bluuebunny/crossref_metadata_2025 huggingface dataset:
Circadian variation in abomasal digesta flow in grazing ewes during lactation
Authors: Dove H. , Milne J. A. , Sibbald A. M. , Lamb C. S. , McCormack H. A.
Published: September 2005

1. Lactating grazing ewes, fistulated at the rumen and abomasum were either not supplemented or offered, individually, 600 g/d of either pelleted, molassed sugar-beet pulp (‘energy’ supplement) or a pelleted 1:1 (w/w) mixture of this feed and formaldehyde-treated soya-bean meal (‘protein’ supplement). Digesta flows at the abomasum were estimated from the concentrations of the markers CrEDTA and ruthenium phenanthroline complex, during their administration by continuous intra-rumen infusion. Digesta samples were taken at 09.00 hours and at six further times at 4 h intervals. This was repeated 2 d later.

2. No significant difference in flow between days was noted. Daily flows of dry matter (DM) and non-ammonia-nitrogen (NAN) (g/d) in supplemented ewes were significantly higher than in unsupplemented ewes, both in total digesta and its particulate phase. However, there were significant differences between sampling times or significant interactions between sampling time and supplement treatment. The results were therefore examined by Fourier analysis for possible circadian variation in digesta flow. As there was marked between-animal variability in flow-rate, the digesta-flow values for each sampling time were re-expressed as percentages of the flows calculated from daily mean marker concentrations.

3. In unsupplemented animals, marked and significant circadian variation was then identified in the flow of DM, total N and NAN in both whole digesta and the particulate phase. There was also significant circadian variation in the flow of DM, total N and NAN in the digesta of the supplemented ewes. Curves were of the same general shape as those for unsupplemented animals, but some significant differences were found, principally for digesta NAN flow. In both supplemented and unsupplemented animals, peak flows occurred in the period 20.00-01.00 hours. The proportion of DM and NAN flowing in the particulate phase was relatively constant through the day for unsupplemented ewes, but significant circadian variation occurred for supplemented ewes.

4. The possible mechanisms generating the circadian variation in digesta flow, such as grazing behaviour and the rumen digestion of supplements, are discussed. Values are also presented to indicate the extent of the likely errors if digesta flows were estimated from samples which did not represent all stages of the circadian pattern.
Passage of indigestible particles of various specific gravities in sheep and goats
Authors: Katoh K. , Sato F. , Yamazaki A. , Sasaki Y. , Tsuda T.
Published: September 2005

1. Eight kinds of indigestible particles with specific gravities (SG) ranging from 0.92 to 1.87 (2 mm diameter and 4 mm length) were injected into the reticulo-rumen of sheep and goats in order to investigate the relation between SG and passage through the gastrointestinal tract, and the difference in passage time in the two species of animals.

2. The percentage of excreted particles significantly increased, while the percentage of ruminated particles in the excreted particles significantly decreased, as the SG increased.

3. The daily and cumulative recovery rates of particles of SG 1.38 were slower in sheep than in goats, while those with SG 0.92 were not different between species.

4. It is concluded that particles with SG higher than 1.27 would pass through the gastrointestinal tract of sheep and goats more quickly than those with SG lower than 1.21.
Effect of level of nutrition on splanchnic blood flow and oxygen consumption in sheep
Authors: Burrin D. G. , Ferrell C. L. , Eisemann J. H. , Britton R. A. , Nienaber J. A.
Published: September 2005

The objective of the present study was to measure changes in splanchnic blood flow and oxygen consumption in sheep fed on a high-concentrate diet ad lib. (ADLIB) or an amount sufficient to maintain body-weight (MAINT) for 21 d. Eleven ram lambs were surgically implanted with chronic indwelling catheters in the portal, hepatic and mesenteric veins and mesenteric artery to measure blood flow and net O2 flux through the liver and portal-drained viscera (PDV). During the 21 d period, PDV (P < 0.05) and liver (P < 0.01) blood flow increased in ADLIB and decreased in MAINT lambs (treatment x day, linear). After 21 d, O2 consumptions in PDV and liver of MAINT lambs were 37 and 63% lower than in ADLIB lambs. In the control period, total splanchnic tissues represented an average of 52% of whole body O2 consumption. After 21 d, the relative contributions of PDV and liver to whole-body O2 consumption were 28 and 41% in ADLIB and 19 and 22% in MAINT lambs respectively. Allometric regression variables indicate that liver O2 consumption responds more rapidly to changes in metabolizable energy intake than portal O2 consumption. These results indicate that blood flow and O2 consumption in both PDV and liver are related to level of nutrition. Furthermore, splanchnic tissues represent a significant component of whole-body O2 consumption that is subject to manipulation by level of nutrition.
Lipid metabolism in shorn and unshorn pregnant sheep
Authors: Symonds M. E. , Bryant M. J. , Lomax M. A.
Published: September 2005

