bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of mesenteric vein L-alanine infusion on liver metabolism in beef heifers fed on diets differing in forage: concentrate ratio
Authors: Reynolds C. K. , Tyrrell H. F.
Published: September 2005

Effects of 24 h mesenteric vein infusion of L-alanine (75 mmol/h) and diet forage: concentrate ratio on net nutrient metabolism by portal-drained viscera (PDV) and liver were measured in four Hereford-Angus heifers. Heifers were fed on diets containing approximately 750 g lucerne (Medicago sativa) or 750 g concentrate/kg every 2 h at similar metabolizable energy intakes in a balanced single reversal design with 6 weeks for diet adaptation. Measurements of blood flow and net metabolism of nutrients were obtained at 30 min intervals starting immediately before (four measurements) and after (five measurements) beginning, immediately before ending (four measurements) and 1.5 h after ending (three measurements) alanine infusion. Only values obtained immediately before beginning and ending alanine infusion were compared statistically. Net total splanchnic (PDV plus liver) release of glucose was greater when heifers were fed on the 750 g concentrate/kg ν. 750 g lucerne/kg diet due to greater net PDV absorption. Net PDV absorption of ammonia-nitrogen, β-hydroxybutyrate (BOHB) and lactate, and net liver and total splanchnic release of urea-N (UN) were greater when heifers were fed on the 750 g lucerne/kg ν. 750 g concentrate/kg diet. Infusion of alanine increased net liver removal of alanine and α-amino-N, net liver release of UN and net total splanchnic release of alanine, UN and lactate. Infusion of alanine decreased net liver release of BOHB and removal of lactate. Mesenteric vein infusion of alanine altered the net availability of precursors for liver glucose synthesis, but did not affect net glucose release by liver in these beef heifers
Tissue protein synthesis in lactating and dry goats
Authors: Baracos Vickie E. , Brun-Bellut Jean , Marie Michel
Published: September 2005

Intravenous infusion of L-[3H] phenylalanine (Phe) was carried out for 8 h in dry, non-pregnant and lactating dairy goats. Nitrogen balance was positive in the dry group and negative in the lactating group. Whole-body Phe flux was 50% greater in lactating goats (P < 0.01). Fractional synthesis rates (Ks) of tissue proteins were estimated from plasma- (Ksp) and tissue- (Ksh) specific radioactivities of Phe. In lactating goats, Ksp for mammary gland, duodenum and diaphragm was increased (P < 0.05). Ksp also tended to increase in liver, kidney and rumen (P < 0.08) of lactating goats, but was not different in uterus, spleen, caecum or heart. Values of Ksh were higher than Ksp; however, these measures agreed qualitatively. When absolute rates of protein synthesis were calculated, an increased contribution of mammary and visceral organs was seen in lactating goats. Ks and absolute rates of protein synthesis of hind-limb skin were less in lactating goats (P < 0.05). A decreased proportion of skeletal muscle (P < 0.01) and decreased Ks resulted in lower absolute synthesis of hind-limb muscle protein in lactating animals (P < 0.05). Decreased rates of muscle and skin protein synthesis would appear to participate in alterations of protein metabolism, permitting lactation to occur at the expense of body reserves.
Sodium, potassium and chloride utilization by rats given various inorganic anions
Authors: Kaup Susan M. , Behling Alison R. , Greger J. L.
Published: September 2005

The purpose of the present studies was to examine the effect of ingestion of sodium and potassium salts of various fixed anions on blood pressure, and to assess interactions among electrolytes. In the first study, Sprague-Dawley rats fed on purified diets supplemented with Na salts of chloride, sulphate, bisulphate, carbonate and bicarbonate for 7 weeks developed higher blood pressures than rats fed on the basal diet. In a second study, rats fed on Na or K salts of HSO4, HCO3or Cl had higher blood pressures than rats fed on the basal diet. Blood pressure measurements were not correlated with plasma volume, plasma renin activity, or plasma atrial natriuretic peptide concentrations at 7 weeks. Plasma renin activity was depressed in rats fed on supplemental Na and even more in rats fed on supplemental K salts rather than the basal diet. Generally, rats fed on supplemental Na excreted Na in urine and absorbed Na in the gut more efficiently than rats fed on the basal diet or diets supplemented with K, but the anions fed also altered Na absorption and excretion. In a third study, rats fed on diets supplemented with any Cl salt, but especially KCI, absorbed K more efficiently than those fed on the basal diet. In studies 1 and 2, the efficiency of urinary excretion of K was greatest when HCO3and CO3salts were fed and least when HSO4salts were fed. Despite large variations in the efficiency of absorption and excretion of Na and K, tissue levels of the electrolytes remained constant.
Nutritional response of growing rats to faba beans (Vicia faba L., minor) and faba bean fractions
Authors: Rubio Luis A. , Grant George , Bardocz Susan , Dewey Peter , Pusztai Arpad
Published: September 2005

