bluuebunny/crossref_metadata_2025 huggingface dataset:
The effects of a supplement of dietary fibre on faecal excretion by human subjects
Authors: Prynne Celia J. , Southgate D. A. T.
Published: September 2005

1. Four human subjects on strictly controlled diets were given a fibre supplement, 25 g Ispaghula husk (Isogel)/d, for 3 weeks.

2. Replicate diets and faeces were collected during two 5 d balance periods. The first period served as control for the second which occurred after the supplement had been fed for 2 weeks.

3. Diets and faeces were analysed for total solids, gross energy, total nitrogen, fat, available and unavailable carbohydrates.

4. Three of the four subjects showed a considerable increase in faecal bulk; total faecal weight was more than doubled in two subjects. In two subjects the increase was brought about mainly by extra fibre in the faeces accompanied by a higher proporation of faecal water whereas in one subject it was also an increased excretion of nutrients. One subject showed very little change in faecal bulk.

5. High values for the apparent digestibility of fibre were found during the control period; from 0.70 to 0.80. There was more variation during the experimental period when apparent digestibility of total fibre ranged from 0.47 to 0.82. Values arrived at for the minimum apparent digestibility of the fibre supplement were generally high; one subject appeared to digest Isogel completely. Isogel was degraded preferentially to the food-derived fibre; in particular, cellulose in the faeces was increased during the experimental period.

6. Only one subject showed distinct decreases in the apparent digestibility of energy, N and fat in the diet. The results do not therefore agree with the generally held view that increased fibre in the diet decreases the apparent digestibility of the other nutrients.
Guar gum and reduction of post-prandial glycaemia: effect of incorporation into solid food, liquid food, and both
Authors: Wolever T. M. S. , Jenkins D. J. A. , Nineham R. , Alberti K. G. M. M.
Published: September 2005

1. The influence of the dose and the form in which guar gum was given on the degree of ‘flattening’of blood glucose curves was studied in five subjects using meals of bread and soup containing 5 or 10 g guar gum.

2. When 5 g guar gum was added to bread the peak increase of blood glucose was reduced by 41% (P < 0.002), with 5 g guar in soup, the reduction was 54% (P < 0.001) while a reduction of 68% (P < 0.001) was seen with 10 g guar gum (5 g in bread and 5 g in soup). The corresponding reduction in insulin peak increases were 37% (P < 0.002), 50% (P < 0.001) and 65% (P < 0.001) respectively.

3. The difference between the two 5 g doses was not significant with respect to the reduction of the peak increases in blood glucose and serum insulin; however the difference between the 5 g dose in bread and the increases in blood glucose and serum insulin; however the difference between the 5 g dose in bread and the 10 g dose was significantly different (P < 0.002 for glucose, P < 0.01 for insulin).

4. The results indicate that as little as 5 g guar gum may reduce the glycaemia following a 45 g carbohydrate meal, but perhaps due to earlier and more complete mixing, guar gum is most effective when added to the liquid phase of the meal.
Efficiency of utilization of volatile fatty acids for maintenance and energy retention by sheep
Authors: ØRskov E. R. , Grubb D. A. , Smith J. S. , Webster A. J. F. , Corrigall W.
Published: September 2005

1. Two experiments were conducted with lambs sustained entirely by intragastric infusion of volatile fatty acids (VFA), protein, minerals and vitamins.

2. In the first experiment to determine the effects of VFA on nitrogen retention four mixtures of VFA (B, C, D and E) were used containing acetic, propionic and butyric acid in the following molar proportions respectively: 45,45 and 10; 55,35 and 10; 65,25 and 10; 75, 15 and 10.The level of infusion was 836 kJ/live weight0.75per d and the design was a 4 × 4 Latin square with 14 d periods. There were no significant differences in the N balance between the different mixtures of VFA though mixture B tended to give the highest N retention.

3. Thirty-two lambs were used in the second experiment for measurements of heat production in closed- circuit respiration chambers. Six mixtures of VFA were used. These included mixtures B-E from Expt I and in addition two mixtures (A and F) containing acetic, propionic and butyric acid in the following molar proportions respectively: 35, 55 and 10; 85, 5 and 10. The heat production was measured both at 450 and 900 kJ/W0.75per d, except for mixture F, where it was not possible to achieve a rate of infusion in excess of 675 kJ/W0.75per d.

4. The energy required for maintenance was determined to be 0.45±0.02 MJ/kg live weight0.75per d regardless of the mixture used.

5. The efficiency of utilization for fattening (kf) values for the six mixtures were 0.78, 0.64, 057, 0.61, 0.61 and 0.59 for mixtures A, B, C, D, E and F respectively. Only mixture A was significantly better utilized than the other mixtures. This mixture also gave the most efficient N utilization.

6. It is concluded from this evidence that differences in k, for diets normally given to ruminants cannot be attributed to differences in utilization of volatile fatty acids.
Studies on the phytate: zinc molar contents in diets as a determinant of Zn availability to young rats
Authors: Davies N. T. , Olpin S. E.
Published: September 2005

1. Studies were carried out in vitro to examine the effects of phytate on the solubility of the trace elements zinc, copper and manganese. Appropriate volumes of a solution of sodium phytate were added to a mineral solution to achieve phytate: Zn values of from 0: 1 to 45:1. In a second series the same values for phytate: Zn were achieved by varying the amount of added Zn at a fixed phytate concentration.

2. In both experiments > 85% of the Zn was rendered insoluble at pH 6.5 even at the lowest value for phytate:Zn (5:1). The effect of phytate on Zn solubility was greater than effects on Cu or Mn.

