bluuebunny/crossref_metadata_2025 huggingface dataset:
Metabolic balance of zinc, copper, cadmium, iron, molybdenum and selenium in young New Zealand women
Authors: Robinson Marion F. , McKenzie Joan M. , Thompson Christine D. , Van Rij Anita L.
Published: September 2005

1. Metabolic balance studies of zinc, copper, cadmium, iron, molybdenum and selenium were made on four young New Zealand women, using brilliant blue and chromic oxide as faecal markers.

2. Zn, Cu, Cd and Fe concentrations in foods, faeces and urine were measured by atomic absorption spectrophotometry, whereas Mo was determined spectrophotometrically with dithiol and Se fluorimetrically with diaminonaphthalene.

3. The dietary intakes of Zn, Cu and Fe were similar to those reported in the USA and the UK, whereas those of Cd, Mo and Se were less. The subjects ate a diet consisting of foods normally consumed by New Zealand women.

4. For each subject there was little variation in the urinary output of each element for three 6 d periods. Day-to-day variation was small for each subject. The individual variation in urinary output of each element among the subjects was smaller when expressed as a ratio of intake, except for Mo.

Retentions were small for Zn, Cu and Fe, all elements which are poorly absorbed. Balances of Se, Mo and possibly Cd were in equilibrium.
Changes in lipid metabolism in genetically different types of calves during chronic hyperthermia
Authors: O'Kelly J. C.
Published: September 2005

1. The effects of chronically raised body temperature on lipid metabolism were studied in groups of 3-month-old British (Shorthorn × Hereford) and Zebu (Africander × British) bull calves. Calves in control groups at ambient temperature were pair-fed to calves housed in a climate room.

2. In control groups, concentrations of plasma cholesterol and phospholipid were significantly higher and the excretion of fatty acids 14:0, 16:0 and 18:0 was lower in the Zebu than in the British calves.

3. In the climate room the constant daily environmental temperature required to maintain an increase in rectal temperature of 1·3° was 33° for British and 38° for Zebu calves. Changes in respiration rate, water metabolism and nitrogen metabolism associated with hyperthermia were similar in both breeds.

4. Hyperthermia in all animals was associated with lowered plasma concentrations of cholesterol and phospholipid and increases in the ratio of free to total cholesterol. It was without effect on the circulating concentrations of non-esterified fatty acids and about twice the amount of fat was excreted without change in its fatty acid composition.

5. The results showed that, when control of normal body temperature was lost, increased rectal temperature led to similar metabolic changes in animals of both breeds.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Williams V. J.
Published: September 2005

1. Three groups of sheep receiving 400, 800 and 1200 g lucerne chaff/d in equal hourly meals were killed. The large intestines were removed and divided into segments 15 cm long to provide information on the amounts and dry-matter contents of digesta and on the rates of passage of digesta and absorption of water along the large intestine.

2. With increasing intakes of food, increases were observed along the entire large intestine in the amounts of wet digesta present, in the transit rates of digesta and in the rates of absorption of water. The mean retention time of digesta in the large intestine decreased with increasing food intake, being 1737, 1056 and 692 min respectively.

3. Four patterns of sodium and potassium concentrations in digesta water along the large intestine were found.
Urinary aromatic acid excretion by fed and fasted sheep in relation to protein metabolism in the rumen
Authors: Martin A. K.
Published: September 2005

1. Two adult wether sheep were maintained on a diet of hay and two on a diet of dried grass for 3 weeks before starvation for a period of 10 d. Urinary excretion of the following acids was determined when the animals were fed and when they were fasted: total diethyl ethersoluble acids of hydrolysed and unhydrolysed urine, hippuric acid, benzoic acid and phenylacetic acid. By the 5th day of fasting, urinary output of all acids had attained stable levels that did not change during the remaining starvation period. The output of all urine fractions except phenylacetic acid declined rapidly during the first 4 d of fasting: phenylacetic acid output by all sheep increased to a maximum during the first 4 d of fast and then declined to stable values (0·42–0·73 g/24 h) which were greater than those observed when the sheep were fed. It is concluded that prolonged retention of food and microbial residues in the digestive tract is responsible for the large output of phenylacetic acid in the urine of fasted sheep.