The effects of raw faba bean (Vicia faba L., minor) meal (VFM) and its fractions on the growth and nitrogen utilization of rats have been determined in two experiments. Two commercial varieties of VFM were tested, local VFM (409–439 g/kg diet) and Troy VFM (439 g/kg diet). The bean fractions tested were V. faba lectin-depleted protein (VFDP), V. faba lectin (VFL) and V. faba cotyledon residue (VFCR). All diets were supplemented with amino acids to target requirements. Body-weight, body N and lipid contents of rats fed on VFM were reduced significantly in comparison with control rats fed on lactalbumin. This was due, in part, to the lower digestibility of the protein, lipid and dry matter (DM) of VFM diets. As a result, net protein utilization (NPU) and biological value (BV) of faba bean proteins were less than expected. Urine and urea-N outputs of the VFM-fed rats were also elevated in both experiments. Increasing the energy content of local VFM diets led to significantly higher dry body-weight, body N and lipid contents, with the result that the NPU and BV values of the protein also increased. However, the NPU values for VFM-fed rats were still significantly lower than those for the controls in both experiments. In contrast, true N, lipid and DM digestibilities in rats given local VFM were not significantly affected by the difference in the energy content of the diets. The replacement of two-thirds of the lactalbumin in the diet with VFDP (65 g/kg) reduced dry body-weight, N and lipid contents, NPU and BV compared with the control rats, even though N, lipid and DM digestibilities were not significantly different. The nutritional performance of rats fed on lactalbumin-based diets containing 7 g VFL/kg was similar to that of the controls. Similarly, the inclusion of the cotyledon residue (237 g VFCR/kg diet) had no appreciable effect on any of the variables studied. As VFL and VFCR had no antinutritional effects in these rats, it appears that the low nutritional value of VFM for rats (NPU 0.66) results not only from the low digestibility of the bean proteins, but also from disturbances in N metabolism.
High-fat diets and the immune response of C57 BI mice
Authors: Crevel R. W. R. , Friend J. V. , Goodwin B. F. J. , Parish W. E.
Published: September 2005

As a basis for studies of the influence of lipids on the immune response and health, adult C57 BI mice were fed for 10 weeks or longer on one of the following diets: high (200 g/kg) polyunsaturated fatty acid, high (200 g/kg) saturated fatty acid and low (50 g/kg) polyunsaturated fatty acid purified diets and a standard commercial diet. The three test-fat diets were compounded to have approximately the same energy content and the mice of each group maintained similar body-weights. High-fat diets significantly reduced their subsequent delayed hypersensitivity response to challenge after sensitization with tuberculin. Immunoglobulin (Ig)M antibody formation againstEscherichia colilipopolysaccaride was transiently decreased, but IgG antibody against sheep erythrocytes and killed salmonella vaccine, IgG and IgE antibodies against ovalbumin remained unaffected. Total and differential blood counts revealed no differences between mice on high-fat and control diets in either the absolute numbers or the proportions of the types of leukocytes. Studies on peritoneal macrophages from mice of each group showed no difference in morphology and they ingested non-toxic and toxic particles releasing similar amounts of lactate dehydrogenase (EC1.1.1.27) and β-glucuronidase (EC3.2.1.31) for each substance, indicating that there were no differences in viability or phagocytic function. The present study shows that the C57 BI mouse can provide a model for the investigation of some consequence of the reduced immunocompetence induced by high-fat diets.
Rumen protein degradation rates estimated by non-linear regression analysis of Michaelis–Menten in vitro data
Authors: Broderick Glen A. , Clayton Murray K.
Published: September 2005

An in vitro method applying Michaelis–Menten saturation kinetics was developed as an alternative approach for estimating protein degradation rates in the rumen. Non-linear regression (NLR) analysis of the integrated Michaelis–Menten equation yielded fractional degradation rates,kd, from direct estimates of the maximum velocity: Michaelis constant ratio (kd=Vmax:Km). Degradation rates obtained using data from a series of 2 h inhibitor in vitro incubations were respectively 0.989, 0.134, and 0.037 /h for casein, solvent soya-bean meal (SSBM) and expeller soya-bean meal (ESBM). Degradation rates obtained from 2 h incubations had lower standard errors than those obtained using 1 h incubations; 2 h rates were not significantly different from 1 h rates, suggesting end-product inhibition was not significant at 2 h. The NLR Michaelis–Menten method was used to determine degradation rates for twelve protein sources: casein, bovine serum albumin, two samples of lucerne (Medicago sativa) hay, and four samples each of SSBM and ESBM. Statistical analysis of NLR results revealed significant differences among the twelve protein sources. Casein was degraded most rapidly (0.827 /h), and the four ESBM samples most slowly (0.050–0.098 /h). Degradation rate for serum albumin was 0.135 /h; rates for SSBM and lucerne hays ranged from 0.160 to 0.208 /h. Degradation rates estimated using the NLR method were more rapid than those obtained with a limited substrate approach; NLR rates were more consistent with in vivo estimates of rumen protein escape. Greater concentrations of slowly degraded proteins were needed with the NLR method to define curvilinearity of the degradation curve more accurately.

Protein degradation rate: Rumen protein escape: Michaelis–Menten kinetics: Non-linear regression
Use of naturally enriched mixed food in 13C breath tests applied in young sucking calves
Authors: Metges Cornelia C. , Schmidt Hanns-Ludwig , Eichinger Hans
Published: September 2005

