bluuebunny/crossref_metadata_2025 huggingface dataset:
The vitamin B6status of pigs given a diet containing linseed meal
Authors: Bishara H. N. , Walker H. F.
Published: May 2005

1. Pigs consuming a diet containing 300 g linseed meal/kg and a pyridoxine supplement showed greater growth, nitrogen retention, blood packed cell volume and haemoglobin than those receiving only the basal diet.

2. Tryptophan-load tests on unsupplemented pigs revealed an increased excretion of kynurenine, Nα-acetylkynurenine and xanthurenic acid compared to those receiving additional pyridoxine.

3. The results suggest that the unsupplemented pigs were marginally deficient in vitamin B6.

4. When the same diet was fed to rats there was no evidence of vitamin B6deficiency.
Fractional catabolic rates of myosin and actin estimated by urinary excretion ofNT-methylhistidine: the effect of dietary protein level on catabolic rates under conditions of restricted food intake
Authors: Nishizawa N. , Shimbo M. , Hareyama S. , Funabiki R.
Published: May 2005

1. Critical studies on the distribution ofNT-methylhistidine (3-methylhistidine; Me-His) among organs and tissues in adult rats are reported. Adult rats contained 46.5 ± 3.6 mg Me-His/kg body-weight. Almost 90% of the Me-His in the body was recovered from skeletal muscle. These results support the hypothesis that fractional catabolic rates of myosin and actin in skeletal muscle can be estimated by measuring urinary excretion of Me-His.

2. Dietary protein level did not affect the total amount of Me-His in the body. However, urinary excretion of Me-His increased as dietary protein intake was increased.

3. From these results it was concluded that fractional catabolic rates of myosin and actin increase as dietary protein intake increases.
Carbohydrate digestion by the domestic cat (Felis catus)
Authors: Morris J. G. , Trudell Jeanette , Pencovic Terri
Published: May 2005

1. Three experiments were conducted on the ability of cats to utilize dietary carbohydrates. In two experiments, the digestibilities of carbohydrates were measured by the chromic oxide-marker technique using a balanced Latin-Square allocation of treatments: in the third experiment, the effect of age and diet on the activity of intestinal β-galactosidase (lactase) (EC3.2.1.23) and β-fructofuranosidase (sucrase) (EC3.2.1.26) of kittens was measured.

2. In Expt 1 the digestibilities of six individual carbohydrates, glucose, sucrose, lactose, dextrin, raw maize starch and wood cellulose added to a meat-based basal diet were measured.

3. In Expt 2, a similar meat-based basal diet was used and the effect of three processing methods (fine and coarse grinding, and cooking) on the apparent digestibility of the starch in maize and wheat grain was measured.

4. In Expt 3 the effects of the inclusion of either 200 g lactose or 200 g sucrose/kg in an all-meat diet and of age on the β-galactosidase and β-fructofuranosidase activities of the small intestine of weanling kittens were measured.

5. Adult cats efficiently (> 0.94) digested all six individual carbohydrates added to the diet with the exception of cellulose, which was indigestible. The digestibility coefficients of glucose, sucrose and lactose were significantly (P< 0.01) greater than that of starch. The inclusion of lactose caused diarrhoea in some cats and significantly (P< 0.01) reduced apparent digestibility of crude protein (nitrogen × 6.25) in the total ration.

6. Fine grinding significantly enhanced the digestion of starch in wheat and maize grain, but the effect was greatest for maize grain. Cooking had a similar effect to fine grinding for wheat grain, but an effect intermediate between coarse and fine grinding for maize grain.

7. Intestinal β-galactosidase activity decreased with age in kittens (71-106 d). Neither β-fructofuranosidase nor β-galactosidase activities were significantly affected by the addition of sucrose and lactose to the all-meat diet.
Human protein requirements: evaluation of the 1973 FAO/WHO safe level of protein intake for young men at high energy intakes
Authors: Garza C. , Scrimshaw N. S. , Young V. R.
Published: May 2005

1. Six Caucasian male Massachusetts Institute of Technology students participated in a 77–87 d metabolic balance study to determine the adequacy of the 1973 FAO/WHO egg protein allowance for men (0.57 g/kg body-weight per d). Each subject was given an initial energy allowance calculated to meet his particular requirements, and these intakes were raised by increments of 10% approximately every 2 weeks until a slightly positive balance was achieved. Each individual's energy intake was maintained at this final level for the remainder of the study.

2. At energy intakes sufficient to meet their estimated requirements, five of six subjects were in negative nitrogen balance. In five subjects, N balance improved with increased energy intake until N balance was achieved. The mean change in N balance was 0.335 mg N/additional kJ consumed. All of the subjects gained weight at the higher energy intakes.

3. Serum aspartate aminotransferase and alanine aminotransferase activities increased with continued intake of the experimental diet and reached abnormal levels in five of the six subjects. In the two subjects showing the earliest increases in serum transferase activity, the levels returned towards normal when protein intake was raised to 0.73–1.0 g/kg body-weight per d. All subjects showed normal serum transferase values on an ad lib. diet 2–3 weeks after termination of the study.

4. The findings indicate that at energy intakes necessary to bring subjects into slightly positive N balance at the level of 0.57 g egg protein/kg per d, a significant proportion of young adults continue to gain weight for as long as 70 d.