2. Solutions of casein which supplied between 6·3. and 26·5 g nitrogen/24 h were infused into the rumens (fifteen experiments) or abomasums (sixteen experiments) of eight adult wether sheep. Ruminal infusions of casein caused increments in the urinary excretion of diethyl ethersoluble acids and phenylacetic acid. Both these increments were described by linear regression equations (P< 0·001), the coefficients of which showed that 284 ± 44 and 220 ± 21 mg benzoic acid equivalent were excreted as diethyl ether-soluble acids and phenylacetic acid respectively per g casein N infused. The phenylacetic acid excreted was equivalent to 95% of the phenylalanine of the infused casein. No increments in urinary benzoic acid were observed. One sheep scoured when it was given an abomasal infusion of casein. This was the only animal to show any increment in urinary aromatic acids when casein was infused into the abomasum.

3. When four sheep were given two rations containing an excess of carbohydrate as sugarbeet pulp or rolled barley, 11 and 16% respectively of their phenylalanine intakes were excreted in the urine as phenylacetic acid. When the same sheep were given two rations containing an excess of N as linseed meal or field beans, 51 and 59% respectively of their phenylalanine intakes appeared in the urine as phenylacetic acid.

4. Methods for the determination of creatinine, and of benzoic, phenylacetic, 3-phenylpropionic, cinnamic, hippuric and phenaceturic acids are described.

5. It is suggested that the amount of phenylacetic acid excreted in the urine is a measure of the equilibrium occurring in the rumen between catabolism of phenylalanine and reutilization of the products of catabolism for phenylalanine synthesis.
Comparison of the development of proteolytic activity in the abomasum of the preruminant calf with that in the stomach of the young rabbit and guinea-pig
Authors: Henschel M. J.
Published: September 2005

1. Proteolytic activity was measured in the abomasal contents of five calves during the first 7 weeks of life and in the stomach contents of rabbits and guinea-pigs during the first 4 weeks of life.

2. The pattern of protease secretion in the abomasum varied considerably among individual calves; in addition to rennin, some pepsin activity was found in most animals from the first sampling at 9 d of age.

3. Only pepsin was secreted in the guinea-pig stomach from birth, at a consistently high level at all ages.

4. The main peak of proteolytic activity in the rabbit stomach during the 1st weekpost partumhad an optimum at pH 3·5–4·0, corresponding to that for calf rennin. During the 3rd week of life the main pepsin peak, with an optimum at pH 1·6–2·0, developed.

5. Agarose gel electrophoresis of an extract of neonatal rabbit stomach mucosa showed the activity peak at pH 3·5–4·0 to be due to two slow-moving components of mobilities similar to that of crystalline rennin. At least one of these cross-reacted with antiserum to crystalline rennin.

6. At 10 d and 3 weeks of age, activity at pH 1·6–2·0 was due to two faster-moving proteases, one being the main pepsin of the adult rabbit, which moved at the same speed as crystalline porcine pepsin, with the antiserum of which it cross-reacted.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Williams V. J.
Published: September 2005

1. The rates of passage of markers of fluid and particulate digesta through the sheep alimentary tract have been described mathematically in single-injection experiments by analysing the concentration curves of marker excretion in faecal dry matter and then predicting these concentrations by means of an equation containing two exponential terms. Three components related to this equation are a transit time for digesta in the intestines, a half-time of marker in the reticulo-rumen and a half-time tentatively associated with the passage of marker through the caecum and proximal colon. With this approach no surgical interference with an animal is required to obtain meaningful information about gut function.

2. Abomasal cannulation did not affect the rate of passage of 51Cr EDTA through the gut.

3. The mean half-times (T1/2) for 51Cr EDTA in the reticulo-rumen and hind-gut, respectively, were 646 and 236 min for a roughage diet and 890 and 607 min for a diet consisting mainly of wheat grain, both diets providing approximately the same amounts of digestible dry matter. These results indicated that the changes in half-times were proportionately much greater in the caecum and proximal colon than in the reticulo-rumen. The mean transit time of marker through the digestive tract also increased from 721 to 1345 min when the concentrate diet was given.

4. The complex of chromium-51 with EDTA was excreted faster in faeces than cerium-144–praseodymium-144 when both were given together as a single injection into the reticulorumen. This was caused mainly by differential rates of elimination of water and particulate matter from the reticulo-rumen.
Proteolytic enzyme activity in the gut of doe-suckled and hand-reared rabbits
Authors: Henschel M. J.
Published: September 2005

1. Proteolytic activity in the stomachs and pancreases of infant doe- and hand-reared rabbits was studied to the age of 3–4 weeks.