Utilization of three milk diets including cream, casein or whey, each naturally labelled with 13C (1 mmol 13C excess) from C4 sources, by six young male calves of the Deutsche Fleckvieh breed was investigated in a Latin-square split-plot design. Each milk diet was examined under resting conditions and during a short period of physical exercise on a treadmill. δ13C values (‰) in carbon dioxide in expired air were measured at intervals of about 1 h during 6·5 h after food intake. Expired air samples for CO2 isolation, subsequent isotopic analysis, measurement of CO2 production and respiratory quotient were taken at about hourly intervals and 13C recovery rates over 6·5 h were calculated. Feeding milk containing enriched milk casein, cream, or whey resulted in maximal significant 13C enrichments over background (δ13C) in CO2 of +1, +2·4 and +2·2‰, and recovery rates of 3·6, 9·9 and 12·2% respectively. This comparison shows the different kinetic behaviour of the main nutrients during the oxidation in tissues. The short exercise period (5 min at 1 J/s per kg body-weight + 5 min at 2 J/s per kg body-weight) did not influence the recovery rates significantly. However, after 10 min of muscular exercise there was a brief decrease in δ13C value of expired air which disappeared within the first 5 min of rest. These experiments demonstrate for the first time the applicability of the 13C breath test with naturally enriched diets in animal nutrition research and that quantitative results may be obtained.
The effect of proanthocyanidin-rich hulls and proanthocyanidin extracts from bean (Vicia faba L.) hulls on nutrient digestibility and digestive enzyme activities in young chicks
Authors: Yuste P. , Longstaff M. , McCorquodale C.
Published: September 2005

Proanthocyanidins were prepared from three bean (Vicia faba L.) varieties by extracting hulls in aqueous acetone. The amounts of freeze-dried extracts recovered were 74, 89 and 97 g/kg hull for the varieties Brunette, Statissa and Minica respectively. Chicks (3 weeks old) were fed on a maize–soya-bean control diet or the same control diet substituted with either 30 g proanthocyanidin extracts/kg or 300 g proanthocyanidin-rich hulls/kg. Chicks were tube-fed diets twice daily for 4 d. Nutrient digestibilities were calculated from amounts present in diets and freeze-dried excreta with the aid of titanium dioxide as a marker. Enzyme activities were measured in digesta removed from the jejunum. Extracts of proanthocyanidins depressed the digestibility of protein by 34%, starch by 3% and had no effect on the digestibility of lipid. Proanthocyanidin-rich hulls depressed the digestibility of protein by 62%, starch by 6% and lipid by 4%. Digestive enzyme activities were depressed to the same extent by extracts and hulls, trypsin (EC 3.4.21.4) by 55 and 62%, α-amylase (EC 3.2.1.1) by 75 and 78% and lipase (EC 3.1.1.3) by 31 and 32% for proanthocyanidin-extract and proanthocyanidin-rich-hull diets respectively. The susceptibility of substrates as well as enzymes to the effects of proanthocyanidins is discussed.
Enhancement of intestinal hydrolysis of lactose by microbial β-galactosidase (EC3.2.1.23) of kefir
Authors: Vrese Michael De , Keller Birgit , Barth Christian A.
Published: September 2005

The effect of microbial β-galactosidase (EC3.2.1.23) activity on intestinal lactose digestion was estimated directly by following post-prandial venous plasma galactose concentrations. To avoid superimposing effects of free galactose, as with yogurt, fresh or heat-treated suspensions of mechanically disintegrated kefir grains in kefir, containing lactose but no free galactose, were fed to ten Göttingen minipigs. Each meal contained 101·1 (SEM 0·1) mmol lactose in kefir supplemented by either native or heat-treated kefir grains corresponding to a mean β-galactosidase activity of either 72 (SEM 8) U or zero. Feeding kefir with β-galactosidase activity resulted in a 30% enhancement of the mean post-prandial plasma galactose peak concentration from 33 (SEM 7) to 43 (SEM 12) μmol/l (n10), as well as in 23% greater mean areas under the galactose-response curves (8·1 (SEM 1·5)v.6·6 (SEM 1·2) mmol/min per 1) if compared with kefir with heat-treated grains. Both differences were significant (P< 0·05; paired Wilcoxon test by ranks). There was no induction of intestinal β-galactosidase (EC3.2.1.108) activity or intestinal lactose-hydrolysing bacteria by lactose feeding. These results give direct evidence of an enhanced lactose digestion and absorption in native fermented milk products due to the microbial β-galactosidase activity.
Gastrointestinal morphology and absorption of monosaccharides in fowls conditioned to different types and levels of dietary fibre
Authors: Savory C. J.
Published: September 2005

To test a possible influence of dietary fibre on intestinal sugar uptake, rates of absorption of 10 mm-d[U-14C] glucose and 10 mm-d-[U-14C] xylose were measured in either jejunum or (distal) caecum, by in vivo lumen perfusion, in immature female fowls preconditioned to a standard diet containing (g/kg) either 0, 100, 200 or 400 added dried grass, 200 powdered cellulose, or 200 grass with a polysaccharidase enzyme supplement. When birds were killed after perfusion, dimensions of (unperfused) parts of their alimentary tracts were determined, and recoveries of14C radioactivity in some body tissues were compared with measured activities absorbed. On average, absorption of glucose was 1·9 and 1·2 times faster than xylose in jejunum and caecum respectively, although these differences varied with dietary treatment and order of perfusion. Increasing grass in the diet caused significant changes in xylose absorption rate in both jejunum and caecum, but only when it was perfused before glucose. With any one sugar and intestinal segment, mean rates of absorption were correlated positively with corresponding mean rates of fluid loss from perfusate. Although their influence on sugar absorption was not well defined, the dietary fibre treatments had more pronounced effects on gross dimensions of parts of the alimentary tract and, hence, potentially on total rates of absorption. Compared with the basal diet, addition of 100, 200 or 400 g grass/kg or 200 g cellulose/kg caused significant increases in small intestine length while 200 g grass/kg with supplementary enzyme did not, and combined caecal length increased with the 400 g grass/kg and the supplementary enzyme treatments. Absorbed14C activity was recovered in plasma after jejunal perfusions but not caecal ones, whereas it was recovered in liver and in the flushed perfused segment after both types of perfusion. Since there was overlap in absorption rates between jejunum and caecum, this result suggests that the liver may be able to distinguish and treat differently compounds absorbed in the two regions.
Metabolic fates of U-14C-labelled monosaccharides and an enzyme-treated cell-wall substrate in the fowl
Authors: Savory C. J.
Published: September 2005

