bluuebunny/crossref_metadata_2025_split huggingface dataset:
Intestinal microflora, morphology and enzyme activity in zinc-deficient and Zn-supplemented rats
Authors: Southon Susan , Gee Jennifer M. , Bayliss Catherine E. , Wyatt G. M. , Horn Nikki , Johnson I. T. 
Published: September 2005

1. Immature, male Wistar rats were given a low-zinc diet (2 mg/kg) for 22–24 d. Control groups received a similar diet supplemented with 58 mg Zn/kg eitherad lib., or in amounts matched to the consumption of the Zn-deficient group. Food consumption, rate of growth and food conversion efficiency were markedly lower in the Zn-deficient group of rats compared with controls. Appetite, growth rate and food utilization improved dramatically over a subsequent 4 d period of Zn supplementation.2. Morphological examination of samples of jejunum and ileum confirmed that Zn deficiency in the rat is accompanied by a reduction in villous dimensions and increase in villous density. After a short period of Zn supplementation, villous density and the basal width and maximum height of individual villi in the jejunum returned to normal. Similar changes occurred in the ileum but to a lesser extent.3. Mucosal alkaline phosphatase (EC3.1.3.1) activity was significantly lower in the small intestine of Zn-deficient rats compared with Zn-supplemented rats. Disaccharidase activities were lower in the Zn-deficient group, compared with their feed-restricted counterparts, but were similar to values forad lib.-fed controls. Tissue alkaline phosphatase and disaccharidase activitities were consistently higher after a 4 d period of Zn supplementation, compared with non-supplemented animals, but this increase was only significant for alkaline phosphatase.4. Although there were striking similarities in the mucosal characteristics of gnotobiotic and Zn-deficient rats, there was no indication that even severe dietary Zn depletion reduced the numbers of viable bacteria present in either the small or large intestine. Changes in intestinal structure and function resulting from variation in dietary Zn intake appear, therefore, to be unrelated to changes in the intestinal flora.
A mechanism for the hypocholesterolaemic activity of saponins
Authors: Sidhu G. S. , Oakenfull D. G. 
Published: September 2005

1. Saponins are steroid or triterpene glycosides which occur in a number of important food plants, including such staples as soya beans (Glycine max) and chickpeas (Cicer arietinurn). They are known to be hypocholesterolaemic.2. Some saponins form an insoluble complex with cholesterol which prevents its absorption from the small intestine. Others cause an increase in the faecal excretion of bile acids, an indirect route for elimination of cholesterol.3. We have investigated the effects of different saponins on absorption of the bile salt sodium cholate from perfused loops of small intestine, in vivo, in the rat. Purified saponins from soapwort (Suponaria Officinalis), soya beans and quillaia (Quillata suponaria) reduced the rate of absorption of the bile salt; soya-bean and soapwort saponins substantially so but quillaia saponin to a much lesser extent.4. These results were explained by the formation of large mixed micelles by bile acid and saponin molecules in aqueous solution. These aggregates can have molecular weights in excess of 106daltons, consequently the bile acid molecules incorporated in them are not available for absorption.5. Control of plasma cholesterol and nutrient absorption through dietary saponins could provide substantial health and nutritional benefits in humans.
Influence of dietary protein concentration on the oxidation of phenylalanine by the young pig
Authors: Ball Ronald O. , Bayley Henry S. 
Published: September 2005

1. Piglets were weaned at 3 d of age and reared to 2.5 kg on a liquid diet in which the protein was supplied by dried skim milk and a mixture of free amino acids. The oxidation of L-[l-14C]phenyIalanine was measured as an indication of the partition of amino acids between retention and catabolism in pigs (2.5 kg) offered meals containing vaned concentrations of crude protein (nitrogen x 6.25).2. The dietary protein concentration was varied either by increasing the inclusion of a mixture of free amino acids in a series of diets containing 100 g protein/kg from skim milk, or by increasing the level of inclusion of the skim milk in a series of diets containing the equivalent of 100 g protein/kg from the free amino acid mixture.3. The oxidation of phenylalanine was minimized by dietary protein concentrations of 240 and 258 g/kg for the diets containing increasing concentrations of free amino acids or skim milk respectively.4. These results show that a mixture of free amino acids is used more effectively than intact protein for promoting retention of essential amino acids.5. The recovery of radioactivity in expired carbon dioxide was inversely related to the recovery of radioactivity in liver tissue when the concentration of dietary crude protein was increased from deficient to adequate, demonstrating that the fractional oxidation of the indicator amino acid was inversely related to protein synthesis.
Taurine concentrations in the diet, plasma, urine and breast milk of vegans compared with omnivores
Authors: Rana Surinder K. , Sanders T. A. B. 
Published: September 2005

