bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of riboflavin deficiency on lipid metabolism of liver and brown adipose tissue of sucking rat pups
Authors: Duerden Julia M. , Bates C. J.
Published: September 2005

1. An increase in 1iver:body-weight and in hepatic triacylglycerol content, together with changes in the fatty acid profiles of hepatic phospholipids, were observed as a result of moderate riboflavin deficiency in sucking rat pups. Oxygen consumption by hepatic mitochondria, with palmitoyl L-carnitine as substrate, was not significantly impaired.

2. Mitochondria from interscapular brown adipose tissue, however, showed a marked impairment of O2Consumption, with palmitoyl L-carnitine as substrate, in the riboflavin-deficient pups. This impairment was also apparent after uncoupling with carbonyl cyanidep-trifluoromethoxyphenylhydrazone, but was not consistently observed after the addition of GDP to suppress uncoupled oxidation. It was much less evident, and did not reach statistical significance, for the mitochondria of brown adipose tissue of the corresponding deficient dams.

3. Binding of3H-labe11ed GDP by brown adipose tissue mitochondria was unaffected by riboflavin deficiency in the pups, suggesting that the effect on O2consumption is more likely to be due to impaired integrity of the mitochondrial respiratory chain, than to impairment of the specific capacity for uncoupling of respiration which is characteristic of brown adipose tissue mitochondria. Total cytochromecoxidase (EC 1.9.3.1) activity of the brown adipose tissue of riboflavin-deficient pups was not significantly reduced.

4. A small but significant impairment was observed in the stimulation ofwhole-body O2consumption by injected noradrenaline in the riboflavin-deficient pups, suggesting that the impairment of brown adipose tissue mitochondrial function may be accompanied by impaired physiological capacity in vivo.
Feeding frequency for lactating cows: effects on digestion, milk production and energy utilization
Authors: Sutton J. D. , Broster W. H. , Napper D. J. , Siviter J. W.
Published: September 2005

1. The results are reported of four feeding experiments in which lactating cows were given fixed rations of hay and high-cereal concentrates at different meal frequencies. In Expt 1 the total ration was given in two and twenty-four meals daily and in Expts 2–4, the concentrates were given in two and five or six meals and the hay was given twice daily. The diets contained 600–900 g concentrate /kg.

2. In all the experiments, more frequent feeding of these low-roughage diets reduced milk fat depression and increased milk fat yield. In each experiment the increase was greater with the diet containing the lower proportion of hay. There was no significant effect on milk yield, the protein or lactose contents of the milk or live-weight gain. Digestibility of dry matter, organic matter and energy was increased in one of the experiments but not in two others in which it was measured.

3. More frequent feeding was calculated to increase the net energy secreted in milk and there was a tendency for it to increase the net energy in live-weight gain with diets containing 600 or 700 g concentrate/kg but to decrease it with diets containing 800 or 900 g concentrate/kg. These results are discussed in relation to theories of energy partition in lactating cows.

4. It is concluded that at fixed feed intakes, the main response to increased meal frequency is likely to be a reduction in milk fat depression and that this will be confined to diets containing not more than about 200 g modified acid-detergent fibre/kg dry matter.
Influences of cold exposure on digestion of organic matter, rates of passage of digesta in the gastrointestinal tract, and feeding and rumination behaviour in sheep given four forage diets in the chopped, or ground and pelleted form
Authors: Kennedy P. M.
Published: September 2005

1. Sixteen sheep, each fitted with cannulas in the rumen and proximal duodenum, were given four diets in the chopped or ground and pelleted form, at fixed intakes at intervals of 2 h. The sheep were closely shorn and exposed to temperatures of 22–25° or 1–4° for four periods of 45 d. Flow of duodenal digesta by reference to the markers CoEDTA and 103Ru-phenanthroline, chewing behaviour and particle size of rumen and duodenal digesta were measured.

2. Apparent digestibility of organic matter (OM) in the gastrointestinal tract was depressed (P < 0.05) by grinding and pelleting the diet, and by exposure of sheep to cold ambient temperatures. This was attributable to depression (P < 0.01) by 0.1 of OM digestion in the reticulo-rumen. No effects on intestinal digestion of OM were observed.

3. Cold ambient temperatures did not affect the content, but increased the rate of digestion for pelleted diets but not for chopped diets, of potentially-degradable cell-wall constituents of ground dietary material incubated in nylon-bags in the rumen.

4. Retention times of markers of the particulate and liquid phases of rumen digesta were not significantly (P < 0.05) affected by ambient temperature, despite significant (P < 0.001) increases in the rate of contraction of the reticulum. Retention time of 103Ru-phenanthroline in the intestines was not affected by cold exposure.

5. Cold exposure was associated with depression (P < 0.05) of volatile fatty acids concentration in the rumen and elevated (P < 0.05) pH. Molar proportions of acetic and isovaleric acid were reduced (P < 0.01), accompanied by increased (P < 0.001) proportions of propionic acid during cold exposure.

6. Cold exposure and pelleting of the diets were both associated with reduction in digesta particle size in the rumen. Duodenal particle size was not affected by cold exposure. Pelleting of the diet markedly reduced (P < 0.001) duration of chewing and number of chews/d during eating and rumination. Cold exposure of sheep resulted in a faster (P < 0.01) rate of eating of the diets.

7. When allowed to express their voluntary feed consumption during a 10 d period, intakes of chopped diets were increased by 0.13 (P < 0.01) by cold exposure, in contrast to lack of significant change in sheep given pellets.