A major benefit of supplementing non-ruminant feedstuffs with exogenous enzymes is presumed to be the degradation of plant cell-wall polysaccharides to metabolizable monosaccharide residues. In the present study, metabolic fates of (U-14C-labelled, 10 mM) glucose, galactose, mannose, xylose and arabinose were compared in the fowl, by measuring recoveries of14C radioactivity in exhaled carbon dioxide, excreta and body tissues after administration either by wing vein (iv) or into the crop (ic). A further comparison was made with a tube-fed, enzyme-treated, U-14C-labelled cell-wall substrate,Festuca arundinaceaand a final experiment tested possible competition for absorption between different cell-wall residues. Delays between iv and is treatments in recovery of14C in CO2, which were assumed to reflect intestinal absorption, indicated that xylose was absorbed more slowly than glucose and galactose, but faster than mannose and arabinose. Total recoveries of14C in CO2and excreta over the whole test period indicated that metabolizabilities were highest with glucose, galactose and mannose, and lowest with arabinose. After testing,14C recovery in caecal contents was highest with is arabinose, and recoveries in body tissues, with all sugar treatments, were in the order liver > breast and leg muscle > abdominal fat > plasma. Results with theFestucasubstrate showed similar patterns of recovery in body tissues and confirmed an increase in metabolizability with addition of enzymes. The timing of the14CO2response withFestucaand a wet enzyme pretreatment was broadly similar to a ‘predictedFestuca’ response, based on the composition of the substrate and the measured responses with individual (ic) monosaccharides. There was no evidence of any competition for absorption or metabolism among cell-wall residues. It was concluded that glucose release from cellulose is potentially the most important product of cell-wall degradation to contribute to enzyme enhancement of metabolizable energy.
The effect of ingestion of guar gum on ileostomy effluent
Authors: Higham S. E. , Read N. W.
Published: September 2005

Randomized, paired studies were carried out on five healthy volunteers equipped with terminal ileostomies to investigate the effect of incorporating 15 g of the viscous polysaccharide guar gum in the normal diet on the volume, weight, composition and physical properties of ileostomy effluent. Subjects ate an identical diet during two 5 d study periods, which were separated by 2 d. Outputs of fat, protein, sodium, potassium, dry weight and water were all increased during guar gum administration, but outputs of carbohydrate, calcium and phosphorus were not significantly altered. Mouth-to-stoma transit was not significantly affected and, surprisingly, the viscosity of the ileostomy effluent was reduced by guar gum. These results show that it is not always possible to predict what will happen to small intestinal function when guar gum is added to the diet from experiments carried out when guar gum is administered alone or with glucose. While our findings show that guar gum will reduce fat absorption, the mechanisms involved are more sophisticated than hitherto envisaged.
Diet selection in sheep: the ability of growing lambs to select a diet that meets their crude protein (nitrogen × 6.25) requirements
Authors: Kyriazakis I. , Oldham J. D.
Published: September 2005

To test the proposition that sheep are able to select a diet that meets their crude protein (N × 6.25; CP) requirements, feeds L, A, B, C and H with the same energy content (11 MJ metabolizable energy/kg feed) but different CP contents (78, 109, 141, 172 and 235 g CP/kg fresh feed respectively) were formulated. In addition, feed U, which was feed L plus 21.4 g urea/kg (CP content 132 g/kg), was also made. The feeds were offered ad lib. either singly (n 4 per treatment) or as a choice between feed H and another feed (pairs LH, AH, BH, CH and UH; n 9 per feed pair) to individually penned Suffolk × Scottish mule wether lambs, over the live-weight range 25–45 kg. On the single feeds the rates of live-weight gain were 273, 326, 412, 418, 396 and 407 g/day (SE of difference (SED) 34; P < 0.01) and protein (excluding wool) gain were 27, 32, 44, 45, 41 and 39 g/d (SED 4; P < 0.001) for feeds L, A, B, C, H and U respectively. When sheep were given a choice between a feed below (L or A) and a feed above their CP requirements (H; as judged by the single-feeding treatments) the CP concentration selected was not different between the two pairs: 131 (SE 4) v. 133 (SE 4) g CP/kg feed for pairs LH and AH respectively. On the choices BH and CH (a choice between two feeds above requirements) the feed lower in CP was constantly preferred (874 (SE 33) and 910 (SE 33) g feed B and C respectively per kg total feed intake; CP selected was 157 and 178 g CP/kg respectively). However, this was not the case with the UH choice on which sheep consumed only 599 (SE 61) g feed U/kg total feed intake, resulting in a selection of a higher CP in their diet (173 g CP/kg). The live-weight gains of the animals given a choice between two feeds were 416, 387, 415, 410 and 383 g/d (SED 37) and protein gains were 45, 40, 46, 50 and 43 (SE 7) for pairs LH, AH, BH, CH and UH respectively, which were comparable with the best performance achieved on a single feed. The results suggest that sheep were able to select a diet that meets their CP requirements and avoid, at least to a certain extent, excess of protein intake. It is also possible that sheep discriminate against a property of feed U, such as an excess of urea, when this feed is paired with a feed high in CP.
New and simple equations to estimate the energy and fat contents and energy density of humans in sickness and health
Authors: Sutcliffe John F. , Knight Grant S. , Pinilla Jaime C. , Hill Graham L.
Published: September 2005