1. The concentration of taurine in the diets, plasma, urine and breast milk were measured in vegans and age- and sex-matched omnivore controls. Plasma and urinary amino acid concentrations were also determined2. Taurine was absent from the vegan diet and occurred in variable amounts in the diets of the omnivores. Urinary taurine levels were less than half those of the omnivores but plasma and breast-milk levels were only slightly lower.3. Dietary energy intakes were similar in the vegans and omnivores, but protein intakes tended to be lower in the vegans.
Perrcentage body fat and prevalence of obesity in a UK offshore population
Authors: Light I. M. , Gibson M 
Published: September 2005

1. Body-weight, body height and skinfold measurements were taken in 419 adult males working in the UK offshsore oil industry. Percentage body fat was estimated from skinfold thicknesses and the Quetelet index (weight: height2) determined.2. The prevalence of overweightness, assessed from the Quetelet index, in the age groups 20–29, 30–39 and 40–49 years was 31.6, 50.0 and 66.2% respectively. The Office of Population Census and Surveys (1981) showed that for age-matched groups, the incidence of overweightness in an onshore population was 26, 40 and 50% respectively.3. The percentage body fat for each respective age group was greater than that reported for an age-matched onshore population.4. The Quetelet index was significantly related to body fat (r 0.765, P < 0.0001) and poorly correlated with height, thus this weight: height relation may be utilized in the assessment of overweightness in offshore personnel.5. In conclusion it appears that the offshore population had a higher percentage body fat than their onshore peers and that the prevalence of overweightness was also greater.
The influence of riboflavin deficiency on absorption and liver storage of iron in the growing rat
Authors: Adelekan Delana A. , Thurnham David I. 
Published: September 2005

1. Iron absorption was measured in weanling riboflavin-deficient (RD) rats or weight-matched (WM) controls fed on appropriate diets for 7 weeks. Concentrations of radio-Fe (68Fe) in plasma were monitored every 30 min for 4 h following intragastric administration.2. Total Fe absorption in RD rats was significantly lower than that in WM controls, and the tissues of the stomach and small intestine of RD rats retained significantly (P < 0.001) more 68Fe by comparison with WM groups.3. In a separate experiment, ferritin-Fe concentrations were measured in the livers of four groups of rats (adlib. (C), pair-fed (PF) and WM controls and RD) at day 0, and subsequently at days 14, 21, 28, 35 and 49.4. Liver ferritin-Fe concentration was significantly lower (P < 0.05) in RD rats than in all other controls after 3 weeks on the respective diets and remained lower for the remainder of the experiment.
Estimation of tissue protein synthesis in sheep during sustained elevation of plasma leucine concentration by intravenous infusion
Authors: Schaefer A. L. , Davis S. R. , Hughson G. A. 
Published: September 2005

1. The fractional rate of protein synthesis (FSR) was determined in skeletal muscle, liver, rumen and cardiac muscle of wether sheep by continuous intravenous infusion of L–[4,5–3H]leucine accompanied by infusion of 0, 7.6, 15.2 or 22.8 mmol leucine/h (three sheep per treatment). FSR was calculated assuming plasma (ksp) or intracellular (ksi) leucine-specific radioactivity (SRA) was representative of the leucine precursor pool SRA for protein synthesis.2. Plasma leucine concentration (plateau) was linearly related to leucine infusion rate, 22.8 mmol/h evoking tenfold increase in plasma concentration.3. Difference between plasma leucine SRA and intracellular leucine SRA in all tissues diminished as plasma leucine concentration increased.4. There were significant differences between ksiand kapestimates for liver and rumen in control sheep.5. As leucine infusion rate increased, differences between kriand kag, diminished in all tissues. With increasing leucine infusion, in liver kstdecreased and kspwas increased, in rumen kgedecreased and kspwas stable, while in cardiac and skeletal muscle ksiand kspboth increased.6. At a leucine infusion rate of 22.8 mmol/h, mean kap, and kstrespectively were: rumen 1 1 (SE 2), 13 (SE 1); liver 19 (SE 2), 21 (SE 2); cardiac muscle 3–6 (SE 0.4), 3.8 (SE 0.3); skeletal muscle 4.1 (SE 0.2), 4.5 (SE 0.5) and did not differ significantly in any tissue.
Longitudinal changes in nutritional habits of teenagers: differences in intake between schooldays and weekend days
Authors: Post Bertheke , Kemper Han C. G. , Strom-Van Essen Lucienne 
Published: September 2005