8. The results did not support the hypothesis that the effect of cold exposure on digestion was dependent on the physical form of the diet given at fixed intake, but did indicate that increased voluntary feed consumption was a result of increased clearance of digesta from the rumen throdgh decreased rumen particle size and increased reticulum motility.
Cellulose and pectin alter intestinal β-glucuronidase (EC 3.2.1.31) in the rat
Authors: Lindop Rosemary , Tasman-Jones Clifford , Thomsen Lindy L. , Lee Sum P.
Published: September 2005

1. Groups of rats were given a fibre-free diet containing none or one of the three fibre components: pectin, cellulose or galactomannan.

2. After feeding for 16 weeks, total protein level and β-glucuronidase (EC 3.2.1.31) activity in the contents and mucosa of jejunum and ileum, and in the contents only of the caecum, were determined.

3. The pectin supplement reduced protein concentration in jejunal contents while cellulose reduced protein concentration in the ileal and caecal contents.

4. β-Glucuronidase activity of caecal contents was significantly reduced in both the pectin- and cellulose-fed groups.

5. Cellulose affected the β-glucuronidase activity of both the ileal contents while pectin reduced the β-glucuronidase of the ileal but not the jejunal contents.

6. Dietary fibre components did not significantly affect jejunal or ileal mucosal β-glucuronidase activity.
The effect of guar gum and level and source of dietary fat on glucose tolerance in growing pigs
Authors: Sambrook Ian E. , Rainbird Anna L.
Published: September 2005

1. Six growing pigs (30–75 kg) were fed on semi-purified diets containing either 30 g maize oil/kg diet (LFM), 30 g soya-bean oil-tallow mixture (1:1, w/w)/kg diet (LFST) or 160 g soya-bean oil-tallow mixture (1:1, ww)/kg diet (HFST) without and with the addition of guar gum (40g/kg diet).

2. Plasma glucose and insulin concentrations following twice daily feeding at 09.00 and 21.00 h were measured, during 24 h periods, in blood sampled from a permanent indwelling vena cava catheter.

3. The source and level of dietary fat had no significant effect on pre-prandial plasma glucose or insulin concentrations except for insulin with diet LFST in the morning (P<0.05). Addition of guar gum to the diets had no significant effect on pre-prandial plasma glucose and insulin levels.

4. The peak post-prandial plasma glucose and insulin levels were not significantly affected by dietary fat. The addition of guar gum, however, significantly reduced (P < 0.05) the peak post-prandial plasma glucose concentration with diets LFM and LFST and also the peak plasma insulin concentration for all diets except for diet HFST in the morning.

5. The time taken to reach the peak post-prandial plasma glucose and insulin concentrations was not significantly affected by dietary fat but it was increased by the addition of guar gum, although the differences were not always significant.
Dietary effects on pancreatic lesions induced by excess arginine in rats
Authors: Takama Shigeyuki , Kishino Yasuo
Published: September 2005

1. The effect of nutrition on the incidence of pancreatic damage was studied. Injection of excess arginine was found to cause more massive necrosis of the acinar cells after 24 h in malnourished rats (those given 50 g casein/kg diet) than in well-nourished rats (those given 200 g casein/kg diet).

2. Ultrastructural examination showed that whorl formation of the endoplasmic reticulum, decreases in the number of zymogen granules and formation of vacuoles in the cytoplasm were more marked in rats given 50 g casein/kg diet. Degradation of zymogen granules within vacuoles in the damaged cells was frequently observed in rats given 200 g casein/kg diet.

3. Necrosis of adipose tissue was associated with pancreatic damage more frequently in rats given 200 g casein/kg diet; rats with large amounts of zymogen granules in the acinar cells showed particularly severe necrosis of adipose tissue. Rats given 50 g casein/kg diet did not show necrosis of adipose tissue.

4. These results indicate that in the malnourished state there were more marked arginine lesions of the pancreas in which to study cellular and histologic changes than in the well-nourished state and that the occurrence of necrosis of adipose tissue may be related to a high content of zymogen granules in the acinar cells before pancreatic damage.
The influence of creatinine, lecithin and choline feeding on aliphatic amine production and excretion in the rat
Authors: Lowis Susan , Eastwood M. A. , Brydon W. G.
Published: September 2005

1. The excretion of aliphatic amines, methylamine, dimethylamine and trimethylamine in the urine and faeces of rats fed on a control diet and diets supplemented with creatinine, lecithin or choline were measured over a 14 d feeding period.

2. The rats were then killed and concentrations of amines in small and large intestinal contents measured.

3. Adding creatinine to the diet resulted in a significant increase of methylamine excretion in the faeces and urine. The amount of methylamine found in all parts of the intestine increased, especially in the caecum.

4. Adding lecithin to the diet resulted in an increase in the methylamine excretion only, and no change in the concentrations of amines found in the intestine, except for trimethylamine which was significantly increased in the caecum and colon.

5. Adding choline to the diet resulted in a significant increase in excretion of trimethylamine and, to a lesser extent, methylamine. The levels of amines found in the gut increased, dimethylamine being increased in the small bowel, and methylamine and trimethylamine in the caecum.
Intestinal absorption of sorbitol and effects of its acute administration on glucose homeostasis in normal rats
Authors: Lauwers A.-M. , Daumerie C. , Henquin J. C.
Published: September 2005

1. Intestinal absorption of sorbitol was studied in a duodeno-jejunal loop of anaesthetized rats. The acute effects of exogenous sorbitol on glucose homeostasis were also evaluated in male and female rats.

