bluuebunny/crossref_metadata_2025_split huggingface dataset:
Movements of the stomach compartments of a young bull during sucking
Authors: Kay* R. N. B. , Ruckebusch Y. 
Published: May 2005

1. Gastric motility was studied in a young bull and two sheep which had retained their sucking behaviour. Pressure tracings or electromyograms were recorded from all compart-ments of the stomach.2. During the sucking of milk or water reticulum contractions either became more fre-quent but weak, or ceased altogether. After sucking, or after the introduction of fluid directly into the abomasum, reticulum contractions slowed down but retained their strength. The rumen and omasum were more fully inhibited than the reticulum.3. It is concluded that the inhibitory response to sucking has two phases, a cephalic phase dependent upon the eagerness of sucking which mainly influences the strength of the contractions of the forestomach, and an abomasal phase dependent on the degree of distension of the abomasum which mainly affects the frequency of the contractions.
The nutrition of the veal calf
Authors: Roy J. H. B. , Stobo I. J. F. , Gaston Helen J. , Ganderton P. , Shotton Susan M. , Thompson S. Y. 
Published: May 2005

1. Eighteen bull calves, comprising twelve Ayrshires, three Friesians and three Jerseys were reared from birth to a slaughter weight equivalent to 22 % of mature cow weight of the breed.2. All the calves were given a milk substitute diet ad lib. in two feeds daily. Six of the calves received this diet alone and the remaining twelve calves were offered roughage ad lib. from I week of age, either as meadow hay or as barley straw. The calf-house was maintained at a mean temperature of 23' and a mean relative humidity of 62 %.3. The mean total intake of meadow hay and barley straw over the experimental period of about 12 weeks was 3.0 kg and 0.4 kg respectively. Only three calves were consuming any meadow hay and only two calves any barley straw at 7 weeks of age.4. The roughage consumed had no effect on the incidence of diarrhoea, on dry-matter intake from milk or on live-weight gain. All the calves offered meadow hay had lung lesions at slaughter. Severity of lung lesions in the Jersey and Friesian calves combined, but not in the Ayrshires, tended to be inversely related to the relative humidity to which they were exposed.5. Dressed carcass weight and killing out percentage tended to be lower for the calves offered meadow hay. There was a highly significant inverse relationship between total intake of hay and killing out percentage. Perirenal fat depositionin relation to carcass weight was significantly lower and carotenoid content of the fat significantly higher for the calves offered the meadow hay. Skin weight per unit of slaughter weight 0.78 or carcass weight OJ* was significantly greater for the calves given the milk substitute diet only.6. It is concluded that the calf shows very little desire to eat roughage when given a good- quality milk substitute diet ad lib. and that, even when the amounts of roughage consumed are small, this has a deleterious effect on carcass quality.
Proposal to use time spent chewing as an index of the extent to which diets for ruminants possess the physical property of fibrousness characteristic of roughages
Authors: Balch C. C. 
Published: May 2005

1. Previous publications by the author and his colleagues have provided extensive records, and additional ruminating behaviour of cows receiving a wide range of diets. These recoreds, and additional unpublished records, have been used to justify a proposed index of the physical property of fibrousness, or roughage, in diets for ruminants.2. It is proposed that the total time spent by ruminants in chewing their food, during eating and during ruminating, should be the basis of the basis of the roughage index3. Experssion of the roughage index as total time spent chewing per kg dietary dry matter largely eliminates differences resulting from variation in the amount of food consumed, and differences resulting from the time of access to the food.4. Examples of the proposed roughasge index are given. The values range from 145 to 191 min/Kg dry matter for oat straw ot under 20 min/kg dry matter for diets of concentrates or of finely ground herbages; hays and silages tend to fall in the region of 90–110 min/kg dry matter. Values for the indx increase with dietary proportaions of hay or straw.
The retention of ascorbic acid by guinea-pig tissues
Authors: Hughes R. E. , Hurley R. J. , Jones P. R. 
Published: May 2005