3. In a dietary study, rats were offered a semi-synthetic egg-albumin-based diet with added phytate. Two series of diets were prepared, the first had a constant Zn content (18.5 mg Zn/kg) and the amount of sodium phytate varied so as to achieve values for phytate: Zn of from 0:1 to 40:1 (series 1). In the second series, the same values for phytate:Zn were achieved by adding a fixed amount of phytate (7.4 g phytic acid/kg) while the amount of Zn was varied (series 2).

4. Dietary phytate caused significant reductions in growth rates, plasma Zn concentrations and hair Zn concentrations and greying of the coat at values for phytate:Zn of 15:1, 10:1, 10:1 and 15:1, respectively.

5. While phytate was apparently slightly more effective in reducing Zn status when phytate:Zn values were achieved at the lower absolute levels of phytate and Zn (series I diets), the differences at equivalent phytate:Zn values were small. It was concluded that phytate:Zn values can be used as an indicator of Zn availability from phytate-rich diets.

Rats offered three diets containing soya-bean-based textured-vegetable-protein (TVP) exhibited low rates of weight gain compared with rats offered an egg-albumen-based diet of similar Zn content (14.5 mg Zn/kg). Additional Zn supplied in drinking-water (25 mg Zn/l) was without effect on rats consuming the egg-albumin diet but significantly improved the weight gain of rats on the TVP diets.

7. It was concluded that phytate naturally present in TVP behaves similarly to phytate added to an otherwise phytate-free diet and that the reduced availability of Zn in TVP diets can be accounted for entirely by their phytate contents.
WHO sponsored collaborative studies on nutritional anaemia in India
Authors: Sood S. K. , Ramachandran K. , Rani Kamla , Ramalingaswami V. , Mathan V. I. , Ponniah J. , Baker S. J.
Published: September 2005

1. The relative efficacy of oral and parenteral iron administration in the prophylaxis and treatment of Fe-deficiency anaemia of pregnancy has been studied.

2. Intravenous administration of Fe by total dose infusion of Fe dextran was not superior to oral Fe 120 mg/d, 6 d/week for 10–12 weeks.

3. Intramuscular Fe dextran, 100 mg twice per week for 10–12 weeks, produced a significantly greater rise in mean haemoglobin concentration than oral Fe therapy.

4. The superiority of intramuscular Fe as compared with intravenous Fe is probably related to the different handling of the Fe dextran by the reticulo-endothelial system.

5. In spite of the better response to intramuscular Fe dextran, it is not recommended for public health practice because of the risks associated with its use and the much higher cost of the preparation and its delivery.
Effect of varying protein and energy intakes on nitrogen balance in Indian preschool children
Authors: Iyengar A. K. , Narasinga Rao B. S. , Reddy Vinodini
Published: September 2005

1. The effect of varying protein intake at two energy levels of 334 and 418 KJ/kg body-weight was studied in four preschool children belonging to the low socio-economic group.

2. Results indicated a curvilinear relationship between N intake and N retention. From this relationship, the protein requirement of the children at adequate energy intake was calculated.

3. At adequate energy intake (418 KJ/kg body-weight) the protein requirement of the children was 1.33 g /kg. On decreasing the energy intake by 20% to 334 KJ /kg body-weight the protein requirement was found to be increased by 20% to 1.64 g/kg.

4. Based on this study, a safe level of protein intake for Indian preschool children subsisting on a diet based predominantly on vegetable proteins has been suggested.
Factors affecting the voluntary intake of food by sheep
Authors: Grovum W. L.
Published: September 2005

1. Sheep equipped with rumen and abomasal cannulas were given ad lib. access to ground and pelleted lucerne (Medicago sativa) hay except for periods of up to 6 h immediately before experimental sessions in which food intake was measured while various stomach compartments were either distended or subjected to tactile stimulation from a probe.

2. Inserting a probe, consisting of two collapsed balloons tied onto the end of a polyethylene tube, into the reticulum depressed intake by 24% after 30 min of feeding (P < 0.025). Compensatory feeding was observed during the 30 min period immediately following removal of the probes. There were no effects of having a probe in the abomasum.

3. Distension of the reticulum with 0–800 ml water in a balloon depressed intake by 0.2 g/ml after 30 min of feeding (P < 0.05). Removing the balloons from the animals allowed them to make up the deficit in intake completely within 30 min. Distending the rumen by 800 ml had no effect on intake (P < 0.05). Distending the abomasum with up to 1000 ml water in a balloon depressed intake by 0.11 g/ml after 30 min of feeding with compensatory feeding being significant (P < 0.05) but incomplete.

4. Combinations of reticular distension up to 800 ml and of abomasal distension up to 1200 ml did not have additive depressing effects on intake.
Estimation of heat production from heart-rate measurements in cattle
Authors: Yamamoto S. , McLean J. A. , Downie A. J.
Published: September 2005

1. Heat production and heart rate of seven steers were measured simultaneously using either a calori- metric chamber or head-cage.

2. The relationship between heat production and heart rate for each animal was best described by linear regression.

3. Differences between individual animals made separate ‘calibration equations’ necessary for each animal.

4. Accuracy of prediction of heat production from heart rate was better than ±10% in all instances.

5. It is concluded that frequent measurement of heart rate appears to offer a practical method for esti- mation of heat production of free-range animals.
Effects of soya-bean protein and casein on serum cholesterol levels in rats
Authors: Nagata Y. , Imaizumi K. , Sugano M.
Published: September 2005

1. The effect of the soya-bean protein isolate and casein, both given 200 g/kg diet for 3–4 weeks, on serum cholesterol was compared in male rats.

