bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of type and level of protein, fibre and starch on nitrogen excretion patterns in rats
Authors: Beames R. M. , Eggum B. O. 
Published: May 2005

1. Three series of nitrogen balance experiments were performed with growing rats to test the effect of type and level of protein, fibre and starch on N excretion patterns. The design involved eighteen treatments in a 3×3×2 factorial experiment with five rats per dietary treatment. The eighteen treatments resulted from a combination of three protein treatments, three fibre treatments and two starch treatments. Protein treatments consisted of onelevel (15 g N/kg DM) of casein fortified with methionine, a protein of high digestibility, and two levels (15 and 20 g N/kg DM) of autoclaved brown beans (Phaseolus vulgaris), a protein source of low digestibility. The fibre treatments were two levels of cellulose powder and one level of barley hulls. The two starch treatments were autoclaved potato starch and autoclaved and raw potato starch (1:1, w/w).2. The inclusion of raw potato starch reduced true protein digestibility markedly when the protein source was casein, but the corresponding biological values were increased significantly with this treatment. This strongly indicated a movement of urea from the blood to the intestines. This assumption was also supported by significantly lower blood urea concentrations in animals given raw starch. The influence of raw starch on true protein digestibility was, however, significantly less when cellulose and barley hulls were included. This is probably due to reduced transit time from fibre inclusion. The nature of the gut contents also supported this hypothesis.3. The inclusion of raw potato starch when brown beans were the source of protein had much less effect on true protein digestibility and biological value than when casein was the protein source. This was probably due to the low digestibility of DM and protein in this food leaving sufficient energy and protein for maximum microbial growth. The inclusion of fibre also had little effect on N excretion patterns with the brown-bean diets.4. An increase in the level of brown bean inclusion reduced true protein digestibility only on the diets containing raw starch whereas the biological value was consistently reduced regardless of starch treatment. The lower biological values were associated with significantly higher blood urea concentrations. Increasing the level of brown bean inclusion also resulted in higher fresh weights of caecum, colon and contents.5. The present work proves that, through dietary manipulation, it is possible to affect nitrogen excretion patterns in rats.
The effect of dietary fibre sources on aflatoxicosis in the weanling male rat
Authors: Frape D. L. , Wayman B. J. , Tuck Mary G. 
Published: May 2005

1. Two experiments with male weanling rats were conducted in which they received individually and restrictedly either a basal semi-purified diet containing starch as the principal carbohydrate or the same diet to which mixed aflatoxins were added in quantities providing from 0·13 to 0·4 mg aflatoxin B1 /kg diet. Various natural ingredients, or semi-purified sources of dietary fibre were substituted for a portion of the starch in the basal diet containing aflaloxin. The diets were fed for 13–14 weeks after which the rats were given ad lib. a commercial rodent diet until they were killed at 109 weeks of age.2. Two further experiments were conducted in which twenty-four rats in each experimentreceived the basal diet plus aflatoxin, or diets in which a portion of the starch was replaced by gum arabic or by wheat offal. After 13 or more weeksthe absorption, retention and excretion of 14C-labelled aflaloxin B1 was measured in each rat.3. The addition of gum arabic or wheat bran to the diet decreased the effects of the toxin in the first two experiments, but as measured by several characteristics, only wheat
bran provided an effect which persisted during the period when neither it nor the toxin was given. The effects included an apparent reduction in tumour incidence. The change in the content of starch in the basal diet, occurring as a consequence of adding the test ingredients is also considered to be an associated cause of the effects observed4. In comparison to starch, wheat offal increased the total 14C in the faeces and the proportion of the total found during the first 48 h after dosing. Rats receiving starch excreted more 14C in their urine and retained more 14C in their livers. The differences between gum arabic and starch were not significant as measured by 14C excretion and retention. Liver size as a proportion of carcass weight was less in rats receiving wheat offal or gum arabic, and rats receiving wheat offal had a lower incidence of fat-loaded hepatocytes.5. The interaction of dietary toxins, or drugs, with the ingredient composition of diet may affect animal response even when the diets are adequate and similar in nutrient composition. This may be of significance both in drug-safety studies and in animal production.
Silage intake, rumination and pseudo-rumination activity in sheep studied by radiography and jaw movement recordings
Authors: Deswysen A. G. , Ehrlein H. J. 
Published: May 2005