5. These findings suggest that the 1973 FAO/WHO safe allowance of 0.57 g egg protein/kg per d is not sufficient for most healthy young men receiving dietary energy intakes appropriate for long-term maintenance of body-weight.
Increased thirst and hunger in adult rats undernourished as infants: an alternative explanation
Authors: Smart J. L. , Dobbing J.
Published: May 2005

1. Rats were undernourished in early life by feeding their mothers a restricted quantity of a good-quality diet throughout lactation. Their undernutrition continued postweaning from 25 to 42 d of age, after which they were fed ad lib. Control rats were well nourished at all times.

2. Behavioural assessment of thirst was carried out on adult males. These were deprived of water for 23 h/d throughout the period of testing. Compared to control rats, previously-undernourished (PU) rats pressed a lever at a higher rate in a Skinner box to gain a water reward, drank more frequently during their first 5 min in an unfamiliar cage, and tended to run more quickly down an alleyway for water. PU rats also drank more (/kg body-weighta0.75) of a quinine solution (1 g/l) when this was available to them ad lib. as their only source of fluid.

3. A second group of rats was growth-retarded during gestation and the suckling and early postweaning periods. The rats had free access to food from 42 d of age. In adulthood their ad lib. food and water consumption was measured. PU males ate and drank more (/kg body-weight0.75) than control males.

4. These results indicate that adult rats which have been undernourished in early life display increased thirst. An attempt is made to explain this finding, together with their previously-demonstrated enhanced hunger drive, purely in terms of gross anatomical and physiological differences.
Effects of diet on the protozoa population in permeable continuous cultures of rumen contents
Authors: Abe M. , Iriki T.
Published: May 2005

1. Responses of the protozoa population to the composition and the components of the diet were studied in permeable continuous cultures of rumen contents.

2. In Expt I a study was made of responses to diets containing different combinations of rice straw, lucerne meal and mixed concentrates given to the cow supplying inocula for cultures. It was found that (1) when a diet devoid of concentrates was fed, entodiniomorphs decreased in numbers; (2) their numbers increased with the increase in the amount of concentrates; (3) holotrich numbers were hardly affected by the type of diet; (4) rice straw and lucerne meal were not essential for protozoa to survive in culture medium.

3. In Expt 2 responses were determined to diets containing different combinations of maize, maize starch, sugars (glucose-sucrose (1:1, w/w)), soya-bean meal and isolated soya-bean protein. The results suggested the following relationship between dietary component and protozoa population. (1) The diet rich in both starch and sugars sustains the increased numbers of protozoa on the whole. (2) The diet rich in starch and deficient in sugars decreases selectively Dasytricha and small species of Entodinium such asEntodinium minimumandE. nanellum.The other species of protozoa, especially large entodiniomorphs such as Ophryo-scolex and Polyplastron, are maintained at relatively high levels. (3) The diet deficient in starch and abundant in sugars decreases general entodiniomorphs except small species, while the numbers of Holotrichs are kept at relatively high levels.
The similarity between alkaline phosphatase (EC 3.1.3.1) and phytase (EC 3.1.3.8) activities in rat intestine and their importance in phytate-induced zinc deficiency
Authors: Davies N. T. , Flett A. A.
Published: May 2005

1. The activities of alkaline phosphatase (EC 3.1.3.1) and phytase (EC3.1.3.8) were similarly distributed in the small intestine of rats. Regional differences in activity were reflected by similar differences in the capacity of ligated intestinal segments to hydrolyse phytate in vivo. Activities were greatest in the duodenum and lowest in the terminal ileum.

2. Specific activities of both enzymes were tenfold greater in the brush border fraction of duodenal mucosa compared with entire mucosal homogenates.

3. Brush-border alkaline phosphatase and phytase activities required both magnesium and zinc ions for maximal activity.

4. Zn deficiency induced by feeding a diet low in Zn (0.5 mg Zn/kg) caused similar reductions in activity of both enzymes.

5. Zn deficiency induced by feeding diets marginally adequate in Zn (12 mg/kg) and phytate (10g/kg) caused reductions in alkaline phosphatase, phytase activities and phytate hydrolysis in vivo.

6. It is suggested that phytase activity is a manifestation of alkaline phosphatase and the significance of this in relation to phytate-induced Zn deficiency is discussed.
Effects of dietary molybdenum and sulphur on the distribution of copper in plasma and kidneys of sheep
Authors: Bremner I. , Young B. W.
Published: May 2005

1. A 30-week study has been made in growing ewe lambs of the effects of dietary supplementation with molybdenum, or Mo plus inorganic sulphate on the distribution of copper in their blood plasma and kidneys.

2. The addition of 25 mg Mo and 5 g SO42-/kg diet increased Cu concentrations in plasma and kidney and decreased those in liver. Plasma caeruloplasmin activities (ferroxidase; EC 1.16.3.1) were unaffected.

3. Subcellular fractionation of the kidney cortex and gel filtration of the plasma and kidney cortex cytosol showed that the increased Cu content of these tissues was associated with abnormalities in the distribution of Cu. It appeared that both Cu and Mo were associated with the same proteins.

4. Dietary supplementation with Mo alone (25 mg/kg) had no effect on plasma or kidney Cu concentrations, suggesting that S metabolism is involved in the formation of the abnormal Cu-binding proteins in plasma and kidney.

5. The results are discussed in relation to the induction of Mo-induced Cu-deficiency states and the possible involvement of thiomolybdates.
Methane production in the rumen and lower gut of sheep given lucerne chaff: effect of level of intake
Authors: Murray R. M. , Bryant A. M. , Leng R. A.
Published: May 2005

1. Methane production rates were estimated simultaneously in the rumen and caecum of sheep given 200, 400, 600, 800 and 1000 g lucerne (Medicago sativa) chaff/d using isotope dilution techniques. Estimates were also made of volatile fatty acid (VFA) production in the rumen at each level of feeding. In all studies three to four animals were used at each level of intake.