2. Soya-bean protein exerted a hypocholesteraemic effect only in a cholesterol-free low-fat (10 g maize oil/kg) diet, when the lowering action appeared independent of the strain of the rat or the feeding pattern. The results obtained with diets containing cholesterol or higher levels of fats or both showed no definite pattern of response.

3. Although the decrease in serum cholesterol appeared greater in α-lipoprotiens than in β-lipoproteins, the proportion of the former to total cholesterol remained almost unchanged. The concentration of serum apo A-I was significantly lower in rats given the vegetable protein.

4. Rats given soya-bean protein excreted significantly more neutral sterols.

5. The serum amino acid pattern did not reflect the difference in dietary protein. Addition of cholesterol to the diets modified the serum aminogarm, the decrease in threonine being most marked in both protein groups.

6. This study shows that the hypocholesteraemic action of soya-bean protein is easily modified by the type of diet.
Further studies on the hypocholesterolæmic effect of soya-bean protein in rats
Authors: Nagata Y. , Tanaka K. , Suganot M.
Published: September 2005

1. The hypocholesterolæmic effect of soya-bean protein compared with that of casein, when fed at 200 g/kg diet for 3 weeks, was studied in rats.

2. Using a cholesterol-free low-fat (10 g maize oil/kg) diet, the hypocholesterolæmic effect was demonstrated not only with soya-bean protein but also with an amino acid mixture simulating this protein. The addition of lysine to these diets did not modify their intrinsic effects on serum cholesterol.

3. By feeding the vegetable protein or its amino acid mixture, both high-density-lipoprotein-and very-low-density-lipoprotein plus low-density-lipoprotein-cholesterol decreased to a similar extent, and the concentration of serum apolipoprotein A-I decreased and that of apolipoprotein B increased.

4. Although rats given soya-bean protein excreted more neutral and acidic steroids, the difference disappeared when the amino acid mixture was fed, indicating that the hypocholesterolæmic effect of the vegetable protein is not ascribed only to the increased elimination of steroids.

5. It is likely that the difference in the amino acid composition between animal and vegetable proteins is in fact responsible for the different response of serum cholesterol.
Breast-milk production in Australian women
Authors: Rattigan S. , Ghisalberti Ann V. , Hartmann P. E.
Published: September 2005

1. Milk productions and 7d dietary records were determined on twenty-seven mothers who had been breast-feeding for 1, 3, 6, 9, 12 and 15 months.

2. The mean milk productions for each group of mothers was 1.187, 1.238, 1.128, 0.884, 0.880 and 0.951 kg/24 h at 1, 3, 6, 9, 12 or 15 months of lactation respectively. There was no significant difference between two milk determinations 3–7 d apart on each mother or between the mean milk production of each group of mothers.

3. Energy intakes of the infants was found to be higher than the usually-accepted values at 1 and 3 months of age but by 6 months were similar to the accepted normal values.

4. Energy intakes of the mothers although greater than those recommended for similar non-lactating women were not sufficient to take into account the energy content of the milk.
Breast-milk fat concentrations of rural African women
Authors: Prentic Ann , Prentice A. M. , Whitehead R. G
Published: September 2005

1. Detailed studies of variations in breast-milk fat concentrations were performed over 12 or 24 h periods on sixty rural Gambian women feeding on demand. The creamatocrit method (Lucas et al. 1978) was used.

2. The complex pattern of within-feed and between-feed changes in fat concentration was largely explained by differences in volume per feed and time interval between feeds.

3. No consistent difference in fat production between the breasts of each individual was found despite the local custom of starting all feeds on the right breast.

4. A marked diurnal variation in the mean fat concentration per feed was noted. On average the highest values occurred in the early morning, the lowest values in the late afternoon.

5. There was significantly greater between-individual than within-individual variation in the mean fat concentration per feed over 12 h (P > 0.001).

6. A simple, rational and non-intrusive sampling procedure was devised for the estimation of whole-day mean fat levels based on the finding that the mean fat concentration of small samples of milk (0.25 ml) taken from both breasts before and after one specific feed of the day was closely correlated with 12 h and 24 h mean fat concentrations.
Food intake and energy expenditure of male and female farmers from Upper-Volta
Authors: Bleiberg Fanny , Brun Thierry A. , Goihman Samuel , Lippman Daniel
Published: September 2005

1. The energy balance of eleven male and fourteen female adult farmers was measured for 6 d after the harvest, in December-January. Their energy intake was recorded by weighing their food consumption and their energy expenditure was determined using indirect calorimetry.

2. Body-weight, expressed as percentage of expected weight-for-height was 91 and 86% of the Inter-departmental Committee on Nutrition for National Development (1963) standard for women and men respectively.

3. The staple foods were sorghum (Sorghum vulgare) and millet (Pennisetum typhoïdes); carbohydrates, fat and protein supplied approximately 80, 13 and 12% of the total energy of the diet respectively.

4. In the male group, the mean energy intake (9.0 MJ (2148 kcal)) was in good agreement with the average energy output (8.91 MJ (2130 kcal)). By contrast, in the female group, the mean energy expenditure (8.11 MJ (1941 kcal)) exceeded the mean energy intake (6.3 MJ (1515 kcal)) and the deficit was statistically significant.