The aim of the present study was to determine how the long-term metabolic adaptations to winter shearing of the pregnant ewe result in significant changes in the rates of lipid mobilization and utilization of non-esterified fatty acids (NEFA) in comparison with unshorn controls. Continuous infusions of [1-14C]palmitic acid, [2-3H]glycerol and NaH14CO3 were used to measure whole-body lipid metabolism in fed (estimated metabolizable energy (ME) intake 9.54 MJ/d) and under-fed (estimated ME intake of 3 MJ/d), shorn and unshorn sheep over the final 4 weeks of pregnancy. Whole-body carbon dioxide, estimated heat production, total NEFA entry and oxidation rates were all significantly higher in fed shorn ewes compared with unshorn controls, even though there was no difference in the arterial plasma NEFA concentration. These differences may be mediated via an increase in the plasma concentrations of thyroid hormones in shorn animals. As a result of under-feeding any significant differences in lipid metabolism between shorn and unshorn groups were removed. In all sheep the mean total NEFA entry rate as measured using [1-14C]palmitic acid was 3.4 times the value obtained using [2-3H]glycerol. It is concluded that when sheep are fed on a diet from which no more than half the required ME for late pregnancy is obtained, then lipolysis of body fat depots occurs via the incomplete breakdown of adipose tissue triglycerides. This effect is significantly greater in the fed shorn pregnant ewe which exhibits higher entry and oxidation rates of NEFA.
Relations between plasma non-esterified fatty acid metabolism and body fat mobilization in primiparous lactating goats
Authors: Dunshea F. R. , Bell A. W. , Trigg T. E.
Published: September 2005

During early lactation ruminants can mobilize considerable amounts of body fat to maintain milk production. The aim of the present study was to evaluate the efficacy of tritiated water (TOH) and non-esterified fatty acid (NEFA) kinetics as means of monitoring adipose tissue fat mobilization in lactating goats. Body fat, as estimated by a two-pool model of TOH kinetics, and NEFA entry rate were measured in four primiparous goats at days 11, 37 and 72 post partum. Estimated body fat decreased by an average of 64 g/d between days 11 and 37 of lactation, tending to increase between days 37 and 72. Plasma NEFA concentrations and NEFA entry rate decreased as lactation advanced, being significantly lower at day 72 than at day 11 of lactation. Both plasma concentrations of NEFA and NEFA entry rate were negatively correlated with calculated energy balance. Plasma NEFA concentrations and NEFA entry rate at days 11 and 37 of lactation were positively related to average body fat losses over the subsequent stage of lactation. These results demonstrate that NEFA kinetics reflect fat mobilization in primiparous lactating goats, particularly during negative energy balance.
Effects of some poorly digestible carbohydrates on bile acid bacterial transformations in the rat
Authors: Andrieux Claude , Gadelle Daniele , Leprince Christine , Sacquet E.
Published: September 2005

The effects of ingestion of poorly digestible carbohydrates on bacterial transformations of cholic acid and β-muricholic acid were studied in rats fed on increasing levels of lactose, lactulose, amylomaize or potato starches. Each level was given for 3 weeks and, at the end of each dietary treatment, bile acid faecal composition was analysed and a group of six rats was killed every 4 h during 24 h to determine the amounts of fermented carbohydrate and fermentation characteristics (caecal pH, volatile fatty acids (VFA) and lactic acid concentrations). Fermentation of carbohydrates decreased caecal pH and enhanced caecal VFA and lactic acid concentrations. Irrespective of the poorly digestible carbohydrate, the variation of bacterial transformation always occurred in the same way: the bacterial transformation of β-muricholic acid into hyodeoxycholic acid was the first to disappear, while ω-muricholic acid formation increased; second, cholic acid transformation decreased and finally all bile acid transformations were strongly affected. There was a significant correlation between bile acid transfer and the minimal caecal pH in vivo. This effect of pH was similar in vitro. To determine whether the levels of bacteria which transformed bile acids were modified, rats fed on the highest amounts of poorly digestible carbohydrates were introduced into isolators and carbohydrate feeding was stopped. Caecal pH recovered its initial value but bile acid transformations remained changed, suggesting that the intestinal microflora were modified by ingestion of fermentable carbohydrates.
Enzyme supplementation of a poultry diet containing rye and wheat
Authors: Pettersson D. , Åman P.
Published: September 2005

A total of 360 I-d-old broiler chickens were fed on a diet based on rye and wheat in equal proportions without or with supplementation of increasing levels (0.11, 0.22, 0.44 and 0.88 g/kg) of a technical enzyme preparation containing pentosanase and β-glucanase activities. In vitro investigations revealed that the enzyme preparation solubilized pentosans, increasing the relative viscosity of buffer extracts from enzyme-supplemented diets. Enzyme supplementation generally improved body-weight by approximately 27% at day 15 and 15% at day 27, increased feed intake by 15 and 8% respectively, and improved feed conversion efficiency by 10 and 5% respectively. There was also a decreased occurrence of sticky droppings. Enzyme supplementation increased the digestibility of organic matter, crude protein (nitrogen x 6.25) and starch measured in the last third of the small intestine, and of organic matter and crude fat measured in excreta. Solubilization of insoluble pentosans by the enzyme included led to negative digestibility values for soluble pentosans in the small intestine at the higher levels of supplementation. Most of the dietary fibre degradation observed occurred before the middle section of the small intestine, with some degradation of soluble fibre in the caeca and colon. The solubilization and disruption of feed endosperm cell walls by enzyme supplementation probably was primarily responsible for the observed improvements in digestibility and production results.
Intestinal zinc transfer by everted gut sacs from rats given diets containing different amounts and types of dietary fibre
Authors: Seal C. J. , Mathers J. C.
Published: September 2005