1. The eating and ruminating activity of four rams given long-chopped silagead lib. in two daily meals was studied by jaw movement recordings. The events of rumination and pseudo-rumination were observed by fluoroscopy and by cineradiography.2. The rate of eating was highest at the beginning of the main meal and then declined gradually.3. The silage intake level was low.4. The swallowed silage did not accumulate at the cardiac region but was forced into the dorsal sac of the rumen by the contractions of the reticulum and cranial sac of the rumen. For regurgitation the solid particles had to return via the ventral and cranial sac of the rumen into the reticulum.5. Liquid reticular contents with floating solid particles were aspirated into the oesophagus during the maximum of the regurgitation contraction of the reticulum.6. The rumination activity during the day presented a high proportion of pseudo-rumination cycles whereas during the night the rumination became progressively normal.7. Pseudo-rumination was caused by delayed return of the fibrous silage particles into the reticulum. Thus in pseudo-rumination the regurgitated material consisted predominantly of fluid containing only a small quantity of solid particles.8. The results explain why long-chopped silage intake is associated with pseudo-rumination, a lower breakdown of particles and a waste of digestion time.
Effects of cobalt deficiency in pregnant and post-parturient ewes and their lambs
Authors: Duncan W. R. H. , Morrison E. Rona , Garton G. A. 
Published: May 2005

1. Two groups of ewes were fed on a cobalt-deficient diet throughout pregnancy; one group (group A) was given the diet from the beginning of pregnancy, whilst the other (group B) received the diet for 16 weeks before mating. The ewes in group A continued to receive the diet for 12 weeks post-partum.2. The vitamin B12 content of serum was estimated on three occasions before parturition and, for group A ewes, at 12 weeks post partum. Urinary concentration of methylmalonic acid was also determined at intervals before the lambs were born.3. Serum values for vitamin B12 indicated that the ewes in both groups were depleted of the vitamin, though those in group B were more severely affected, as was evidenced by the high incidence of perinatal mortality among the lambs born to these ewes. Perinatal mortality appeared to be associated with abnormally-high values for urinary concentration of methylmalonic acid.4. Analysis of liver lipids and adipose tissue triacylglycerols of some of the vitamin B12-deprived lambs which died before, or within 1 d of, birth showed that, compared with the corresponding tissues of control lambs, these lipids contained unusually high proportions of odd-numbered fatty acids (mostly 15:0, 17:0 and 19:0). This observation is discussed in relation to the likelihood that, in vitmain B12-deprived lambs, propionate becomes available as a primer unit for fatty acid synthesis when the metabolism of its carboxylation product, methylmalonic acid, is impaired due to partlal lack of a vitamin B12-containing enzyme system.
Glutathione peroxidase activity and erythrocyte stability in calves differing in selenium and vitamin E status
Authors: Siddons R. C. , Mills C. F. 
Published: May 2005

1. Glutathione peroxidase activity (EC1.11.1.9) and erythrocyte stability were measured in Friesian bull calves which were given for 36 weeks semi-purified diets either adequate or low in selenium or vitamin E or both.2. Dietary Se or vitamin E content had no effect on growth rate and haematological vaiues. None of the calves exhibited clinical deficiency symptoms and serum aspartate amino transferase (EC 2.6.1.1) and creatine phosphokinase (EC 2.7.3.2) activities remained normal. Heart and skeletal muscles of all calves appeared macroscopically and microscopically normal at autopsy.3. Glutathione peroxidase activity in plasma, blood and other tissues, except the testis, was significantly lower in calves receiving low dietary Se but was independent of dietary vitamin E content.4. Plasma vitamin E levels decreased rapidly and to very low levels in calves given low vitamin E diets irrespective of the Se content of the diet.5. A low dietary vitamin E intake increased the susceptibility of erythrocytes to auto- and peroxidative haemolysis whereas a low Se intake in the presence of adequate vitamin E did not. However, erythrocytes from calves receiving low Se and low vitamin E were more susceptible to peroxidative haemolysis than erythrocytes from calves receiving low vitamin E and adequate Se. The effect of dietary vitamin E content on osmotic haemolysis induced by hypotonic saline was variable.6. The results suggest that measurement of blood glutathione peroxidase activity and the susceptibility of erythrocytes to auto- or peroxidative haemolysis could be used for the differential diagnosis of subclinical Se and vitamin E deficiency in ruminants.
Protein synthesis in tissues of growing lambs
Authors: Davis S. R. , Barry T. N. , Hughson G. A. 
Published: May 2005