1. Longitudinal changes in nutritional habits were studied in Dutch adolescents from 12 to 17 years of age (131 girls and 102 boys). The dietary differences on schooldays and weekend days are reported.2. In girls only small changes in nutritional habits were seen as they grew older. In boys there was a gradual increase in food intake with age.3. Overall, higher nutrient intakes could be seen on weekend days. The energy intake on weekend days was consistently higher for girls and boys in all age-groups. The proportional intakes of fat and sugar were rather high, especially on weekend days. The alcohol consumption increased with age for girls as well as boys, and was for some individuals extremely high (boys) on weekend days.4. The observed levels of intake compared with the recommendations showed a rather low intake of polyunsaturated fatty acids, polysaccharides and iron.
In vitro estimation of iron availability from a range of plant foods: influence of phytate, ascorbate and citrate
Authors: Hazell T. , Johnson I. T. 
Published: September 2005

1. Plant foods were digested in vitro and the proportion of iron which diffused across a ssemi-permeable membrane was used as an index of Fe availability.2. The mean (with SEM) Fe diffusibility from a group of eighteen cereals, legumes and nuts was very low, 2.1 (0.25)%, whereas from a group of sixteen fruits and vegetables it was high, 13.7 (1.09)%. The difference between the two food groups was highly significant (P< 0.001).3. The results for Fe diffusibility correlated well with literature values for the in vivo absorption of Fe from similar foods (r0.84,P< 0.01).4. When phytate, citrate and ascorbate were added to selected foods in amounts corresponding to endogenous levels, only phytate and citrate gave the expected effects on Fe diffusibility. Ascorbate only enhanced Fe diffusibility to the expected extent when it was added in much larger amounts, not normally found in foods.5. When added to cereal foods, orange juice was found to enhance greatly Fe diffusibility even when its content of ascorbate was completely destroyed by boiling followed by prolonged storage. When citrate and ascorbate were added to cereal foods in amounts equivalent to those found in fresh orange juice, both enhanced Fe diffusibility but citrate was far more effective.6. It is concluded that phytate is a major inhibitor of Fe diffusibility in cereals, legumes and nuts. However, citrate rather than ascorbate would appear to be the major enhancer of Fe diffusibility from many fruits and vegetables.7. The implications of the present results are discussed in relation to the relative influence of phytate, citrate and ascorbate on dietary Fe availability.
Methane excretion in the growing pig
Authors: Christensen Kirsten , Thorbek Grete 
Published: September 2005

1. Total methane excretion (CH4 in breath+flatus) was measured in two experiments with thirty-six castrated male pigs (Danish Landrace) during the growth period from 20 to 120 kg live weight (LW). In Expt A, twenty-eight pigs were fed on a commercial diet alternately at high (HFL; metabolizable energy (ME) 1234 (SE 41) kJ/kg LW0.75) or low (LFL; ME 784 (SE 31) kJ/kg LW0.75) feed levels in different weight classes. In Expt B, eight pigs were constantly fed on a semi-purified diet at HFL without (-oil) or with 90 g soya-bean oil/kg diet (foil) corresponding to daily intakes of ME of 1339 (SE 11) and 1413 (SE 8) kJ/kg LW0.75 respectively.2. CH4 excretion was measured during 24 h respiration trials in open-air-circulation chambers.3. About 1 litre CH4 was excreted per day at 20–25 kg LW increasing to a maximum of 12 litres at 120 kg LW, which corresponded to no more than 1.2% of dietary gross energy.4. In Expt A, CH4 excretion increased linearly with LW, while in Expt B the increase was linear until about 70 kg LW, when it reached a plateau. On average LFL reduced CH, excretion by 23% compared with HFL. When related to dry matter (DM) intake, however, the pigs on LFL excreted 3.1 litres CH4/kg dietary DM and those on HFL 2.5 litres CH4/kg dietary DM, the difference being significant (P < 0.05). In Expt B the inclusion of soya-bean oil in the basal diet (+oil) reduced CH, excretion by 26% compared with the diet without oil (-oil). The pigs receiving the basal diet excreted 5.2 litres CH4/kg DM and the pigs receiving soya-bean oil 4.3 litres CH4/kg DM, the difference being highly significant (P < 0.001). All differences between Expt A and B in CH4 excretion based on DM intake were highly significant (P < 0.001).5. The results are discussed in relation to gas production in ruminants, rats and humans. It is suggested that flatus production may not only be reduced by changing the composition of the dietary carbohydrates, but also by inclusion of a polyunsaturated oil in the diet of simple-stomached animals and humans.
The role of rumen protozoa in the utilization of paspalum (Paspalum dilatatum) hay by cattle
Authors: Punia B. S. , Leibholz Jane , Faichney G. J. 
Published: September 2005

