bluuebunny/crossref_metadata_2025 huggingface dataset:
The nutritive value of rumen micro-organisms in ruminants
Authors: Strom E. , Øskov E. R.
Published: September 2005

1. Four experiments were carried out to identify and quantify the limiting amino acids (AA) in rumen microbial protein (RMP).

2. A method was developed which involved first, an assessment of the efficiency of utilization of absorbed AA-nitrogen (U) of RMP, defined as the retention of AA-N from RMP absorbed from the small intestine, and second, addition of a mixture of AA similar to the absorbed AA profile in a quantity defined by the U of RMP and equal to (1 – U)/U. Third, it involved removal of each AA in turn and measurement of the resultant N retention. Using this approach it was possible to calculate both the order and extent of AA limitations in RMP.

3. Apart from methionine which was found to be the most limiting AA, only lysine, arginine and histidine reduced N retention when omitted, and accordingly only these AA were limiting in RMP.

4. The method is discussed in detail and the amount of supplementary AA required to utilize RMP fully is calculated.
Dietary supplementation increases milk output in the rat
Authors: Roberts Susan B. , Coward W. A.
Published: September 2005

1. The effects of dietary supplementation on milk output and maternal body composition were investigated in the lactating rat. The supplement was a cooked homogeneous mixture of eggs and maize oil, and had the same protein-energy: total energy value as the control diet.

2. During 2–12 d post partum rats were fed ad lib., either on the control diet alone or on the control diet plus the supplement. Measurements were made of milk output using an isotope-dilution technique, milk composition, and dam and litter body-composition changes.

3. Compared with the dams receiving only the control diet, dams provided with the supplement consumed 19.7% more energy and protein and produced 31.2% more milk and mobilized less body fat.

4. By 12 d of age, pups in litters of dams receiving the supplement were significantly heavier than those in litters of dams receiving the control diet only, and they contained more protein and more fat.

5. It is concluded that dietary supplementation of lactating rats can enhance lactational performance.
Effects of meal consumption on whole body leucine and alanine kinetics in young adult men
Authors: Hoffer Leonard J. , Yang Russell D. , Matthews Dwight E. , Bistrian Bruce R. , Bier Dennis M. , Young Vernon R.
Published: September 2005

1. The effects of meal consumption on plasma leucine and alanine kinetics were studied using a simultaneous, primed, continuous infusion of L-[I-13C]leucine and L-[3,3,3-2H3]alanine in four healthy, young, adult male subjects. The study included an evaluation of the effect of sampling site on plasma amino acid kinetics, with blood being drawn simultaneously from an antecubital and dorsal heated hand vein.

2. In comparison with the postabsorptive state, the ingestion of small hourly meals resulted in a 35% increase in plasma leucine flux and a 77% increase in leucine oxidation. Calculated entry of leucine into the plasma compartment from endogenous sources decreased by 65%. Plasma alanine flux more than doubled, indicating a significant enhancement in de now alanine synthesis.13C enrichment of leucine in venous and arterialized plasma did not differ significantly, but alanine flux calculated from isotopic measurement in venous plasma was substantially greater than that based on analysis of arterialized blood plasma.
Relation of antigenic structure of cereal proteins to their toxicity in coeliac patients
Authors: Ciclitira P. J. , Ellis H. J. , Evans D. J. , Lennox E. S.
Published: September 2005

1. Unfractionated gliadin and its α-, β-, γ- and ω-gliadin subfractions were used as rabbit immunogens. The antisera were characterized by (1) Ouchterlony double diffusion, (2) binding of 125I-labelled gliadin subfractions, (3) inhibition by several gliadin subfractions of binding between γgliadin antiserum and 125I-labeIled γgliadin.

2. Double diffusion showed identical cross-reactivity between the antisera and the gliadin subfractions with the exception of ω-gliadin. Precipitin lines of partial identity with gliadin were observed against rye secalins and barley hordeins but not oat avenins or maize zeins.

3. Binding was observed between unfractionated 125I-labelledα-, β-, γ- and ω-gliadins and all the antisera. There was binding of 125I-labelled ω-gliadin to the ω-gliadin antiserum but poor binding of 125I-labelled ω-gliadin to unfractionated α-, β- and γ-gliadin antisera. Competitive inhibition of binding between 125I-labelled γ-gliadin and γ-gliadin antiserum diluted 1:250 (v/v) demonstrated similar competition between α-, β- and γ-gliadins and this antiserum but poor competition between ω-gliadin, wheat glutenins, albumins and globulins, rye secalins, barley hordeins and oat avenins.

4. These findings suggest that there is a good correlation between the antigenic structure of gliadin proteins and their toxicity to patients with coeliac disease.
Gluconeogenesis from caecal propionate in the horse
Authors: Ford E. J. H. , Simmons H. A.
Published: September 2005

1. The production of propionate in the caecum of the horse has been measured in two Shetland-type ponies fitted with caecal and colonic cannulas and fed on hay or on hay and wheat bran. A continuous intracaecal infusion of14C-labelled sodium propionate was used and samples were obtained from a cannula at the origin of the right ventral colon. A simultaneous intravenous infusion of [2-3H]glucose was used to measure total glucose entry.

2. On a hay diet which provided 177 kJ/kg body-weight per d, mean caecal propionate production was 19.6 (range 17.2–21.2) mg/h per kg body-weight and on a hay and wheat bran diet, which provided 187 KJ/kg body-weight per d, mean caecal propionate production was 34.0 (range 28.9–38.3) mg/h per kg body-weight.