2. Production of VFA and of methane were both related to digestible energy (de) intake. Regression lines for both VFA production and methane productionv.deintake had significant intercepts indicating an input of endogenous, fermentable organic matter into the rumen in excess of 50 g/d.

3. The values obtained for rates of methane production were compared with those calculated from stoicheiometric equations relating rates of methane and VFA production. Comparisons of methane production with that predicted fromdeintake were also made.

4. Balances for digestion of food determined for the rumen indicated that the energies in the end-products were more than 100% of thedeintakes at low intakes of lucerne chaff. Correction for fermentation of apparent endogenous materials resulted in more realistic values. Endogenous materials appeared to make a significant contribution to VFA and methane production, particularly at low levels of intake.
Fat-free body mass from skinfold thickness: a close relationship with total body nitrogen
Authors: Hill G. L. , Bradley J. A. , Collins J. P. , McCarthy I. , Oxby C. B. , Burkinshaw L.
Published: May 2005

Fat-free body mass is an important component of body composition which is of particular interest to nutritionists and related workers. Fat-free mass has been determined from the simple measurement of skinfold thickness and it has been demonstrated that there is a close correlation with total body nitrogen even though the test subjects had a wide range of nutritional status.
The energy content of rat carcasses prepared for analysis by different methods
Authors: Leppington Irene M. , Djoleto-Nattey E. , Wheeler Erica F.
Published: May 2005

The effect of oven-drying on the gross energy content of rat carcasses was investigated. No losses of carcass energy could be ascribed to oven-drying per se.
Calcium digestibility in cows as influenced by the excess of alkaline ions over stable acid ions in their diets
Authors: Lomba F. , Chauvaux G. , Teller E. , Lengele L. , Bienfet V.
Published: May 2005

1. Statistical analyses were carried out on results obtained under strictly-controlled conditions in metabolism stalls with forty-one different rations fed to 127 adult non-pregnant dry cows, and with fourteen other different rations fed to thirty-five adult non-pregnant lactating cows that had calved 2–6 months earlier and whose daily milk production ranged from 11 to 20 kg.

2. Correlations between calcium digestibility and values for the sum of the alkaline ions sodium and potassium minus the sum of the stable acid ions chloride, sulphate and phosphate were calculated for all fifty-five experimental diets.

3. The results showed that the excess of the anions over the cations, in rations maintaining a positive Ca balance but not in rations allowing a negative Ca balance, increases the absorption of Ca from the intestine. Phosphorus, not alone but with chloride and sulphate, is the most important component of this effect.
A human calorimeter for the direct and indirect measurement of 24 h energy expenditure
Authors: Dauncey M. J. , Murgatroyd P. R. , Cole T. J.
Published: May 2005

1. A calorimeter for the continuous measurement of heat production and heat loss in the human subject, for at least 24 h, is described. The calorimeter operated on the heat-sink principle for direct calorimetry and an open-circuit system for indirect calorimetry.

2. Sensible heat loss was measured using a water-cooled heat exchanger, and the temperature of water entering the heat exchanger was controlled to maintain a mean temperature gradient of zero across the chamber walls.

3. Evaporative heat loss was determined from ingoing and outgoing wet-and-dry bulb temperatures and air flow-rates.

4. Problems associated with the calculation of evaporative heat loss and the estimation of the volume of incoming air in open-circuit systems are considered.

5. The calibration, limits of accuracy, sources of error and experiments with subjects are discussed.
Necessity of vitamin B12for growth of rats fed on an odd- or even-carbon-number fat
Authors: Bitman J. , Weyant Joan R. , Wood D. L. , Wrenn T. R.
Published: May 2005

1. The effect of vitamin B12on growth was studied in young male and female rats fed on diets sufficient (+B12) or deficient (−B12) in vitamin B12containing 30% of the dietary energy as fat, either maize oil (CO) or triundecanoin (TUD).

2. Vitamin B12deficiency severely depressed growth. After 6 weeks the weight gain of CO(−B12) rats was only 72% of that of CO(+B12) rats and the gain of TUD(−B12) rats was only 47% of TUD(+B12) rats.

3. After fasting 24 or 96 h TUD-fed rats, both + B12and −B12, had greater glycogen reserves and higher plasma glucose levels than CO-fed rats.

4. It is concluded that vitamin B12is required for the metabolism and utilization of both an odd-carbon-number medium-chain fat, TUD, and an even-C-number long-chain fat, CO, during growth in rats.
Copper, manganese, zinc, nickel, cadmium and lead in human foetal tissues
Authors: Casey Clare E. , Robinson Marion F.
Published: May 2005

1. Concentrations of copper, manganese, zinc, nickel, cadmium and lead were measured in samples of liver, kidney, brain, heart, lung, skeletal muscle and vertebral bone from forty foetuses of 22–43 weeks gestation.

2. Cu concentrations in the liver were up to 100 times those in other tissues, but only those in the brain showed a significant increase with gestational age.

3. Mn concentrations were similar in all tissues; the over-all range was 0.35–9.27 μg/g dry matter (dm).

4. Concentrations of Zn in the liver were much higher than in other tissues and decreased with gestational age, whereas levels in skeletal muscle increased.