1.Six Friesian heifers (250 kg live weight) with permanent cannulas in the rumen and abomasum were allocated at random into two groups of three. One group was treated with Teric GN9 (ICI (Aust.) Ltd) to defaunate the animals during the first two of the four periods of the experiment, after which they were refaunated. The second group was treated with Teric at the end of the first two periods. The dietary treatments were: paspalum (Paspalum dilatatum) hay (4.1 kg/d) given alone and the hay supplemented with urea (20 g/kg dry matter).2. Defaunation was not complete but the approximate volume of protozoa in the rumen of treated animals was less than 6% of that in the untreated animals.3. The amount of organic matter (OM) digested in the stomach was lower (P< 0.01) in animals with reduced fauna than in those with normal fauna. There were reductions in both the apparent OM digestibility in the total tract (from 0.56 to 0.52,P< 0.01) and the proportion of the digestible OM digested in the rumen (from 0.82 to 0.79, not significant) of animals with reduced fauna. Apparent digestibilities of acid-detergent fibre and neutral-detergent fibre were significantly lower (P< 0.01) in animals with reduced fauna.4. The amount of nitrogen disappearing from the stomach was significantly higher (P< 0.01) with the urea supplement; effects due to concentrations of protozoa were not significant. The flow of non-ammonia-N from the abomasum was higher (P< 0.05) in animals with reduced fauna than in animals with normal fauna. The flows of bacterial N from the abomasum and the efficiencies of bacterial N synthesis were not significantly affected by the treatments. N retention was higher (P< 0.01) in animals receiving the urea supplement but differences due to protozoa were not significant.5. Protozoal contribution to the microbial N flowing from the rumen of animals with normal fauna was estimated to be 24 and 27% with and without the urea supplement respectively.6. Concentrations of rumen-fluid ammonia-N were reduced (P< 0.05) and those of volatile fatty acids were increased (P< 0.01) with reduction in protozoal numbers. Molar proportions of propionic acid increased (P< 0.05) and of butyric acid decreased (P< 0.01) with reduced rumen fauna.7. Rumen water volume was lower (P< 0.05) and the mean retention time of indigestible acid-detergent lignin tended to be higher in animals with reduced fauna. Rumen dry-matter pool and mean retention time of CrEDTA were not significantly different between treatments.
Effects of a β-agonist (clenbuterol) on growth, carcass composition, protein and energy metabolism of veal calves
Authors: Williams P. E. V. , Pagliani L. , Innes G.M. , Pennie K. , Harris C. I. , Garthwaite P. 
Published: September 2005

