bluuebunny/crossref_metadata_2025_split huggingface dataset:
Partition of portal-drained visceral net flux in beef steers
Authors: Reynolds Christoper K. , Huntington Gerald B. 
Published: September 2005

1. Blood from chronic indwelling catheters in the caudal aorta and anterior mesenteric, gastrosplenic and hepatic portal veins was used to measure blood flow and net flux of oxygen, glucose and nitrogenous compounds across hepatic portal-drained viscera (PDV), post-stomach (anterior mesenteric-drained viscera (MDV)) and stomach tissues of two beef steers (390 kg mean live weight).2. Steers were fed in sequence on (1) chopped lucerne (Medicago sativa) hay (twelve meals/d), (2) chopped lucerne hay (two meals/d) and (3) a pelleted concentrate diet containing 780 g ground maize/kg (two meals/d). The lucerne hay and concentrate contained 26.5 and 16.8 g nitrogen/kg respectively.3. Five measurements of net flux (blood flow multiplied by venous-arterial concentration differences (VA)) were obtained hourly on 2 d for each dietary regimen, beginning 0.5 h before feeding at 08.00 hours. Blood flow was measured by downstream dilution of p-aminohippurate (PAH).4. Blood flow across MDV averaged 42% of PDV blood flow (665 litres/h).5. Net use of O2 across MDV accounted for 51 % of net PDV use of O2 (920 mmol/h). This disproportionate use of O2 in relation to blood flow was due to greater VA for O2 across MDV than across stomach tissues. Dietary regimen had no effect on the proportions of PDV blood flow and net O2 consumption attributable to MDV or stomach tissues.6. When lucerne was given, net glucose use across MDV represented 69% of PDV use (35 mmol/h). When concentrate was given, MDV glucose use switched to net absorption (29 mmol/h), reducing net PDV glucose use to I mmol/h.7. When concentrate was given, net MDV absorption of α-amino-N (AAN) increased from 98 to 190 mmol/h, yet net PDV absorption (101 mmol/h) was not affected. Net stomach AAN flux increased from -7 to -69 mmol/h when concentrate was given, negating the increase in net MDV absorption.8. Net absorption of ammonia-N across MDV represented 28 and 52% of net PDV absorption when lucerne and concentrate were given respectively. Net NH3-N absorption across PDV was lower when lucerne was given than when concentrate was given (295 v. 154 mmol/h), reflecting lower dietary N intake (153 v. 83 g/d). Net MDV absorption of NH3-N was not affected by diet. Net removal of blood urea-N (BUN) across PDV (101 mmol/h) was not affected by diet. Across MDV, BUN removal was lower when concentrate was given than when lucerne was given (32 v. 77 mmol/h). In beef steers, MDV tissues account for substantial portions of net flux of non-protein-N across PDV and are responsible for essentially all PDV absorption of AAN.
Partition of portal-drained visceral net flux in beef steers
Authors: Reynolds Christopher K. , Huntington Gerald B. 
Published: September 2005

1. Net flux of volatile fatty acids (VFA), D-β-hyroxybutyrate (BOHB) and L-lactate across post-stomach (anterior mesenteric-drained viscera (MDV)), stomach and total hepatic portal-drained viscera (PDV) tissues was measured in two beef steers (mean live weight 390 kg).2. Net flux was measured while steers were fed, in sequence, on (1) chopped lucerne (Medicato sativa) (twelve meals/d), (2) chopped lucerne (two meals/d) and (3) a pelleted concentrate diet containing 780 g ground maize/ kg (two meals/d).3. Five hourly net flux measurements were obtained on 2 d for each dietary regimen, beginning 0.5 h before a meal delivered at 08.00 hours. Net flux was calculated as venous-arterial concentration differences (VA) multiplied by blood flow (measured by downstream dilution ofp-aminohippurate (PAH)).4. Stomach tissues accounted for 85 to over 100% of net VFA and BOHB appearance across PDV. Net appearance across stomach tissues represented 74% of net PDV L-lactate appearance.5. When lucerne was given, there was net utilization of arterial acetate and BOHB across MDV. This MDV utilization may reflect acetate and BOHB use as an energy source or their incorporation into mesenteric fat.6. When concentrate was given, moren-butyrate andn-valerate and less L-lactate appeared across PDV and less 3-methylbutyrate appeared across stomach tissues than when lucerne was given. Postprandial increases in VFA, BOHB and L-lactate net flux across PDV followed meal-feeding of lucerne.7. On a net basis, the relative contribution of MDV tissues to total PDV net appearance of VFA and BOHB was small (< 15%) in these steers.
The effects of dietary fat content on the growth and body composition of lean and genetically obese Zucker rats adrenalectomized before weaning
Authors: Fletcher J. M. , McKenzie N. 
Published: September 2005