Two experiments were carried out in which rats were offered diets containing different amounts and types of dietary fibre, i.e. commercial stock diet and three semi-purified diets containing no fibre, 200 g wheat bran or 200 g pectin/kg. Dietary inclusion of fibre, and especially pectin, stimulated large bowel fermentation, as indicated by caecal hypertrophy and reduced caecal pH. After 3 weeks, mucosal:serosal zinc transfer and Zn accumulation by tissue were measured using the everted-gut-sac technique. In Expt 2, incubations were carried out in the presence and absence of 0.25 mm-ouabain to assess the importance of transfer by Na+, K+-ATPase-dependent mechanisms, and some observations on glucose transport were also made. Ouabain reduced rates of transfer of both Zn and glucose and also tissue Zn accumulation. There were no significant differences in rates of Zn transfer by everted sacs from duodenal, ileal and colonic sites, but accumulation of Zn by tissue was a more important fate than transfer across the serosal surface, and accumulation by duodenal tissue was approximately twice as great as by other tissues. Mucosal:serosal transfer of glucose by ileal tissue was much more sensitive to ouabain than was Zn transfer. Previous diet appeared to alter the capacity of the intestinal tissue to transfer Zn, with the highest rates of transfer being by colonic tissue from pectin-fed rats.
Effects of dietary copper deficiency on male offspring of heterozygous brindled mice
Authors: Prohaska Joseph R.
Published: September 2005

Female C57BL mice heterozygous for the brindled gene were mated to normal males and fed on a purified diet low in copper throughout gestation and lactation with (+ Cu) or without (−Cu) Cu-supplemented drinking water. Male offspring of two genotypes (control, + /y and brindled, Mobr/y) were compared when 10–12 d old. Brindled mice from dams on the – Cu treatment were smaller and had lower packed cell volumes than brindled mice from dams on the + Cu treatment. The −Cu brindled mice were smaller than their littermate brothers (+/y) but had equivalent biochemical features consistent with severe Cu deficiency. Compared with control mice from dams on the +Cu treatment, caeruloplasmin (EC1.16.3.1) activity was lower in offspring of all three other groups including Mobr/y mice who were not anaemic. Iron levels were similar in organs and bone marrow from all four groups of offspring. When dietary Cu is limiting in brindled mice a more severe Cu deficiency ensues. Thus, appropriate Cu nutriture is important to the management of Menkes' disease in humans, a genetic analogue of the brindled mouse.
Calcium, magnesium and phosphorus status of elderly inpatients: dietary intake, metabolic balance studies and biochemical status
Authors: Thomas Anita J. , Bunker Valda W. , Sodha Nidish , Clayton Barbara E.
Published: September 2005

The calcium, magnesium and phosphorus status of a group of elderly inpatients was studied by use of duplicate meal analysis over a 5 d period and biochemical indices in twenty-one patients, and metabolic balance (5 d) in six of these. Mean daily Ca intake was lower than that of apparently healthy elderly subjects in metabolic equilibrium, although commensurate with present UK recommendations. Metabolic balance was negative for Ca. Mean daily Mg intake was approximately half the US recommendation, and half the intake at which metabolic balance has been observed in healthy elderly people. The five patients studied were in metabolic balance for Mg. Mean daily P intake was close to the UK recommendation, but negative metabolic balance was observed. The disparity between official recommendations for Ca intake, factors contributing to suboptimal Ca status, and measures that may improve Ca status in this group are discussed.
Brain glutamate and γ-aminobutyrate (GABA) metabolism in thiamin-deficient rats
Authors: Page Martyn G. , Ankoma-Sey Victor , Coulson William F. , Benders David A.
Published: September 2005

The brain metabolism of glutamate and γ-aminobutyrate (GABA) was investigated in thiamin-deficient and pair-fed control rats, in order to determine whether the GABA shunt may provide an important alternative to 2-oxo-glutarate dehydrogenase (EC1.2.4.2) in energy-yielding metabolism in thiamin deficiency. Brains from thiamin-deficient animals contained less glutamate, 2-oxo-glutarate and GABA than those from control animals. The brain content of ATP was unaffected by thiamin deficiency. After intracerebroventricular injection of [14C]glutamate, the specific radioactivity of GABA in the brains from deficient animals was 45–50% higher than that in controls, suggesting a considerable increase in the metabolic flux through the GABA shunt in thiamin deficiency. Brain GABA showed a marked circumannual variation, with a peak in mid-summer and a minimum value in mid-winter.
The optimum dietary amino acid pattern for growing pigs
Authors: Fuller M. F. , McWilliam R. , Wang T. C. , Giles L. R.
Published: September 2005

Experiments were made to estimate separately the amino acid requirements of growing pigs for maintenance and for protein accretion. The relationship between nitrogen retention and amino acid intake was estimated for each essential amino acid (except histidine) by giving, at rates of N intake of 0.25 and 2.0 g/kg body-weight (W)0.75per d, diets in which one amino acid was made specifically deficient. From the regression coefficients it was calculated that, for the accretion of 1 g body protein, the dietary amino acid requirements were (mg) threonine 47, valine 53, methionine+cystine 36, methionine 19, isoleucine 43, leucine 78, phenylalanine+tyrosine 84, phenylalanine 41, lysine 68 and tryptophan 12. The daily amino acid requirements for N equilibrium were also estimated. From the relationship between N retention and amino acid intake the daily amino acid requirements for N equilibrium were estimated to be (mg/kg W0.75per d) threonine 53, valine 20, methionine+cystine 49, methionine 9, isoleucine 16, leucine 23, phenylalanine+tyrosine 37, phenylalanine 18, lysine 36 and tryptophan 11. It was estimated that both for maintenance and for protein accretion tyrosine could provide close to half the total phenylalanine+tyrosine needs. Cystine could supply close to half the total sulphur amino acid needs for protein accretion but 0.8 of the needs for maintenance.
The effect of clenbuterol on basal protein turnover and endogenous nitrogen loss of sheep
Authors: Inkster J. E. , Deb.Hovell F. D. , Kyle D. J. , Brown D. S. , Lobley G. E.
Published: September 2005