1. Twenty-two British Friesian bull calves were used in a comparative slaughter experiment to determine the effects of a β-agonist (clenbuterol) on body composition and energy retention. Four calves were slaughtered at 18 d of age and constituted the initial slaughter group. Of the remaining calves, eight (group A, controls) were given milk replacer only, and ten calves (groups B and C, five calves per group) were given milk replacer plus clenbuterol(O.1 and 1.0 mg clenbuterol/kg milk replacer equivalent to approximately 2 and 20 μg/kg body-weight respectively over the 105±3 d of the experimental period). Calves were slaughtered over the weight range 146–177 kg.2. Clenbuterol had no significant effect on dry matter (DM) intake, daily live-weight gain or feed conversion ratio. DM digestibility of the milk replacer was not affected by treatment. Nitrogen balance was measured on three separate occasions starting when the calves weighed approximately 60, 110 and 130 kg. N retention was increased over the experimental period in clenbuterol-treated calves, although the effect only achieved significance in calves weighing approximately 110 kg live weight (P< 0.05).3. Clenbuterol (20 μg/kg body-weight) increased estimated mean daily N retention in the carcass of the calves from 22 to 25 g whilst N retention in the non-carcass components decreased from 10 to 8 g/d. Effects of clenbuterol on N retention occurred mainly in skeletal muscle. Fat in both carcass and non-carcass components was reduced by treatment with clenbuterol. The total energy content of live-weight gain was reduced from 1077 to 897 MJ in clenbuterol-treated calves and mean daily heat production was estimated to increase from 23.1 in controls to 25.9 MJ/d in calves in group C.4. In calves of mean live weight during balance of 120 and 136 kg, clenbuterol significantly increased daily urinary creatinine excretion and in 120 kg calves NT-methylhistidine was significantly decreased (P< 0.05). Based on estimates of muscle mass from urinary creatinine and protein degradation fromN7-methylhistidine NT-methylhistidine excretion, the fractional breakdown rate of muscle protein in clenbuterol-treated calves was only 0.66 of that in the controls when the calves weighed 120 kg.
Effect of fasting and of methionine deficiency on L-methionine, DL-methionine and DL-2-hydroxy-4-methylthiobutanoic acid metabolism in broiler chicks
Authors: Saunderson C. Linda 
Published: September 2005

1. Metabolism of L-[1-14C]methionine, DL-[l-14C]methionine and DL-[ 1-14C]2-hydroxy-4-methylthiobutanoic acid (DL-HMB) by broiler chicks which had been fasted overnight or given a methionine-deficient diet was compared with fed (control) birds.2. The excretion of14C-labelled material, total14CO2exhaled,14C incorporation into tissue proteins and the14C-labelled material in perchloric-acid-soluble tissue fractions were measured 6 h after injection of the14C-labelled materials.3. The incorporation of14C into tissue proteins and the relative rates of conversion of D-methionine and DL-HMB to L-methionine in tissues under different nutritional regimens were compared using protein-bound14C:protein-free14C values.4. Fasted birds exhaled more14CO2than control birds but excreted less14C, while methionine-deficient birds behaved very similarly to the control animals in these respects.5. Fasted birds incorporated much less14C into proteins of tissues other than liver and kidney from all three labelled tracers. The values for protein-bound14C: protein-free14C were lower in all tissues.6. Methionine-deficient birds had similar levels of14C in tissue proteins but lower values for protein bound14C: protein-free14C.7. Examination of the values for protein-bound14C:protein-free14C suggest that brain and probably liver tissues from fasted and methionine-deficient birds showed improved rates of conversion of D-methionine and DL-HMB to L-methionine compared with control animals.
Porto-arterial plasma concentration differences of urea and ammonia-nitrogen in growing pigs given high-and low-fibre diets
Authors: Malmlöf Kjell 
Published: September 2005

1. The effects of a high-(HF) and a low-(LF) fibre diet on porto-arterial plasma concentration differences and plasma levels of urea and ammonia-nitrogen were compared in six Swedish Landrace x Yorkshire pigs (30–52 kg). Portal and arterial blood samples were drawn during 8 h following two consecutive meals, given at 08.00 and 16.00 hours.2. The HF diet, in comparison with the LF diet, was found to produce significantly lower portal plasma urea levels. However, concomitant arterial plasma levels were equally depressed, consequently leaving the porto-arterial urea differences unchanged.3. In no instance during the 16 h studied could negative porto-arterial urea differences clearly be observed. It was thus concluded that none of the diets induced an important net flux of plasma urea directly from the circulation into the gastrointestinal tract.4. The significantly lower circulating plasma urea levels that were observed when the pigs received the HF diet were also associated with significantly lower urinary excretions of urea.5. The HF and LF diets had similar effects on portal and arterial plasma levels of ammonia-N. This was also true with regard to porto-arterial ammonia-N differences.