2. In the presence of lumen concentrations of sorbitol ranging from l μM to 200mM, a fairly constant low percentage (about 12%) of the loop's contents was absorbed after 30 min. This amount increased only slightly with time, but this was not due to sorbitol accumulation in the mucosal layer of the loop.

3. 3-O-methylglucose was absorbed much more quickly than sorbitol, but did not interfere with sorbitol absorption. The latter was not impaired by omission of lumen sodium ions nor by phloridzin, both of which inhibited 3-O-methylglucose absorption.

4. Gastric administration of sorbitol did not affect plasma glucose or insulin levels. Glucose or sucrose administration caused a similar rise in plasma glucose, but the increase in plasma insulin levels was larger after glucose than after sucrose administration.

5. Intravenous administration of sorbitol slightly increased plasma glucose and insulin levels. These changes were, however, considerably smaller than those occurring after glucose administration.

6. In the normal rat, intestinal absorption of sorbitol is passive and proceeds at a low rate. Acute oral administration of sorbitol does not affect glucose homeostasis, which is only slightly disturbed by a large intravenous load of sorbitol.
α-1-Antitrypsin metabolism in the protein-deficient weanling rat
Authors: Lewis Eric C. , Glew Robert H. , Chambers James , Coyle Patrick , Coppes Jhon
Published: September 2005

1. Protein-deficient weanling rats fed on a 30 g casein/kg diet for 3 weeks lost albumin but maintained the level of serum α-1-antitrypsin, the most abundant protease inhibitor in blood.

2.α-1-Antitrypsins from malnourished rats and control rats (given 250 g casein/kg diet) differed; the protease inhibitor from protein-deficient animals: (1) was more acidic, (2) appeared slightly larger (57400 v. 56000 daltons) on sodium dodecyl sulphate (SDS)-polyacrylamide gels, (3) had a more acidic Pitype and increased anodal mobility at pH 8.9, (4) bound more concanavalin-A and contained more carbohydrate, specifically two to three extra sialic acid residues. The amino sugar and neutral sugar contents of both preparations of α-1-antitrypsin were the same.

3. Analysis of the products of cyanogen-bromide cleavage revealed that α-1-antitrypsin preparations from protein-deficient rats contain an extra glycopeptide that was not present in α-1-antitrypsin from control animals.

4. In vivo studies showed that the increased sialic acid content of α-1-antitrypsin of protein-deficient rats did not alter the half-life of the molecule in the blood of control rats. However, the fractional catabolic rate of α-1-antitrypsin from either well-nourished or protein-deficient rats was significantly (P < 0.01) lower in protein- deficient rats than in control rats (0.0247/h v. 0.0406/h).

5. The decreased fractional catabolic rate could not be explained by changes in hepatic mannosyl-, galactosyl- or N-acetylhexosaminyl receptors since liver perfusion studies showed that bovine serum albumin, when covalently modified separately with each of these ligands, was extracted from the perfusion medium as rapidly or more rapidly by livers from malnourished animals.

6. Perfused livers from protein-deficient rats secrete three times more α-1-antitrypsin than do livers from well-nourished animals.

7. The decreased fractional catabolic rate and increased rate of biosynthesis and secretion of the glycoprotein by livers from protein-deficient animals may account for the maintenance of α-1-antitrypsin levels during protein malnutrition.
The importance of the non-protein components of the diet in the plasma cholesterol response of rabbits to casein
Authors: Allotta E. C. , Samman S. , Roberts D. C. K.
Published: September 2005

1. To characterize the hypercholesterolaemic effect of casein further, four groups of young male rabbits in two separate experiments were placed on cholesterol-free semi-purified diets for 12 weeks. The diets were similar in composition, with either casein or soya-bean-protein isolate providing the protein source (250 g/kg). In two of these diets the salt mix was reduced by 45% (normally 40 g/kg) and replaced by potassium bicarbonate.

2. Growth was unaffected by these alterations in dietary salts except for one group given the soya-bean-reduced-salts diet.

3. The mean concentrations of plasma cholesterol were significantly higher in all casein-fed groups as compared with their soya-bean-fed counterparts but the response was much greater in those given the casein—reduced-salts diet.

4. Contrary to expectations, analysis of the diets showed the zinc and copper concentrations of the casein diets to be less than those of the soya-bean diets. This was due to the greater concentrations of Cu (threefold) and Zn (twofold) in the soya-bean-protein isolate compared with casein.

5. The mean concentration of Zn in fur was significantly decreased in casein-fed rabbits and these animals also excreted less Zn but more Cu in their urine than those given the casein—reduced-salts diet.

6. The rabbits given the casein diet with the least salt mix showed the greatest degree of hypercholesterolaemia, suggesting an interaction between trace elements and the casein effect.
The effect of increasing methionine supply on the methionine conversion to cyst(e)ine in sheep
Authors: Pisulewski P. M. , Buttery P. J.
Published: September 2005

1. The conversion of methionine to cyst(e)ine was determined in sheep infused with different amounts of methionine (0-5 g/d) into the duodenum by assaying the incorporation of36S from intravenously-infused L-[35S]methionine into cyst(e)ine in wool, plasma albumin and the free plasma pool.

2. The percentage of cystine-S in the plasma originating from methionine increased linearly from 4.5 to 18 with increasing supplemental methionine supply.