5. This study allows an evaluation of the adequacy of food intake for subjects living in a particular hostile environment, by using their actual energy output instead of current standard values. The energy deficit found for female farmers whose energy intake was similar to that reported in other developing countries emphasizes the need for a better understanding of the regulation of energy balance in such conditions.
The effects of intraruminal infusions of sodium bicarbonate, ammonium chloride and sodium butyrate on urea metabolism in sheep
Authors: Norton B. W. , Janes A. N. , Armstrong D. G.
Published: September 2005

1. Three sheep fitted with rumen cannulas were fed hourly a daily ration of 1000 g pelleted-grass cubes, and during four successive 2-week periods were intraruminally infused (0·45 l/d) with solutions containing sodium chloride (0·47 mol/d), sodium bicarbonate (0·47 mol/d), ammonium chloride (0·47 mol/d) and sodium butyrate (0·47 mol/d). Each solution, except that for NaHCO3, was adjusted to pH 7 before infusion, and provided equal sodium intakes for sheep in all periods.

2. In the final week of each infusion period, a balance trial was conducted and on separate days each sheep was continuously infused with [14C]urea and NaH14CO3 intravenously and NaH14CO3 intraruminally. Carbon transfer rates between blood urea, blood bicarbonate and rumen fluid bicarbonate were calculated from the specific radioactivity of urea and bicarbonate samples and isotope infusion rates during each experimental period.

3. There was no significant effect of intraruminal infusions on N balance, and with the exception of sheep in fused with NH4Cl, all sheep utilized apparently digested N with similar efficiency for N retention. Sheep infused with NH4Cl (6·2 g N/d) excreted the equivalent of 93% of the infused N as urea in urine.

4. Infusion of NaHCO3. NH4Cl and sodium butyrate significantly (P < 0·05) increased the rurnen fluid concentrations of bicarbonate, ammonia and butyric acid respectively, and all infusions significantly (P < 0·05) increased total volatile fatty acid concentrations. Both NaHCO3 and sodium, butyrate significantly (P < 0·05) increased the pH of rumen fluid There was no significant effect of infusion on the proportions of propionic acid or the osmolality of rumen fluid.

5. Intraruminal infusions of NH4Cl significantly (P < 0·05) increased and infusion of sodium butyrate significantly (P < 0·05) decreased plasma urea concentrations. Sheep infused with NH4Cl had higher rates of urea synthesis and urinary urea excretion compared with sheep on the other treatments, and a significantly (P < 0·05) lower proportion of urea synthesized by these sheep was degraded in the digestive tract. Sheep infused with sodium butyrate degraded a significantly (P < 0·05) greater amount (3·2 g N/d) and proportion (0·24) of total urea synthesis in the rumen than did sheep infused with NaCl. Corresponding values for the control (NaCl) sheep were 1·5 g N/d and 0·13 respectively. There was no significant effect of other infusions on the amount of urea recycled to the rumen or on the distribution of total urea degradation between the rumen and lower digestive tract. Plasma urea clearance to the rumen was significantly (P < 0·05) increased during sodium butyrate infusion, and the clearance of urea to the lower digestive tract was significantly (P < 0·05) decreased during NH4Cl infusion.

6. The mechanism by which urea entry into the rumen is regulated by rumen metabolite levels is discussed.
Glycosyl ureides in ruminant nutrition
Authors: Merry R. J. , Smith R. H. , McAllan A. B.
Published: September 2005

1. Glucosyl urea, lactosyl urea and galactosyl urea were prepared from pure sugars and urea and their purity confirmed by determination of their melting points, specific rotations and by mass spectrometry.

2. Using whey as a lactose source, a range of conditions were examined for the preparation of lactosyl urea on a laboratory scale. Yields of 60% were achieved when lactose and urea (molar ratio, urea: lactose 0:6) were reacted for 15 h in sulphuric acid at pH 2·0 and a temperature of 70°.

3. Methods of detection and estimation of all three ureides in whey preparations and ruminant digesta samples were developed. Two quantitative methods, one involving acid-hydrolysis, the other ion-exchange chromatography, were used. The latter method enabled determination of individual quantities of ureides in mixtures.
Estimation of the proportion of non-ammonia-nitrogen reaching the lower gut of the ruminant derived from bacterial and protozoal nitrogen
Authors: Steinhour W. D. , Stokes M. R. , Clark J. H. , Rogers J. A. , Davis C. L. , Nelson D. R.
Published: September 2005

1. A method for estimating the proportions of bacterial- and protozoal-N in the total non-ammonia-N reaching the lower gut of the ruminant under steady-state conditions was evaluated. Three trials using two different diets were conducted with a Holstein steer equipped with a rumen cannula and duodenal re-entrant cannulas.

2. An intraruminal primed infusion of (15nh4)2so4was administered for 68 h during each trial. Bacteria and protozoa samples were isolated from rumen fluid at approximately 6 h intervals during each infusion period. Total non-ammonia-N was isolated from duodenal digesta samples taken at approximately the same times. All of these samples were analysed for15N enrichment. A computer program was used to fit equations to the15N-enrichment curves of bacterial- and protozoal-N. Models of both bacterial- and protozoal-N kinetics consisted of a small pool which equilibrated rapidly with rumen NH3and a large pool with a fractional turnover rate of 0.045–0.070/h for bacterial-N and 0.056–0.069/h for protozoal-N.

3. Abomasal fluid turnover was estimated by a single injection of polyethylene glycol (molecular weight 4000) into the rumen followed by sampling of rumen fluid and duodenal digesta.