5. In all tissues Ni concentrations were within the range 0.04–2.8 μg/gdmand levels in kidney and muscle decreased significantly with age.

6. Cd was detected in most of the tissue samples and concentrations were within the range 0.01–0.58μg/gdm.

7. Concentrations of Pb, where it was detected, varied from 0.1 to 2.4 μg/gdmin the soft tissues and from 0.4 to 4.3 μg/gdmin the bone samples.
The effect of simulated altitude on the heat increment of feed in sheep
Authors: Blaxter K. L.
Published: May 2005

1. Sheep given constant feed were exposed to environments in which the oxygen concentration in air was either 200 or 150 ml/l. There were no differences in daily heat production, methane production, urinary energy or faecal energy losses measured over periods of 4 d.

2. When the sheep were fasted there were no differences in heat production to be ascribed to the O2 concentration in air. The thermic response to feed was unaffected by the O2 concentration in the air.
Haematological studies on vegans
Authors: Sanders T. A. B. , Ellis F. R. , Dickerson J. W. T.
Published: May 2005

1. The concentrations of vitamin B12 and folate in the serum and folate in the erythrocytes were determined and full blood counts made on a series of caucasian vegans and omnivore controls.

2. The blood counts and films were normal in all the vegans and no subject had a haemoglobin concentration below the lower limit of normality.

3. Although within the normal range, male but not female vegans had lower values for erythrocyte counts and higher values for mean corpuscular volume and mean corpuscular haemoglobin than their controls regardless of whether they were taking vitamin B12 supplements or not.

4. The mean serum vitamin B12 concentration was lower in the vegans not taking vitamin B12 supplements and in those using foods supplemented with the vitamin than in the controls, but in no subject was it below 80 ng/l.

5. The serum folate concentrations were higher in the vegans than in their controls. The mean value for erythrocyte folate tended to be greater in the vegans not taking vitamin B12 supplements. No subject had an erythrocyte folate concentration of less than 100μg/l.

6. It is concluded that megaloblastic anaemia is very rare in caucasian vegans and that a diet consisting entirely of plant foods is generally adequate to promote normal blood formation providing it is composed of a mixture of unrefined cereals, pulses, nuts, fruit and vegetables and is supplemented with vitamin B12.
The effects on chicks of dietary fibre from different sources: a growth factor in wheat bran
Authors: Hegde S. N. , Rolls B. A. , Turvey A. , Coates Marie E.
Published: May 2005

1. Groups of chicks were given a low-residue diet with or without supplements of dietary fibre in the form of wheat bran, wheat straw or bagasse. Growth and food conversion efficiency (g weight gained/g food eaten; FCE) during the first 4 weeks of life were measured.

2. In every one of seven experiments supplementation of the diet with 100 g wheat bran/kg resulted in improved growth, and in three experiments FCE was also increased.

3. Supplementation with coarsely-milled wheat straw to provide an amount of unavailable carbohydrate equivalent to that in the bran diet resulted in poorer growth; finely-milled wheat straw had little effect on growth.

4. The growth-promoting effect of bran was destroyed by sterilization with heat or gamma-radiation.

5. In some experiments weights, lengths and volumes of small intestines were measured. Differences in intestinal dimensions between birds given the diet with and without fibre were not consistent, nor were they correlated with growth rate or FCE.

6. Histometric observations on small intestines from a few birds indicated that those given coarse wheat straw had longer villi and thicker muscularis layers, and the caecal tonsils had a greater area of lymphoid tissue and more follicles.
Gastric secretion in suckling pigs and early-weaned pigs given a dry cow's-milk formulaad lib.
Authors: Decuypere J. A. , Bossuyt R. , Henderickx H. K.
Published: May 2005

1. Twelve gastric-cannulated litter-mate pigs were used to study secretion and proteolytic activity in the stomach of suckling and early-weaned pigs in relation to age and food intake.

2. Results demonstrate that from the first observation at day 8, piglets were able to secrete acid. pH and acid concentration did not change during the first 4 weeks of life.

3. Proteolytic activity was low during the first 2–3 weeks of life and rapidly increased thereafter.

4. Two phenomena differentiated suckling pigs from pigs given dry cow's milk: (1) a low buffering capacity the gastric contents, beginning 1 h after feeding the dry cow's-milk formula, results in a low total acid concentration in the weaned pigs and (2) the increase in proteolytic activity in relation to the age is much more pronounced in the artificially-reared pigs.

5. These two phenomena are discussed and related to the formation of a hard casein clot in the stomach of the cow's-milk-fed pigs, which has a long retention time and stimulates gastrin release.
The effect of dihomo-γ-linolenic acid (20: 3,n-6) on the composition of phospholipid fatty acids in the liver of rats deficient in essential fatty acids
Authors: Hassam A. G. , Crawford M. A.
Published: May 2005

1. Rats were fed on either a diet deficient in essential fatty acid (EFA) or one supplemented with dihomo-γ-linolenic acid (20:3,n-6) at levels that represented 0.25, 0.5, 1.0 and 2.0% of the dietary energy.

2. Supplementation of the diet of EFA-deficient animals with 20:3,n-6 reversed most of the fatty acid changes induced in the liver phospholipid fraction.