Seven measurements of the effect of clenbuterol on basal nitrogen excretion (UNE), and protein turnover were made in six female sheep. The sheep were sustained by the intraruminal infusion of energy as volatile fatty acids to provide maintenance, but given no protein (N-free) for 12 d (6 d control, 6 d clenbuterol). Clenbuterol reduced UNEby 20 %, but only on day 2 of the 6 d subperiod. Protein flux (equivalent to degradation on N-free nutrition), measured on day 6 by the irreversible loss of leucine was significantly increased (12%) by clenbuterol. Amino-N oxidation measured by N excretion was unchanged and, therefore, protein synthesis was also increased. During the 12 d N-free period, the recovery of urinary total N (Kjeldahl) as the sum of urea, ammonia, creatinine and purine derivatives, declined from 87.7 to 74.2 %. The form of this missing N was not identified. The effect of clenbuterol of increasing both degradation and synthesis is unlike that reported in the literature for animals receiving protein when, in general, synthesis is unchanged and degradation reduced. This could be due to a different effect of clenbuterol in the N-free state, or to unchanged effects on protein pools other than muscle whose relative contribution to protein metabolism is different in the N-free state.
The influence of rumen volatile fatty acids on protein metabolism in growing lambs
Authors: Abdul–Razzaq H. A. , Bickerstaffe R.
Published: September 2005

The effect of acetic or propionic acid rumen fermentation patterns on whole-body protein turnover, tissue protein synthetic rates and body composition was investigated in growing lambs. Protein turnover was assessed using a continuous intravenous infusion of [2,3-3H]tyrosine and tissue protein fractional synthetic rates (FSR) from the specific activities of plasma free, intracellular free and tissue bound tyrosine. Only the FSR of muscle tissue approached significance. The high FSR in the propionic group was attributed to the high plasma insulin concentration. Values for whole-body protein synthesis, corrected for tyrosine oxidation, were similar to those obtained by summating protein synthesis in individual tissues, confirming that tyrosine oxidation should be measured accurately if reliable whole-body protein synthesis values are required. Tyrosine oxidation and flux were high in the acetic acid group, suggesting that amino acids are used for gluconeogenesis. The high protein turnover rate probably ensures an adequate supply of gluconeogenic amino acids and that the penalty of mobilizing body proteins for gluconeogenic amino acids is minimal. In the propionic acid group, high plasma glucose and insulin concentrations were associated with a low protein turnover rate, high ratio of deposited: synthesized protein and a high body fat content. It is concluded that changing the proportion of ruminal volatile fatty acids influences protein turnover, protein synthesis and the efficiency of protein retention. Such factors probably contribute, indirectly, to the observed differences in body composition.
Energy expenditure of Gambian women during peak agricultural activity measured by the doubly-labelled water method
Authors: Singh J. , Prentice A. M. , Diaz E. , Coward W.A. , Ashford J. , Sawyer M. , Whitehead R. G.
Published: September 2005

The doubly-labelled water (2H218O) method was used to measure total energy expenditure (TEE) in ten non-pregnant, non-lactating (NPNL), six pregnant (P) and fourteen lactating (L) women in a rural Gambian community. Measurements were made on free-living subjects at a period of peak energetic stress when high agricultural work loads coincided with a hungry season to induce moderately severe negative energy balance. TEE averaged 10.42 (SD 2.08) MJ/d, equivalent to 1.95 (SD 0.38) times resting metabolic rate (RMR). The energy cost of physical activity plus thermogenesis, derived as TEE – RMR, averaged 4.94 (SD 1.96) MJ/d. Expressed per kg body-weight (103 kJ/kg per d) this component of expenditure was 2.5 times greater than comparative values from inactive, affluent women studied previously (39 kJ/kg per d). Estimated energy intake (EI) in a subset of the women (n 13) was only 4.80 (SD 1.58) MJ/d, yielding an apparent deficit of 6.08 MJ/d between EI and TEE. Weight changes suggested that endogenous fat oxidation accounted for only about 0.85 MJ/d, leaving an unexplained difference of over 5 MJ/d. Critical analysis of possible errors suggests that the new doubly-labelled water method has provided the most reliable estimates and that the estimates of EI were substantially in error. This finding has important consequences for other food intake studies.
Changes in serum cholinesterase (EC 3 1 * 1 * 8) activity in rats consuming a high-fat diet
Authors: Osada Jesus , Aylagas Hortensia , Cao Gonzalo , MIRo−Obradors Maria Jesus , Palacios−Alaiz Evangelina
Published: September 2005

Adult male rats were fed on a control diet containing (g/kg) carbohydrate 600, lipid 35 and protein 190, or on a high-fat diet containing carbohydrate 360, lipid 420 and protein 120. After 30 d, the high-fat diet provoked a decrease in serum cholinesterase (EC3.1.1.8) activity which was reversed by feeding rats on the control diet. The observed decrease after 90 d on the high-fat diet was not seen if a simultaneous daily intraperitoneal injection of a lipotrophic agent containing (mg/kg) S-adenosyl-l-methionine 3, coenzyme A 0.1, UDP-glucose 30 and CDP-choline 1.5 was given to rats on the high-fat diet. The findings are discussed in relation to the apparent susceptibility of serum cholinesterase to dietary components and its possible role in lipid metabolism.
The social diets of pregnant and post-pregnant women in different groups in London and Edinburgh: calcium, iron, retinol, ascorbic acid and folk acid
Authors: Schofield Claire , Stewart Judith , Wheeler Erica
Published: September 2005