1. The fractional rate of protein synthesis (FSR) in tissues of nine growing lambs (4–5 months of age) was estimated following continuous infusion of L-[4,5–3H]leucine for a period of 7 h. Minimum and upper estimates of FSR were obtained assuming that the specific radioactivity (SRA) of leucine in blood plasma and tissue homogenate respectively defined that of leucyl tRNA.2. Mean upper estimates of tissue protein FSR (/d) were skin 0·35, longissimus dorsi muscle 0·05, biceps femoris muscle 0·04, liver 0·54, rumen 0·79, cardiac muscle 0·09. Minimum estimates of tissue protein FSR ranged from 0·03 (muscle) to 0·15 (liver).3. Plasma leucine flux was closely related to body protein content and dietary leucine absorption (r0·94).4. The rate of whole-body protein synthesis (WBS) derived from plasma leucine flux corrected for oxidation and localized recycling of leucine into protein was similar to that calculated from the sum of daily protein synthesis in individual tissues using the upper estimate of FSR, i.e. 610 g/dv. 581 g/d.5. The estimate of WBS derived from plasma leucine flux directly (241 g/d) was similar to that calculated from the sum of minimum estimates of daily protein synthesis in individual tissues (214 g/d).6. The ratio, intracellular leucine SRA:plasma leucine SRA tended to increase with increasing dietary leucine absorption in all tissues although these factors were only significantly correlated (P< 0·05) in cardiac muscle, skin and rumen. Such relationships suggest an increased exchange of plasma leucine with intracellular leucine with increased food intake.7. It was estimated that the energy cost of protein synthesis accounted for approximately 42% of daily heat production.
The effect of dietary protein source and saponins on serum lipids and the excretion of bile acids and neutral sterols in rabbits
Authors: Pathirana Chitra , Gibney M. J. , Taylor T. G. 
Published: May 2005

1. Four groups of six rabbits were given purified diets in which the dietary variables were protein source (isolated soya-bean protein or cow's-milk protein) with or without saponin supplementation (10 g/kg).2. Rabbits given soya-based diets showed significantly lower serum concentrations of triglyceride and cholesterol (P< 0·01). The latter changes were confined to the cholesterol fractions of β-lipoproteins.3. These changes in serum cholesterol were associated with a significantly increased excretion of acid and neutral sterols in animals given soya-bean protein.4. There was no evidence to suggest that the effect of dietary protein source on serum lipids and the excretion of total and individual sterols was influenced by saponin supplementation.5. These results do not support the hypothesis that the hypocholesterolaemia associated with plant proteins is due to the presence of saponins.
Changes in the composition of digesta during passage through the small intestines of steers
Authors: McAllan A. B. 
Published: May 2005