3. The EFA potency of 20:3,n-6 was found to be similar to that of γ-linolenic acid (18:3,n-6) which has been shown to be higher than that of linoleic acid (18:2,n-6).
The effects of plane of nutrition and environmental temperature on the energy metabolism of the growing pig
Authors: Close W. H. , Mount L. E. , Brown D.
Published: May 2005

1. Measurements of energy and nitrogen balances were made on thirty-eight individually housed pigs (initial body-weights 21–38 kg) at environmental temperatures of 10, 15, 20, 25 and 30° with four levels of feeding at each temperature. Values for energy retention (ER), protein (P) and fat (F) deposition and body weight gain (δW) were calculated at each temperature at metabolizable energy (me) intakes equivalent to once (M; 440 kJ/kg0.75 per d), twice (2M), three (3M) and four (4M) times the thermoneutral maintenance energy requirement.

2. ER at each plane of nutrition increased with temperature to maximal values between approximately 20 and 25° ER was negative at four of the five environmental temperatures at M.

3. P increased significantly with increase in me intake but was dependent on environmental temperatures only at intakes of M and 2M. The increase in P per unit increment in me intake decreased from 0.16 at 10° to 0.12 at 30°. The net efficiency of protein utilization also decreased with increase in environmental temperature from 0.54 at 10° to 0.39 at 30°.

4. F increased significantly with increase in me intake, but was more temperature-dependent than P, increasing to maximum values estimated to be between 20 and 25° at each level of intake; F at 30° was less than that at 25°. The increase in F per unit increment in me intake decreased from 0.63 at 10° to 0.51 at 30°.

5. The optimum temperature for ΔW was dependent upon me intake, varying from above 30° at M to less than 20° at 4M. The reduction in ΔW per 1° at 15° was also dependent upon the level of intake decreasing from 1.63 g/kg0.75 per d at M to -0.09 at 4M.

6. For a 35 kg pig the reduction in P, as a result of a 1° decrease in temperature at 15° at an intake corresponding to 2.5M, was equivalent to a 4 g/d reduction in food intake; the corresponding equivalent for F was 28 g/d.
Absorption of magnesium by the young steer
Authors: Horn Jane P. , Smith R. H.
Published: May 2005

1. Steers with rumen and simple duodenal cannulas were allowed to graze pasture or were given diets of dried grass or flaked maize with or without hay. For an experiment a solution or suspension of magnesium chloride, polyethylene glycol (molecular weight 4000) and either 144Ce (as cerous chloride) or chromic oxide was added to the rumen with a morning feed. Conditions in the rumen were sometimes modified by adding sodium chloride or hydrochloric acid.

2. Changes in magnesium: marker in samples of strained rumen contents with time interval after adding the dose were due partly to changes in Mg distribution between different phases. Results indicated, but not unequivocably, that negligible amounts of Mg were absorbed in the first few hours.

3. Relative recoveries of Mg and markers at the duodenum indicated that proportions of Mg intake absorbed (net) varied from approximately zero for pasture to 0.2–0.5 for flaked maize. Significant correlations between absorption efficiency and sodium: potassium in rumen contents (positive) and rumen pH (negative) were observed.

4. Steers with simple duodenal and re-entrant ileal cannulas were given a diet of flaked maize and hay supplemented with different amounts of magnesium oxide. Little net change in Mg relative to an unabsorbed marker was found between these sites even for a diet containing an Mg supplement of 8 g/kg dry matter.
Subcutaneous fat accumulation during pregnancy in a malnourished population
Authors: A P. , GarcÍa Deyanira , Llerena C. , Quiroz Sara E.
Published: May 2005

1. Total skinfold thicknesses (sum of seven sites) were measured in fifty-seven pregnant women with low energy and protein intake, at weeks 24, 30 and 35 of gestation.

2. Women were classified in two groups (overweight and low weight), according to their weight-for-height at week 24 of gestation.

3. Half of the women did not increase, or even reduced the amount of subcutaneous fat during the observation period. The lowest mean value of total skinfold thickness was found in the low-weight women who showed a reduction of the subcutaneous fat.

4. This finding shows that a significant proportion of malnourished women do not follow the average pattern of subcutaneous fat accumulation seen in healthy pregnant women without food intake restriction, during the second half of pregnancy.
Behaviour, brain and body growth of guinea-pigs after prenatal growth restriction
Authors: Byrne Elizabeth A. , Smart J. L. , Dobbing J. , Sands Jean
Published: May 2005

1. Guinea-pigs were growth-retarded in early life by feeding their mothers a restricted quantity of food during the second half of pregnancy. After birth, all animals were fedad lib.Body-weights were recorded weekly and behavioural tests were made on adult males. The animals were then killed and their brains dissected into forebrain, cerebellum and brain stem. These regions were weighed and DNA-phorphorus content measured.

2. At 14 weeks each male was paired with another male for 10 min on four consecutive days and their social behaviour scored. Tests 1 and 2 were on like-treatment pairs and tests 3 and 4 on unlike-treatment pairs. At 25 weeks the same animals were subjected to six graded series of brief, unavoidable shocks and their responses recorded. After 3 d, thresholds of aversion to electric shock were measured by recording the period of time spent on the ‘safe’ side of a rectangular box at five shock levels.

3. Undernourished guinea-pigs were significantly lighter than controls at birth but not at adulthood. Regional brain weights and DNA-P content of previously-undernourished guinea-pigs were significantly lower than those of controls, with the greatest deficit in brain stem.