Dietary records were obtained twice in pregnancy and once post-partum, from 265 women in all social classes in London and Edinburgh. Some Edinburgh women, and lactating women, showed the higher levels of calcium intake. For iron, retinol, ascorbic acid and folic acid, there was a consistent and significant regional and social class gradient in intakes. This favoured English women in ‘non-manual’ social groups, leaving the Scottish ‘manual’ class, after pregnancy, with the lowest intakes. Mean intakes of Ca and Fe were consistently below the current UK recommended daily amount (RDA). Intakes of retinol were all above it, and ascorbic acid intakes ranged above and below the RDA.
Studies on calcium absorption from milk using a double-label stable isotope technique
Authors: Fairweather-Tait Susan J. , Johnson Amanda , Eagles J. , Ganatra Smita , Kennedy H. , Gurr M. I.
Published: September 2005

Calcium absorption was measured in ten male volunteers from skimmed milk, Ca-enriched skimmed milk or watercress (Nasturtium officinale) soup. The foods were labelled extrinsically with 30 mg44Ca. Shortly after consuming the labelled meal, each subject was given an intravenous injection of 3 mg42ca. Fractional absorption from the oral dose was determined from plasma and urine samples collected 24–72 h later, using fast atom bombardment mass spectrometry to measure isotope ratios. The values for urine and plasma were in good agreement. Mean percentage absorption was 45.5 (SEM 1.9)% from the skimmed milk, 35.7 (SEM 4.7) % from the Ca-enriched milk and 27.4 (SEM 1.9) % from the watercress soup. The effect of consuming 568 ml (1 pint) Ca-enriched milk each day for 4 weeks on the efficiency of absorption of Ca was studied. Although there was no statistically significant difference between Ca absorption before and after the supplementation period, the results were considered to be somewhat inconclusive due to the small number of subjects and wide individual variation in Ca absorption.
The effect of varying the sodium or potassium intake, or both, on magnesium status in the rat
Authors: Charlton Judith A. , Armstrong D. G.
Published: September 2005

Alterations in sodium or potassium intake, or both, affect the distribution and excretion of magnesium in man and animals. Experiments were performed on rats to investigate the effect of varying Na, K or Na+K intakes on Na, K and Mg excretion and plasma and tissue concentrations. In Expt 1, increasing the Na intake in a linear fashion produced a significant (P < 0.05) quadratic response in urinary Mg excretion, with a decrease followed by an increase as Na intake rose. No effect was observed on faecal excretion of Mg. Plasma and tissues were sampled at the end of an 18 d collection period; concentrations of aldosterone in plasma and Mg, Na and K in plasma and tissue were determined. Increasing Na intake in a linear fashion produced a significant (P < 0.05) quadratic effect on Mg concentration in heart and muscle, i.e. a decrease followed by an increase as Na intake rose; Na intake did not affect liver or bone Mg concentrations. There were no significant effects of Na intake on plasma Mg, Na or aldosterone but plasma K fell significantly (P < 0.01) as Na intake increased. In Expt 2, constant amounts of four diets supplying adequate or high levels of Na and adequate or high levels of K but a constant intake of Mg were given to rats. The rats fed on the adequate-Na diet had a significantly (P < 0.05) higher urinary Mg excretion than those fed on the high-Na diet; Na intake did not affect faecal Mg excretion.
Nutrient effects on the hepatic production of somatomedin C (IGF,) in the milk-fed calf
Authors: Coxam VÈronique , Bauchart Dominique , Durand Denis , Davicco Marie-jeanne , Opmeer Fred , Barlet Jean-pierre
Published: September 2005

The present study was aimed at determining the influence of nutrients supplied by a milk diet (glucose, amino acids, triglycerides) on hepatic somatomedin C (IGF1) production in vivo in four 30-d-old milk-fed calves fitted with chronically indwelling catheters in hepatic (HV), portal (PV) and mesenteric veins and in the hepatic artery (HA), and with electromagnetic flow-meters on HA and PV. Fasting for 16 h induced a decrease (P< 0.01) in hepatic IGF1production (nmol/kg body-weight (BW) for 6 h) (1.1 (SE 0.2) ν. 6.6 (SE 0.7) in control animals). Infusion of glucose (1.8 g/kg BW for 4 h) or a mixture of amino acids (Azonutril; R. Bellon, Neuilly sur Seine; 62.5 mg nitrogen/kg BW for 3 h) in a mesenteric vein led to no significant effect on hepatic IGF1production for 6 h (1.2 (SE 0.3) and 0.7 (SE 0.3) nmol/kg BW respectively) compared with fasted calves. Infusion of chylomicrons purified from milk-fed calves (10.5 mg/h per kg BW, i.e. 0.16 mg triglycerides/kg BW per min) enhanced significantly (P< 0.01) the hepatic production of IGF1(mean value for 6 h: 5.3 (SE 0.8) nmol/kg BW). Infusion of Intralipid (7 mg triglycerides/kg BW per min) induced a slight but significant hepatic IGF1production which amounted to 3.5 (SE 0.4) nmol/kg BW (P< 0.01 compared with chylomicron treatment) and it began only 5 h after starting the infusion. Neither triglyceride nor chylomicron infusion significantly modified hepatic blood flow. Thus, these results demonstrate for the first time the role of lipids in the regulation of hepatic IGF1production in vivo.
Laboratory studies of the dental properties of soft drinks
Authors: Grenby T. H. , Phillips A. , Desai T. , Mistry M.
Published: September 2005