3. Mean total glucose production (mg/h per kg body-weight) in one pony was 104 (range 100–110) and in the other 135 (range 123–153). Rates were not influenced by diet.

4. About 7% of total glucose production was derived from propionate produced in the caecum and this percentage was unaffected by diet or by individual animals.
Differences in intestinal protein synthesis and cellular proliferation in well-nourished rats consuming conventional laboratory diets
Authors: Southon Susan , Livesey G. , Gee Jennifer M. , Johnson I. T.
Published: September 2005

1. Male Wistar rats (100 g) were given a commercial pellet feed or a semi-synthetic dietad lib. Although the pellet-fed group grew slightly faster than the other group during the early part of the feeding period, there was no significant difference between the final weights of the groups.

2. The fractional rates of protein synthesis in jejunum, proximal ileum and liver were measured by a technique based on the determination of L-[4−3H]phenylalanine incorporation over a short time period. Protein synthesis was higher in both jejunum and ileum of the pellet-fed rats compared with those eating the semi-synthetic diet, but there was no difference between the rates of protein synthesis measured in the livers of the groups.

3. The rate of mucosal cell division was significantly faster in the ileal mucosa of the pellet-fed group compared with the other group, and there were significant differences in some aspects of mucosal morphology.

4. The maintenance of higher rates of cell turnover and protein synthesis in animals given commercial pellet feed is unexplained, but it may be related to the presence of non-absorbable polysaccharides or other complex plant materials in the pellet feed.
The effect of iron substrate on mitochondria1 haem synthesis in copper deficiency
Authors: Williams Darryl M. , Kennedy F. Scott , Green Brenda G.
Published: September 2005

1. Studies of iron utilization and haem synthesis were carried out with hepatic mitochondria obtained from copper-deficient and pair-fed control rats.

2. Ferric chloride can be used as Fe substrate for mitochondrial haem synthesis in the presence of succinate. Utilization is further enhanced by the addition of FMN.

3. Ferritin does not support haem synthesis in the presence of succinate alone, but does support haem synthesis when FMN is added.

4. Mitochondria1 haem synthesis is impaired in Cu deficiency when either FeCl3or homologous ferritin is used as Fe substrate.

5. The results of the present study suggest that impaired haem synthesis in Cu deficiency occurs at a step following the chemical reduction of Fe substrate.
The digestion of protein in young pigs and the utilization of dietary methionine
Authors: Leibholz Jane
Published: September 2005

1.Forty pigs between 23 and 51 d of age were given adlib. diets containing wheat and one of five protein concentrates: meat meal A, meat meal B, soya-bean meal, milk and lupins (Lupinus augustifolius). Twenty of these pigs were given indigestible markers from 51 to 56 d of age and were killed at 56 d of age.

2.The diets containing meat meals A and B, soya-bean meal and milk contained 2.3 g total methionine/kg and the diet containing lupins contained 2.1 g/kg.

3.A further forty pigs of the same age were given the same diets supplemented with 1 g synthetic methionine/kg.

4.The weight gains and feed conversion ratios of the pigs given the diets containing 2.1–2.3 g methionine and 3.1–3.3 g methionine/kg were not significantly different.

5. The weight gains of the pigs given lupins (2.1 g methionine/kg) were less than those of the pigs given the diets containing 2.3 g methionine/kg.

6. The apparent digestibility of dry matter (DM) and nitrogen was less for the diets containing the meat meals (0.75 and 0.78 respectively) than for those containing the other protein concentrates (0.80 and 0.84).

7.The retention times in the large intestine of the diets containing soya-bean meal and lupins were 965 and 1083 min which were greater than those of the diets containing the other protein concentrates, mean 732 min.

8. The major site of N digestion and absorption for the diet containing milk was the area of the small intestine 25–50% of total length from the pylorus, while for the other protein concentrates the major site was 50–75% of its total length from the pylorus.

9. The digestion and absorption of N in the large intestine was less (3.4%) for the diet containing milk than for those containing the other protein concentrates (7.5–11.3%).

10. The apparent digestibility of the methionine to the ileum for the five diets ranged from 0.74 to 0.86 while the calculated retention of the apparently-absorbed methionine was 1.00. It was suggested that methionine digestibility could be used as an indicator of availability.

11. The calculated retention of apparently absorbed N in the carcass was 0.71 for the pigs given the diet containing milk and 0.51–0.58 for the pigs given the other diets.
Some effects of vitamin E and selenium deprivation on tissue enzyme levels and indices of tissue peroxidation in rainbow trout (Salmo gairdneri)
Authors: Bell J. G. , Cowey C. B. , Adron J. W. , Shanks Aileen M.
Published: September 2005

1. Duplicate groups of rainbow trout (Salrno gairdnert) (mean weight 11 g) were given for 40 weeks one of four partially purified diets that were either adequate or low in selenium or vitamin E or both.

2. Weight gains of trout given the dually deficient diet were significantly lower than those of trout given a complete diet or a diet deficient in Se. No mortalities occurred and the only pathology seen was exudative diathesis in the dually deficient trout.

3. There was significant interaction between the two nutrients both with respect to packed cell volume and to malondialdehyde formation in the in vitro NADPH-dependent microsomal lipid peroxidation system.

4. Tissue levels of vitamin E and Se decreased to very low levels in trout given diets lacking these nutrients. For plasma there was a significant effect of dietary vitamin E on Se concentration.