1. Male and female guinea-pigs with high tissue concentrations of L-xyloascorbic acid (ascorbic acid, AA) and male guinea-pigs with high tissue concentrations of D-araboascorbic acid (isoascorbic acid, isoAA) were given a scorbutogenic diet and the rates of depletino from various tissues were measured fro both isomers.2. The loss of AA from the brain and eye lens was considerably less rapid than the loss from the adrenal glands, spleen and aqueous humour. After 14nd on the AA-free diet the AA concentrations in the brain and eye lens were 24 and 27% respectively of the initial concentrations; the corresponding values for the aqueous humour, adrenal glands and spleen were 3,4 and 5%. There was no apparent sex difference in the rate of loss of AA.3. The loss of isoAA was much more rapid than that of AA in the spleen, adrenal glands and aqueous humour; in the brain and eye lens the depletion patterns of the two isomers were similar.
The effect of tertiary branched-chain carboxylic acids on the energy metabolism of sheep
Authors: Clapperton J. L. , Czerkawski J. W. 
Published: May 2005

1. The introduction of certain tertiary branched-chain carboxylic acids into the rumen of sheep, either by continuous infusion or by direct incorporation of the acids in the concentrate food mixture, had no effect on the oxygen consumption or carbon dioxide production of the sheep. Methane production was depressed, the extent of the depression increasing with the molecular weight of the carboxylic acid.2. There was a small decrease in the apparent digestibility of the food and a small increase in urinary energy output.3. There was no significant increase in the metabolizable energy intake of the sheep. There was, however, a small increase in the amount of energy stored in the body. This small increase was about 84 % of the gross energy of the branched-chain acids added.4. It is concluded that any practical advantage to be gained from the addition of branched-chain carboxylic acids to the diet of ruminants remains unproven.
Body iron and its distribution between haem and non-haem fractions in the suckling rat
Authors: Leslie A. J. , Kaldor I. 
Published: May 2005

1. Total body iron and some of its subfractions, i.e. haem iron, non-haem iron and ferritin iron, as well as ferritin were measured in groups of newborn rats and of rats aged 4,15 and 24 d.2. Iron accumulated in the rats throughout suckling, with slightly more going into the haem than into the non-haem fraction.3. Per unit body-weight, haem iron was maintained well throughout the study period but total body iron and non-haem iron were both significantly diminished at 15 d.4. Within the non-haem fraction, ferritin iron was severely diminished at both 15 and 24 d, but the non-ferritin portion of non-haem iron was increased.5. The results were interpreted in terms of the relationship between the growth of body mass and the supply of iron to the young animal.
Digestion of concentrates in sheep
Authors: Ørskov E. R. , Fraser C. , McDonald I. 
Published: May 2005

1. The effect of the extent of ruminal fermentation of starch on the postruminal digestion of starch and protein was investigated in sheep, differences in rumen fermentation being obtained by giving diets based on barley, maize, or maize plus sodium chloride. The mean percentages of starch (α-linked glucose polymers) fermented in the rumen wert 91, 79 and 78 respectively with these diets, but there was considerable variability, particularly with the maize diets.2. When large amounts of starch escaped fermentation in the rumen, substantial quantities passed the terminal ileum and were mostly fermented in the large intestine; the greatest amount of starch found in the faeces was 2 % of intake.3. A decrease in the extent of rumen fermentation of starch was associated with a decrease in the concentration of crude protein and of diaminopimelic acid (DAPA) in the abomasal fluid, but there was no difference in quantity of crude protein disappearing from the small intestine. The concentration of DAPA was greater with the barley diet than with the maize diet, indicating that more dietary protein, originating from maize than from barley, escaped the rumen un-degraded. This conclusion was supported by a greater similarity between the amino acid composition of the abomasal fluid and the diet when maize was given.
Level of food intake and the passage of markers and nitrogen along the alimentary tract of sheep
Authors: Weller R. A. , Pilgrim A. F. , Gray F. V. , Taylor M. N. , Weller R. A. , Reid C. S. W. 
Published: May 2005

1. The relative rates of passage of polyethylene glycol (PEG) and lignin through the alimentary tracts of sheep were examined through the ratio of these two markers in the fodder and in the contents of various segments of the gut. A much faster turnover of PEG than of lignin in the stomach compartments suggested that samples from these organs could not be representative of the digesta flowing through them. Average PEG:lignin ratios in the small and large intestines were close to the ratio in the fodder, indicating that sampling from the duo-denum in the living animal could possibly yield material representative of that flowing from the stomach to the small intestine. Similar results were obtained for high and low levels of fodder intake.2. A procedure was developed for automatic sampling from the duodenum for prolonged periods, and the material collected was shown to be representative of digesta flow. Simpler methods of sampling from the duodenum were shown to be liable to relatively large errors.3. The amount of nitrogen reaching the duodenum in sheep given lucerne hay pellets was found to be equivalent to practically 100 % of the dietary N, whether the intake of fodder was 600 g/d or 1500 g/d.
Use of the constant infusion technique for measuring rates of protein synthesis in the New Zealand White rabbit
Authors: Nicholas G. A. , Lobley G. E. , Harris C. I. 
Published: May 2005