1. Dry matter (DM), organic matter (OM), nitrogenous constituents, carbohydrate constituents and pH were estimated in digesta taken from eight different sites in the small intestines of slaughtered steers given different diets. Amounts of constituents passing different sites were compared using cellulose as a non-digestibte marker.2. Amounts of the different constituents entering the small intestines varied with the type of diet given but the patterns of removal of each constituent were similar regardless of diet.3. DM and OM were removed uniformly down the length of the small intestines. Net digestibilities of 0·62 and 0·63 for DM and OM respectively of the amounts measured in segment 1 digesta (first 3 m post-pylorus) were found at the terminal ileum. DM and OM contents of segment 1 digesta were 5 and 8% higher respectively than in abomasal digesta. Significantly smaller amounts of digesta were found in the proximal quarter of the small intestines than in more distal sections. There was a 10% addition of water to digesta in segment 1 compared with abomasal digesta. Of the water entering the small intestines a net 65% was absorbed therein, most absorption occurring in the first half.4. Ammonia nitrogen was removed uniformly down the length of the small intestines to a net extent of 75% of that in segment 1 digesta. There was an apparent increase of approximately 18% in the total N (TN) content of segment 1 digesta compared with abomasal digesta. There was an approximate net removal of 80% of the TN measured in segment 1 digesta during passage down the small intestines. Over 95% of the digestible TN was removed in the section of tract between 3 and 15 m from the pylorus. Net removal of nucleic acid N (NA–N) up to the distal ileum was 78% of that in segment 1 digesta, most removal occurred in the proximal quarter of the small intestine. Little or no net loss of diaminopimelic acid–N (DAP–N) occurred in the small intestine.5. Of the carbohydrates entering the small intestines, there was little or no removal of rhamnose, arabinose or xylose. Net removal of ribose, mannose, galactose and ‘starch’ glucose up to the distal ileum was 82, 76, 54 and 70% respectively of the amounts found in segment 1 digesta. All disappeared uniformly down the length of the small intestine.
The excretion of selenium in bile and urine of steers: the influence of form and amount of Se salt
Authors: Symonds H. W. , Mather Denise L. , Vagg M. J. 
Published: May 2005

1. The excretion of 75Se and stable Se in bile and urine was measured in four steers during 6 h after intravenous injections of 75Se as either selenite or selenate containing either 5 or 5000 μg carrier Se.2. When 5000 μg Se were given, the rate of urinary excretion and plasma clearance of 75Se was similar for both salts. Approximately 23% was excreted in urine and plasma clearance was triexponential, the mean half-life (t½) of the successive components, α, β and γ, being 2·3, 15·2 and 465 min respectively. The amount of 75Se excreted in bile was small; 1·94% of the 75SeO32− and 0·86% of the 75SeO42− dose.3. When 5 μg Se were given the plasma clearance of 75Se was initially biexponential but the entry of 75Se-labelled protein from the liver caused an increase in plasma radioactivity after 30–40 min. The effect was most marked after 5 μg 75SeO32− when plasma 75Se radioactivity returned to 60% of the activity present at 2 min. Values for t½ of the two components of clearance for 75SeO32− and 75SeO42− were respectively α 2·6 and 2·5 min, and β 15·9 and 36·6 min. Similar amounts of 75Se appeared in bile (0·2% of the dose) after injections of either salt but much less 75Se was excreted in urine after 75SeO32− (6%) than after 75SeO42− (37%).4. At low dosage rates (5 μg) Se is more readily incorporated into tissues from SeO32− than from SeO42−.
Availability of lysine in protein concentrates as determined by the slope-ratio assay with chicks and comparisons with rat, pig and chemical assays
Authors: Major E. J. , Batterham E. S. 
Published: May 2005

1. A slope-ratio assay was developed to determine the availability of lysine in protein concentrates for chicks, Two protein concentrates were assessed per assay, using three levels of incorporation into the basal diet.2. Availability of lysine, expressed as a proportion of total lysine in five protein concentrates was: cottonseed meal 0·83, fish meal 1·00, meat-and-bone meal 0·86, soya-bean meal 0·93, sunflower meal 1·01.3. The five protein concentrates had previously been assayed for available lysine with slope-ratio assays for pies and rats (Batterham et al. 1979; Batterharn et al. 1981), There was little relationship between the results for chicks and those for pigs and rats. For pigs, availability estimates ranged from 0·43 for cottonseed meal to 0·89 for fish meal. For rats, availability estimates ranged from 0·49 for sunflower meal to 1·04 for fish meal.4. The results for chicks were in closer agreement with values obtained using the Silcock available-lysine assay (Roach et al. 1967) and the direct 1-fluoro-2,4-dinitrobenzene procedure (Carpenter, 1960). By contrast, there was litlle relationship between the chemical tests and results for pigs or rats.
Protein metabolism in growing lambs fed on fresh ryegrass (Lolium perenne)–clover (Trifolium repens) pasture ad lib. 1. Protein and energy deposition in response to abomasal infusion of casein and methionine
Authors: Barry T. N. 
Published: May 2005