5. Glutathione (GSH) peroxidase (EC1. 1 1. 1.9) activity in liver and plasma was significantly lower in trout receiving low dietary Se but was independent of vitamin E intake. The ratios of hepatic GSH peroxidase activity measured with cumene hydroperoxide and hydrogen peroxide were the same for all treatments. This confirms the absence of a Se-independent GSH peroxidase activity in trout liver.

6. Se deficiency did not lead to any compensatory increase in hepatic GSH transferase (EC2. 5. 1. 18) activity; values were essentially the same in all treatments.

7. Plasma pyruvate kinase (EC2. 7. 1.40) activity increased significantly in the trout deficient in both nutrients. This was thought to be due to leakage of the enzyme from the muscle and may be indicative of incipient (subclinical) muscle damage.
Evidence suggesting that the elevated plasma triiodothyronine concentration of rats fed on protein deficient diets is physiologically active
Authors: Sawaya Ana Lydia , Lunn P. G.
Published: September 2005

1. Some metabolic indicators of thyroid hormone activity have been investigated in rats fed on either protein-deficient or energy-restricted diets.

2. Rats were divided into three groups. Control animals were maintained on a diet of protein energy: total energy (P:E) value of 0.20, while the low-protein group (LP) were allowed adlib. access to food of P:E 0.03. Energy-restricted (ER) rats were given limited amounts of a control diet (P:E 0.20) such that their rate of growth matched that of LP animals.

3. Animals fed on the LP diet had elevated plasma concentrations of both total and free triiodothyronine (T3)concentrations whereas those on the ER regimen showed values below those of controls.

4. The activities of mitochondria1 α-glycerol-3-phosphate dehydrogenase (EC1. 1.99.5) and of the αglycerol-3-phosphate shuttle system were elevated in the liver of LP rats, but malate-aspartate shuttle operation was reduced. All three activities were reduced in ER animals.

5. Cytochrome c oxidase (EC1.9.3.1) activity of brown adipose tissue indicated a high rate of thermogenic activity in this tissue in LP rats, but ER animals showed some evidence of below normal function.

6. The results indicate that both the raised plasma T3of LP rats and the reduced levels observed in ER animals are physiologically significant.
Urea turnover and transfer to the digestive tract in the rabbit
Authors: Forsythe S. J. , Parker D. S.
Published: September 2005

1.14C and15N isotopes of urea were infused intravenously into rabbits for 6–8 h in order to measure urea synthesis and the extent of degradation in the digestive tract. The results indicate that 0.62 of the urea flux was excreted in the urine and that re-incorporation of urea-N following hydrolysis in the gut represented 0.3 of the urea synthesis rate.

2. Sampling of metabolites from the caecum by dialysis provided an opportunity to assess the contribution of urea-N to the caecal ammonia pool. This contribution is calculated to be 0.25 of caecal ammonia turnover.

3. Infusion of a urease (EC3. 5. 1. 5) inhibitor during a continuous infusion of [14C]urea into the caecum permitted the measurement of urea turnover within the caecum.

4. Results obtained for urea entry into the caecum are contrasted with the measured urea degradation rate in the gut.
Influence of chronic ethanol intake on obesity, liver steatosis and hyperlipidaemia in the Zucker fa/fa rat
Authors: Karsenty C. , Chanussot F. , Ulmer M. , Debry G.
Published: September 2005

1. The effect of chronic alcohol intoxication on metabolic disturbances and fatty infiltration and degeneration was studied in genetically obese, hyperlipoproteinaemic, fa/fa Zucker rats.

2. Sixteen obese Zucker (fa/fa) rats, sixteen lean Zucker rats (Fa/-)and sixteen Wistar rats, all male rats aged 7–8 weeks, were given either a control (C)diet (13% of energy from protein, 37% from fat, 50% from carbohydrate) or an ethanol (E) diet (13% of energy from protein, 37% from fat, 14% from carbohydrate, 36% from ethanol) for 4 weeks.

3. The fa/fa rats given diet E consumed more energy than those given diet C, but after 4 weeks the weight gains and degrees of obesity were similar for both groups. With both diets, the developed hyperlipidaemia could be explained by the hyperinsulinaemia. Both hypertriglyceridaemia and hypercholesterolaemia were lower in fa/fa rats eating diet E than in those given diet C. Fatty infiltration of the liver, as assessed by hepatic triacylglycerol and cholesterol contents, was observed with both diets, but for fa/fa rats it was less extreme in those given diet E.
Paradoxical effect of ethanol on liver lipogenesis in the genetically-obese Zucker rat
Authors: Karsenty C. , Ulmer M. , Chanussot F. , Ratanasavanh R. , Debry G.
Published: September 2005

1. Sixteen obese (fa/fa) Zucker rats, sixteen lean (Fa/-)Zucker rats and sixteen Wistar rats, all male rats aged 7–8 weeks, were given either a control (C) diet containing no ethanol or an ethanol (E) diet in which 36% of the energy was supplied by ethanol, for a period of 4 weeks.