1.To study the potential of the constant-infusion technique for measuring rates of protein synthesis in New Zealand White rabbits, animals were infused for up to 6 h with radioactively-labelled tyrosine.2.Labelled tyrosine from plasma and tissues was isolated from labelled metabolites by ion-exchange chromatography.3.Analysis of serial blood and muscle biopsy samples removed under anaesthesia showed that the specific radioactivity (SR) of the free tyrosine pools reached an approximately constant value within 2 h.4.Certain commercial preparations of L-[side-chain 2,3-3H]tyrosine were contaminated with 300 mg radioactive D-tyrosine/g. The D-isomer appeared to enter the muscle intracellular pool.5.In constant-infusion experiments L-[3H]tyrosine could replace the uniformly-14C-labelled L-isomer for the determination of rates of protein synthesis in muscle. L-[side-chain 2,3-3H]tyrosine may not be suitable for use as a precursor for measuring rates of liver protein synthesis.6.Evidence is presented that the precursor of liver protein synthesis may not be well defined by the SR for free tyrosine of the homogenate.7.The technique was used to measure the rates of protein synthesis in adult rabbits. The rates of protein synthesis in liver and muscle were measured and from measurements of tyrosine flux the mean rate of whole-body protein synthesis was calculated as 13.8 g/kg per d.
Effect of dietary protein level on some key enzymes of the tryptophan-NAD pathway
Authors: Satyanarayana U. , Narasinga Rao B. S. 
Published: May 2005

1.Six groups of rats were given diets containing protein at three levels (SO, 100 and 200 g/kg), with and without nicotinic acid. After 4 weeks on these diets some key enzymes of the tryptophan and nicotinic acid-NAD pathway, liver nicotinamide nucleotide concentration, and urinary metabolites of tryptophan and nicotinic acid were studied.2.Liver nicotinamide nucleotide levels were lower in rats given the diet with 50 g protein/kg as compared to those in rats given diets with 100 and 200 g protein/kg. The addition of nicotinic acid to the diet resulted in a significant increase in the levels of nicotinamide nucleotides only in rats given 50 g protein/kg diet but not in those given either 100 or 200 g protein/kg diet.3.Liver tryptophan oxygenase (EC1.13.1.12) activity increased with increasing dietary protein level. Nicotinic acid in the diet had no effect on its activity.4.Quinolinate phosphoribosyltransferase (EC2.4.2.a) activity in liver was inversely related to dietary protein level, and nicotinic acid in the diet had no effect on its activity.5.Liver nicotinate phosphoribosyltransferase (EC2.4.2.11) activity and kidney picolinate carboxylase (EC4.1.1.45) activity were not altered either by dietary protein level or nicotinic acid in the diet.6.The addition of nicotinic acid to the diet resulted in increased excretion of W-methylnicotinamide at all dietary protein levels.7.The inverse relationship between protein level in the diet and liver quinolinate phosphoribosyltransferase activity, the rate-limiting enzyme of the tryptophan-NAD pathway suggests that the efficiency of conversion of tryptophan to NAD is related to protein level in the diet, the efficiency decreasing with an increase in the level of dietary protein.
The effect of dietary calcium on the activity of 25-hydroxycholecalciferol-l-hydroxylase and Ca absorption in vitamin D-replete chicks
Authors: Swaminathan R. , Sommerville Barbara A. , Care A. D. 
Published: May 2005