1. Lean (Fa/–) and obese (fa/fa) Zucker rats were adrenalectomized or sham-operated at 18 d of age (3 d before weaning). After weaning the rats were fed ad lib. on semi-synthetic diets containing either a low (8 g/kg) or a high (178 g/kg) proportion of fat. Other groups of sham-operated rats were given the same amount eaten by adrenalectomized animals (restricted intake). Rats were killed at 40 d of age.2. Adrenalectomy reduced the body lipid content of lean and obese rats compared with intact animals fed ad lib. or given a restricted intake. Adrenalectomized obese rats contained more body lipid than intact or adrenalectomized lean rats.3. Sham-operated obese rats given a restricted intake had less body protein than similarly treated lean animals and this phenotypic difference was abolished by adrenalectomy.4. There were no effects of diet on growth or body composition of intact or adrenalectomized rats.5. It is concluded that preweaning adrenalectomy prevented development of the obese phenotype when rats were fed on either diet. Comparison of these results with a previous study, in which adrenalectomized Zucker rats were fed on a stock diet (Fletcher, 1986b), showed, however, that feeding either of the semi-synthetic diets caused greater deposition of body lipid in obese rats.
Effects of age, and protein malnutrition followed by a balanced diet on the non-parallel change in digestive enzymes in the pancreas and their secretion in the rat
Authors: Prost Josiane , Belleville Jacques , Valantin-Rollet Carole 
Published: September 2005

1. Ninety male Wistar rats were divided into two groups. A control group (C) was fed on a balanced diet, containing 200 g protein/kg for 51 d. An experimental group (E) was fed on a low-protein diet containing 50 g protein/kg for 28 d (PM), and then on a balanced diet for 23 d (BR). At different days of PM and BR, the pancreas and the pancreatic juice were collected 40 min after injection of 0.1 mCi [3H]leucine. The amounts of amylase (EC3.2.1.1), trypsinogen 2 (EC3.4.21.4), chymotrypsinogen 1 (EC3.4.21.1) and lipase (EC3.1.1.3) were determined after separation by the isoelectric focussing technique. Incorporation of [3H]leucine into the four hydrolases of pancreatic juice and pancreas was also determined.2. In control rats a progressive increase in the concentration of digestive enzymes and the amounts secreted were observed with age. Maturation was reached when the rats were 9 weeks old. In rats E, PM inhibited maturation of the pancreas. However, individual enzymes were not affected to the same extent and at the same time. As soon as re-feeding was initiated, pancreas maturation took place and a significant increase in these variables was observed. The increases varied according to the hydrolase and did not appear at the same time.3. In control rats, a preferential secretion of newly synthesized enzymes was observed in young rats, whereas with age, the proportion of newly synthesized enzymes excreted decreased slowly. In group E rats, at the beginning of PM, the proportion of newly synthesized enzymes secreted was very low and increased with time.4. In rats C and E, our results indicated a non-parallelism between pancreatic enzyme levels and amounts secreted. This non-parallelism was different in both groups, it was changed with age and pancreas maturation in group C, and according to nutritional state in group E.
The relation between dietary restriction or clenbuterol (a selective β2 agonist) treatment on muscle growth and calpain proteinase (EC3.4.22.17) and calpastatin activities in lambs
Authors: Higgins Janet A. , Lasslett Yvonne V. , Bardsley R. G. , Buttery P. J. 
Published: September 2005

