eslinger Loren L. 
Published: May 2005

1. The nitrogen requirement of the weanling kitten was determined in a series of three experiments. In each experiment, diets were formulated to provide the growing kitten with the essential amino acids at or above the level of requirement. Expt 1 utilized a 4 x 4 balanced Latin square design with two groups of kittens (four male and four female). The crystalline L-amino acid diets were presented at four levels of dietary crude protein (N x 6.25) of 140, 160, 180 and 200 g/kg diet. The design for Expts 2 and 3 was a 6 x 6 balanced Latin square. For each of these experiments, groups of six male and six female kittens were assigned to diets. The six levels of dietary crude protein were 120, 140, 160, 180, 200 and 220 g/kg diet; dietary N was supplied by crystalline L-amino acids for Expt 2 and casein plus a supplementary amino acid mix for Expt 3. Food intake, weight gain and N retention were determined in each experiment.2. A sigmoidal model y =P1+ P2/[1 +e(p2+p4. x)] was fitted to the response of weight gain and N retention to dietary N. The calculated requirement (95% of the upper asymptote, P1 + P2) for these experiments varied from 170 to 230 g protein/kg diet with the majority of these values falling between 180 and 200 g protein/kg.3. On the basis of these three experiments, the kitten's requirement for dietary crude protein is between 180 and 200 g/kg diet (28.8–32.0 gN/kg) for purified diets which provide a calculated 21 MJ metabolizable energ//kg diet.
The digestion of fibre by pigs
Authors: Stanogias George , Pearce G. R. 
Published: May 2005

1. The effect of including lupin (Lupinussp.) hulls, maize cobs, wheat bran and lucerne (Medicago sutiva) stems in a basal fibre-free diet on the concentrations and the relative proportions of volatile fatty acids (VFA) in the proximal colon of pigs, 17–18 h after feeding, was studied.2. Concentrations of total VFA in the proximal colon increased with increasing levels of neutral-detergent fibre (NDF) intake, and this increase was highly dependent on the source of NDF in the diet.3. Molar proportions of the VFA were significantly affected by the level of NDF intake only in the cases of acetic and butyric acids, whereas the source of dietary NDF had a marked influence on the molar proportions of all acids.4. The results indicate that the extent of fermentative breakdown of fibre in the pig intestine can be influenced substantially by the type and the level of fibre in the diet.
The digestion of fibre by pigs
Authors: Stanogias George , Pearce G. R. 
Published: May 2005

1. The aim of the study was to determine the relative effects of feeding growing pigs with graded amounts of neutral-detergent fibre (NDF) from various sources on the empty wet weight of segments of the pig gastrointestinal tract, on the weight and moisture content of their digesta, and on the pattern of digesta movement in them.2. Increased NDF intakes were associated with significantly higher wet weights of all gastrointestinal segments and increased lengths of the caecum. The lengths of both the small and the large intestines were unaffected by the ingestion by the pigs of different amounts of NDF from various sources. However, the caecum responded to these increased intakes of NDF by significant increases in length. The source of NDF in the diet was a factor that markedly influenced both the length and the weight of the distal colon. The nature of these increases in weight and length morphologically and their biological significance have not been determined.3. Despite some significant differences, neither the type nor the level of dietary NDF had any appreciable effect on the dry weight and on the proportion of dry matter (DM) of the contents in the stomach. As the level of NDF intake was increased, more undigested dietary material was found in all segments of the digestive tract of the pigs. The proportion of DM in the residues decreased progressively from the caecal contents to the contents of the distal colon. In most cases the degree to which the level of NDF intake affected the weight of the contents and the proportion of DM in them was highly dependent on the source of NDF in the diet.4. The distribution of the feed consumed in the morning and in the evening, as measured with stained feed particles and polyethylene beads, was extremely variable. It is concluded that prolonged intakes by pigs of diets containing high levels of fibre may lead to a hypertrophy and hence increased weight of segments of the gastrointestinal tract.
The effect of indigestible particles on digestive transit time and colonic motility in dogs and pigs
Authors: Cherbut Ch. , Ruckebusch Y. 
Published: May 2005