The composition and dental properties of eight different soft drinks, representing some of the most popular types used in the UK, were examined. Demineralization experiments were conducted on hydroxylapatite, the basic component of dental enamel, determining calcium dissolving by atomic absorption spectroscopy and phosphorus by u.v. visual spectrophotometry. The titratable acid content of the drinks was found to give a better guide than their pH to their potential dental erosiveness. The sugar content, in their ready-to-drink form, varied from zero in a low-calorie product up to almost 14 % in a blackcurrant drink, but using a technique with a relatively long contact time, and in the absence of intact dental plaque, the demineralizing action on hydroxylapatite of the acids already in the drinks eclipsed the effects of the acid generated by oral micro-organisms from the sugars in the drinks. The pure citrus juices showed potentially the worst dental properties, followed by the orange and blackcurrant concentrates after dilution to their ready-to-drink form, with least demineralization from the carbonated drinks, and a cola drink giving especially low values.
A quantitative model of reticulo-rumen particle degradation and passage
Authors: Lirette A. , Milligan L. P.
Published: September 2005

Labelled particles were prepared by mordanting low concentrations (0.1 or 5 g/kg dry matter) of chromium to neutral-detergent-extracted stems (1–2 mm or 10 mm in length) of bromegrass (Bromus inermis). These were used in the study of reticulo-rumen particle kinetics of four steers given bromegrass hay and from the results a quantitative model of particle digestion and passage was developed. At the 0.1 g Cr/kg concentration there was minimal interference with digestibility of the feedstuff. The ratio, dry weight of the reticulo-rumen large-particle pool (> 3.35 mm):small-particle pool (< 3.35 mm) was 2:1. It was derived from the model that volatile fatty acids (VFA) and carbon dioxide in the rumen were produced mainly from large particles, and that between 500 and 700 g/kg hay dry matter was digested in the reticulo-rumen. It was also derived from the model that a major portion, 200 (SE 110) g/kg, of the hay dry matter was rapidly solubilized and that the material leaving the reticulo-rumen was composed of small particles (500–840 g/kg), large particles (100–160 g/kg) and an unknown portion of soluble dry matter of hay (0-400 g/kg). Disappearance from the large-particle pool in the model involving the lowest Cr level was directed to formation of VFA and CO2(0.68 (SE 0.04) of total flow) to the small-particle pool (0.25 (SE 0.06) of total flow) and direct passage from the reticulo-rumen (0.07 (SE 0.002) of total flow). The disappearance from the small-particle pool was to VFA and CO2production and to the omasum accounting for 0.14 (SE 0.18) and 0.86 (SE 0.24) respectively, of the total flow. It was concluded that the low-level-mordanting technique in combination with appropriate sampling yielded a realistic quantitative description of forage breakdown and movement processes in the digestive tract of cattle.
Lignocellulose degradation and subsequent metabolism of lignin fermentation products by the desert black Bedouin goat fed on wheat straw as a single-component diet
Authors: Silanikove N. , Brosh A.
Published: September 2005

Bedouin goats were fed on wheat straw as a single-component diet under two watering regimens, drinking once daily or once every 4 d, in order to clarify whether lignin-degradation products were absorbed, metabolized and excreted in urine. Acid-soluble lignin accounted for 220 g/kg total lignin, its digestibility was the highest (0.87) and was unaffected by water deprivation. Acid-insoluble lignin accounted for 780 g/kg total lignin and its digestibility increased during water deprivation from 0.21 to 0.41. Alkali-soluble lignin accounted for 320 g/kg total lignin and its digestibility increased during water deprivation from 0.44 to 0.53. Digestibility of structural carbohydrate was considerably higher than that observed in other domesticated ruminants fed on wheat straw. It responded positively to water deprivation, increasing from 0.63 to 0.73 with cellulose and from 0.61 to 0.68 with hemicellulose. The amount of urinary aromatic acids, mainly in the form of hippuric acid, considerably exceeded the potential contribution of any non-lignin component which might affect the excretion of aromatic acids. A considerable percentage (71−76) of the apparently digested lignin was not accounted for as soluble phenolic compounds in faeces or as aromatic acids in urine, and hence was apparently completely metabolized. Lignin is a key substrate which is extensively digested in goats fed on low-quality forage, with subsequent absorption of end-products. This enhanced the availability of structural carbohydrates for fermentation and was associated with excretion of high-energy metabolites in the form of benzoic and hippuric acids.
Growth, digestibility, and enzyme activities in the pancreas and intestines of guinea-pigs fed on raw and heated soya-bean flour
Authors: Hasdai A. , Nitsan Zafrira , Volcani R. , Birk Yehudith
Published: September 2005

The nutritional effects of giving raw (RSF) or heated (HSF) soya-bean flour to young guinea-pigs were investigated in trials 1 and 2, in which the levels of dietary protein were 120 and 190 g/kg diet respectively. The growth rate of animals fed on RSF was lower than that of those fed on HSF. Growth retardation of guinea-pigs fed on RSF was accompanied by a lower apparent digestibility of the protein (0.49–0.53) compared with HSF (0.67–0.76) and lower food conversion efficiency. In RSF-fed animals, increasing dietary protein affected growth and food conversion efficiency negatively. The pancreas of animals fed on RSF and HSF was similar in weight but secreted less trypsin, chymotrypsin and amylase, in RFS-fed animals. It was concluded that the mechanism by which raw soya-bean negatively affects the growth rate of guinea-pigs by reducing the activity of intestinal enzymes, differs from that suggested for rats and chicks, but is similar to that of pigs and calves.
Bile acid conjugation and hepatic taurine concentration in rats fed on pectin
Authors: Ide T. , Horii M. , Kawashima K. , Yamamoto T.
Published: September 2005