Two formulas were derived to estimate the energy content of the human body which use only body mass, total body water by 3H2O dilution space and body minerals assessed by anthropometry. The formulas were tested in a body composition database of 561 patients and 151 normal volunteers using established metabolizable energy values for protein, fat and glycogen. Total body protein was determined by in vivo neutron activation analysis (IVNAA), body water by dilution of tritium and body minerals from skeletal frame size. Body glycogen was assumed to be 14.6 % of the mineral component. Body fat was obtained by difference, body mass less the sum of water, protein, minerals and glycogen. The standard deviation in the estimate of body energy content was 30 MJ or 4.1 % of the energy content of reference man. Two formulas for body energy content were derived by regression with body mass, total body water and body minerals or height. Two formulas for energy density and formulas for percentage body fat were similarly derived.
Comparison of body composition assessments by bioelectrical impedance and by anthropometry in premenopausal Chinese women
Authors: De Waart Frouwkje G. , Li Ruowei , Deurenberg Paul
Published: September 2005

Fat-free mass (FFM) was estimated in forty-seven premenopausal Chinese women, aged 18–43 years, from anthropometric data (skinfolds, body mass index (weight/height2; BMI)) or bioelectrical impedance, using several prediction formulas for body composition from the literature, and values compared with the mean of these three individual methods used as a frame of reference. In thirty-six women these values could be compared with FFM calculated from total body water (TBW) determined by D2O dilution. The prediction formulas used were developed from studies on Caucasian adults and their validity will have to be shown in populations with different ethnic backgrounds. The mean difference between FFM predicted from BMI and the frame of reference was 0.1 kg (95 % confidence interval (CI) -0.1, 0.4), from bioelectrical impedance it was 0.5 kg (95% CI 0.3, 0.7), and from skinfolds it was -0.6 kg (95% CI -0.9, -0.4). The mean difference between FFM calculated from TBW and the frame of reference was higher (2.2 kg, 95 % CI 1.2,3.3). The results of the present study indicate that the three methods may be valid for predicting body composition in adult Chinese females, but further research is needed on development and cross-validation of prediction equations for body composition for Chinese.
Nutritional assessment and adequacy of dietary intake in hospitalized patients with alcoholic liver cirrhosis
Authors: Nielsen Klaus , Kondrup Jens , Martinsen Lars , Stilling Birgitte , Wikman Berit
Published: September 2005

Nutritional assessment and adequacy of spontaneous dietary intake was evaluated in thirty-seven clinically stable hospitalized patients with alcoholic liver cirrhosis. About two-thirds of the patients had ascites or oedema, or both, and, therefore, body weight could not be used for assessment of nutritional status. Lean body mass (LBM; measured by three consecutive 24 h creatinine excretions) was 62 (range 40–95)% of reference values, mid-arm-muscle area (MAMA) was 70 (range 43–115)% and triceps skinfold (TSF) was 45 (range 20–113)% of reference values (all median values). In patients without ascites or oedema, or both, there was a rectilinear correlation between body weight and LBM and between body weight and MAMA (r 0.93 and 0.85 respectively). In patients with ascites or oedema, or both, the correlation between body weight and LBM was poor as could be expected. We suggest that LBM is a useful measure of nutritional status when body weight is unreliable because of ascites or oedema, or both. Energy balance for the group was calculated from energy intake recorded by a 24 h dietary recall and energy expenditure calculated by the factorial method. Median intake was 102 (range 34–176)% of expenditure. N loss was calculated from the average of three 24 h urea excretions. Protein intake was calculated from the 24 h dietary recall. The N balance was positive in the patients as a group (median intake was 120 (range 26–183)% of output). The most malnourished patients tended to have the most positive N balance which was due to a significantly lower N excretion. The protein requirement for N balance was 0.83 (SE 0.05) g/kg per d and only at an intake above 1.20 g/kg per d were all patients in positive N balance. The median intakes of thiamin, folacin, vitamin D, vitamin E, Mg, and Zn were judged to be insufficient. It is concluded that impaired nutritional status is common among patients with liver cirrhosis, even in a stable clinical condition. It is suggested that nutritional status in these patients is evaluated by dietary recalls, in combination with measurement of body weight in patients without ascites or oedema, or both, or in combination with determination of LBM by three 24 h creatinine excretions in patients with ascites or oedema, or both. Criteria for selection of patients that might benefit from nutritional therapy are discussed.
Metabolic effects on growth and muscle of soya-bean protein feeding in cod (Gadus morhua)
Authors: Von Der Decken A. , Lied E.
Published: September 2005