3. The percentage of cysteine-S in albumin increased from 15 to 50; methionine supply increased to 3 g/d but then remained constant, indicating that the transsulphuration pathway of the liver was exceeded.

4. The percentage of wool cysteine-S originating from methionine was high (∼ 70) at all methionine supplementation rates.
The effect of intragastric infusion of glucose, lipids or acetate on fasting nitrogen excretion and blood metabolites in sheep
Authors: Asplund J. M. , Ørskov E. R. , Hovell F. D. DEB. , Macleod N. A.
Published: September 2005

1. Two experiments are reported in which the effect of the intragastric infusion of non-protein energy on fasting nitrogen losses was studied. Expt 1 was a preliminary trial with two 35 kg lambs given 0, 144, 288 or 432 kJ/kg live weight (W)0.75per d as lipid or glucose infused into the abomasum for periods of 3 d. Expt 2 was of a 4 x 4 Latin square design with four sheep of about 30 kg live weight. The four treatments were control (fasted with water infusion), or the infusion of 144 W/kg W0.75per d as glucose or lipid into the abomasum or as acetic acid into the reticulo-rumen.

2. Compared with the fasted control, glucose infusion reduced (P < 0.05) N excretion to about 0.6 of that of the control, increased (P < 0.05) plasma glucose, decreased (P < 0.05) plasma urea and β-hydroxybutyrate, and was without effect on plasma amino-N or creatinine excretion.

3. Lipid and acetate infusions were without statistically significant effect on N or creatinine excretion or any of the blood indices measured, with the exception of plasma glucose which was reduced (P < 0.05) with acetate infusion.
The efficiency of utilization of metabolizable energy and apparent absorption of amino acids in sheep given spring- and autumn-harvested dried grass
Authors: Macrae J. C. , Smith J. S. , Dewey P. J. S. , Brewer A. C , Brown D. S. , Walker A.
Published: September 2005

1. Three experiments were conducted with sheep given spring-harvested dried grass (SHG) and autumn-harvested dried grass (AHG). The first was a calorimetric trial to determine the metabolizable energy (ME) content of each grass and the efficiency with which sheep utilize their extra ME intakes above the maintenance level of intake. The second examined the relative amounts of extra non-ammonia-nitrogen (NAN) and individual amino acids absorbed from the small intestine per unit extra ME intake as the level of feeding was raised from energy equilibrium (M) to approximately 1.5 M. The third was a further calorimetric trial to investigate the effect of an abomasal infusion of 30 g casein/d on the efficiency of utilization of AHG.

2. The ME content of the SHG (11.8 MJ/kg dry matter (DM)) was higher than that of AHG (10.0 MJ/kg DM). The efficiency of utilization of ME for productive purposes (is. above the M level of intake; kf,) was higher when given SHG (kf 0.54 between M and 2 M) than when given AHG (kf 0.43 between M and 2 M).

3. As the level of intake of each grass was raised from M to 1.5 M there was a greater increment in the amounts of NAN (P < 0.001) and the total amino acid (P < 0.05) absorbed from the small intestines when sheep were given the SHG (NAN absorption, SHG 5.4 g/d, AHG 1.5 g/d, SED 0.54; total amino acid absorption SHG 31.5 g/d, AHG 14.3 g/d, SED 5.24).

4. Infusion of 30 g casein/d per abomasum of sheep given AHG at M and 1.5 M levels of intake increased (P < 0.05) the efficiency of utilization of the herbage from kf 0.45 to kf 0.57. Consideration is given to the possibility that the higher efficiency of utilization of ME in sheep given SHG may be related to the amounts of extra glucogenic amino acids absorbed from the small intestine which provide extra reducing equivalents (NADPH) and glycerol phosphate necessary for the conversion of acetate into fatty acids.
The role of condensed tannins in the nutritional value ofLotus pedunculatusfor sheep
Authors: Barry T. N.
Published: September 2005

1.Lotus pedunculatus(cv. Grasslands Maku) grown on acid low-fertility soil and containing high concentrations of condensed tannin (76–90 g/kg dry matter (DM)) was grazed by growing sheep for 31–42 d periods in three experiments. In Expt 2 an additional group of lambs grazed areas oversown with white clover (Trifolium repens) and red clover (Trifolium pratense). Lambs were transferred from grazing ryegrass (Lolium perenne) – white clover straight on to lotus in all experiments (unconditioned sheep). In Expt 3 a second group was included which had grazed high-tannin lotus for a pre-experimental period of 8 weeks (conditioned sheep).

2. Effects of condensed tannin on body and wool growth were assessed by studying responses to daily oral administration of polyethylene glycol (PEG; molecular weight 3350, 75–100 g/d). PEG forms a complex with condensed tannin, which is assumed to be inert in its passage through the digestive system, and so effectively reduces the nutritional effects attributable to high condensed-tannin concentrations.

3. Live-weight gain (LWG) in the absence of PEG was low (27–125 g/d) for sheep grazing high-tannin lotus, and PEG administration increased LWG by 41–61 g/d and increased wool growth. In Expt 3, responses to PEG supplementation tended to be less with conditioned than with unconditioned sheep, indicating that conditioned sheep had partially adapted to the high-tannin diet.