A relationship between bile acid conjugation and hepatic taurine concentration was investigated in rats fed on citrus pectin. When rats were fed on the diets containing varying amounts of pectin (10, 30, 60 and 100 g/kg dietary levels), biliary excretion of bile acids increased as the dietary levels of pectin increased. The increase was entirely due to the glycine-conjugated bile acids. The biliary excretion of taurine-conjugated bile acid was somewhat decreased as the dietary level of the fibre increased. Consequently, most of the bile acids were conjugated with glycine in rats fed on the diet containing 100 g pectin/kg. On the other hand, dietary cellulose (60 and 100 g/kg) did not affect the biliary bile acid excretions. The major proportion of bile acids in rats receiving a fibre-free diet and the diets containing cellulose were conjugated with taurine. Hepatic taurine concentrations decreased as the dietary levels of pectin, but not of cellulose, increased. Although dietary pectin (100 g/kg) also slightly decreased the taurine concentration in the kidney, those concentrations in other non-hepatic tissues examined (heart, brain and serum) were unaffected by the dietary fibre. Supplementation of the diet containing 100 g pectin/kg with methionine (10 g/kg) and taurine (10 and 50 g/kg) strikingly increased hepatic taurine concentrations. In this situation, the conjugation of bile acid with glycine was almost abolished and taurine conjugates became abundant in the bile of these animals. It is suggested that dietary pectin mediated an increase in the biliary bile acid excretion which may have depleted the hepatic pool of taurine available for bile acid conjugation and, thus, increased glycine conjugation of bile acids.
Digestion of fibre polysaccharides of pea (Pisum sativum) hulls, carrot and cabbage by adult cockerels
Authors: Longstaff M. , McNab J. M.
Published: September 2005

Characterization of the carbohydrates of pea (Pisum sativum) hulls, carrot and cabbage using both colorimetric and gas–liquid chromatographic techniques permitted a detailed investigation into the extent of digestion of differing types of fibre. These digestion studies were greatly aided by the development of a rapid bioassay employing starved adult cockerels. Total collection of undigested residues, uncontaminated by food spillage, could be made from trays placed under the cockerels. Chemical analysis showed that pea hulls consisted mainly of fibre with very little available carbohydrate present, whereas more than half of freeze-dried carrot and cabbage consisted of available carbohydrate (sucrose, glucose, fructose, starch) and consequently considerably less fibre was present. The fibre of carrot and cabbage was similarly composed of nearly equal amounts of neutral and acidic polysaccharides, whereas pea-hull fibre had four times as much neutral as acidic polysaccharides. The digestibility of total neutral polysaccharides from all three foodstuffs was extremely low. However, there appeared to be preferential digestion of polysaccharides composed of rhamnose, arabinose and galactose residues, all associated with pectic material, in contrast to the indigestibility of polysaccharides composed of fucose, xylose and glucose. Acidic polysaccharides were digested to a greater extent than neutral ones, and those of carrot and cabbage more so than pea hulls. The polysaccharides which were the most soluble were also the most digestible, but due to the arbitrariness of polysaccharide solubility, quantification of their total digestibilityper sewas considered not possible.
Basal metabolic rate and energy expenditure of pregnant Nigerian women
Authors: Cole A. H. , Ibeziako P. A. , Bamgboye E. A.
Published: September 2005

The purpose of the present study was to compare basal metabolic rates (BMR) of pregnant Nigerian women from rural and urban areas with values from similar studies in other Third World countries. We also investigated possible changes in BMR during the course of pregnancy. An open-circuit indirect calorimeter was used to measure BMR and energy expenditure (EE) during sedentary activity in forty-one pregnant Nigerian women. The results showed marked variability in BMR among individuals. A correlation analysis between BMR and other biological and physical characteristics revealed body-weight and gestation as the only variables related to BMR and oxygen consumption.

The study revealed no significant difference between BMR and EE of sedentary activity in the subjects. The wide variability may have been due to the nutritional status of the subjects studied, who were drawn largely from the lower socioeconomic groups of Nigerian society. The present study shows that socioeconomic status and nutritional interventions should be taken into account when framing recommendations for maternal nutrition during pregnancy.
Tissue protein synthesis and nucleic acid concentrations in steers treated with somatotropin
Authors: Eisemann J. H. , Hammond A. C. , Rumsey T. S.
Published: September 2005

The effect of injection with bovine somatotropin (bST) on the fractional rate of protein synthesis (FSR) in tissues of beef steers was studied using a continuous infusion of [1-14C]leucine. Minimum and maximum FSR were calculated from free leucine specific radioactivity (SRA) in plasma or tissue homogenate respectively. Tissue nucleic acid concentrations were also quantified. Tissue samples were obtained from several muscles, sections of the small intestine and liver. In response to bST, both minimum and maximum FSR increased in muscle but not liver or intestinal tissues. Absolute synthesis rate increased in several muscles and small intestine tissues. Treatment with bST increased the relative SRA of protein-bound leucine in muscles compared with liver; increased the amount of protein synthesis per unit empty body-weight (EBW) in most muscles; and increased weight of small intestine relative to EBW, suggesting a differential response between liver and the other tissues measured. Compositional changes in response to bST occurred only in muscles. DNA concentration increased while protein:DNA decreased in the gastrocnemius muscle and RNA:DNA increased in the longissimus dorsi. The maximum percentage contribution of tissue protein synthesis to whole-body protein synthesis was 12·6, 25·7 and 20·5, and 13·0, 29·4 and 25·8 for liver, muscle, and small intestine in placebo-treated and bST-injected steers respectively.
Breast milk fatty acids in mothers of children with atopic eczema
Authors: Wright Stephen , Bolton Colin
Published: September 2005