1. Lamb growth trials were designed to modify growth and protein content of muscle by diet and also by β-agonist treatment, and to correlate any changes to the activities of calpain proteinases (EC3.4.22.17) and their inhibitor calpastatin.2. Wether lambs in a control group were fed on a barley-based diet designed to give a growth rate of 350 g/d; a second group was fed on the same diet but the intake was restricted to give an expected gain of 44 g/d; a third group was fed on the same diet as the first group but the diet included 2 mg clenbuterol/g. At the end of a 6-week trial, longissimus dorsi wet weights were 635 (n6), 377 (n4) and 788 g (n6) (standard error of difference 53.0) in the three groups respectively.3. Minced L. dorsi was extracted in low-salt buffers and analysed by a fast protein liquid-chromatographic system for calpain I (low calcium-requiring), calpain II (high Ca2+-requiring) and calpastatin activities. No significant changes in the three activities were associated with reduced muscle weight in the restricted-intake group. The inclusion of clenbuterol in the diet, however, led to highly significant increases (P< 0.001) in calpain II and calpastatin to approximately double the control values.4. The results did not support a direct relation between these activities and muscle growth, except when protein accretion was stimulated by a β-agonist, suggesting a role for this enzyme system in the mechanism by which these agents exert their effect.
The degradation of different protein supplements in the rumen of steers and the effects of these supplements on carbohydrate digestion
Authors: McAllan A. B. , Cockburn J. E. , Williams A. P. , Smith R. H. 
Published: September 2005

1. Four steers with simple rumen and abomasal cannulas were given diets consisting of ground and pelleted alkali-treated straw, rolled barley and tapioca supplemented with urea (diet U) or containing single-cell protein (diet SCP), maize-gluten meal (diet MGM) or rapeseed meal (diet RSM) in place of some of the tapioca. The isoenergetic diets were given in a 4 x 4 Latin square design in eight feeds/d at 3-h intervals and provided sufficient metabolizable energy to support a growth rate of approximately 0.5 kg/d. Chromic oxide and polyethylene glycol were given as markers and appropriate samples taken from the rumen and abomasum. Flows (g/d) at the abomasum of organic matter and nitrogenous and carbohydrate constituents were calculated.2. Rumen ammonia levels were similar with all three protein supplements at about 9 mmol/l, which was significantly lower (P < 0.05) than that in animals on diet U (16 mmol/l). Rumen liquid outflow rates (/h) were 0.099, 0.139, 0.125 and 0.160 for diets U, SCP, MGM and RSM respectively; the difference between diet U and diet RSM was significant (P < 0.05). Corresponding values for Cr2O3 outflow rates were 0.027, 0.032, 0.027 and 0.030/h respectively, which did not differ significantly from each other.3. RNA, 35S and diaminopimelic acid (DAP) were used as microbial markers. Efficiencies of microbial-N (MN) synthesis, expressed as g MN/kg apparently digestible organic matter, truly digestible organic matter or carbohydrate fermented, were generally not significantly affected by the diet and averaged 29, 22 and 29 respectively based on mean RNA and 35S markers. Corresponding values derived from DAP of 22, 16 and 21 g MN/kg respectively were all significantly (P < 0.001) lower. Using 35S as microbial marker, MN flows at the abomasum as a proportion of non-ammonia-nitrogen flow were 0.78, 0.64, 0.51 and 0.78 for diets U, SCP, MGM and RSM respectively. Derived true rumen degradability values (g/g intake) of the total dietary N were 0.91, 0.79, 0.69 and 0.90 for diets U, SCP, MGM and RSM respectively. Protein supplement degradabilities for single-cell protein, maize-gluten meal and rapeseed meal were 0.73, 0.51 and 0.98 respectively.4. Mouth-to-abomasum digestibility coefficients of the main neutral-sugar components of dietary poly-saccharides were 0.68, 0.63 and 0.61 for arabinose, xylose and cellulose-glucose on diet U. These values were generally significantly increased with protein supplementation, but to different extents depending on the source. Maximum digestibility values of 0.81, 0.79 and 0.76 were obtained for arabinose, xylose and cellulose-glucose with diet RSM. Starch-glucose digestibility was high (0.90) on all diets and unaffected by supplementation.
Nutrient supply and growth of cattle offered straw-based diets
Authors: Ortigues Isabelle , Smith T. , Oldham J. D. , McAllan A. B. , Siviter J. W. 
Published: September 2005