4. PEG supplementation had no effect on either LWG or wool growth of sheep grazing areas oversown with mixed clovers, confirming its effects as specific to forages containing condensed tannins. These experiments therefore conclusively show that high concentrations of condensed tannin induced by growingLotus pedunculatusunder low soil fertility conditions prevent maximum expression of LWG and wool growth in grazing sheep. These results contrast with high LWG (153–315 g/d) observed in growing sheep grazing the same lotus cultivar grown in high fertility soil and containing 20 g condensed tannin/kg DM, a level considered to be nutritionally beneficial.
Vitamin B12absorption in the neonatal piglet
Authors: Trugo N. M. F. , Ford J. E. , Salter D. N.
Published: September 2005

1. The influence of the vitamin B12-binding protein isolated from sows' milk on the uptake of vitamin B12was investigated using microvillus membrane vesicles prepared from the small intestine of 7- and 28-d-old piglets. Uptake of radioiodinated purified binder was also examined.

2. The binder strongly promoted uptake of vitamin B12at both ages; in the absence of the binder there was little uptake. The uptake mechanism was specific and operative in vesicles prepared from all regions of the small intestine. Uptake was a rapid process, exhibiting saturation kinetics, with a pH optimum at about 7.0, and dependent on the presence of magnesium or calcium ions for maximum activity. Atfinity constants of the binding sites for the milk binder were determined.

3. Competition experiments using complexes of the binder with vitamin B12and with non-cobalamin analogues (cobinamide and Co-α-[2-methyladenyl]cobamide) showed that the bound analogues competed with bound vitamin B12for uptake but with lower efficiency.

4. Intrinsic factor also promoted vitamin B12uptake by the vesicles but it did not compete with the milk binder for the same binding sites. It promoted uptake only in microvilli isolated from the lower third of the small intestine, and was more effective with preparations from 28-d-old piglets, whereas the milk binder was more effective with the 7-d-old piglets. Porcine gastric cobalophilin competed with the milk cobalophilin, but with lower efficiency.

5. It was concluded that a specific transport mechanism for absorption of vitamin B12, mediated by the vitamin B12-binder in milk, exists at the intestinal brush border of neonatal piglets and strongly reinforces the developing intrinsic factor-mediated mechanism during the early days or weeks of life.

6. It is suggested that the binder in the milk has a wider physiological significance and acts also as a ‘host protective’ factor and as a scavenger of adventitious vitamin B12.
Ammonia-nitrogen turnover in the rabbit caecum and exchange with plasma urea-N
Authors: Forsythe S. J. , Parker D. S.
Published: September 2005

1. Continuous infusion and single-shot administration of15NH4Cl into the caecum of the conscious rabbit was used to measure caecal ammonia flux.

2. Continuous infusion of15NH4Cl and sampling from both the caecal ammonia and blood urea pools indicated that 0.27 of plasma urea-nitrogen was derived from caecal ammonia-N.

3. Values from intravenous [15N]urea and intracaecal15NH4Cl infusions were used to produce two models of the movement of N between these two metabolic pools.

4. Further analysis of the results suggested an alternative model involving a third pool associated with the caecal mucosa and values for this model are also presented.
The development of acid and pepsin (EC 3. 4. 23. 1) secretory capacity in the pig; the effects of age and weaning
Authors: Cranwell Peter D.
Published: September 2005

1. The development of gastric secretory capacity of hydrochloric acid and pepsin (EC 3. 4. 23. 1) was studied in thirty-eight Large White x Landrace pigs from the litters of six sows (three pairs of two), 9–38 d of age. The pigs of each pair of sows were born within 24 h of each other. The pigs of a litter were paired according to sex and size and cross-fostered, i.e. one pig from each pair was allocated to each sow.

2. One litter from each pair was reared entirely by the sow (milk-fed, MF) whereas the other litter was reared by the sow for 21 d, but was allowed access to solid food (210 g crude protein (nitrogen x 6.25)/kg) at 12 d and was entirely dependent on solid food after 21 d (creep-fed, CF).

3. Following a 14–18 h fast, pigs were anaesthetized (Halothane–sodium pentobarbitone) and their stomachs perfused a a constant rate with Ringer solution. Gastric secretion was stimulated by intravenous infusion of betazole hydrochloride (Histalog) at 3 mg/kg per h for 2 h. Hydrochloric acid and pepsin were measured in the perfusate which was collected at 15-min intervals.

4. There were significant positive correlations between stomach weight and body-weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly greater than that for MF pigs (P < 0.01).

5. There were significant positive correlations between maximal acid output and stomach weight for both MF and CF pigs.

6. There were significant positive correlations between maximal pepsin output and stomach weight for both MF and CF pigs. The slope of the regression line for CF pigs was significantly different from that for MF pigs (P < 0.01). There were also significant positive correlations between maximal pepsin output per unit stomach weight and stomach weight for both MF and CF pigs.

7. The pattern of development of pepsin secretory capacity in both CF and MF pigs was different from that for acid secretion. Maximal outputs of acid per unit stomach weight for MF and CF pigs remained relatively constant. Maximal outputs of pepsin per unit stomach weight and per unit body-weight increased with age for both MF and CF pigs.

8. The results indicate that pigs given access to solid food before weaning and weaned on to solid food have heavier stomachs and greater acid and pepsin secretory capacity than pigs fed entirely on sows' milk.
Effect of dietary protein, dichlorodiphenyltrichloroethane (DDT) and hexachlorocyclohexane (HCH) on hepatic microsomal enzyme activity in rats
Authors: Balakrishnan Girija , Ramachandran M. , Banerjee B. D. , Hussain Q. Z.
Published: September 2005

1. Albino rats were fed on diets containing 30, 120 or 200 g protein/kg with or without the incorporation of dichlorodiphenyltrichloroethane (DDT) or hexachlorocyclohexane (HCH) at 100 mg/kg diet for 4 weeks.