2. In the stomachs of both the doe- and hand-fed animals total proteolytic activity at birth was low, rising slowly during the first 2 weeks and then rapidly, until at 3 weeks of age the level was similar to that of the adult.

3. In the pancreases of the doe-suckled pups the level of proteolytic activity was highest during the 1st week of life, falling steadily after that to a minimum at 3 weeks of age. In contrast in the hand-reared rabbits, it fell sharply during the 1st week and then rose, reaching at 2 weeks of age a level slightly higher than that found in the doe-suckled pups.

4. Growth and survival of hand-reared rabbits during the first 12 d of life were improved by predigestion of the diet with trypsin and α-chymotrypsin.
The effect of bypassing the rumen with supplements of protein and energy on intake of concentrates by sheep
Authors: Ørskov E. R. , Fraser C. , Pirie R.
Published: September 2005

1. Two experiments were conducted with young early-weaned lambs to measure the voluntary intake of dry concentrates when additional protein or lactose was given as a fluid preparation from a bottle.

2. The voluntary intake of a barley–urea diet (130 g crude protein/kg) was increased by 10–15% as a result of giving 2·3 g nitrogen/d as a fish-protein concentrate in fluid suspension. Amounts greater than 2·3 g N/d did not further increase voluntary intake but increased growth rate and food conversion ratio. Urea given as a solution in water in the same way in amounts equivalent to 4·6 N/d had no effect on voluntary intake.

3. The voluntary intake of a high-protein barley–fish-meal diet was decreased by giving 10 or 20% of the estimated intake as lactose by bottle. The results indicated that maximum energy intake was achieved with the basal diet, since the decrease in energy intake was about equal to the amount given in the solution bypassing the rumen.
Rate of passage of digesta in sheep
Authors: Grovum W. L. , Phillips G. D.
Published: September 2005

1. Sheep were given 800 g lucerne chaff/d and the mean half-times of cerium-144 – praseodymium-144 and the complex of chromium-51 with EDTA were 811 and 604 min in the reticulo-rumen, 37 and 17 min in the abomasum and 413 and 406 min in the caecum and proximal colon respectively. The average time available for digestion and absorption in the abomasum was therefore very short relative to that in the other two organs.

2. The half-times of the markers also indicated that particulate matter and water had different rates of turn over in the reticulo-rumen and abomasum but not in the caecum and proximal colon.

3. Evidence is presented which suggests imperfect mixing of the digesta in the caecum and proximal colon.
Sulphur as a nutrient for Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M.
Published: September 2005

1. Faecal and urinary sulphur excretions of Merino sheep given fifty-one forage diets were measured in 205 balance experiments to derive estimates of the dietary requirements of Merino sheep for S.

2. Faecal S excretion varied with the S, organic matter and digestible organic matter intakes. Non-dietary faecal S excretion was estimated by regression analysis and was approximately 0·7 g S/kg organic-matter intake. Apparent S digestibility declined linearly with the reciprocal of dietary S content, and was predicted to be zero when the dietary S content was 0·81 g S/kg organic matter.

3. Both urinary S excretion and S retention varied with the digestible S and digestible organic-matter intakes. Endogenous urinary S excretion was taken to be the urinary S excretion when digestible S intake was zero, and the sheep was at zero energy balance. It was estimated by regression analysis to be 38 mg S/d.

4. The S and digestible S intakes necessary to maintain the fleece-free tissues in S equilibrium can be calculated from the equations derived in this study. An example is presented.
Sulphur as a nutrient for Merino sheep
Authors: Langlands J. P. , Sutherland H. A. M. , Playne M. J.
Published: September 2005

1. Estimates of sulphur retention by Merino sheep during growth, pregnancy and wool production, and of S excretion during lactation were obtained to derive estimates of the S requirements of Merino sheep.

2. The S content of fifty Merino sheep was related by weighted regression analysis to age, live weight and (age × live weight). The quantity of S stored was calculated for varying rates of live-weight gain in sheep differing in age and live weight.

3. The S contents of twenty-five samples of foetus, foetal membranes and uteruses were determined. Relationships between S content and days from mating were calculated, and differentiated to give daily net changes in S content during pregnancy.

4. Milk production of twenty-seven Merino ewes was estimated on eight to ten occasions at approximately weekly intervals to the 84th day of lactation. The average S content was 472 mg/l; it increased on average by 1·0 mg/l per d of lactation. The mean S content of ninety-seven samples of wool averaged 34 g S/kg clean dry wool.