2. The activities of glucose-6-phosphate dehydrogenase (EC 1.1.1.49), glucose-6-phosphatase (EC 3.1.3.9) and glycerol kinase (EC 2.7.1.30) and the glycogen content in the livers of obese (fa/fa)rats were lower in animals given diet E than in those given diet C. As a result, hepatic lipogenesis and fatty degeneration of the liver were reduced in obese (fa/fa) rats given diet E.
Further studies in rats on the influence of previous iron intake on the estimation of bioavailability of Fe
Authors: Fairweather-Tait Susan J. , Swindell Tina E. , Wright A.J.A.
Published: September 2005

1. Iron retention from 3 g wholewheat flour was measured in male Wistar rats previously given one high-Fe or control diet meal 12,24, 36,48 or 60 h before the test meal (Expt 1). The control diet was given at all other times. The procedure was then repeated in rats given one high- or low-Fe meal 12, 24, 36 or 48 h before the test meal (Expt 2).

2. There was a significant difference between groups given a high- or medium-Fe meal at 12,24,36 h (P < 0.001) and 48 h (P < 0.05) but not at 60 h. In the second experiment, there was a significant difference between groups given a high- or low-Fe meal at 12, 24 or 36 h but no difference when given the two diets 48 h before the test meal. The high-Fe meal depressed and the low-Fe meal enhanced subsequent59Fe retention: the effects were greatest at 12 h and diminished as the time interval between the high- or low-Fe meal and the test meal increased. The estimated mean time for the absorptive capacity of the mucosal cells to return to equilibrium was 54.0 (SEM 7.6) h.

3. Male Wistar rats were given high-, control or low-Fe diets for either 3 d or 28 d before an in vivo investigation in which the luminal loss of59Fe-labelled ferric citrate from duodenal and ileal loops was measured, and the proportional distribution between the carcass and the washed loop measured (Expt 3).

4. The luminal loss of59Fe-labelled ferric citrate was significantly affected by the previous diets (P < 0.001). Rats given a low-Fe diet absorbed more than those given a high-Fe diet but the period of time on the diet (3 or 28 d) had no effect on luminal loss. Significantly more59Fe was lost from duodenal than from ileal loops in all groups.
Protein turnover of breast muscle in germ-free and conventional chicks
Authors: Muramatsu T. , Salter D. N. , Coates M. E.
Published: September 2005

1. The effect of the gut microflora on protein turnover in pectoral muscle (M. pectoralis profundus) was studied by means of dietary infusion of L-[UJ-14C]phenylalanine and of massive dose injection of L-[4-3H]phenylalanine in chicks fed on a semi-purified casein—gelatin (SCG) diet until 19 d of age, and in those subsequently given either a nitrogen-free (NF) diet or NF supplemented with methionine and arginine (MA) for a further 9 d.

2. Time-course changes in radioactivity released in expired carbon dioxide during the 8 h infusion period showed that isotopic equilibrium was reached in 4 h with the SCG diet and in 5 h with the MA diet. However, with the protein-deprived chicks given the NF diet, isotopic equilibrium was not achieved since radioactivity in CO2increased linearly throughout.

3. On feeding the NF diet, fractional protein synthesis rate and the absolute amount of protein synthesized in chick breast muscle were reduced. These reductions were partially alleviated by supplementing the NF diet with methionine and arginine.

4. The fractional degradation rate of breast muscle was increased in chicks given the NF diet, while the absolute amount of protein degraded was decreased. The addition of methionine and arginine counteracted these changes brought about by protein starvation.

5. Generally speaking, the presence of the gut microflora had little, if any, effect on protein turnover rate in chick-breast muscle.
Effect of monensin on feed utilization and gastrointestinal fermentation in the hamster (Mesocricetus auratus)
Authors: Sakaguchi Ei , Matsumoto Tatsuro
Published: September 2005

1. Three experiments were conducted to examine the effect of monensin on growth performance, feed utilization and volatile fatty acids (VFA) in the forestomach and caecum of hamsters.

2. In Expt 1, monensin was fed at levels of 0, 5, 10 and 20 mg/kg to the growing male and female hamsters given a commercial diet (major component: lucerne (Medicago sativa) meal). In Expt 2, monensin was fed at levels of 0, 5, 15, 45 and 135 mg/kg to the growing male hamsters given a semi-purified diet containing 10 g urea/kg (main components: maize starch, sucrose, casein and cellulose). In Expt 3, monensin was fed at levels of 0 and 40 mg/kg to the growing male hamsters given the commercial diet containing lucerne meal or a semi-purified diet.

3. In Expt 1, monensin improved feed conversion efficiency and growth performances in the young growing hamsters, but monensin did not affect the hamsters at a later growing stage.

4. In response to monensin the proportion of acetic acid increased and that of propionic acid decreased in the forestomach, whereas the proportion of acetic acid decreased and that of propionic acid increased in the caecum in Expt 2. The hamsters given 135 mg monensin/kg ate less, developed diarrhoea and died.

5. The apparent digestibility of crude protein (nitrogen x 6.25) was improved by monensin but those of dry matter and neutral-detergent fibre (NDF) were decreased in hamsters given the semi-purified diet in Expt 3. Monensin did not appear to have a significant effect on the apparent digestibility of the diet containing lucerne meal.

6. The responses to monensin in hamsters are compared with those in ruminants.
The rate of degradation of myofibrillar proteins of skeletal muscle in broiler and layer chickens estimated by Nr-methylhistidine in excreta
Authors: Hayashi Kunioki , Tomita Yuichiro , Maeda Yoshizane , Shinagawa Yoshiyuki , Inoue Kengo , Hashizume Tokuzo
Published: September 2005

1. AfterNr-methylhistidine (Nr-MH) distribution among the various organs or the tissues was determined in male broiler chickens of 15 d of age, the rates of degradation of myofibrillar proteins in male layer and broiler chickens at different stages of growth were determined by means ofNr-MH.