4. Pairs of previously-undernourished guinea-pigs began to interact more quickly and threatened and nosed each other more often than pairs of controls. In mixed pairs previously-undernourished animals chased controls more than their control partners chased them. There were no differences between groups in responsiveness to unavoidable shock or in aversion thresholds.
The influence of a maternal diet rich in linoleic acid on brain and retinal docosahexaenoic acid in the rat
Authors: Sanders T. A. B. , Mistry M. , Naismith D. J.
Published: May 2005

1. Female rats were given throughout pregnancy and lactation a semi-synthetic diet, in which the fat was provided entirely by a soft margarine rich in linoleic acid (18:2ω6) or by mixture of butter and lard, and the influence on the fatty acid composition of fetal and pup brain and retinal phosphoglycerides was studied.

2. The percentage of docosahexaenoic acid (22:6ω3) was much lower but that of docosapentaenoic acid (22:5ω6) was correspondingly higher in the brains of the day-22 fetuses and the 21-d-old pups from the margarine group compared with those from the group given the animal fats. Similar changes were noted in the synaptosomal and retinal phosphoglycerides, being most marked in the ethanolamine phosphoglycerides.

3. The remaining pups from two groups were weaned on day 21 post partum on to the same stock diet that contained preformed 22:6ω3. After 9 weeks of this diet, the differences between the two groups in the fatty acid composition of the brain phosphoglycerides were barely discernible. The percentage of 22:5ω6 had decreased and had been replaced by 22:6ω3.

4. It is concluded that the consequences of consuming a diet rich in linoleic acid and almost devoid of 22:6ω3 on brain fatty acid composition deserve consideration in man.
Intestinal radiocalcium absorption in the goat: measurement by a double-isotope technique
Authors: Hove Knut
Published: May 2005

1. Intestinal radiocalcium absorption was measured in goats by a double-isotope technique involving injection of45CaCl2intravenously and47CaCl2into the abomasum. Cumulative absorption of radiocalcium was calculated by deconvolution analysis form curves of plasma radioactivity.

2. Repeated measurements at 2 d intervals gave highly reproducible results (r0.94,P< 0.001). No systematic difference between two consecutive measurements was observed. A good agreement between absorption of radiocalcium from simultaneously administered47CaCl2and45Ca-labelled hay (r0.93,P< 0.001) seems to justify the use of inorganic47Ca as a tracer for Ca in ruminant diets.

3. Two- to three-fold increases in radiocalcium absorption 48 h after oral treatment with 1,25- dihydroxycholecalciferol or leaves ofSolanum malacoxylonshowed the usefulness of the method in situations of rapidly changing Ca absorption.

4. Endogenous adaptations in intestinal radiocalcium absorption from 20 to 43% were observed in lactating goats when Ca intakes decreased from 12 to 4 g/d.

5. It is concluded that the double-isotope technique is a suitable method for studies of Ca absorption in ruminants when tracer is introduced into the abomasum. The test is completed in 3–4 h and may therefore be used in situations where the absorption of Ca undergoes rapid changes.
Influence of dietary phosphorus and sulphaguanidine levels on P utilization in rats
Authors: Moore Robert J. , Reeves Philip G. , Veum Trygve L.
Published: May 2005

1. The effects of dietary phosphorus and sulphaguanidine levels, and sex differences on: (a) phytate digestibility, (b) calcium and P utilization, (c) the activities of alkaline phosphatase (EC3.1.3.1), alkaline phytase (EC3.1.3.8) and acid phosphatase (EC3.1.3.2) in the intestinal mucosa of male and female rats were investigated.

2. There was a linear increase in femur ash, Ca and P contents and the maximum force withstood by the fresh femurs as dietary P level was increased from 1.5 to 3.0 to 4.5 g/kg diet.

3. The apparent digestibilities of Ca, P and phytate-P decreased as the level of P in the diet increased. Rats given the diets with 1.5 or 3.0 g P/kg were hypercalciuric and hypophosphaturic compared with rats receiving 4.5 g P/kg diet.

4. The level of Ca retained was similar for all treatments. The level of P retained increased as the dietary P level increased. This suggests that P deprivation was a result of inadequate amounts of P retained and not due to the absorption of inositol phosphates formed during the enzymic hydrolysis of phytate.

5. The addition of sulphaguanidine increased phytate digestibility without changing the activities of acid and alkaline phosphatase or alkaline phytase of the intestinal mucosa. This suggests that these enzymes did not play a role in the increase in phytate digestibility. However, dietary sulphaguanidine enhanced phytate digestibility, suggesting that alterations in the diet which modify either the composition or metabolism of the gastrointestinal microflora may be beneficial in enhancing the in vivo hydrolysis of phytate.

6. Differences between males and females are reported and discussed.
The zinc requirements of broiler chicks and turkey poults fed on purified diets
Authors: Dewar W. A. , Downie J. N.
Published: May 2005

1. Chicks and turkey poults were fed for 3 weeks on low-zinc diets, prepared from purified ingredients, supplemented with zinc oxide at graded levels.

2. Birds of both species given the unsupplemented basal diets grew poorly, with high mortality rates. All had severe hyperkeratosis but bone development was normal. Only when birds received diets with low concentrations of added Zn were leg abnormalities observed.

3. Zn requirements were assessed visually from dose-response graphs. The chick required 18 mg Zn/kg diet for maximal live weight and 24 mg Zn/kg for maximal Zn concentration in blood serum. The responses of tibial Zn and net retention of Zn did not reach plateaux within the range of dietary Zn concentrations studied. The turkey poult's Zn requirement for maximal live weight was 25 and 28–29 mg/kg for net retention of Zn and for maximal concentration of Zn in blood plasma and in the tibia; 41 mg Zn/kg diet was required for maximal Zn in blood serum.