An experiment was conducted using steers cannulated at the rumen, duodenum and ileum to study the effects of increasing the levels of barley and fishmeal in straw-based diets. Diets A, B, C and D contained ammonia-treated straw, barley and fishmeal in the ratios, 67:33:0, 66:23:11, 53:47:0 and 52:36:12 (by weight) and were offered in daily amounts of 3·9, 3·9, 4·8 and 4·8 kg dry matter. The effects of barley were attributable to increased intakes of digestible organic matter and consequently to increased flows of microbial matter to the duodenum. There were no modifications in the balance of energy to nitrogen-yielding nutrients available for absorption. Introducing fishmeal into diets improved digestibility of cellulose and xylose by up to 6.7 and 4.7 % respectively, and shifted digestion towards the large intestine. Second, it increased amino acid N supply to the small intestine which averaged 52·2, 63·2, 68·8 and 84·0 g/d with diets A, B, C and D. Some changes were also noted in the balance of amino acids absorbed. Consequently, the contribution of amino acids to metabolizable energy intake increased with the proportion of fishmeal in diets (0·17, 0·20, 0·18 and 0·21 for diets A, B, C and D).Growth rates measured in heifers amounted to 259, 431, 522 and 615 g/d for diets A, B, C and D. They appeared to be related to intestinal amino acid supply.
The effect of exercise and improved physical fitness on basal metabolic rate
Authors: Bingham S. A. , Goldberg G. R. , Coward W. A. , Prentice A. M. , Cummings J. H. 
Published: September 2005

1. The suggestion that there is a sustained enhancement in metabolic rate after exercise was investigated during the course of a study in which six normal-weight volunteers (three men, three women) took part in a 9-week training programme. Baseline values were assessed in a 3-5 week control period of minimal activity before training. At the end of the study the subjects were capable of running for I h/d, 5 d/week.2. Throughout the entire study the subjects were maintained on a constant diet. Measurement of energy expenditure by the doubly-labelled water (2H218O) method showed that the subjects had an energy imbalance of +3% in the control and -20% at the end of the training period. The subjects were in positive (1·1 (se 0·2) g) nitrogen balance in the second week of the control, and in negative (-0·6 (se 0·3) g) N balance in the last week of the exercise period.3. Over the course of the study maximum oxygen consumption (Vo2max) and high-density-lipoprotein-cholesterol levels increased by 30%. Heart rate at rest and when performing a standard step test fell significantly.4. Body composition was assessed weekly by40K counting and skinfold thickness measurements, in addition to2H2dilution at the beginning and end of the study. Fat-free mass was apparently gained in the early phases of the study, but there was lack of agreement between the different methods of assessing body composition. Changes in body-weight were not significant.5. Basal metabolic rate (BMR), overnight metabolic rate (OMR) and sleeping metabolic rate (SMR) were measured on three occasions: in the control period, and the beginning and end of the training periods. Average BMR in the control period was 5·91 (se 0·39) MJ/24 h and was not changed with activity. There were no changes in OMR (5·71 (se 0·27) MJ/24 h in the control) nor in SMR (5·18 (se 027) MJ/24 h in the control), nor in BMR, OMR or SMR when expressed per kg body-weight, or per kg fat-free mass.6. These results do not support the suggestion that there is a sustained increase in BMR following exercise that can usefully assist in weight-loss programmes.
Thermogenic responses to graded doses of noradrenaline in undernourished Indian male subjects
Authors: Kurpad A. V. , Kulkarni R. N. , Sheela M. L. , Shetty P. S. 
Published: September 2005

1. Seventeen male subjects with an energy intake of 10.6 (sd 1.7) MJ/d and ten male undernourished labourers with an energy intake of 8.0 (sd 1.2) MJ/d were studied. The controls were subdivided into ten underweight controls with a body mass index (weight/height2; BMI) < 18 (17.2 (sd 0.9)) and seven normal-weight controls with a BMI > 20 (21.3 (sd 1.6)), while the undernourished labourers had a BMI < 18 (16.8 (sd 1.2)).2. Comparison of thermogenic responses to increasing doses of noradrenaline showed no overall significant inter-group differences when subjected to a nested analysis of variance (ANOVA). For the initial doses of 0.05 and 0.1 μg noradrenaline, significantly lower responses were seen in the undernourished subjects, while the highest dose showed comparable responses in all three groups. Thermogenic responses to the initial two doses, when corrected for fat-free mass (FFM) differences, were 40 % lower in the undernourished group when compared with the underweight group with similar BMI and FFM values. However, this finding was not statistically significant.3. The basal oxygen consumption of the undernourished group, expressed per unit FFM, was significantly higher than that of the controls.
The effect of incorporating fat into different components of a meal on gastric emptying and postprandial blood glucose and insulin responses
Authors: Cunningham K. M. , Read N. W. 
Published: September 2005