1.As most of the studies on the regulation of renal 25-hydroxycholecalciferol-1-hydroxylase (25-HCC-1-hydroxylase) activity have been done in marginally-vitamin D-defieient animals and as it is known that vitamin D administration suppresses the specific activity of the 25-HCC-1-hydroxylase, it was decided to study the effect of dietary calcium on the activity of 25-HCC-1-hydroxylase and on Ca absorption in vitamin Dreplete chicks.2.Chicks, 10 d old, were given diets differing in their Ca contents (65 nmol cholecalciferol/kg diet) for 10 d and the activity of 25-HCC-1-hydroxylase in kidney homogenates, Ca absorption from the duodenum, Cabinding protein (CaBP) activity in the duodenal mucosa and plasma Ca and phosphate concentrations were all determined.3.The CaBP activity and the efficiency of Ca absorption both decreased with increasing dietary intake of Ca. Ca absorption and CaBP activity were significantly correlated (r0.995,P< 0.01).4.The activity of 25-HCC-1-hydroxylase decreased as the dietary level of Ca increased and was significantly correlated with Ca absorption (r0.900, P < 005). The plasma Ca concentration and the activity of 25-HCC-1-hydroxylase were inversely related (r-0.940,P< 0.01).5.It is concluded that in the vitamin D-replete chick the efficiency of duodenal Ca absorption is regulated by the renal 25-HCC-1-hydroxylase activity via production of 1,25-dihydroxycholecalciferol and CaBP synthesis.
Distribution of copper and zinc in the liver of the developing sheep foetus
Authors: Bremner I. , Williams R. B. , Young B. W. 
Published: May 2005

1.A study has been made of the copper- and zinc-binding proteins in the livers from sheep foetuses of 80-142 d gestational age.2.Metallothionein was found to constitute the major Zn-binding component in the cytosol at all times and to be identical to Zn-thionein from adult sheep liver.3.Zn also occurred in two fractions, not normally found in sheep liver, with approximate molecular weights of 28000 and 47000. The relative proportions of these were age-dependent.4.Between 15 and 35 % of the hepatic Cu, corresponding to most of the Cu in the cytosol, also occurred in the metallothionein-containing fraction.
The effect of dietary copper sulphate on laying performance, nutrient intake and tissue copper and iron levels of the mature, laying, domestic fowl
Authors: Jackson N. 
Published: May 2005

1.A cereal-based diet containing 16 mg copper/kg was fed ad lib. to a group of laying hens for 35 d. Five other groups were given this control diet to which was added 120, 240, 480, 960 and 1920 mg Cu/kg (as copper sulphate).2.Records were kept of daily food intake, water intake and egg production.3.After 35 d the hens were slaughtered and blood haemoglobin, packed cell volume, Cu and aspartate aminotransferase (EC2.6.1.1) levels assayed. Liver, oviduct, kidney and breast muscle Cu and iron concentrations were measured.4.Food and water intakes were depressed by the two highest levels of dietary Cu and water intake was increased by the diet with 240 mg added Cu/kg. Both food and water intake showed a quadratic relationship with the level of added dietary Cu.5.Body-weight loss was increased by the addition of Cu and showed a significant linear relationship with the concentration of added Cu in the diet. Liver and oviduct weights were depressed at the two highest levels of Cu addition.6.Liver and oviduct Cu and Fe concentrations were significantly increased by high dietary Cu and mean total liver and kidney Cu and Fe showed an increase although for the liver this was not statistically significant.
Determination of rumen microbial growth in vitro from32P-labelled phosphate incorporation
Authors: Van Nevel C. J. , Demeyer D. I. 
Published: May 2005

1.The extracellular phosphate pool in incubations of rumen fluid or washed cell suspensions of mixed rumen bacteria (WCS) was labelled with32P. From the constant extracellular phosphate pool specific activity and the amount of radioactivity incorporated during incubation, the amount of P incorporated in the microbial fraction was calculated. From the value for nitrogen: P determined in microbial matter, the amount of N incorporated was calculated as a measure of microbial growth.2.Incorporation of soluble non-protein-N in incubations devoid of substrate protein was 50 and 80 % of the values obtained using the isotope method for rumen fluid and WCS respectively. It is suggested that results obtained using the former method reflect 'net growth' of micro-organisms which is the result of simultaneous growth and degradation. The isotope method measures 'total growth', as isotope incorporation is not affected by degradation of non-growing cells.3.Incorporation of32P in P-containing microbial components (mainly nucleic acids) was compared with net synthesis of these components in incubations of WCS. The results showed different specific rates of synthesis and degradation for all components studied. It is concluded that the composition of microbial matter changed during growth.4.When N incorporation, calculated from results obtained using the isotope method in incubations with rumen fluid, was compared with the amount of carbohydrate substrate fermented and the type of fermentation, values between 18.3 and 44.6 g N incorporated/kg of organic matter fermented were obtained. Low values were associated with large proportions of the substrate being fermented to lactate and the use of glucose instead of disaccharides as substrate. Part of the variation could also be attributed to differences in incubation period, reflected in different proportions of polysaccharide formed.5.The use of isotopes for determination of rumen microbial growth in vitro is critically discussed.
Reasons why hypoalbuminaemia may or may not appear in protein-energy malnutrition
Authors: Coward W. A. , Whitehead R. G. , Lunn P. G. 
Published: May 2005