1. The myoelectric activity of the colon was examined in three dogs and three pigs when they were given a basal diet or a basal diet plus indigestible particles (IP), 2 mm in diameter, at 100 g/kg dry matter. The mean retention time was determined using coloured discs as a marker added to the daily meal.2. Colonic electromyograms of dogs and pigs given IP revealed a 30% reduction in the number of long spike bursts (LSB) when compared with controls. The other components, propulsive migrating spike bursts (MSB) or non-propulsive short spike bursts (SSB), were unchanged. Mean retention time was decreased from 28.6 h to 17.6 h in dogs and from 129 h to 94.2 h in pigs.3. These changes developed progressively during 3–4 d in both species, suggesting that the reduction in motor activity was an adaptation to the changes in bulk contents.4. From the decreased motility of the colon linked to the reduction of LSB and paralleled by an increased transit time, it was concluded that one of the functions of the LSB is to impede the passage of digesta.
Retention time of chromium-labelled feed particles and of water in the gut of sheep given hay and concentrate at maintenance
Authors: Lindberg J. E. 
Published: May 2005

1. Sheep were given a diet of 400 g chopped grass hay/d and 500 g crushed barley/d in three equal meals. The mean retention time in the whole gut (MRT) and the rumen retention time (RRT) of chromium-labelled feed particles and of water were estimated from marker concentrations in faecal samples.2. MRT of Cr-labelled hay (Cr-H), barley hulls (Cr-Bh), crushed peas (Pisum sativum) (Cr-CP) and rapeseed meal (Cr-RSM) were 53.5, 52.3, 44.3 and 37.0 h respectively when estimated from total faecal collections. The estimates obtained from spot samples of faeces were almost identical.3. RRT of Cr-H, Cr-Bh, Cr-CP, Cr-RSM (Expts 1, 2 and 3) and Cr-labelled cottonseed meal (Cr-CSM) was 35.9, 36.7, 25.3, 18.8, 19.8, 22.8 and 25.3 h respectively.4. The Cr-labelled feed particles showed marked variations in density in water (Dω). However, both MRT and RRT were closely related to Dω, (r—0.88 and —0.95 respectively).5. Rumen outflow rates of Cr-RSM in individual animals were related to the rumen outflow rates of water (r 0.76).
The threshold growth response ofLactobacillus caseito 5-methyl-tetrahydrofolic acid: implications for folate assays
Authors: Wright A. J. A. , Phillips D. R. 
Published: May 2005

1. The comparative and absolute growth response of Lactobacillus casei was measured nephelometrically for time periods of 17–23 h in the microbiological assay of folic acid and 5-methyl-tetrahydrofolic acid at concentrations of 0–8 ng/10 ml basal medium at pH 6.8.2. At concentrations of 0–1 ng/10 ml the comparative growth response to 5-methyl-tetrahydrofolic acid was markedly depressed whereas growth was the same at 2 ng/10 ml and above. Comparative growth was unaffected by the length of assay incubation, depressed growth being due to differences in log-phase growth rates with the rate-plot for 5-methyl-tetrahydrofolic acid being sigmoidal and for folk acid being a rectangular hyperbola with linearity only in the 0–1 ng/10 ml range. The reciprocal rate-plot for folic acid was linear whereas that for 5-methyl-tetrahydrofolic acid was coincidental only in part, giving rise to the same estimate of maximum velocity and substrate concentration for half-maximum velocity, with the exhibition of a strong threshold at low concentration.3. A previous observation (Phillips & Wright, 1982) that the L. casei growth response to 5-methyl-tetrahydrofolic acid may be significantly less than that to folic acid is confirmed as is the long-established view that the response to both folates may be equal. In the light of current knowledge regarding folate-binding, transport and metabolism by L. casei, it is argued that the intracellular oxidation of 5-methyl-tetrahydrofolic acid to 5, 10-methylene-tetrahydrofolic acid is a rate-limiting step at low substrate concentrations, subsequently giving rise to a threshold growth response peculiar to 5-methyl-tetrahydrofolic acid. Since the rate of L. cusei growth with folk acid is not linearabove 1 ng/10 ml, it is recommended that microbiological folate assays be conducted only in the 0–1 ng/10 ml range and at a pH that elicits the same growth response from L. casei to 5-methyl-tetrahydrofolic acid as to folic acid and other folate monoglutamates.
The retention of 59Fe and 65Zn by preruminant lambs given milk-substitutes based on either casein or soya-bean-protein isolate
Authors: Hill R. , Walker D. M. 
Published: May 2005