The aim of the present study was to investigate the effect of soya-bean protein on growth and muscle metabolism in fish. Cod,Gadus morhua, were fed on a fish-feed formula with the high-quality fish-meal protein being replaced by 100, 200 or 300 g soya-bean protein/kg fish-meal protein. The feeding experiment lasted for 43 d at a water temperature of 7–8º and a sea water salinity of 3.5%. At the 200 g/kg level of soya-bean protein, food intake and growth rate were similar to those of the controls. At the 300 g/kg level of soya-bean protein, food intake was diminished by 6 % and growth by 67 % relative to control levels. In muscle, sarcoplasmic protein (/g wet weight) was significantly decreased by 14%. Myofibrillar protein (/g wet weight) was unchanged. Levels of RNA in the myofibrillar fraction decreased at all three levels of soya-bean protein, and that of the sarcoplasmic fraction decreased at the highest level of legume-protein. With increased levels of soya-bean protein, RNA: DNA declined by 18% from 1.88 to 1.54. The contractile protein myosin heavy chain (/mg protein and /g wet weight) and myosin heavy chain-specific mRNA (/mg RNA) were not significantly affected by dietary conditions. Expressed per g wet weight, the decline by 21 % of the specific mRNA depended on the total RNA content which decreased with the increase in soya-bean protein. Acid proteinase activity was lowest at the 200 g/kg level, showing a decrease of 23%. Glycogen content fell by 46% at both the 200 and 300 g/kg level of dietary soya-bean protein. The results show that muscle metabolic functions responded to the dietary plant protein before there were any measurable changes in growth rate. From the results it is concluded that 200 g/kg or less of the high-quality fish-meal protein may be replaced by soya-bean protein in a fish-feed formula.
Rumen digestion and urinary excretion of purine derivatives in response to urea supplementation of sodium-treated straw fed to sheep
Authors: Balcells J. , Guada J. A. , Castrillo C. , Gasa J.
Published: September 2005

The present study examined the effect of urea-N supplementation of a N-deficient diet on digestion and metabolism in the rumen. Five Rasa Aragonesa ewes, each fitted with a rumen cannula, were offered alkali-treated barley strawad lib. alone or supplemented continuously via the cannula with four levels of urea-N (3, 6, 9 and 12 g/d). Rumen NH3concentrations increased in response to urea infusion (6–128 mg/l;P< 0.001). At the highest level of rumen NH3concentration there was a significant increase, compared with the unsupplemented treatment, in dry matter (DM) intake (846–1206 g/d;P< 0.001) and apparent digestibility of DM (0.38–0.43), organic matter (0.38–0.45) and neutral-detergent fibre (0.41–0.49;P< 0.01). Rumen outflow rates of particulate matter and potential DM disappearances, assessed using nylon bags, were not affected by the experimental treatments, although fractional rate of DM disappearance increased significantly with increasing levels of urea infusion (2.4–4.6 per h). Urinary excretion of total purine derivatives increased with N supplementation, although the response was exclusively due to an increase in allantoin excretion (26.9–66.4 mg/kg live weight (W)0.75per d;P< 0.001). Xanthine, hypoxanthine and uric acid excretion rates were constant, averaging 1.8 (SE 0.17); 5.4 (SE 0.21) and 7.2 (SE 0.36) mg/kg W0.75per d respectively. The maintenance of a minimum rumen NH3concentration (approximately 50 mg/l) was necessary to avoid significant reductions in DM intake and fermentation rate. Higher levels, however, may further increase microbial N flow at the duodenum, as suggested by the response in urinary allantoin excretion over the range of rumen NH3concentrations.
Intestinal and hepatic nitrogen balance in the rat after the administration of an oral protein load
Authors: Fernández-López José Antonio , Casado Javier , Esteve Montserrat , Rafecas Immaculada , Argilés Josep Maria , Remesar Xavier , Alemany Maria
Published: September 2005

The fate of a small oral dose of protein given to overnight-starved rats was studied. After 3 h, 62 % of the protein amino acids had been absorbed. Most of the absorbed N went into the bloodstream through the portal in the form of amino acids, but urea and ammonia were also present. About one-quarter of all absorbed N was carried as lymph amino acids. The liver was able to take all portal free ammonia and a large proportion of portal amino acids, releasing urea. The hepatic N balance was negative, indicating active proteolysis and net loss of liver protein.
Effects of feeding medium-chain triacylglycerols on maternal lipid metabolism and pup growth in lactating rats
Authors: Souza Paulo F. A. , Williamson Dermot H.
Published: September 2005

To study the effects of medium-chain triacylglycerols (MCT) on maternal lipid metabolism and pup growth, MCT (200 g/kg) were incorporated into a commercial chow diet and fed to lactating rats for 8–10 d. The results were compared with similar diets containing sunflower oil (polyunsaturated fatty acids; PUFA), tristearin (saturated fatty acid) or triolein (monounsaturated fatty acid). There was decreased food and energy intake with the MCT diet and this was accompanied by decreased (35%) pup growth. All the high-fat diets inhibited lipogenesisin vivoin the lactating mammary gland, the order of effectiveness being PUFA > triolein > tristearin > MCT. Only the MCT diet increased the rate of hepatic lipogenesis (180%). Experiments feeding an MCT meal containing [l-14C]octanoate indicated that very little (3–4%) of the C was present in mammary gland lipid, unlike the findings with [l-14C]triolein meal (40%). The major portion (65%) of the absorbed [l-I4C]octanoate was oxidized to14CO2. There was no evidence for adaptation of the mammary gland to increased dietary lipid uptake on the triolein or MCT diets. It is concluded that the decreased pup growth on the MCT diet is due in part to the decreased energy intake and to the inability of dietary medium-chain fatty acids to provide substrates for milk lipid synthesis.
The effect of dietary 1,25-dihydroxycholecalciferol in preventing tibial dyschondroplasia in broilers fed on diets imbalanced in calcium and phosphorus
Authors: Rennie J. Sarah , Whitehead Colin C. , Thorp Barry H.
Published: September 2005