5. It was concluded that wool represented the major demand for S by the Merino since approximately 70 g S were secreted in producing 2 kg clean wool, 50 g S in a lactation yielding 100 l milk and 8 g S in giving birth to a single lamb.
The metabolism of palmitic, stearic, oleic and linoleic acids in broiler chickens
Authors: Infield Jennifer M. , Annison E. F.
Published: September 2005

1. Interrelationships between the level of dietary fat and the metabolism of palmitate, stearate, oleate and linoleate in the broiler chicken have been studied by means of isotope dilution techniques.

2. The composition of the free fatty acid (FFA) and triglyceride fractions of plasma lipids was influenced by the level of dietary fat, but the only effect of diet on plasma concentration was the higher FFA levels after feeding in birds given the high-fat diet.

3. The rates of entry and oxidation of the individual fatty acids were correlated with their concentrations in plasma, but were unrelated to the level of dietary fat. Slight differences in the metabolism of the individual fatty acids were observed.

4. Acetyl-CoA carboxylase (EC6.4.1.2) and desaturase activities were higher in the livers of birds given the low-fat diet.
Kwashiorkor in western Nigeria: a study of traditional weaning foods, with particular reference to energy and linoleic acid
Authors: Naismith D. J.
Published: September 2005

1. The fatty-acid composition of the plasma total lipids of children with kwashiorkor and of healthy infants was determined by gas–liquid chromatography. Breast milk from Yoruba mothers, and traditional weaning foods, were also analysed for fatty acids, and for protein, fat and carbohydrate.

2. Evidence of essential fatty acid (EFA) deficiency was obtained in the children with kwashiorkor. The proportions of linoleic and arachidonic acids were reduced in the plasma lipids, whereas the endogenous eicosatrienoic acid showed a marked increase. The triene:tetraene ratio had the abnormally high value of 1·08. These changes were consistent with the prolonged ingestion of suboptimal amounts of linoleic acid.

3. Breast milk was of good quality, with a particularly high concentration of retinol. The milk was also rich in linoleic acid, and was thus discounted as a factor in the development of EFA deficiency, but the weaning foods were found to provide substantially less than the minimum recommended intake of 1% of the total energy as linoleic acid.

4. The maize pap with which the children with kwashiorkor had been fed for several months before the appearance of acute symptoms provided almost 7% of the energy as protein, but only 1·21 MJ (290 kcal)/kg. To satisfy energy requirements, it would have been necessary to consume 3–4 kg of the pap each day.

5. It is concluded that the protein deficiency which leads to the development of kwashiorkor in the Yoruba community arises from a very severe restriction in energy intake rather than from the consumption of foods very low in protein at adequate or excessive levels of energy intake.
Iron fortification of dried skim milk and maize–soya-bean–milk mixture (CSM): availability of iron in Jamaican infants
Authors: Ashworth Ann , March Yvette
Published: September 2005

1. The availability of iron added to dried skim milk and to maize–soya-bean–milk mixture (CSM) was measured by whole-body counting in thirty clinically healthy children and compared with the availability of Fe from ferrous ascorbate alone.

2. The mean absorption of Fe added as ferrous sulphate to a test meal of dried skim milk was 9·5% when the test meal was given as a sweetened drink. When maize meal was added to the dried skim milk to produce a porridge the mean absorption of the supplementary Fe was reduced to 6·3%. The mean absorption of Fe given as ferrous ascorbate alone was 59·6%.

3. These results differed from those reported for indirect tests done with animals in which the absorption of inorganic Fe added to milk-based feed preparations for infants was substantially greater than that of dietary Fe.

4. The mean absorption of Fe added as ferrous fumarate to a test meal of maize–soya-bean–milk mixture was 6·0%, whereas that of Fe given as ferrous ascorbate alone was 63·5%.

5. The amount of supplementary Fe added to maize–soya-bean–milk mixture (USA Department of Agriculture specification) was considered to be adequate.
Free amino acid patterns of plasma, erythrocytes and leucocytes in hypoproteinaemia
Authors: Gupta Meera , Agarwal K. N.
Published: September 2005

1. In pregnancy, severe hypoproteinaemia, cirrhosis and anaemia, plasma free α-amino nitrogen (FαAN) was found to be lowered. The non-essential:essential amino acid ratios, determined by paper chromatography, were increased in hypoproteinaemia and anaemia.

2. The erythrocytic FαAN content increased in early hypoproteinaemia and values lower than normal were found in severe hypoproteinaemia. There was also a rise in anaemia, which was due to increased cellular non-essential amino acids.