1. Three studies were carried out in each of six normal volunteers to investigate how lipid, when given at different stages during the course of a meal, affects gastric emptying and postprandial blood glucose and insulin concentrations.2. The control meal consisted of 300 ml beef consommé (50 kJ, 12 kcal), followed 20 min later by 300 g mashed potato (908 kJ, 217 kcal). In the two test meals, 60 g margarine were incorporated into either the soup or the mashed potato.3. The addition of margarine to either component of the meal delayed gastric emptying of the mashed potato (P< 0.05), but the pattern varied according to the component to which the fat was added.4. Incorporation of fat into the soup increased the lag phase (P< 0.05) but did not influence the slope of emptying of the mashed potato, while incorporation of fat into the mashed potato reduced the slope of emptying of the mashed potato (P< 0.05) but did not influence the lag phase.5. Addition of fat to either component of the meal reduced postprandial blood glucose (P< 0.05) and insulin responses, but when the fat was incorporated in the soup, peak glucose and insulin responses were delayed as well (P< 0.05).6. The results show that the effect of fat on gastric emptying and absorption of nutrients depends on when, in relation to the other components of the meal, the fat is consumed.
Utilization of α-amylase (EC 3.2.1.1) resistant maize and pea (Pisum sativum) starch in the rat
Authors: Faulks R. M. , Southon Susan , Livesey G. 
Published: September 2005

1. The extent of utilization of α-amylase (EC 3.2.1.1)-resistant retrograded starches in vivo was assessed in male Wistar rats (about 100 g body-weight). All animals were given a fibre-free semi-synthetic basal diet (SS) containing sucrose as the only carbohydrate source, ad lib., for 13 d. On day 14, after an overnight fast, rats were allocated to one of five dietary treatments (n 30):1, fibre-free basal SS diet; 2-5, basal SS diet supplemented with 100 g sucrose, Solka floc (cellulose), resistant maize starch (RCS) or resistant pea (Pisum sativum) starch (RPS)/kg diet. Animals allocated to each dietary treatment were divided into three groups of ten rats which were given the appropriate diet for 8 or 9, 17 or 18 and 29 or 30 d (8/9, 17/18 or 29/30 d groups respectively). Rats were fed on 12 g diet/d (treatment 1) or 13.2 g diet/d (treatments 2-5) for the first 20 d, and 14 or 15.4 g/d respectively until the end of the experiment. Rats fed on the supplemented basal diets were thus given 10% more food to allow for the addition of the test carbohydrate. Faecal carbohydrate excretion was determined at intervals in the 17/18 d groups. At the end of each experimental period animals were killed after consuming their daily food ration and small intestinal length, weight of caecal and ileal contents and tissue, and pH of caecal contents measured. The amount of carbohydrate in the caecal and ileal contents from the 8/9 and 17/18 d groups was determined.2. Weights of ileal and caecal contents, caecal tissue and faecal output were significantly greater at all time points for rats fed on the resistant starches compared with those fed on basal and sucrose-supplemented diets. Values were higher for RPS-fed rats than for RCS-fed rats.3. The quantity of carbohydrate recovered from ileal and caecal contents showed that both RCS and RPS were partially digested and absorbed as carbohydrate, but that RPS was digested to a lesser extent.4. The concentration of carbohydrate decreased between the ileal and caecal sites when RPS and RCS were given but was essentially unchanged when cellulose was given. This is consistent with rapid fermentation of a fraction of these starches.5. Faecal carbohydrate elimination in the 17/18 d groups fed on RCS and RPS declined with time, which suggested an adaptive response resulting in increased utilization of the starches. This adaptive response was slower in the RPS-fed rats than the RCS-fed rats.6. The present study indicates that, in the rat, there are significant differences in the utilization of resistant starches from different sources.