2. About 75 and 8% of the totalNr-MH in the tissues occurred respectively in skeletal muscle and stomach, and most of the remainder in the intestine and the skin.

3. The rates of degradation of myofibrillar proteins in the male layer and broiler chickens of 21, 42 and 63 d of age were calculated to be 6.1, 4.5 and 2.4%/d (layer) and 5.0, 2.8 and 0.9%/d (broiler) respectively. These calculations involve the assumption that 80% of the total excretedNr-MH was derived from skeletal muscle.

4. The results strongly indicate that the rapid growth of the broiler chicken is facilitated by the reduced rate of protein degradation.
Endocrine regulation of metabolism in sheep given kale (Brassica oleracea) and ryegrass (Lolium perenne) – clover (Trifolium repens) fresh-forage diets
Authors: Barry T. N. , Manley T. R. , Redekopp Carolyn , Allsop T. F.
Published: September 2005

1. Diets of fresh kale (Brassica oleracea) and ryegrass (Loliumperenne) – elover (Trifolium repens) herbage were fed to growing sheep in three experiments. In Expts 1 and 3 the sheep were confined indoors and fed at hourly intervals, and all were given supplementary iodine to counteract kale goitrogens. Lambs grazed the two forages for 24 weeks in Expt 2, with and without intramuscular injections of iodized oil. The kale and herbage contained respectively 11 and <0.1 g S-methyl-L-cysteine sulphoxide (SMCO)/kg dry matter (DM) and values for readily fermentable: structural carbohydrate (CHO) were 3.1 and 0.8, respectively.

2. Blood samples were withdrawn from indwelling catheters (Expts 1 and 3) or venipuncture (Expt 2) and the plasma analysed for a range of hormones using radioimmunoassay procedures. Glucose irreversible loss (GIL) was measured in Expt 1 using primed continuous infusions of D-[U-14C]glucose. Samples of adipose tissue were removed from the shoulder area in Expt 3, and rates of D-[U-14C]glucose and [U-14C]acetate incoporation and oxidation were measured in vitro, together with the rate of glycerol release.

3. In the presence of supplementary I2, kale feeding was associated with an elevation in plasma concentration of free thyroxine (T4) Regardless of I2 supplementation, sheep fed on kale had much higher plasma growth hormone concentrations than sheep fed on ryegrass-clover herbage, and this was accompanied by reduced plasma somatostatin concentrations.

4. Plasma insulin and glucagon concentrations were similar for sheep fed on the two diets; GIL tended to be slightly but not significantly greater (9.4%) for sheep fed on kale than for those fed on ryegrass-clover herbage.

5. Kale feeding was associated with increased uptakes of acetate and glucose into adipose tissue, reduced rates of oxidation of both substrates and no difference in rate of glycerol release. Each 1 nmol increase in glucose uptake was associated with 8.7 nmol acetate uptake ( P < 0.001).

6. It is proposed that ruminants counteract protein inactivation, caused by production of dimethyl disulphide from SMCO in the rumen, through increasing circulating concentrations of growth hormone and T4, which then stimulate synthesis of replacement body proteins.
Vitamin B12absorption in the neonatal piglet
Authors: Trugo N. M. F. , Ford J. E. , Sansom B. F.
Published: September 2005

1. The vitamin B12in sows' milk is strongly attached to a specific ‘binder’ protein, which is present in excess. The influence of this ‘binder’ on the uptake and retention of cyanocobalamin and two natural analogues(cobinamide and Co-α-[2-methyladenyl]cobamide) was investigated with neonatal piglets.

2. Retention of a single oral dose of cyano[58Co]cobalamin given before 7 d of age was consistently higher with suckled than with early-weaned piglets, as determined by measurement of whole-body radioactivity.

3. Efficiency of retention declined with age, more rapidly in early-weaned than in suckled animals; when the dose was given at 14 d approximately 30% was retained by both groups.

4. Distribution of the retained cyano[58Co]cobalamin within the body of the piglets was the same in both groups; about half was present in the liver.

5. Foraging piglets may ingest adventitious vitamin B12and its analogues, which are present in the sow's faeces and in contaminated litter. The influence of the vitamin B12-binder in sows' milk on the uptake and retention of two non-cobalamin analogues, and the effects of the analogues on the uptake and retention of vitamin B12from 2 to 14 d after parturition, were investigated with early-weaned piglets.

6. The analogues were detected in the liver but not in the body organs. They were also present in blood plasma, urine and bile, in high concentration relative to that of vitamin B12. The content of analogues in the liver was very small in relation to the amounts ingested, and much less than that of vitamin B12. There was no indication that the vitamin B12-binder in sows' milk influenced uptake and retention of the analogues, or that ingestion of analogues affected the content of vitamin B12in the body organs and fluids examined.
Vitamin B12absorption in the neonatal piglet
Authors: Trugo N. M. F. , Newport M. J.
Published: September 2005

1.It has been postulated that the vitamin B12-binding protein in the sows' milk may facilitate the intestinal absorption of vitamin B12in the piglet. This implies that the binder is not rapidly and completely degraded by gut proteases, and the present experiments were devised to test this assumption.