3. The leucocytic FαAN was reduced in all hypoproteinaemic states. The increased FαAN values in patients with thyrotoxicosis demonstrated that, in catabolism, leucocytic uptake of amino acids is increased. The non-essential:essential amino acid ratios were decreased in cirrhosis, possibly due to poor biosynthesis of non-essential amino acids by the liver.
Studies on the control of gluconeogenesis in sheep: effect of glucose infusion
Authors: Judson G. J. , Leng R. A.
Published: September 2005

1. Effect of glucose infusions on the rate of gluconeogenesis, as indicated by changes in the irreversible loss of plasma glucose, synthesis of glucose from ruminal propionate or fixation of blood bicarbonate into glucose, has been examined in sheep.

Sheep, feeding at hourly intervals, received intravenous infusions of [U-14C]glucose, NaH14CO3, or [6-3H]glucose, infused simultaneously with an intraruminal infusion of [2-14C]propionate. Glucose (4–144 mg/min) was infused intravenously at a single rate or at two different successive rates of equal duration. The glucose infusions were over a 6 h period and followed estimates of pre-infusion kinetic measurements.

2. The infusion of glucose suppressed endogenous glucose production in direct proportion to that infused for sheep given diets of lucrene or wheat. The maximum rate of suppression recorded was equivalent to about 50–60% of the endogenous production rate of glucose.

Transfer rates of carbon-14 from blood bicarbonate or ruminal propionate to plasma glucose were reduced during glucose loadings. The results indicate that administration of glucose was more effective in suppressing the synthesis of glucose from substrates other than ruminal propionate.

3. The percentage of glucose carbon derived from blood bicarbonate was lower in sheep given wheat than in sheep given lucerne. It was suggested that this difference may have been due to absorption of glucose from the alimentary canal of sheep on the former ration. Approximately 8% of the wheat starch may have escaped fermentation and been absorbed as glucose in these animals.
Studies on the control of gluconeogenesis in sheep: effect of propionate, casein and butyrate infusions
Authors: Judson G. J. , Leng R. A.
Published: September 2005

1. Short-term effects of infusions of propionate, amino acids and butyrate on gluconeogenesis, as indicated by changes in the irreversible loss of plasma glucose, synthesis of glucose from ruminal propionate or fixation of blood bicarbonate into glucose have been examined in sheep given their daily ration in twenty-four equal portions at hourly intervals.

Sheep received intravenous infusions of [6-3H]glucose usually, in combination with [U-14C]glucose or NaH14CO3or with intraruminal infusions of [2-14C]propionate. Substrates were infused over a 3–7 h period and followed estimates of pre-infusion kinetic measurements.

2. It was demonstrated that intraruminal and intramesenteric vein infusions of sodium propionate and intra-abomasal infusions of casein hydrolysate stimulated gluconeogenesis. Glucose synthesis showed a linear response to the infusion of these substrates, which varied from 0·35–6·35 mmol propionate/min and 50–160 mg casein/min.

3. The increment in the measured production rate of propionate in the rumen was consistently less than the rate of addition of propionate to the rumen.

4. Intramesenteric vein infusions of sodium butyrate at successive rates of 0·25 and 0·50 mmol/min produced only an initial transient increase in plasma glucose production. Since the rate of glucose synthesis from ruminal propionate was not altered, it was suggested that butyrate initiated glycogen mobilization.
Relation between diet and protozoal population in the rumen
Authors: Abe M. , Shibui H. , Itiki T. , Kumeno F.
Published: September 2005

1. Four feeding trials were made to investigate relations between diet and protozoal population in the rumen.

2. When a ration containing no concentrate was used, the number of entodiniomorphs decreased rapidly. The number of entodiniomorphs increased with the amount of concentrate. Rice straw, which was used as a sole source of roughage, was not always necessary for protozoa to survive in the rumen.

3. The type of diet affected the holotrich population to a much smaller extent than the entodiniomorph population.
Effects of magnesium deficiency on reproduction in the white rat
Authors: Andrieux-Domont C. , Hung Le Van
Published: September 2005

1. Groups of rats were maintained from weaning on magnesium-deficient (30 mg Mg/kg) and control (460 mg Mg/kg) diets.

2. Mg deficiency for a period of more than 3 months resulted in sterility of both males and females.

3. A Mg deficiency of less than 3 months caused abortions or resorptionsin uteroof foetuses in pregnant females before other physical signs appeared.