1. Eight newborn lambs were given milk-substitutes based on casein (n 4) or a soya-bean-protein isolate (n 4). On the morning before a 10 d collection period, the milk-substitutes were supplemented with 59Fe as ferric chloride and 5Zn as zinc chloride. Faeces and urine were collected daily and determinations of 59Fe and 65Zn were made on these separately. During a second 10 d period the dosing procedure and collection were repeated but the diet of each lamb was reversed.2. Mean retention of 59Fe in lambs given the casein diet was 0.50 (SE 0.12) and in those given the soya-bean-protein diet 0.06 (SE 0.05). There were large variations among animals but the treatment effect was significant at P < 0.05. Retention of 65Zn was significantly greater than that of 59Fe for all lambs but the effect of dietary treatment was similar to that for Fe. 65Zn retention values for casein and soya-bean-protein diets were 0.84 (E 0.06) and 0.52 (SE 0.03) respectively, and the difference was significant at P < 0.01.3. There were only very small amounts of 59Fe and 65Zn in urine, representing 0.002–0.003 of the dose.
Intestinal cellular proliferation and protein synthesis in zinc-deficient rats
Authors: Livesey Susan Southon G. , Gee Jennifer M. , Johnson I. T. 
Published: May 2005

1. Immature male Wistar rats were given a low-zinc semi-synthetic diet (2 mg Zn/kg) for 28 d. Control groups received a similar diet supplemented with 58 mg Zn/kg either adlib.or in amounts matched to the consumption of the Zn-deficient group. Rates of growth, food consumption and small intestinal length were significantly reduced in the Zn-depleted rats.2. Zn deficiency in the rat was associated with a reduction in the ratio, crypt:villus and a lower rate of crypt cell division in the jejunum. This resulted in a substantial decrease in the net influx of new cells into the villi of the Zn-deficient animals compared with controls.3. The fractional rates of protein synthesis in jejunal mucosa were measured by a technique based on the determination of L-[4-3H]phenylalanine incorporation. There was no evidence of a decline in the protein synthetic rate in total mucosa from Zn-deficient rats.4. It is suggested that a reduction in cell influx into the villi may be responsible for the morphological and functional changes observed in the small intestine of rats fed on a low-Zn diet.
Influence of feed intake and starvation on the magnitude of Na+,K+-ATPase(EC 3.6.1.3)-dependent respiration in duodenal mucosa of sheep
Authors: McBride B. W. , Milligan L. P. 
Published: May 2005

1. Oxygen consumption and Na+,K+-ATPase(EC 3.6.1.3)-dependent (ouabain-sensitive) and -independent respiration were measured for duodenal mucosa biopsies from 10-month-old sheep given two levels of digestible energy (DE) intake (7.6–7.7 and 14.8 MJ lucerne (Medicago sativa) pellets/d) and following 48 h of starvation.2. The mucosal biopsies were determined to be structurally intact and free of adherent bacteria on histological and scanning-electron-microscope examinations.3. The use of D-glucose as a substrate during incubations did not elevate (P > 0.05) the respiration indices of the biopsies over those measured during acetate incubations.4. Glucose uptake did not (P > 0.05) influence the Na+,K+-ATPase-dependent respiration of the mucosal biopsies.5. Na+,K+-ATPase-dependent respiration accounted for 50% of the total O2, consumption of the mucosal biopsies of sheep given the lower level of DE.6. Total O2, consumption of the duodenalmucosa was not (P > 0.05) increased when sheep were given the higher level of DE but Na+,K+-ATPase-dependent respiration of the mucosa was elevated (P < 0.01) by 37% during this period.7. When sheep were starved for 48 h, total O2, consumption of the mucosal biopsies was not (P > 0.05) affected, however, Na+,K+-ATPase-dependent respiration of the biopsies dropped (P < 0.01) by 45%.8. Na+,K+-ATPase-dependknt respiration accounted for 61.3% of the O2, uptakes of mucosa from the sheep given the higher level of DE and 28.3% of the 02, uptake of mucosa from fasted sheep.
Effects of undernutrition and exercise during late pregnancy on uterine, fetal and uteroplacental metabolism in the ewe
Authors: Chandler K. D. , Leury B. J , Bird A. R. , Bell A. W. 
Published: May 2005