2. The activities of the liver microsomal enzymes NADPH-cytochrome reductase (EC 1.6.2.4), flavoprotein- linked monooxygenase (EC 1.14.14.1)and O-demethylase were significantly greater in animals fed on 120 and 200 g protein/kg diet compared with those fed on 30 g protein/kg diet.

3. The inclusion of DDT or HCH at all protein intakes led to further significant rises in microsomal enzyme activities but the increases were much greater for animals receiving the 120 and 200 g protein/kg diets than for those receiving the 30 g protein/kg diet.

4. The results imply that detoxification of DDT or HCH was carried out more effectively at the higher protein intakes.
Retinol transport proteins and concentrations in human amniotic fluid, placenta, and fetal and maternal sera
Authors: Sklan D. , Shalit I. , Lasebnik N. , Spirer Z. , Weisman Y.
Published: September 2005

1. The proteins binding retinol, and retinol concentrations, were determined in amniotic fluid, placental cytosol and in the fetal and maternal circulation.

2. In non-pregnant women, plasma retinol was almost exclusively found in a transthyretin-retinol-binding-protein complex whereas, in pregnant women, retinol-binding-protein-bound retinol was observed not complexed to transthyretin. This latter fraction increased in concentration with fetal age. These two fractions were the major retinol-protein complexes in amniotic fluid and their relative amounts changed with progress of gestation.

3. In fetal blood both of these fractions were again found, with higher proportions of retinol-binding- protein-bound retinol in the umbilical artery than in the umbilical vein.
The effect of ‘fibre-filler’ (F-plan diet) on iron, zinc and calcium absorption in rats
Authors: Fairweather-Tail Susan J. , Wright A. J. A.
Published: September 2005

1. The availability of iron, zinc and calcium in a diet containing 400 g ‘fibre-filler’ (a mixture of bran, fruit and nuts, used in the F-plan diet)/kg diet (HF diet) was measured by whole-body counting in rats, using59Fe,66Zn and47Ca as extrinsic labels, and compared with a diet of similar mineral content but no ‘fibre-filler’ (LF diet). Absorption of Fe and Ca was significantly higher from the HF than from the LF diet but there was no difference in Zn availability between the two diets.

2. The ability of rats given LF or HF diets for 3 or 28 d to absorb Fe, Zn and Ca was measured using ferrous sulphate, zinc chloride and calcium chloride in a cooked starch-sucrose (1: 1 w/w) paste, extrinsically-labelled with the appropriate isotope. There was no difference in Fe absorption between the HF- and LF-fed groups but both Zn and Ca absorption were higher in LF- than in HF-fed animals after 3 and 28 d.

3. The mineral status of the animals given HF or LF diets for 28 d was examined, and there were no differences in blood haemoglobin, liver and bone Zn and plasma and bone Ca levels. The total liver Fe was significantly lower (P < 0.05) in the HF-fed animals.

4. It was concluded that ‘fibre-filler’did not have an adverse effect on Fe, Zn or Ca metabolism in rats although the long-term effect on Fe status warrants more detailed investigation. Further work is required to extend these studies to man.
Masked vitamin B12 and folate deficiency in the elderly
Authors: Craig G. M. , Elliot C. , Hughes K. R.
Published: September 2005

1. A high incidence of vitamin B12 or folate deficiency, or both, may be found in the elderly, particularly those in hospital. This report concerns fifty cases detected in an inner-city-area geriatric unit during the course of routine clinical investigation. The majority had none of the classical haematological signs of vitamin B12 or folate deficiency, and all the patients reported had a mean corpuscular volume (MCV) of less than 100 fl.

2. There was a significant negative correlation between the MCV and the erythrocyte folate (P< 0.01), supporting earlier published work using a low serum folate as an index of folate deficiency.

3. There was no correlation between the MCV and the serum vitamin B12. Published work differs on this point.

4. Serum iron, total Fe-binding capacity and percentage Fe saturation results were available in forty patients in this series. There was a significant positive correlation between the serum Fe and the MCV (P<0.01) and 34% of patients had haematological evidence of Fe deficiency. In the majority, however, there was no evidence that associated Fe deficiency had masked the haematological signs of vitamin B12 or folate deficiency.

5. More attention should be paid to the problem of ‘masked’ vitamin B12 and folate deficiency in the elderly. There is a case for routine screening of the elderly for vitamin B12 and folate deficiency irrespective of the MCV.
Comparative metabolism of L-methionine, DL-methionine and DL-2-hydroxy 4-methylthiobutanoic acid by broiler chicks
Authors: Saunderson C. Linda
Published: September 2005

1. Metabolism, in broiler chicks, of DL-2-hydroxy 4-methylthiobutanoic acid (DL-HMB), DL-methionine and L-methionine was compared in vivo using14C-labelled tracers.

2. The distribution of L-[1-14C]methionine and DL-[1-14C]HMB in the major body tissues was examined for a period of 120 min after administration.

3. The relative oxidation (14CO2, exhaled), excretion and incorporation into tissue protein of L-[l-14C]methionine, DL-[l-14C]methionine and DL-[1-14C]HMB were measured in fed birds.