4. Liver Zn was not correlated with dietary Zn in either species.
The role of condensed tannins in the nutritional value of Lotus pedunculatus for sheep
Authors: Barry T. N. , Manley T. R.
Published: May 2005

1. Primary growth vegetativeLotus pedunculatuscontaining 46 and 106 g/kg dry matter (DM) of total condensed tannin and 3 and 14 g/kg DM of free condensed tannin, was cut and fed fresh at hourly intervals (750 g DM/d) to sheep fitted with permanent cannulas into the rumen and duodenum. Low- and high-tannin lotus contained respectively 41.3 and 31.6 g total nitrogen/kg DM and 132 and 152 g lignin/kg DM. The two forms of lotus were similar in carbohydrate composition.

2. Nutrient intake was recorded and faecal output measured by direct collection. Digesta flow to the duodenum was estimated by measuring dilution at the duodenum of inert ruthenium phenanthroline (Ru-P) and chromium-EDTA markers continuously infused into the rumen.

3. Effects attributable to condensed tannins were assessed by comparing the digestion of the two diets, and by comparing the digestion of each with predicted values for non-tannin-containing fresh forages fed at similar intakes.

4. Apparent digestibility of all nutrients measured was less for high- than for low-tannin lotus (P< 0.01). The levels of cellulose digested ruminally and post-ruminally in both forms of lotus were similar to predicted values. However, less hemicellulose and readily fermentable carbohydrate (RFC; soluble carbohydrate + pectin) was digested in the rumen in sheep given both forms of lotus than would be predicted for non-tannin-containing fresh forage diets, but this was compensated for by greater post-ruminal absorption of both nutrients.

5. Total N gains across the rumen (duodenal N flow – total N intake) were 1.8 and 10.5 g/d for low- and high-tannin lotusv.predicted losses of 3.7 and 2.1 g/d for non-tannin-containing fresh forages given at the same total N intakes. Post-ruminal digestion of non-amonia-N (NAN; proportion NAN flowing at duodenum) was 0.71 and 0.67 for low- and high-tannin lotus respectivelyv.0.76 for comparable non-tannin-containing fresh forages. Energy absorbed as amino acids from the small intestine was calculated to be 0.29 of metabolizable energy for both forms of lotus, compared with 0.17 and 0.21 for perennial ryegrass and white clover.

6. It was concluded that the presence of condensed tannins in lotus markedly increased post-ruminal NAN absorption compared with non-tannin-containing fresh forage diets, but depressed ruminal digestion of RFC and hemicellulose.
Protein utilization in the young steer: digestion and nitrogen retention of 15N-labelled rumen bacterial protein
Authors: Salter D. N. , Smith R. H.
Published: May 2005

1. 15N-labelled mixed rumen bacteria, obtained from a steer that had received [15N]urea in its diet, were disrupted ultrasonically and freed from nucleic acids and their degradation products. Samples were subjected to a simulated abomasal digestion with pepsin.

2. The digests were infused with a non-absorbable marker (polyethylene glycol) into the duodenum of four steers equipped with simple duodenal and re-entrant ileal cannulas and adapted to a diet of barley straw, flaked maize and urea. The outflow from the ileum was collected for 6–7 h. The mean value for the digestibility of 15N bacterial proteins in the small intestine was estimated to be 0.74.

3. [14C]urea was administered intravenously during the infusion of the 15N-labelled protein into the duodenum. Urine and faeces were collected for the next 48 h and the proportion of urea-N produced, that was excreted in the urine, estimated from urine 14C excretion. Total urea 15N production was estimated from this value and the amount of 15N excreted in the urine. The mean proportion of 15N absorbed that was deposited in body protein, 0.70, was calculated by difference. The over-all efficiency of utilization of 15N in the infused rumen bacterial protein was 0.52.

4. An approximate estimate of the mean rate of protein synthesis calculated from the data was 24 g/kg body-weight (W)0.75 per d and compared with an estimated net deposition of protein of 1.67 g/kg W0.75 per d.

5. The importance of these values in factorial schemes for estimating ruminant N requirements is discussed.
Stability of tryptophan during food processing and storage
Authors: Nielsen Henrik K. , Klein A. , Hurrell R. F.
Published: May 2005

1. Tryptophan losses in stored milk powders and in different model systems representing the major reactions of food proteins during processing and storage were determined using four different chemical methods and in a rat assay.

2. Similar tryptophan values were obtained by the three chemical methods which included high pressure liquid chromatography (HPLC) after sodium hydroxide hydrolysis. colorimetric reaction withp-dimethylamino- benzaldehyde (p-DAB) after barium hydroxide hydrolysis, and fluorescence of the Norharman derivative after NaOH hydrolysis.

3. Tryptophan losses in the treated proteins as measured by the alkaline-hydrolysis methods were generally smaller than those determined by the rat assay. Good agreement however was obtained when the chemical value was multiplied by the true nitrogen digestibility.

4. Determination of tryptophan by reaction withp-DAB after papain (EC 3.4.22.2) digestion gave lower values in the processed proteins than the other chemical methods or the rat assay.

5. A method using alkaline-hydrolysis is recommended, preferably combined with HPLC-measurement of the liberated tryptophan.
Increase in the ileal absorption rate of sodium taurocholate in germ-free or conventional rats given an amylomaize-starch diet
Authors: Riottot M. , Sacquet E.
Published: May 2005

1. Twenty germ-free and twenty conventional male Fischer 344 rats, 3 months old, were fed ad lib. diets based either on normal or on amylomaize starch for 1 month. The absorption rate of sodium taurocholate. 25 mmol/l, was determined in vivo in jejunal or ileal segments. Each determination included five rats.