4. Estimates of abomasal fluid turnover, bacterial-N turnover, and protozoal-N turnover were entered into an equation which was adjusted by computer iteration to fit the15n-enrichment curve of duodenal digesta non-NH3-N generated from each (15nh4)2so4infusion period. The computer fit of this equation to the observed results gave estimates of 0.39–0.45 and 0.22–0.41 for the proportion of duodenal non-NH3-N derived from bacterial-N and protozoal-N respectively.

5. This method is potentially useful in estimating microbial protein passage to the lower gut in ruminants. Sampling digesta from the omasum rather than the duodenum would simplify the method and possibly increase the reliability of the estimates.
The influence of cooked kidney beans (Phaseolus vulgaris) on intestinal cell turnover and faecal nitrogen excretion in the rat
Authors: Fairweather-Tait Susan J. , Gee Jennifer M. , Johnson I. T.
Published: September 2005

1. Male Wistar rats were fed on semi-synthetic diets containing cooked white kidney beans (Phaseolus vulgaris) or equivalent levels of protein and carbohydrate.

2. No change was observed in over-all nitrogen balance in animals fed on the bean diet, but there was a two-to three-fold increase in their faecal excretion, compared with control rats. This was compensated by a decrease in urinary-N excretion.

3. Homogenized small intestinal mucosa, prepared from bean-fed animals, showed at 28%increase in protein content compared with control material.

4. Measurements of 3H-labelled thymidine turnover indicated that mucosal cell exfoliation was increased by approximately 35% in the small intestines of bean-fed rats compared with controls.

5. It is concluded that though a diet rich in cooked P. vulgaris leads to someincrease in mucosal cell turnover in the small intestine of rats, the consequent increasein mucosal protein loss could not account for the increased faecal-N excretion seen in these animals.
Apparent amino acid absorption from feather meal by chicks
Authors: Bielorai Rachel , Harduf Z. , Iosif B. , Alumot Eugenia
Published: September 2005

1. The apparent absorption values of individual amino acids from two samples of feather meal (FM) were determined in the lower ileum of chicks fed on diets containing magnesium ferrite as a marker.

2. The average absorption values for FM amino acids were low, approximately 0.50, as compared with approximately 0.85 for soya bean, used as a control. Values for individual amino acids from FM differed distinctly, ranging from 0.20 to 0.70. Low values were obtained for aspartic acid, histidine, lysine, glutamic acid and cystine.

3. An indication of the low absorption of the previously-mentioned amino acids was obtained by analysing the amino acid composition of the FM residues undigested by pepsin or pancreatin.

4. The reasons for testing the apparent rather than the true absorption are discussed.
Methionine requirement of kittens given amino acid diets containing adequate cystine
Authors: Smalley Katherine A. , Rogers Quinton R. , Morris James G.
Published: September 2005

1. The effects of feeding either high-protein (HP) or low-protein (LP) diets between 1.8 and 15 kg live weight (LW) and a low-energy (LE) or high-energy (HE) intake subsequently on the cellularity of muscle and adipose tissue in pigs growing to 75 kg LW were investigated.

2. The effects of the nutritional treatments on muscle tissue were assessed from the weight and DNA content of them. adductor. For adipose tissue the total DNA content and fat cell size of the subcutaneous adipose tissue contained in the left shoulder joint were determined.

3. Feeding the LP diets in early life reduced the weight and DNA content of them. adductor (P< 0.01) and increased fat cell size (P< 0.01) at 15 kg LW.

4. Subsequent to 15 kg there was an almost linear increase in muscle DNA with increasing LW, and the difference between pigs from the initial protein treatments progressively diminished and was no longer apparent at 60 kg LW.

5. At 30 kg LW, pigs given the LP diets before 15 kg LW contained less DNA in the subcutaneous adipose tissue from the shoulder joint (P< 0.01) and had larger fat cells (P< 0.05) than pigs given the HP diets initially. However, adipose DNA and fat cell size increased with increasing LW and the differences resulting from the initial protein treatments progressively diminished. On the LE and HE treatments subsequent to 15 kg these differences were no longer evident at 45 and 60 kg respectively.

6. Pigs given the HE intake subsequent to 15 kg, contained less DNA in muscle tissue (P< 0·05) at 60 and 75 kg LW and had larger fat cells (P< 0·05) at 45, 60 and 75 kg LW, than pigs on the LE treatment.
Blood flow and nutrient exchange across the liver and gut of the dairy cow
Authors: Lomax M. A. , Baird G. D.
Published: September 2005

1. The rate of blood flow in the portal and hepatic veins, and the net exchange across the gut and liver of volatile fatty acids (VFA), glucose, lactate, pyruvate, amino acids, ketone bodies, glycerol, non-esterified fatty acids (NEFA) and oxygen, were measured in lactating and non-lactating cows (a) in the normal, fed state and (b) before, during and after 6 d of fasting.

2. Blood flow rate through the liver was 52% higher in normal, fed, lactating cows as compared with non-lactating cows, and was decreased by fasting in both groups of cows. Portal blood flow rate increased with an increase in metabolizable energy (ME) intake.

3. Lactating, as compared with non-lactating, cows exhibited lower arterial concentrations of glucose and lactate, higher net portal outputs of VFA and ketone bodies, a higher net hepatic output of glucose, and higher net hepatic uptakes of propionate and lactate. The splanchnic outputs of acetate, glucose and hydroxybutyrate were all apparently greater in the lactating cows.