4. Tissue distribution of L-[1-14C]methionine and DL-[1-14C]HMB differed during 60–90 min following administration.

5. The production of14CO2, from each of the tracers was similar but excretion of14C-labelled material was very different with the greatest excretion from DL-[1-14C]HMB and the least from L[1-14C]methionine.

6. The incorporation of14C into tissue proteins varied with the tracer given and the tissue examined. Liver and kidney had equivalent incorporation from each of the tracers while other tissues examined showed lower incorporation from DL-[1-14C]methionine and DL-[1-14C]HMB.

7. The results show that DL-HMB, D-methionine and L-methionine are metabolized differently in vivo and that they are excreted in differing proportions. There is also a difference in the ability of each to act as a precursor for protein synthesis in tissues other than liver.
Acid-base balance in ruminating calves given sodium hydroxide-treated straw
Authors: Wamberg Søren , Engel Knud , Stigsen Peter
Published: September 2005

1. Studies of whole-body balances of non-metabolizable base (NB) and several minerals, and of relevant acid-base quantities in blood and urine, were carried out in two 6-month-old ruminating Holstein × Friesian bull calves fed on fixed rations containing 500 g barley straw/kg diet (group A) to examine the quantitatively important components of the balance of NB and determine the rates of mineral and NB retention associated with normal body growth.

2. Parallel balance studies were conducted in six other bull calves given fixed rations containing 500 g alkali-treated barley straw/kg diet to evaluate the effects of long-term alkali-straw feeding on the rates of body growth and skeletal mineral and NB deposition and the renal control of extracellular electrolyte and acid-base status. The straw component was treated either with 50 g sodium hydroxide/kg dry matter (DM) (group B; two calves), or with 50 g or 100 g NaOH/kg DM and subsequently neutralized with hydrochloric acid (groups C and D; two calves per group). In all groups the animals were given free access to tap water.

3. Throughout the total 105 d experiment, all animals remained healthy and gained weight. Normal body growth (group A) was associated with a positive balance of NB (1–2 mmol/kg live weight (LW) per d) due to continuing deposition of dietary NB in ‘new tissue’, largely in the developing skeleton.

4. During 105 d alkali-straw feeding, the animals showed a remarkable ability to cope with dietary loads of NaOH or sodium chloride, up to about 30 mmol/kg LW per d, without any significant disturbance of extracellular acid-base and electrolyte status or body growth rate. The surplus mineral and NB loads were absorbed and subsequently excreted in an increased volume of urine. Rates of mineral and NB retention were not significantly different from the reference values of group A and remained within the range of values reported from similar studies. In all groups, maintenance of normal whole blood and plasma acid-base and electrolyte status was accounted for by efficient renal control of the composition of the extracellular fluid compartment.
The effects of a combined implant of trenbolone acetate and oestradiol-17β on protein and energy metabolism in growing beef steers
Authors: Lobley G. E. , Connell Alexmary , Mollison G. S. , Brewer A. , HARRIS C. I. , Buchan Vivien , Galbraith H.
Published: September 2005

1. The effects on growth performance, energy and nitrogen retention, and leucine metabolism of a subcutaneous combined implant of 140 mg trenbolone acetate (TBA)+20 mg oestradiol-17β (OE) have been examined in Hereford × Friesian beef steers (280–520 kg). Comparisons were made both with the same animals before implantation and with untreated control animals maintained under similar physiological and nutritional conditions.

2. Over a 10 week period the implanted steers showed an improvement in rate of live-weight gain (LWG) of 0.5–0.6 with an even greater proportional increase in N retention compared with control animals. Total energy retention was unaffected and thus the ratio, protein energy: total energy gain was 0.43 for implanted steers compared with 0.26 for untreated animals.

3. Estimates of protein synthesis and protein oxidation were obtained from the specific radioactivities of blood free-leucine and exhaled carbon dioxide during continuous infusions of [1-14C]leucine. Whole-body protein synthesis, based on metabolic size, and amino acid fractional oxidation remained similar for control steers throughout the experiment. Steroid-treated steers showed a slight decline in synthesis which was significant (P < 0.05) at week + 5 post-implant while amino acid oxidation was significantly lower at weeks +2 (P < 0.01) and + 5 (P < 0.05) compared with control animals. The ratio, protein deposition: protein synthesis was 0.05 for control animals but 0.08–0.10 for steroid-treated animals after implantation.

4. There was a slight decrease in urinary NT-methylhistidine elimination after implantation which suggested that muscle protein degradation may be reduced although the estimated decrease was insufficient to account for the total improvement in growth rate and N retention.

5. The results suggest that for both control and treated steers, less than 0.5 of total urine N elimination was derived directly from tissue catabolism of protein and amino acids.

6. The combined action of the exogenous steroids in the promotion of protein gain, primarily through a decrease in total protein degradation with little alteration of total energy retention, is compared with present understanding of the role of the endogenous sex hormones.
Effect of leucine on intestinal absorption of tryptophan in rats
Authors: Umezawa Chisae , Maeda Yuko , Haba Kanji , Shin Mariko , Sano Keiji
Published: September 2005

1. To elucidate the causal relation between leucine and the lowering of hepatic NAD content of rats fed on a leucine-excessive diet (Yamadaet al.1979), the effect of leucine on intestinal absorption of tryptophan was investigated.