1. Male lambs that had been born in autumn and wintered on forage diets were cannulated in the abomasum, confined indoors in individual pens, and fed on fresh primary growth ryegrass (Lolium perenne) – clover (Trifolium repens) pasture ad lib, for a 12-week period during spring. Mean diet organic matter digestibility (OMD) was 0/76, nitrogen content 29 g/kg dry matter (DM) and metabolizable energy (ME) content 11.1 MJ/kg DM. Thirteen lambs were infused into the abomasum with 44 g sodium caseinate +0/5 g L-methionine/d and 12 lambs were similarly infused with equivalent amounts of inorganic sodium and phosphorus. Initial live weight was 16/5 kg.2. The twenty-five treatment lambs were slaughtered at the end of the experiment, and thirteen similar lambs were slaughtered when the experiment commenced. Body composition was determined and rates of protein, fat and energy deposition were calculated using comparative slaughter procedures.3. Voluntary herbage DOM intakes tended to be slightly greater for control than protein-infused lambs, but calculated ME intakes including that infused as amino acids were similar for the two groups. Live-weight gains were 79 and 99 g/d for control and protein-infused lambs respectively (P < 0/05) and corresponding values for carcass gain: live-weight gain were 0/44 and 0/50 (P < 0/01), Wool growth was markedly increased by the amino acid infusion.4. Carcass and whole body protein content was increased 10 g/kg by the protein infusion (P < 0/01) and fat content depressed approximately 25 g/kg (P < 0/05). Rates of protein deposition in both carcass and wool-free whole body were markedly increased by protein infusion, and total deposition including wool was 12.6 and 21.0 g/d for control and protein-infused lambs (P < 0/001). Energy deposited in protein as a proportion of total energy deposition was 0/27 and 0/41 for control and protein-infused lambs (P < 0/001), but total energy retention and the efficiency of utilization of ME for growth did not differ between the two groups of lambs.5. It was estimated that 60 and 100 g total amino acids/d were absorbed from the small intestine in the control and protein-infused lambs respectively, corresponding to 0.16 and 0/25 of total ME intake. It was concluded that absorption of protein from the small intestine was limiting protein deposition in the growing lambs fed on fresh ryegrass-based spring pasture in this study. Absorption of cystine+methionine was specifically shown to be limiting. However, the protein deficiency was not a major factor in the low value for the efficiency of utilization of ME for growth for this diet (0/30).
Influences of dietary sucrose and urea on transfer of endogenous urea to the rumen of sheep and numbers of epithelial bacteria
Authors: Kennedy P. M. , Clarke R. T. J. , Milligan L. P. 
Published: May 2005

1. The rates of transfer of plasma urea to the rumen of six sheep given brome grass (Bromus inermis) pellets alone or with supplements of sucrose or urea were determined using [14C]urea and14C-labelled sodium bicarbonate infusions during three periods.2. The sheep were slaughtered after the third period and samples of rumen epithelium were taken for assessment of numbers of adherent bacteria.3. Maximum transfer (0·31 g nitrogen/h) of urea to the rumen was observed for sheep given supplements of 150 g sucrose/d plus 20 g urea/d. Maximum clearance of plasma urea to the rumen (rate of urea transfer to the rumen per unit plasma urea concentration, 5·8 1/h) was observed for sheep given 300 g sucrose/d.4. Urea clearance to the rumen was negatively related to rumen ammonia concentration; the slope of the relationship was increased with each addition of sucrose to the diet.5. Numbers of facultative bacteria adherent to the rumen epithelium were increased by urea and sucrose supplements.6. The results are discussed in relation to a hypothesis which relates the ureolytic capability of the bacteria adherent to the rumen epithelium to the control of the rate of transfer of urea into the rumen.