2. Piglets aged 7 and 28 d were given a test feed of sows' milk whey both with and without cyano[3H]cobalamin to saturate the binder, and with14C-labeHed polyethylene glycol (PEG) as a marker. Control piglets were given a milk substitute containing no vitamin B12-binder. At 80 min after the test meal the piglets were killed and the contents of the stomach and small intestine were removed for analysis.

3. Recovery of [14C]PEG, mainly from the middle and distal portions of the small intestine, ranged from 49 to 78%. Apparent loss of vitamin B12-binder from the intestine was calculated from the ratio, PEG: binder. In both 7- and 28-d-old piglets, the content of saturated binder in the middle and lower small intestine was about 20% depleted relative to that in the test feed. With the unsaturated binder the loss was more variable and generally greater, at about 50%.

4. At slaughter the stomach was nearly empty and the high unsaturated binding capacity of the contents was attributed to endogenous binders. However, in the middle and lower small intestine, the binding capacity was derived mainly from sows' milk given with the test meal. No free cyano[3H]cobalamin was found in the intestinal contents of piglets given sows' milk to which enough cyano[3H]cobalamin had been added to saturate the binder.

5. There was no change in the molecular weight of the vitamin B12-binder during its passage down the intestine, as judged by its behaviour on filtration in Sephadex gel G-150.

6. The results indicate that a high proportion of saturated binder, and a smaller proportion of unsaturated binder, survived unchanged in the intestine of piglets at both ages.
Biochemical aspects of malabsorption in marasmus: effect of dietary rehabilitation
Authors: Mehta H. C. , Saini A. S. , Singh Harjit , Dhatt P. S.
Published: September 2005

1. Sixty marasmic children were investigated for the absorption of xylose, proteins and fats. Their duodenal juice samples were also analysed for bile salts and microflora.

2. The marasmic children were then studied in three groups of twenty by allocating them to three different dietary schedules: a high-protein diet (30% of the total energy from protein), a high-fat diet (40% of the total energy from fat) and a high-carbohydrate diet (70% of the total energy from carbohydrate) for 2 weeks and the previous measurements repeated.

3. Whereas the high-fat diet resulted in improved fat absorption, along with an increase in total and conjugated bile acids, and the high-carbohydrate diet led to improved xylose absorption, the diet rich in protein resulted in an improvement in the absorption of all three dietary ingredients. It appears that a high-protein diet improves the overall absorption process by improving the intestinal environment as a whole, while high-carbohydrate and high-fat diets bring about adaptive changes related to the respective absorptive processes.
Some nutritional properties of unrefined sugar and its promotion of the survival of new-born rats
Authors: Omer Ahmed Eisa , John Yudkin
Published: September 2005

1. The claims that rats fed on diets with ‘brown sugar’ (unrefined muscovado) perform better in a number of ways than do rats fed on refined white sugar (sucrose) have been examined.

2. Male Wistar rats were fed on purified diets from weaning, in which the carbohydrate component was either maize starch or unrefined sugar or sucrose. The sugars produced no differences in growth rate, body composition, or the weights of liver or kidneys. Compared with sucrose, unrefined sugar produced an increase in blood cholesterol and in the activity of hepatic fatty acid synthetase, and a greater increase in blood triglyceride. In confirmation of earlier results, rats fed on either sugar had heavier livers and kidneys, increased activity of hepatic glucose-6-phosphate dehydrogenase (EC1.1.1.49) and a higher concentration of plasma triglyceride compared with rats fed on maize starch.

3. Female Sprague-Dawley rats were fed on the same three diets as the male rats, and mated when they weighed about 200 g. No difference was seen in their ability to mate, the progress of pregnancies, or the sizes of the litters. Does fed on unrefined sugar produced litters of higher viability than did does fed on starch or sucrose. Survival was between 85 and 100% with unrefined sugar and between 30 and 75% with starch or sucrose.

4. Unrefined muscovado sugar has thus been shown to contain a factor required by female rats for the proper viability of their pups. This may be the same ‘Reproductive Factor R’ as that described by Wiesner & Yudkin (1951). In certain circumstances, unrefined muscovado sugar might therefore contribute to the nutritional value of a human diet, although in what circumstances, in what respect and to what extent it might do so, is by no means clear.
Human protein requirements: obligatory urinary and faecal nitrogen losses and the factorial estimation of protein needs of Nigerian male adults
Authors: Atinmo T. , Mbofung C. M. F. , Hussain M. A. , Osotimehin B. O.
Published: September 2005

1. The present study was designed to use the factorial approach to estimate protein requirements of Nigerian male adults by measuring obligatory nitrogen losses via urine, faeces and sweat when N intake was very low and energy intake adequate.

2. Eight adult men from Osegere village near Ibadan and seven medical students from the University of Ibadan, who volunteered to participate as subjects in the study, were given a low-protein diet (based on staple foods habitually consumed by subjects) for 10 d. Mean daily total protein intake was 4.68 g while that of energy was 0.2 MJ/kg body-weight. After an initial 5 d adaptation period, 24 h urine and faeces were collected in marked containers for five consecutive days for N determination. N losses from the skin were also determined in the village adults.

3. Mean daily urinary, faecal and sweat N losses (mg N/kg body-weight) were 45.88 (SD 4.84), 21.79 (SD4.19), and 7.46 (SD1.71) from the village adults. The corresponding urinary and faecal N losses from the university students were 43.45 (SD 2.28) and 18.32 (SD4.66) (sweat N loss not measured). Thus the total daily obligatory N losses (per kg body-weight) from the village adults and university students were 75.13 and 69.23 mg N respectively (assuming a sweat N loss of 7.46 mg for the university students). After adjusting for requirement and making a 30% allowance for individual variability, the safe level of protein intake was calculated to be 0.78 and 0.73 g protein/kg body-weight for the village men and university students respectively.