2. Co-administration of [3H]tryptophan and leucine, with leucine at ten times the level of tryptophan, delayed absorption of L-[side chain 2,3-3H]tryptophan from the digestive tract and incorporation of [3H]tryptophan into portal blood, the liver and a protein fraction of the liver. After 120 min, more than 95% of tryptophan was absorbed whether [3H]tryptophan was administered with or without leucine.

3. Co-administration of a mixture of ten essential amino acids, in proportions simulating casein, with [3H]tryptophan markedly delayed absorption of tryptophan from the digestive tract. The addition of supplementary leucine to the amino acid mixture, however, caused no further delay.

4. In rats prefed a leucine-excessive diet for 1 week [3H]tryptophan was absorbed at the same rate as in rats fed on a control diet.

5. The results indicate that competition between tryptophan and leucine for intestinal absorption did not cause lowering of hepatic NAD.
The effect of potassium and magnesium infusion on plasma Mg concentration and Mg balance in ewes
Authors: McLean A. F. , Buchan W. , Scott D.
Published: September 2005

1. Concentrations of magnesium in plasma, the ionic concentration in rumen digesta supernatant fractions, Mg balance and electropotential differences were measured in three ewes which were fed on grass and suppleyented with potassium and Mg by intraruminal infusion.

2. Mean plasma Mg concentrations were unaltered by combined K and Mg treatments, but fell (P < 0.001) when K alone was infused.

3. The mean concentrations, in rumen digesta, of sodium and K varied reciprocally (P < 0.001) with each other when K was infused, but were unaffected by Mg infusion. The mean Mg concentrations in rumen digesta fell (P < 0.01) with K infusion but rose (P < 0.001) with Mg infusion.

4. Absorption and excretion of Mg rose (P < 0.001) when Mg intake was increased but was unaffected by K intake.
The effect of provision of the first-limiting amino acid, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibility in rats
Authors: Eggum B. O. , Beames R. M. , Bach Knudsen K. E.
Published: September 2005

1. The present work with growing rats was undertaken to study the effect of protein quality, gastrointestinal microbial activity and the level of nitrogen intake on protein utilization and energy digestibiiity. The experiment involved a total of thirty-six dietary treatments in a 9 x 4 factorial design, with five rats per treatment. The thirty-six diets resulted from nine protein sources. Each diet was composed of a basal N-free mixture plus minerals and vitamins, with N sources added at the expense of the N-free mixture to provide 15.0 gN/kg dry matter (DM) in the first three protein-addition treatments and 30.0 gN/kg DM in the fourth protein-addition treatment. The nine protein sources were soya-bean meal, casein, wheat gluten, skim-milk powder, meat-and-bone meal, wheat bran, barley, wheat and cooked brown beans (Phaseolus vulgaris). The four formulations for each protein source incorporated the protein unsupplemented at 15.0 gN/kg DM, unsupplemented at 30.0 gN/kg DM, or supplemented at 15.0 gN/kg DM with the estimated first-limiting amino acid or the antibiotic Nebacitin.

2. With all protein sources, the inclusion of the first-limiting amino acid had no effect on either protein or energy digestibility.

3. The microbial activity in the digestive tract affected protein utilization and energy digestibility to a different degree depending primarily on the level and type of dietary fibre. True protein digestibility (TD) of skim-milk powder and brown beans, both rich in easily-fermentable energy, increased from 0.959 to 1.000 and from 0.680 to 0.777 respectively by the addition of Nebacitin. TD of the other protein sources was only marginally affected by the antibiotic treatment. Only with brown beans was the biological value (BV) markedly affected by Nebacitin with an increase from 0.482 to 0.557 by the treatment. Energy digestibility was significantly lower in rats given antibiotic with soya-bean meal, wheat bran, barley, wheat and brown beans.

4. The effect of level of N intake on protein utilization was dependent on both protein quality and the fibre concentration of the diet. Protein sources with high BV were more affected than proteins of lower BV. It was concluded that TD is not always independent of dietary protein concentration.
Comparative effects of wheat bran and barley husk on nutrient utilization in rats
Authors: Donangelo Carmen M. , Eggum B. O.
Published: September 2005

I. The present work with growing rats was undertaken to compare the effect of wheat bran and barley husk on nutrient bioavailability. The experiment involved a total of nine dietary treatments consisting of a control group, without wheat bran or barley husk, and two series of four groups with increasing amounts of fibre from 50 to 117 g/kg dry matter (DM) from the two fibre sources. Dietary nitrogen concentration was kept constant at 15 gN/kg DM by adjusting the diets with an N-free mixture. Protein sources were casein, fortified with methionine and white wheat flour. True protein digestibility (TD), biological value (BV), net protein utilization (NPU) and digestible energy (DE) were estimated.

2. TD decreased when total dietary fibre (TDF) increased, the effect being greater in the case of wheat bran. The difference in response can be explained by the larger N contribution from bran than from barley husk. N from barley husk was actually digested less than N from wheat bran.

3. Changes in TD due to fibre were small, both for wheat and barley husk. It was concluded that decreased TD with fibre at moderate levels was due to poor digestibility of the N associated with the fibre source rather than decreased digestibility of N from other dietary components.

4. BV was only marginally affected by the fibre levels, indicating that the relatively high lysine content in both wheat bran and barley husk had a low availability.

5. Wheat bran and barley husk showed almost the same negative effect on DE and DM digestibility (DMD). DMD correlated significantly with DE, demonstrating that DMD is a simple and convenient means of monitoring DE.