4. Fasting caused a rapid decrease in the blood concentrations of the VFA and an increase in those of glycerol and NEFA. The portal, i.e. gut, outputs of VFA, lactate, ketone bodies, alanine and (serine+threonine), and the portal uptake of O2, were all decreased by fasting. Fasting for 6 h also decreased the hepatic output of glucose and acetate by 77 and 95% respectively, increased the hepatic uptake of pyruvate, glycerol and NEFA, and doubled hepatic ketone-body output. The splanchnic output of acetate and glucose and the splanchnic uptake of O2were also decreased by fasting.

5. The net portal outputs of VFA, lactate and hydroxybutyrate, and the net hepatic output of glucose, were all correlated with ME intake in fed and fasted cows. Hepatic glucose output was also correlated with milk yield.

6. The net hepatic uptake of gluconeogenic precursors measured in this study could account for net hepatic glucose output in the fasted cows, but not in the fed cows. The net hepatic uptake of the ketogenic precursors butyrate and NEFA was sufficient to account for the hepatic output of ketone bodies in both fed and fasted cows, but it is unlikely that the hepatic uptake of ketogenic precursors could also account for the observed hepatic output of acetate.
The influence of pancreatic juice on 64Cu absorption in the rat
Authors: Jamison M. H. , Sharma H. , Braganza J. M. , Case∥ R. M.
Published: September 2005

1. The absorption of 64Cu from closed duodeno-jejunal loops in anaesthetized rats was significantly less in the presence of pancreatic juice compared with that in the presence of saline (9 g sodium chloride/1). The inhibition of 64Cu absorption caused by pancreatic juice was similar to that achieved with bile.

2. Studies using solutions of electrolytes and of pancreatic extracts showed that the inhibitory effect of pancreatic secretions was due to its protein-enzyme content and not to its bicarbonate content.

Pancreatic secretion and bile influence Cu absorption and thereby affect Cu homeostasis.
Tissue S-adenosylmethionine levels in fruit bats (Rousettus aegyptiacus) with nitrous oxide-induced neuropathy
Authors: van der Westhuyzen J. , Metz J.
Published: September 2005

1. The effect of cobalamin inactivation by the anaesthetic gas nitrous oxide on the concentration of S-adenosylmethionine (Ado Met) in brain and liver of fruit bats (Rousettus aegyptiacus) was examined.

2. Test animals exposed to N2O–oxygen (50:50, v/v) developed ataxia and paralysis leading to death after an average of 9·8 weeks (n 6). Animals receiving pteroylmonoglutamic acid supplements in the diet became ataxic earlier (mean 8·8 weeks) while those receiving methionine supplements survived for significantly longer periods (12·5 weeks, P < 0·01).

3. Plasma cobalamin levels indicated severe depletion of cobalamin stores in N2O-exposed animals.

4. The mean concentration of Ado Met in the brain of N2O-treated bats was nearly 50% higher than that of untreated controls. Ado Met levels in treated bats receiving pteroylmonoglutamic acid or methionine supplements were respectively 18 and 25% higher than in controls. In contrast, the concentration of Ado Met in the liver of all the N2O-treated groups was slightly lower than in controls.

5. These results suggest that the N2O-induced neuropathy in the fruit bat is not related to a depletion of Ado Met in the nervous system.
Determination of amino acid requirements of young pigs using an indicator amino acid
Authors: Kim Kyu-Il , McMillan Ian , Bayley Henry S.
Published: September 2005

1. Mixtures of skim milk and free amino acids were compared as diets for pigs which would allow manipulation of dietary amino acid levels. Piglets gained 208 g/d between 3 and 14 d of age on the skim-milk diet, but replacement of 600 g/kg of the dietary nitrogen with free amino acids reduced growth rate to 148 g/d.

2. Supplementation of a lysine-deficient diet with lysine reduced the catabolism of [14C]phenylalanine showing that phenylalanine catabolism could be used as an indicator of the adequacy of diet with respect to another essential amino acid.

3. The dietary level of phenylalanine which would provide an excess for catabolism by the piglet was estimated directly by measuring the influence of dietary phenylalanine level on [14C]phenylalanine oxidation. Reduction of the dietary phenylalanine level below 7 g/kg had no effect on phenylalanine oxidation, whereas increasing the dietary phenylalanine level above 7 g/kg resulted in a linear increase in phenylalanine oxidation.

4. An indirect estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]phenylalanine oxidation. In diets containing more than 4 g histidine/kg, phenylalanine oxidation was minimal. In diets containing less than 4 g histidine/kg, [14C]phenylalanine oxidation increased as the level of dietary histidine was reduced. This showed that the utilization of the essential amino acid phenylalanine, for protein synthesis, was not limited by histidine supply in diets containing more than 4 g histidine/kg.

5. A direct estimate of histidine requirement was made by examining the influence of dietary histidine level on [14C]histidine oxidation. Diets with more than 4 g histidine/kg contained an excess which was catabolized: there was a linear increase in histidine oxidation in response to dietary histidine levels greater than 4 g/kg. This confirmed the previous indirect estimate of histidine requirement.
Effect of high vitamin A or tocopherol intake on hepatic lipid metabolism and intestinal absorption and secretion of lipids and bile acids in the chick
Authors: Sklan David
Published: September 2005

1. The effect of high dietary vitamin A or tocopherol, or both, on lipid absorption and secretion in the gastrointestinal tract and on serum and hepatic lipids was determined in the chick.