The total lipid fatty acid composition of mature breast milk has been analysed in a group of twenty-five mothers of children with atopic eczema, and compared with breast milk from twenty-two controls. Total lipids were extracted into chloroform–methanol (2:1, v/v) and the methyl esters prepared by alkali-catalysed trans-esterification were separated by gas–liquid chromatography and identified by comparison with standard fatty acid methyl esters. Results show that mothers of children with atopic eczema have a significantly greater proportion of linoleic acid, and a smaller proportion of dihomo-γ-linolenic acid in their total breast milk lipid than the controls. Proportions of total derived fatty acids were similar between groups and there were no differences in the principal saturated and monounsaturated fats. It was concluded that mothers of children with atopic eczema have an abnormal breast-milk fatty acid composition. This supports previous evidence of a defect of conversion of linoleic acid into its long-chain polyunsaturated metabolites in the condition.
Dietary intakes and adipose tissue levels of linoleic acid in peptic ulcer disease
Authors: Kearney J. , Kennedy N. P. , Keeling P. W. N. , Keating J. J. , Grubb Louise , Kennedy Margaret , Gibney M. J.
Published: September 2005

Adipose tissue levels of linoleic acid were determined from biopsies of subcutaneous abdominal fat of normal healthy controls (n 40) and from two patient groups with endoscopically evaluated non-ulcer dyspepsia (n 40) or peptic ulcer disease (n 38). The level (g/100 g) of adipose tissue linoleic acid in the normal healthy controls (15·0 (sd 4·1)) was significantly (P < 0·05) greater than that in patients with non-ulcer dyspepsia (12·8 (sd 3·5)) and in patients with peptic ulcer disease (11·7 (sd 2·7)). A dietary history revealed a lower intake of linoleic acid and a significantly (P < 0·05) lower intake of dietary fibre (g/d) for both the non-ulcer dyspepsia (15·9 (sd 6·2)) and peptic ulcer disease (15·2 (sd 7·8)) patients compared with normal healthy controls (20·2 (sd 11·2)). Adipose tissue linoleic acid tended to increase with indices of increasing socioeconomic status, although the differences between patient and controls were not confounded by socioeconomic status. Patients with dyspepsia reported more foods causing symptoms (onion, fried foods, alcohol, citrus fruits and spices) and more foods giving relief (milk, bread) compared with control orthopaedic patients.
Biotin studies in pigs
Authors: Kopinski J. S. , Leibholz Jane , Bryden W. L.
Published: September 2005

Eight pigs were given a semi-purified diet based on maize flour and casein containing 10 μg biotin/kg. The diet was given ad lib. with or without a supplement of 70 μg biotin/kg diet from 5 to 94 d of age. The flow of biotin in the stomach was similar to the biotin intake (13.5 and 112 μg/d) for the unsupplemented and biotin-supplemented pigs respectively. The flow of biotin through the small intestine decreased for the biotin-supplemented pigs from 39 μg/d in the first quarter of the small intestine to 7.9 μg/d in the last quarter. The flows of biotin in the caecum, large intestine and colon were similar for both the unsupplemented and biotin-supplemented pigs, with values of 17–54 μg/d, indicating the synthesis of biotin in the hind-gut.
Biotin studies in pigs
Authors: Kopinski J. S. , Leibholz Jane , Leibholz Jane , Love R.J.
Published: September 2005

Six pigs were given a biotin-deficient diet (10 μg biotin/kg) for 14 weeks. The pigs were given the same diet for a further 42 d with one of three biotin treatments: no supplement, 400 μg biotin/d given orally, 400 μg biotin/d infused into the caecum. The concentrations of biotin in the liver, kidney and heart, at the conclusion of 42 d were greater in the pigs given the oral biotin supplement than in the unsupplemented pigs. The values for the pigs given the caecal infusion of biotin were intermediate. The excretion of biotin in faeces was increased from 35 to 101 μg/d by the caecal biotin infusion, and the urinary excretion was increased from 35 to 83 μg/d. The oral dose of biotin increased urinary biotin excretion from 35 to 345 μg/d, but there was no change in faecal biotin excretion. Two pigs were fitted with ileal cannulas and catheters in the vena cava. The pigs were given a dose of [14C] biotin either into the caecum, when the ileum was occluded by a bladder catheter, or orally. [14C] biotin was measured in the urine and plasma and showed that post-ileal biotin absorption was 8 % as efficient as the absorption of biotin after oral dosing.
The Kilkenny Health Project: food and nutrient intakes in randomly selected healthy adults
Authors: Gibney M. J. , Moloney Mary , Shelley Emer
Published: September 2005

1. Sixty healthy subjects aged 35-44 years (thirty men and thirty women) were randomly selected from electoral registers to participate in a dietary survey using the 7 d weighed-intake method during June-August 1985.

2. Energy intake (MJ/d) was 12.5 for men and 8.4 for women. Fat contributed 36.0 and 39.1% of the total energy intake of men and women respectively. When this was adjusted to exclude energy derived from alcoholic beverages, the corresponding values were 38.8 and 39.7 % respectively. The major sources of dietary fat (%) were spreadable fats (28), meat (23), milk (12) and biscuits and cakes (11).

3. The subjects were divided into low- and high-fat groups both on the relative intake of fat (< 35 % or > 40 % dietary energy from fat) and on the absolute intake of fat (> or < 120 g fat/d). By either criterion, high-fat consumers had lower than average intakes of low-fat, high-carbohydrate foods such as potatoes, bread, fruit and table sugar, and higher intakes of milk, butter and confectionery products. Meat intake was higher among high-fat eaters only when a high-fat diet was defined as a percentage of energy.