4. These values suggest that the Joint FAO/WHO ad hoc Expert Committee (1973) safe allowance of 0.57 g egg protein/kg per d is not sufficient for most young adults in this environment when energy intake is adequate.
Effect of gold thioglucose-induced obesity on adipose tissue weight and cellularity in male and female mice suckled in large and small litters: investigations into sex differences and site differences
Authors: Enser Michael , Roberts Jennifer , Whittington Frances
Published: September 2005

1. Over- or undernutrition of newborn mice was caused by suckling in litters consisting initially of four or eighteen pups. After weaning, mice were fed ad lib. At 13 weeks some mice received gold thioglucose (GTG, 600 mg/kg, intraperitoneally) to induce hyperphagia, and all were killed at 39 weeks.

2. Mice suckled in small litters were heavier, with more body fat and protein. GTG treatment induced rapid weight gain and treated mice from large litters were heavier than untreated mice from small litters. However, the effect of litter size was not totally removed since GTG-treated small-litter mice were heavier than GTG-treated large-litter mice and had more fat, although body protein was not different.

3. Fat distribution between the depots was related to total body fatness and not to the treatment.

4. In male mice, preweaning undernutrition resulted in smaller fat depots containing smaller cells. GTG treatment of large-litter mice restored both to the levels found in small-litter mice: the depots of the latter mice were not significantly different after treatment.

5. In female mice, preweaning undernutrition resulted not only in smaller depots and cells but also fewer cells in all depots except mesenteric. GTG-treatment caused larger depots and cells in all mice with no difference in cell size whether mice were from large or small litters. The number of cells in the perirenal and mesenteric depots was greater in GTG-treated mice and was the same whether mice were from large or small litters.

6. We conclude that the level of preweaning nutrition does not affect the ability of adipose tissue to develop subsequently through hypertrophy or hyperplasia of the adipocytes or both, given a sufficient energy surplus consisting of normal pelleted feed, low in lipid.
Digestion of polysaccharides, protein and lipids by adult cockerels fed on diets containing a pectic cell-wall material from white lupin (Lupinus albus L.) cotyledon
Authors: Carré B. , Leclercq B.
Published: September 2005

1. The cell-wall material of white lupin (Lupinus albus L.) cotyledon is characterized by low contents of cellulose (47 g/kg) and lignin (17 g/kg) and a high content of pectic substances (710 g/kg). The digestion of lupin cell-wall material by adult cockerels was estimated using gas-liquid chromatographic analyses of alditol acetates derived from polysaccharide sugars. The analyses were performed in the destarched water-insoluble fractions of feed and excreta. Digestibility measurements were carried out using a 3 d balance period including a 2 d feeding period and a 24 h final starvation period.

2. In the first experiment, six animals were given a diet containing 510 g white lupin cotyledon flour/kg which was the only source of protein and cell walls in the diet. The apparent digestibility of cell-wall components was near zero.

3. In the second experiment, three diets were prepared by diluting a fibre-free basal diet (diet A) by a semi-purified cell-wall preparation introduced at two different levels: 100 g/kg (diet B) and 200 g/kg (diet C). The semi-purified cell walls were prepared from the white lupin cotyledon flour used in the first experiment. The true digestibilities of polysaccharides measured in birds given diets B and C were near zero. It is suggested that the measurement of the neutral-detergent fibre (NDF) content according to Van Soest & Wine (1967) is not a suitable procedure for estimating the undigestible fibre content in poultry nutrition as the cell-wall pectic substances are not included in the NDF measurement.

4. Addition of the semi-purified cell-wall preparation (Expt 2) resulted in a slight decrease in the apparent protein digestibility. This decrease might be explained by the addition of undigestible cell-wall protein.

5. Addition of the semi-purified cell-wall preparation (Expt 2) had no effect on the apparent lipid digestibility.

6. The metabolizable energy values of the basal diet fraction of diets B and C were calculated assuming that the added plant cell-wall fraction was of no energy value. These calculated values were similar to the measured metabolizable energy value of diet A (basal). Thus, the tested pectic plant cell walls seemed to act as a diluent. It is suggested that, on the point of the digestion yields, all types of plant cell walls would act as diluents, in poultry.
Effects of supplemental dietary energy on leucine metabolism in sheep
Authors: STEVEN Nissen , PIOTR Ostaszewski
Published: September 2005

1. Mixed-breed wethers (40–50 kg), 9 months old, were maintained on high-energy (HED) and low-energy (LED) diets for 2 weeks.

2. After a 15 h fast, a primed-dose constant infusion of L-[U-14C]leucine and α-[4,5-3H]ketoisocaproate (KIC) was given.

3. After 2 h, plasma samples were taken and plasma-specific radioactivities of I4C- and 3H-labelled leucine and KIC were measured and analysed by using an open two-pool model.

4. Less than 20% of the total leucine-C entering the circulation was converted to the KIC pool, and 42% of the KIC was converted back to the leucine pool; transamination of the leucine to KIC and reamination of KIC to leucine was much less than in other species.