2. High dietary vitamin A increased secretion of cholesterol, bile acids, phospholipids and fatty acids to the duodenum, and tocopherol enhanced cholesterol and bile acid secretion to the duodenum. No differences in over-all absorption were observed.

3. Serum cholesterol was depressed by vitamin A and hepatic lipids were enhanced, except phosphatidyl choline which was depressed. Tocopherol increased hepatic triglycerides and cholesterol.

4. In vitro fatty acid synthesis from lactate by liver homogenates was enhanced by vitamin E and cholesterogenesis enhanced by both vitamin A and tocopherol. Δ9Desaturation was also enhanced by vitamin E.

5. It is concluded that both vitamin A and tocopherol affect the hepatic synthesis and catabolism of cholesterol and that vitamin E also influences fatty acid metabolism.
The nutritive value of rumen micro-organisms in ruminants
Authors: Storm E. , Ørskov E. R. , Smart R.
Published: September 2005

Four experiments were conducted with eighteen lambs sustained entirely by intragastric nutrition at gross energy inputs varying from 430 to 860 kJ/kg live weight0·75 (W0·75). Isolated rumen micro-organisms (RMO) were infused into the abomasum in quantities varying from 0 to 2 g digestible N/kg W0·75 to assess the increase in N balance as a result of increasing RMO input when N was limiting.

The over-all utilization of N from RMO (RMO-N) could be described by the equation y = 0·543 x −0·457, residual SD = 0·037, where y is the N balance and x is the abomasal input of RMO-N, both expressed in g/kg W0·75. Thus the coefficient of efficiency of utilization of infused RMO-N was 0·543 (SE 0·008). The coefficient of efficiency of utilization of RMO-N truly digested (i.e. the biological value) was 0·659 (SE 0·015).

The RMO-N input (mean with SE) at N equilibrium was 0·843 (0·009) g/kg W0·75. The true digestibility of RMO-N was 0·813 (0·004). The urinary N excretion when no N was infused was 0·329 (0·008) g/kg W0·75 and the N excreted via the faeces with zero N input was 0·036 (0·009) g/kg W0·75.
Effect of guar gum on nitrogen secretion into isolated loops of jejunum in conscious growing pigs
Authors: Low A. G. , Rainbird Anna L.
Published: September 2005

1. Four pigs, initially of 30 kg live weight, were surgically prepared with two re-entrant cannulas in the jejunum, 1.0 m apart. This allowed an isolated loop to be formed through which Ringer solutions were continuously perfused for 6.5-h periods per day.

2. The effects of two Ringer solutions of contrasting composition on nitrogen secretion were measured in a preliminary study.

3. The effects of guar gum (6.7 g/l) on N secretion during perfusions of solutions of glucose or of maltose (20 g/l) were measured.

4. N secretion did not differ significantly between the two Ringer solutions.

5. Addition of guar gum to the solution of glucose increased mean N secretion from 69.2 to 133.9 mg/m per 2 h; the corresponding values for the maltose solution were 75.5 and 120.2 mg/m per 2 h. In both cases the differences were significant (P< 0.001). Differences between N secretion into glucose and maltose solutions were not significant, either without or with guar gum.

6. Guar gum addition had a greater effect on N secretion in hours 5 and 6 than in hours 1 and 2 of perfusion.

7. It was calculated that guar gum would have increased N secretion by the mucosa of the whole small intestine from approximately 15 to 27 g/d under the conditions of the study, assuming uniform secretion throughout the organ. These results suggest that certain types of dietary fibre may be important determinants of N secretion by the mucosa of the small intestine. They also suggest that changes in N secretion of this magnitude are of importance in N metabolism because the overall rate of protein synthesis in these pigs was probably about 100 g/d (expressed as N), using values from the literature.
Magnesium absorption in mature ewes infused intrarumenally with magnesium chloride
Authors: McLean A. F. , Buchan W. , Scott D.
Published: September 2005

1. The effects of magnesium Supplementation on Mg absorption proximal and distal to the pylorus in ewes maintained on a grass diet were investigated using a combination of balance, digesta flow and electropotential Measurements.

2. Three mature ewes each received by intrarumenal infusion a supplement of 0, 1, 2 and 3g Mg/d in sequence over four 10-d periods.

3. Net Mg absorption distal to the pylorus took place down its electrochemical gradient, although the quantity absorbed remained small during the control and first infusion periods.

4. The bulk of Mg absorption occurred before the pylorus and, during the control and first infusion periods, took place against its electrochemical gradient. The net Mg absorption proximal to the pylorus rose with declining efficiency as Mg intake was increased. It is suggested that saturation of the absorption process at this site was occurring.
Modifications to swede (Brassica napusL.) anterior to the terminal ileum of pigs: some implications for the analysis of dietary fibre
Authors: Millard P. , Chesson A.
Published: September 2005

1. The degradation of a swede (Brussica nupusL., cv. Danestone) diet anterior to the terminal ileum was studied in two pigs fitted with T-shaped cannulas 150 mm before the ileo-caecal junction. Digestibility was calculated with reference to chromic oxide and polyethylene glycol.

2. In addition to the total loss of free glucose and fructose, there were substantial modifications to cell-wall material recovered in digesta. These included the apparent loss of 46–50% of uronic acid residues, 72–78% of phenolic material and 10–24% of cellulose initially present in the feed, and a partial solubilization of some hemicellulose components.