1. Uterine, umbilical and, by difference, uteroplacental net uptakes of oxygen, glucose, lactate and 3-hydroxybutyrate (uterine uptake only) were measured in single-pregnant ewes which were either well-fed throughout, or severely undernourished for 8–20 d during late pregnancy. All animals were studied while standing at rest and then while walking on a treadmill at 0.7 m/s on a 10° slope for 60 min.2. Undernutrition did not significantly affect fetal or placental weights at 143 d gestation but caused a 14% decrease in maternal live weight. Uterine blood flow was decreased by 32% and was associated with a significant decrease in uteroplacental oxygen uptake; neither umbilical blood flow nor fetal O2, uptake were affected by maternal plane of nutrition. Maternal and fetal hypoglycaemia in underfed ewes was accompanied by 46–63 % decreases in uterine, umbilical and uteroplacental net uptakes of glucose, and similar declines in uterine and umbilical glucose/O, quotients. Moderate maternal hyperketonaemia was associated with 2.5-fold and 3-fold increases in uterine net uptake of 3-hydroxybutyrate and 3-hydroxybutyrate/O2quotient respectively.3. Exercise caused significant decreases in uterine blood flow in fed and underfed ewes but did not affect uterine or umbilical O2uptakes; uterine net glucose uptake increased in most ewes but umbilical uptake was not significantly affected. Umbilical net uptake of lactate was significantly reduced. In underfed ewes, the extent of hyperketonaemia was significantly reduced by exercise.4. Contrary to earlier proposals, the ovine pregnant uterus is sensitive and adaptable to long- and short-term alterations in maternal energy balance, as achieved by chronic undernutrition and exercise respectively. Thus, the fetus and placenta significantly add to, but do not necessarily have priority over the energy demands of other tissues of the ewe.
Utilization of low-quality roughage by Bos taurus and Bos indicus cattle
Authors: Hunter R. A. , Siebert S. D. 
Published: May 2005

1. Six Hereford and six Brahman steers were fed ad lib. Pangola grass (Digztaria decumbens) and Spear grass (Heteropogon contortus) hay alone and supplemented with rumen-degradable nitrogen and sulphur and minerals. The rumen digestion of the two feeds was determined by reference to the disappearance of substrate from nylon bags suspended in the rumen and withdrawn after intervals ranging from 8 to 120 h.2. The digestion of the unsupplemented Pangola grass diet occurred more rapidly in Brahmans than in Herefords and was associated with higher rumen ammonia concentrations in Brahmans (40 v. 16 mg/l). The rumen NH3, concentrations were increased to over 100 mg/l by supplementation. The digestion rate increased in both breeds after supplementation and the breed difference disappeared. Increases in digestion rate were not achieved above NH3, concentrations of 60–80 mg/l.3. Spear grass, especially the cell-wall-constituent fraction, was more resistant to digestion than Pangola grass. Digestion of the unsupplemented Spear grass diet proceeded more rapidly in Brahmans than in Herefords. The digestion rate in Brahmans were similar irrespective of whether the diet was supplemented or not. Supplementation increased digestion rate in Herefords.
A multicompartmental model to describe marker excretion patterns in ruminant faeces
Authors: Dhanoa M. S. , Siddons R. C. , France J. , Gale D. L. 
Published: May 2005

1. A multicornpartmental model, which assumes first-order kinetics, is proposed to describe digesta flow along the gastrointestinal tract of ruminants.2. Solution of the model yields a multiplicative equation, containing a single-exponential term and a double-exponential term, for describing faecal outflow rate.3. The logarithmic transformation of the equation was fitted to eighty-two excretion curves obtained after the administration of marker into the rumen of cattle and sheep, and compared with other published models.4. It was found to be superior to the other models in that it fitted all the data sets successfully.
Digestion, absorption and utilization of single-cell protein by the preruminant calf
Authors: Sedgman Cynthia A. , Roy J. H. B. , Thomas Joanne 
Published: May 2005