1.Investigations have been carried out in experimentally-malnourished rats in an attempt to explain the reasons for the development of the two main forms of protein-energy malnutrition in children, kwashiorkor and marasmus.2.Isoenergetic diets with values for protein: energy (P:E) of 0.21 (control diet; C) 0.032 (low-protein diet; LP) and 0.005 (very-low-protein diet; VLP) were fed to groups of twenty-six rats eitherad lib.or in restricted amounts from 5 weeks of age. Rats were killed at the start of the experiment and 1, 2 and 3 or 4 weeks later. Estimations were made of plasma albumin, insulin, corticosterone and amino acid concentrations and of the total protein content of the gastrocnemius muscles and liver.3.Rats given diet LPad lib.gained weight slowly and by week 1 plasma albumin concentration was slightly reduced. Rats given diet VLPad lib.gradually lost weight and plasma albumin concentrations decreased continuously.4.In contrast the major effect of dietary restriction during the first 2 weeks of the experiment was to maintain plasma albumin concentrations at normal values, irrespective of the diet given.5.At later stages, however, when the ‘restricted’ animals had become very severely wasted, albumin concentrations decreased rapidly to values approaching those found in rats given diet VLPad lib.6.When diets LP and VLP were givenad lib.body protein was proportionally distributed in favour of muscle rather than liver. For ‘restricted’ rats the reverse was true, at least up to the time when plasma albumin concentration began to decrease.7.Plasma corticosterone concentrations increased and insulin concentrations decreased when diets LP and VLP were fed in both anad lib.and a ‘restricted’ regimen but the effects were significantly greater in the latter situation.8.Ad lib.feeding of diets LP and VLP produced a distorted plasma amino acid pattern resembling that of kwashiorkor, but although dietary restriction resulted in a decrease in total amino acid concentration, the plasma concentration ratio, non-essential amino acids:essential amino acids was virtually unaffected.9.It was concluded that whilst the lower the protein concentration in the diet the greater is the extent of hypoalbuminaemia which develops, dietary restriction with an increase in plasma glucocorticoid concentration and body-wasting can initially delay the development of the hypoalbuminaemia. However, in the final stages of wasting which ensue, low plasma albumin concentrations can appear because of a failure of the mechanisms which had earlier been able to preserve them at normal levels. It is possible that these two separate and distinct routes to hypoalbuminaemia observed in this study may have parallels in human situations in developing countries.
The influence of α-linolenic acid (18: 3ω3) on the metabolism of γ-linolenic acid (18: 3ω6) in the rat
Authors: Hassam A. G. 
Published: May 2005

1.Essential fatty acid-deficient rats were fed γ-linolenic acid (18:3ω6) at 2 % dietary energy and α-linolenic acid (18:3ω3) at 0, 1.6, 2.8 and 4.0 % of the dietary energy.2.18:3ω3 at 1.6% apparently inhibits the synthesis of the C20 and C22 ω6 long-chain polyunsaturated fatty acids (ω6 LC-PUFA) metabolized from 18:3ω6.3.However, increasing the dietary levels of 18:3ω3 from 1.6 to 4.0% has no further influence.4.The results suggest that dietary 18:3ω6 is an efficient precursor for the ω6 LC-PUFA synthesis even in the presence of 18:3ω3.
Dry matter and nitrogen in the duodenal contents of growing pigs: a discrepancy explained
Authors: Low A. G. , Zebrowska Teresa 
Published: May 2005

1.Discrepancies between the results obtained from experiments on pigs with re-entrant duodenal cannulas have been investigated with reference to diet, cannula site and collection procedure.2.The results obtained from a sealed automatic collection system were different from those obtained from an open manual method and it was concluded that the maintenance of gut intra-luminal pressure in the automatic system was the causative factor.