Three experiments were carried out to investigate the effects of supplemental dietary 1·25-dihydroxycholecalciferol (1·25(OH)2cholecalciferol) and a low dietary Ca:P ratio on the occurrence of tibial dyschondroplasia (TD) in 3-week-old broilers. Histopathology was used to diagnose TD. In the first experiment, feeding a diet containing 7·5 g Ca and 7·6 g P/kg gave a higher incidence of TD than a control diet containing normal amounts of Ca and P (12 and 6 g/kg respectively). Increasing the dietary supplement of cholecalciferol in the imbalanced diet prevented rickets but did not decrease the incidence of TD. In the second experiment, supplementing the imbalanced diet with 10 μg 1·25(OH)2cholecalciferol/kg prevented TD completely but also gave a slight growth depression. In the third experiment the imbalanced diet was supplemented with 0, 2·5, 5 or 10 μg 1·25(OH)2 cholecalciferol/kg. The supplement of 2·5 μg/kg depressed and the higher supplements prevented the occurrence of TD, this time without a growth depression. Feeding the 10 μg/kg supplement for the first week only did not prevent TD. Plasma total Ca, inorganic P and alkaline phosphatase (EC 3·1·3·1) were unaffected by diet but 1·25(OH)2cholecalciferol was higher on the imbalanced than on the control diet. Supplementation of the imbalanced diet with 1·25(OH)2cholecalciferol did not increase plasma levels. It is concluded that 1·25(OH)2cholecalciferol is exerting a powerful biological effect in this model of TD, but the mechanism is unclear.
Absorption of pteroylpolyglutamates in mothers of infants with neural tube defects
Authors: Bower Carol , Stanley Fiona J. , Croft Maxine , De Klerk Nicholas H. , Davis Richard E. , Nicol Darryl J.
Published: September 2005

The ability to hydrolyse and absorb pteroylpolyglutamates (PteGlun) included in a standard meal in mothers who had given birth to an infant with a neural tube defect was tested by comparing them with mothers who had not had any infants with this defect. When compared with control mothers working in the research unit in which the study was performed, case mothers had significantly lower baseline serum and erythrocyte folate levels, and smaller increases in serum folate following the meal containing PteGlun. However, all estimates of folate were similar when case mothers were compared with a group of mothers who were friends of the case mothers. The results show that the higher the baseline levels of serum and erythrocyte folate the greater the increase in serum folate after the test meal. Fitting a model for the serum folate response curve resulted in coefficients which differed significantly between case mothers and all control mothers. We conclude that intestinal hydrolysis of PteGluntaken orally is not impaired in mothers who have had infants with neural tube defects when compared with control mothers with similar baseline folate levels, although the curves describing the response to the meal for the two groups do differ significantly. Further investigation is required to determine the mechanism underlying this difference.
The effect of feeding xanthan gum on colonic function in man: correlation with in vitro determinants of bacterial breakdown
Authors: Daly J. , Tomlin J. , Read N. W.
Published: September 2005

Xanthan gum (15 g/d) was given for 10 d to eighteen normal volunteers. In vivo measurements of stool output, transit time, frequency of defaecation and flatulence were compared with a preceding control period of 10 d. At the end of the control and test periods fresh faecal homogenate from each subject was anaerobically incubated with xanthan gum and control solutions to assess the ability of the bacteria to break down the gum. Xanthan gum was found to be a highly efficient laxative agent causing significant increases in stool output (P < 0.01), frequency of defaecation (P < 0.05) and flatulence (P < 0.01) whilst having variable effects on transit time. Before feeding xanthan gum, faecal samples from twelve of the eighteen subjects could reduce the viscosity of the gum in vitro. This rose to sixteen of the eighteen with significantly greater amounts (P < 0.05) of hydrogen and short-chain fatty acids also being produced, indicating bacterial adaptation in the presence of the substrate. Correlations between the in vivo and in vitro findings did not substantiate claims that the in vivo effect of a given polysaccharide can be predicted from its fermentation characteristics in vitro.
Deuterium dilution as a method for determining total body water: effect of test protocol and sampling time
Authors: Van Marken Lichtenbelt Wouter D. , Westerterp Klaas R. , Wouters Loek
Published: September 2005

Deuterium dilution for the measurement of total body water (TBW) has been conducted using varying protocols for equilibration. We measured TBW from deuterium dilution in urine samples in twenty-eight subjects using three protocols: (1) early morning dosage without breakfast, measuring deuterium in a second voiding at 4h and 6h; (2) early morning dosage with breakfast with the same measurement times; (3) dosage as last consumption before overnight sleep, measuring deuterium in a second voiding at 10 h. Results were compared with TBW estimates from underwater weighing (UWW). Because UWW is an indirect measure of TBW, it is used as an independent reference method in order to compare only relative discrepancies between the two methods. TBW values in the fasted state were not significantly different from those obtained in the fed state. The urinary deuterium enrichment was higher at 4 h than at 6 h (resulting TBW differences: 0·6 (SD 0·4)I). At 4h and 6h, differences in TBW measurements from deuterium and densitometry were positively related to the amount of TBW, indicating incomplete equilibration in larger water compartments. At 10h no such relationship existed, indicating complete mixing of deuterium. It is concluded that 10h equilibration is preferable to the shorter 4h and 6h, for the determination of TBW.
Pancreatic digestive hydrolase activities in growing rats fed alternately on raw and heated soya-bean flour
Authors: Khalifa Fatima , Prost Josiane , Belleville Jacques , Sarda Louis
Published: September 2005