2. Jejunal absorption rate was not modified either by the amylomaize-based diet or by the digestive microflora.

3. Ileal absorption rate was slightly higher in germ-free than in conventional rats.

4. Ileal absorption rate was largely increased by the amylomaize-based diet. This increase was slightly larger in germ-free rats than in conventional rats.

5. It is suggested that dietary amylomaize starch has an action on the active absorption process of bile acid.
The effect of lumen conditions on oxygen uptake in perfused omasal laminae
Authors: Lozeman F. J. , Milligan L. P.
Published: May 2005

1. The vascular anatomy of the bovine omasal lamina permitted perfusion of a discrete area of the tissue. As occurs in vivo, oxygen was provided through the vascular system, while the luminal sides of the tissue could be kept in an anaerobic environment, thus allowing study of foregut tissue metabolism under physiologically realistic conditions.

2. O2consumption of perfused leaves in the presence of anaerobic buffer was 64.9 and 73.5 nmol O2/mg dry weight per h in Expts 1 and 2 respectively, and was elevated (P< 0.05) when the lumen side of the tissue was exposed to an atmosphere of nitrogen gas.

3. In Expt 1, the rate of O2consumption was increased (P< 0.01) by 35% as a result of suspension of a boiled preparation of rumen micro-organisms and particles (< 1 mm) in the anaerobic lumen buffer. Replacement of the boiled preparation with an unboiled suspension increased O2consumption further by 11 %, but this was not statistically significant (P> 0.05).

4. In Expt 2, sequential addition of the following substrates or preparations to the lumen chambers all resulted in stepwise increases (P< 0.05) in O2consumption; 8 mM-butyrate, boiled rumen micro-organisms and particles and, finally, unboiled rumen micro-organisms and particles.

5. Identities of the heat-labile and heat-stable components of the microbial and particle suspensions that caused enhancement of O2removal across the perfused tissue are discussed.
Performance of dairy cows offered isonitrogenous diets containing urea or fishmeal in early and in mid-lactation
Authors: Oldham J. D. , Napper D. J. , Smith T. , Fulford Rosemary J.
Published: May 2005

1. Sixteen Friesian cows were used in Expt 1 to measure the effect of substituting urea-N with fishmeal-N either in early lactation (Part 1) or in mid-lactation (Part 2).

2. In Part 1 (days 15–84 of lactation) the major N constituent of the concentrate was urea (U), urea-N: fishmeal-N in the ratio 2:1 (UF) or 1:2 (FU), or fishmeal (F). In Part 2 (days 84–1 75 of lactation) only urea (UM) and fishmeal (FM) were used.

3. Replacement of urea-N with fishmeal-N significantly (P < 0.05) increased yield of milk protein both in early and in mid-lactation. At both stages of lactation the cows were, by calculation, in positive energy balance. In mid-lactation replacement of urea-N by fishmeal-N significantly depressed (P < 0.001) the concentration of fat in milk.

4. Blood urea concentration decreased with increasing fishmeal inclusion (P < 0.05) from U to FU.

5. In Expt 2 the diets used in Expt 1, Part 1, were offered at a maintenance level of feeding to non-pregnant, non-lactating heifers in a 4 x 4 Latin square design experiment. Digestibility of dry matter, organic matter and cell-wall constituents increased progressively (P < 0.05) with the first two increments of fishmeal inclusion.

6. A major effect of replacing urea-N with fishmeal-N was to increase digestible organic matter intake (DOMI) and differences in DOMI between treatments in Expt 1, Part 1, accounted for observed differences in performance.
Effect of dietary protein concentration and ambient temperature on the energy, protein and water metabolism of the rat
Authors: Harri M. , Brockway J. M.
Published: May 2005

1. Groups of rats (n 8) were offered, to appetite, diets containing 10 (LP), 25 (MP) and 45 (HP)% of gross energy as protein energy from 45 d of age to slaughter 50 d later. At 53 d of age, half the rats on each diet were left at 22°while the other half were transferred to 6°. Water balances were measured daily, and digestibilities of energy and nitrogen and the metabolizability of the diets were measured for each rat over a 7 d period at some stage between the age of 74 and 95 d. The rats were slaughtered at day 95 and their carcasses were analysed for protein, lipid, energy and ash contents. Energy expenditure was calculated as the difference between metabolizable energy intake and energy retained.

2. Growth performance was best on the MP diet at both temperatures. At 22° the rate of gain of body-weight and of energy retention, although not of protein, were slightly reduced on the HP diet while overall performance was markedly inferior on the LP diet. At 6° the LP diet, while not so good as the MP diet, led to significantly better all-round growth performance than did the HP diet. Cold increased the energy expenditure of the rats by 50% (109–138 kJ/d); the increase was greater for the LP group than for the HP group.

3. Intrascapular brown adipose tissue hypertrophied in response to cold and to the LP diet.

4. Adrenal gland size was significantly increased by cold exposure and by increasing level of dietary protein concentration.

5. Urine volume was more closely related to the intake of protein than to that of energy. Urinary N concentration for the HP rats was approximately double that for those on the LP diet. Cold-exposed rats had a high water content in their fat-free carcasses, but there were no differences between the dietary treatments.