1. Two experiments of Latin square design, with four Friesian bull calves fitted with re-entrant duodenal cannulas at 4–10 d of age, were made to study the effect of giving varying levels of single-cell protein on the abomasal outflow and composition of digesta.2. In Expt 1, diets in which 0,220,440, and 660 g/kg milk protein were replaced by the bacterial protein Pruteen were compared from 14 d of age. In Expt 2, which began at about 61 d of age, a comparison was made of diets in which 0, 220, 440 and 660 g/kg milk protein were replaced by the yeast protein Toprina.3. Collection of abomasal outflow was made for 8 h after feeding for 2 d within each 6 d period of the Latin square design experiment. The amount of diet offered daily was 50 g dry matter/kg body-weight0.75.Polyethylene glycol (PEG), which was used as an indigestible marker, total nitrogen (TN), protein-N (PN), fat, and potassium, sodium and chloride ion outflows were measured together with pepsin (EC 3.4.23.1) and chymosin (EC 3.4.23.4) activities, pH and titratable acidity.4. In Expt 1 there was little difference in the outflow of liquid digesta between diets and about 0.9 of the dietary PEG was recovered within the 8 h collection period. With increasing amounts of Pruteen in the diet, outflows of TN, PN, fat and Na+increased, and the pH of digesta increased. However, the volume of 'apparent secretion' into the abomasum (outflow - intake), pepsin activity, chymosin activity, titratable acidity, (outflow of C1--outflow of Na+) as a measure of outflow of HC1, and outflows of K+and of C1-were reduced. All outflows decreased with the time interval after feeding, except (Cl--Na+) outflow.5. In Expt 2, the same trends as in Expt 1 were apparent, but since one calf had to be slaughtered and the experiment had to be analysed as a randomized block, only PN and K+outflows and pH were significantly affected by dietary treatment, with K+outflow increasing, rather than decreasing, with increasing concentration of single- cell protein in the diet.6. Reduced proteolysis in the abomasum, associated with a faster and greater outflow of protein as a result of poor or no coagulation of protein in the abomasum, and a reduction in secretion of enzymes and in acidity may partly explain the poor protein digestibility and growth rate obtained in other experiments when diets containing more than 100 g single-cell protein/kg diet (about 200 g protein/kg total protein) were given to young calves.
Description of a human direct calorimeter, with a note on the energy cost of clerical work
Authors: Webster Joan D. , Welsh Gillian , Garrow J. S. 
Published: May 2005

1. A heat-sink calorimeter, suitable for the measurement of energy expenditure in human subjects over periods up to 26 h, is described.2. The performance of the calorimeter is illustrated by a study of four normal subjects at rest or performing clerical work for a period of 7.5 h. Each condition was measured in duplicate in each subject. On the resting days the subjects were recumbent, and on the working days they were seated throughout the measurement period. Heart rate was monitored by infra-red telemetry and physical activity by an ultrasound movement detector. Urinary cortisol excretion was also measured as an indicator of stress.3. In each subject the mean heat loss on working days was higher than that on resting days: the increase ranged from 5.1 % to 16.7, with a mean value of 10.0% (P = 0.015). There was no significant difference between resting and working days in heart rate, physical activity or urinary cortisol excretion.4. The present study confirms that tiring clerical work has very little effect on 24 h energy expenditure.
Changes in plasma fibronectin during acute nutritional deprivation in healthy human subjects
Authors: Chadwick S. J. D. , Sim A. J. W. , Dudley H. A. F. 
Published: May 2005

1. Plasma fibronectin, a glycoprotein, is an opsonin of the reticuloendothelial system.2. In ten healthy volunteers starved for 4.5 d, daily measurements showed a rapid reduction in plasma fibronectin, no alteration in either C3 or plasma transferrin and, at the end of the starvation period, an elevated serum albumin.3. On refeeding, plasma fibronectin rapidly returned to its prestarvation level but plasma transferrin was significantly reduced and did not recover by the end of the study.4. Changes in plasma fibronectin may be a sensitive index of nutritional status. The reduction of plasma fibronectin in short-term starvation may compromise host defence tolerance of injury and sepsis.