3. Since ‘fibre’ recovered at the terminal ileum differed in a number of important respects from ingested fibre, a number of methods for the analysis of dietary fibre were examined to establish (1) the extent to which analysis of feed represented material recovered at the terminal ileum and (2) whether such methods could be applied directly to digesta samples. Results were compared with a complete analysis of water-soluble (620 g/kg dry matter) and water-insoluble (380 g/kg dry matter) fractions of feed.

4. Chemical fractionation techniques gave more reliable quantitative estimates of fibre than in vitro enzymic digestion methods which overestimated fibre. Acid- and neutral-detergent methods both gave too low an estimate of fibre. As none of the methods could allow for the loss of components (particularly pectic polysaccharides) found by sampling at the terminal ileum, none gave an accurate qualitative or quantitative representation of fibre at this point in the gut.

5. It is suggested that, as vegetable fibre recovered at the terminal ileum has already undergone partial hydrolysis, a more dynamic model of dietary fibre, in which the action of gut micro-organisms is considered, may be required to establish possible physiological roles of fibre or fibre components in the digestive tract. Recovery of digesta from sites of interest may be the only way of reliably estimating fibre or specific fibre components at different levels of the gut. This approach to dietary fibre may be impractical when applied directly to humans but the digestive tract of the pig may be a suitable alternative model.
Effect of riboflavin deficiency on reproductive performance and on biochemical indices of riboflavin status in the rat
Authors: Duerden Julia M. , Bates C. J.
Published: September 2005

1. Young female rats were made riboflavin-deficient by feeding a purified diet containing casein (210 g/kg). This basal diet provided 0.40 mg riboflavin/kg diet, to which was added additional riboflavin at 0, 0.12 or 0.25 mg/kg diet. Control animals received the same diet with 15 mg added riboflavin/kg. The diets were given for 4 weeks before mating, then throughout pregnancy and for 15 d of lactation.

2. With no added riboflavin in the diet, reproduction was severely impaired and fetal resorption was usually observed. With 0.12 mg added riboflavin/kg diet, however, reproduction was usually successful, and the growth of dams and pups was only marginally depressed in comparison with pair-fed controls optimally supplied with riboflavin.

3. The activation coefficient (stimulated: basal activity) of erythrocyte glutathione reductase (NAD(P)H) (EC 1.6.4.2)was high, and the concentration of riboflavin in the liver was correspondingly low in the dams receiving diets containing 0.12 or 0.25 mg added riboflavin/kg and in their sucking pups at 15 d post partum. Riboflavin levels in the milk from both groups of dams were about eightfold lower than in controls. There was little evidence that the sucking pups could maintain their riboflavin level at the expense of that in the maternal tissues.
Effect of kidney bean (Phaseolus vulgaris) toxin on tissue weight and composition and some metabolic functions of rats
Authors: Greer Fiona , Brewer Alan C. , Pusztal Arpad
Published: September 2005

1. Inclusion of raw kidney bean (Phasealus vulgaris) proteins in the diet for rats was shown to affect the weight of some internal organs. Of these, in addition to the well-known hypertrophy of the pancreas attributable to dietary trypsin inhibitors, the observed atrophy of the thymus and the doubling in weight of the small intestine are related to the protein or lectin content of the bean diet, or both.

2. Changes in tissue composition of the small intestine were also recorded. Its protein content increased by about 40–50% and carbohydrate content doubled suggesting the occurrence of increased mucinous glycoprotein secretion. Increased DNA content (by about 30–40 %) however also indicated mucosal hyperplasia.

3. Changes were also observed in mineral content, urea concentration and some enzyme activities in sera and urine, possibly as a result of disturbances in systemic metabolism or hormone levels, or both.

4. The results gave further support to previous suggestions that the oral toxicity of kidney-bean lectins involves local reactions in the small intestine in combination with their effects on the systemic immune system and general metabolism.
Quantitative effects of defaunation on rumen fermentation and digestion in sheep
Authors: Rowe J. B. , Davies A. , Broome A. W. J.
Published: September 2005

1. Studies on the quantitative significance of protozoa on carbon and nitrogen digestion and metabolism in the rumen were carried out in sheep given a diet of pelleted concentrate (500 g/d) and chopped hay (500 g/d).

2. Measurements were made of apparent digestibility; flows of organic matter and dietary and microbial non-ammonia N (NAN) (using 15NH+4) to the duodenum; and rates of production, interconversion and metabolism of the major C fermentation end-products (from mathematical modelling of 14C isotope values).

3. The population density of bacteria in the rumen increased as a result of defamation (28.6 compared with 8.2 x 10° organisms/ml). This high density was associated with greater utilization of volatile fatty acids (VFA) within the rumen.

4. The rate of irreversible loss (IL) of bicarbonatefcarbon dioxide from the rumen was greater in the defaunated animals (98.5 v. 57.2 g C/d) but the IL from the blood was greater in the faunated group (138.6 v. 106.1 g C/d). This is consistent with the hypothesis that the high population density of bacteria found in the rumen fluid of defaunated animals may result in increased fermentation of rumen VFA and digestible dietary carbohydrate, thereby increasing the output of CO2 from the rumen and reducing the quantity of VFA (hence energy) available to the host.

5. There was no difference in the flow of organic matter (OM) to the duodenum but there was a higher faecal excretion of OM in defaunated animals (apparent OM digestibility: 0.72 in faunated, 0.67 in defaunated).

6. Defamation did not significantly increase the flow of NAN to the duodenum, the percentage of duodenal NAN of bacterial origin or the quantity of microbial NAN synthesized/g organic matter fermented. Faecal excretion of NAN was higher in defaunated animals (5.3 v. 3.6 g N/d).