5. Additional dietary energy resulted in a decrease in tissue protein synthesis, leucine oxidation and interconversion of leucine and KIC. Total leucine-C entry was also lower in sheep given HED, which was most likely due to a suppression of endogenous proteolysis.

6. Plasma glucagon concentration was significantly higher (P < 0.05) in sheep given LED compared with those given HED. The concentration of glucagon was closely correlated in all treatments with the leucine-C entry (proteolysis + absorbed leucine) and also with KIC-C exit (oxidation).
Responses to oral methionine supplementation in sheep fed on kale (Brassica oleracea) diets containing S-methyl-L-cysteine sulphoxide
Authors: Barry T. N. , Manley T. R.
Published: September 2005

1. Responses to twice-weekly oral supplementation with 4.0 g methionine were measured with lambs (27 kg) grazing kale (Brassica oleracea) for 10 weeks (Expt 1). In a second experiment with sheep fed on kale at hourly intervals, rumen fractional outflow rates of CrEDTA and ruthenium Tris(1, 10 phenanthroline) markers were measured from the rates of decline in their concentrations. Rumen turnover of S-methyl-L-cysteine sulphoxide (SMCO) and of carbohydrate (CHO) constituents were also measured. The kale fed contained 11.4 g SMCO/kg dry matter and the ratio, readily-fermentable: structural CHO was high at 2.9.

2. Severe haemolytic anaemia, associated with low live-weight gain (LWG), occurred in the lambs during the initial 5 weeks of grazing, due to rumen fermentation of SMCO. Oral methionine supplementation raised plasma concentrations of methionine and cysteine, increased wool growth rate, and increased LWG during the initial 5 weeks. Methionine supplementation also increased rumen pool and plasma SMCO concentrations, suggesting reduced rumen SMCO fermentation.

3. In Expt 2, rumen degradation rate of SMCO (1.2/h) was calculated to be twice as fast as that of the most rapidly fermented dietary CHO constituents and eight times faster than the rate of water outflow (0.16/h), thus explaining its virtually complete rumen degradation and toxicity in brassica diets. It was estimated that 1.2 g of each 4.0 g methionine administered would have escaped rumen degradation, due to the high rate of water outflow from the rumen.

4. Disappearance rates of CHO constituents from the rumen were as predicted for normal ruminant diets, showing that rumen metabolism of SMCO did not have a depressive effect. Hemicellulose disappeared at a slower rate than the other CHO, suggesting that hemicellulose digestion may be rate-limiting for cell-wall digestion.

5. It is suggested that the responses to oral methionine supplementation can be explained through methionine reducing rumen SMCO degradation, and through a significant portion of the methionine escaping rumen degradation.
Digestion of the zinc in human milk, cow's milk and a commercial babyfood: some implications for human infant nutrition
Authors: Blakeborough Peter , Gurr Michael I. , Salter Dallyn N.
Published: September 2005

1. The digestion of zinc present in human milk, cow's milk and a commercial babyfood was compared, using the piglet as a model for the human infant.

2. In piglets given human milk the pH of stomach contents was approximately 1 and 0.4 units lower than that of animals given respectively cow's milk and babyfood. The pH values of intestinal contents were approximately neutral and did not vary with the type of feed.

3. Hard casein curds were present throughout the stomachs and small intestines of animals fed on cow's milk or babyfood and between 55 and 70% Zn in these digesta samples were recovered in an insoluble form by centrifugation. In contrast, little solid material was observed in the digesta of animals fed on human milk, and 57 and 93% respectively of the Zn in digesta were recovered in a soluble form in the stomach and small intestine.

4. Soluble fractions prepared by centrifugation of digesta were analysed by filtration on Sephadex G-150. After any of the three feeds, soluble Zn in stomach contents was mainly in a low-molecular-weight form. In intestinal samples, however, Zn was present in low- and high-molecular-weight forms. Whilst there were similar amounts of Zn in the low-molecular-weight form in all samples, approximately three times as much of the total intestinal Zn was in a soluble high-molecular-weight form complexed to proteins in the animals fed on human milk compared with those fed on cow's milk or babyfood.

5. Analysis of protein-bound soluble Zn in intestinal samples on SDS-polyacrylamide gels resulted in a similar pattern of proteins for all feeds. Results indicated that at least some of these proteins were derived from intestinal secretions of the piglet.

6. Some implications of these results in respect of the mode of digestion of Zn and its biological availability to the human infant are discussed.
An in vitro method for estimating biologically available vitamin B6 in processed foods
Authors: Ekanayake Athula , Nelson Philip E.
Published: September 2005

1. An in vitro method which used enzymic digestion of the food matrix to release biologically available vitamin B6 is described.

2. Vitamin B6-fortified liquid model foods were thermally processed. After these foods had been freeze-dried, one part was subjected to enzymic hydrolysis at pH 2.0 with pepsin (EC 3.4.23.1) followed by a hydrolysis at pH 8.0 with pancreatin. The vitamins that were found in the supernatant fraction, after an acidified methanol treatment of the hydrolysate, were estimated by high-performance liquid chromatography (HPLC). The other part was given to rats who were kept on a vitamin B6-depleted diet.

3. The biologically available vitamin B6 content of the processed model foods, as determined by rat bioassay, showed good correlation with the vitamin B6 determined by HPLC.

4. It has proved possible to use this in vitro, two-stage enzymic digestion system followed by HPLC determination to determine biologically available vitamin B6 in vitamin B6-fortified processed model foods.