The time-course effects of two diets containing raw (RSF) or heated (HSF) soya-bean flour on the digestive enzyme levels in the pancreas and in pancreatic juice were investigated in growing rats fed, alternately, on RSF or HSF diets for two 4-week periods. These values were compared with those obtained in a control group fed on a casein diet. RSF and HSF diets lowered N balance (84.8 (SE 0.9), 82.6 (SE 0.8) and 79.9 (SE 0.8) % with control, HSF and RSF diets respectively, at the third week). However, they increased protease activities compared with the control diet (3-fold for trypsin (EC3.4.21.4) and chymotrypsin (EC3.4.21.1) activities in pancreas contents and outputs with the RSF diet; 2-fold for trypsin in pancreas contents and outputs and by 60% for chymotrypsin contents with the HSF diet). The poorer nutritional N utilization might be attributable to soya-bean flour heat-stable (lectins) and heat-labile components (trypsin inhibitors). The decrease in lipid apparent digestibilities in RSF and HSF diets (97.0 (SE 0.8), 91.1 (SE 09) and 90.4 (SE 0.7) % with control, RSF and HSF diets at the seventh week) were correlated with a diminution in apparent lipase (EC3,1.1.3; measured without addition of exogenous colipase), potential lipase (measured with addition of saturated amounts of exogenous colipase) and colipase activities. Compared with control values, gains in potential and apparent lipase outputs were diminished by nearly 40% and gain in colipase outputs by 60% with RSF and HSF diets. These results show clearly that heated or raw soya-bean flours have a significant inhibitory effect on lipase digestive enzyme activities in the pancreas and in its secretion, which might explain impaired lipid digestibility.
Fibre-mediated physiological effects of raw and processed carrots in humans
Authors: Wisker Elisabeth , Schwejzer Thomas F. , Daniel Martina , Feldheim Walter
Published: September 2005

Fibre-mediated physiological effects of raw and processed carrots were investigated in twenty-four young women under strict dietary control in two randomized crossover studies. For 3 weeks between 405 and 688 g of either raw frozen, blanched or canned carrots (first study), or raw or raw frozen carrots (second study) were consumed in addition to a low-fibre basal diet. Carrots provided 15 g dietary fibre (DF)/d. Total DF intake was 16.0 to 1.90 g (control periods) and 31 to 34 g (experimental periods). Faecal bulking effects of raw and processed carrots were similar (between 2.4 and 3.7 g additional stool/g carrot fibre in the diet). Faecal excretion of dry matter, fibre, and protein also increased significantly during carrot consumption. Fermentability of carrot fibre constituents was high (91–94%) and independent of processing, in spite of differences in the distribution of soluble and insoluble fibre and in the texture of raw and processed carrots. There was no effect of either type of carrot on serum total and high-density-lipoprotein-cholesterol or on faecal bile acid excretion.
Biochemical indices and neuromuscular function tests in rural Gambian schoolchildren given a riboflavin, or multivitamin plus iron, supplement
Authors: Bates C. J. , Evans P. H. , Allison G. , Sonko B. J. , Hoare S. , Goodrich S. , Aspray T.
Published: September 2005

Ninety preselected children, aged between 8 and 14 years, living in two rural West African (Gambian) villages, were randomly divided into three groups, matched for age and sex. One group received a placebo (lactose) tablet, one received riboflavin (5 mg) on 5 d every week, which was sufficient to correct an endemic riboflavin deficiency, and one received a multivitamin supplement (Protovit; Hoffmann La Roche), on 5 d every week, together with FeSO4(200 mg) once weekly, and the supplements were given for 1 year. Neuromuscular tests, including arm tremor and manipulative skills, were performed on three occasions: once just before the introduction of the supplements; again 6 weeks after commencing the supplements; and again 1 year later. Venous blood samples were collected at the same time as the first two sets of neuromuscular tests. These samples were used for haematology and nutrient status indices: plasma ferritin, ascorbic acid, cyanocobalamin and pyridoxal phosphate, and erythrocyte tests for folate status, for riboflavin status (erythrocyte glutathionc reductase activation coefficient) and thiamine status (erythrocyte transketolase activation coefficient). The riboflavin in both supplements achieved a clear-cut response in biochemical status, which was dose-dependent. The pyridoxine, ascorbic acid and Fe components of the multivitamin also affected the associated biochemical indices. Although overall the arm tremor and related neuromuscular function tests did not respond significantly to the supplements, significant improvement was seen in the boys for the arm-tremor test in both the supplemented groups.
Effects of mild zinc deficiency, plus or minus an acute-phase response, on galactosamine-induced hepatitis in rats
Authors: Parsons Susan E. , Disilvestro Robert A.
Published: September 2005

Zn deficiency is hypothesized to produce poor resistance to injury involving oxidative stress. This could occur by impairing Zn antioxidant function(s) or by indirectly limiting adaptive protective mechanisms such as a rise in acute-phase proteins. The present study examined rats fed diets adequate or moderately low in Zn (4 or 25 μg/g diet) for 9 d. The lower intake produced a mild Zn deficiency based on body weight, plasma Zn and plasma alkaline phosphatase (EC 3.1.3.1) activity. Galactosamine injection, an oxidative stress, produced much more liver injury in the mildly Zn-deficient rats. However, injury was strongly inhibited in rats from each dietary group by an acute-phase response due to turpentine-induced leg inflammation. Mild Zn deficiency did not prevent a rise in levels of the acute-phase protein caeruloplasmin (EC 1.16.3.1), but did limit the usual inflammation-induced rise in hepatic levels of metallothionein, a Zn protein with possible antioxidant function. In conclusion, high degrees of galactosamine-induced hepatitis were associated with mild Zn deficiency, but the liver injury was blocked by prior stimulation of an acute-phase response, regardless of Zn status.