4. Mg deficiency during lactation rendered the survival of young rats uncertain. The mother rat died of exhaustion if she did not devour her litter.

5. The growth of surviving young rats born of Mg-deficient mothers was noticeably retarded when they were nursed by mothers receiving the Mg-deficient diet.
Iron metabolism in the veal calf. The availability of different iron compounds
Authors: Bremner I. , Dalgarno A. C.
Published: September 2005

1. The haematological status of Ayrshire bull calves reared on fat-supplemented skim milk from about 17 d of age has been examined. The calves were moderately anaemic after an 11-week experiment and it was shown that their performance was related to their blood haemoglobin concentration.

2. The relative availabilities of iron from FeSO4, ferric citrate, ferric-ethylenediaminetetra-acetate and iron phytate were compared at a supplementary dietary concentration of 30 μg Fe/g. No significant differences were noted between the three soluble Fe sources but the Fe of the insoluble iron phytate was less available.

3. The decreases in blood haemoglobin concentrations in all calves were greatest in the early weeks of the experiment. In calves given supplementary Fe, however, there was generally an improvement in haematological status after 6 weeks. Plasma Fe concentrations fell to 0·20 μg/ml in the most deficient animals. Total Fe binding capacities averaged about 10 μg Fe/ml in the later stages of the experiment.

4. Some of the calves were copper-deficient, and in some animals the effects of dietary Cu supplementation on both Cu and Fe metabolism were studied. About 50% of the supplementary Cu was retained in the livers of the calves.

5. A dietary intake of 40 μg Fe/g milk powder appears to be sufficient to prevent all but a very mild anaemia, provided the Fe is presented in soluble form.
The effect of a traditional low-fat diet on energy and protein intake, serum albumin concentration and body-weight in Ugandan preschool children
Authors: Rutishauser Ingrid H. E. , Frood J. D. L.
Published: September 2005

1. A group of ten Ugandan children were given, ad lib., under supervision, the traditional home diet and their intakes of energy and protein and changes in body-weight and concentrations of serum albumin compared with those of a similar group of nine children fed on a milk-based diet with the same protein concentration.

2. The energy and protein intakes of the children fed on the home diet were significantly lower than those of the children fed on the milk-based diet, as was their rate of weight gain and serum albumin regeneration.

3. The significance of the findings is discussed in relation to the low intakes of energy and protein and the hypoalbuminaemia found in Ugandan preschool children.
Absorption of iron from maize (Zea maysL.) and soya beans (Glycine hispidaMax.) in Jamaican infants
Authors: Ashworth Ann , Milner P. F. , Waterlow J. C. , Walker R. B.
Published: September 2005

1. The absorption of iron from59Fe-labelled maize and soya-bean preparations was measured by whole-body counting in forty-two apparently healthy Jamaican infants and compared with the absorption of ferrous ascorbate.

2. The mean absorption of Fe from maize was 4·3% and from soya beans baked at 300°, 9·4%, compared with 28·5% for ferrous ascorbate. In a group of children given boiled soya beans the mean absorption of Fe was 2·8%, and of ferrous ascorbate 16·7%.

3. There was much variability between replicate tests made on the same child at intervals of 1–2 weeks.

4. The absorption of food Fe was not increased in children who were considered to be anaemic (haemoglobin less than 100 g/l) or Fe-deficient (serum Fe less than 500 μg/l and saturation of total Fe-binding capacity less than 15%).

5. The poor availability of Fe in maize meal, which is a staple food of children in Jamaica, is probably an important cause of the high prevalence of Fe-deficiency anaemia.
Portal blood flow and heat production in the digestive tract of sheep
Authors: Webster A. J. F. , White F.
Published: September 2005

1. A method is described for measurement of portal blood flow in the sheep by the principle of continuous thermal dilution produced by injection of cool saline into the portal circulation at 1 mg/s for 30 s.

2. In most animals phlebitis developed only around the catheter in the right ruminal vein. This affected their appetite and condition after surgery. When all catheters were introduced into the anterior mesenteric veins there was no phlebitis and appetite postoperatively was normal.

3. Portal blood flow in six out of nine sheep was 33–34 mg/kg body-weight per min in the morning before feeding. After a meal of dried grass it increased during the period about 2–6 h later.

4. Total heat production and oxygen consumption of the digestive tract were estimated from portal blood flow and arteriovenous differences in temperature and oxygen concentration. When the heat production of the digestive tract was increased by 1·77 kJ/min by the inclusion of a heating element in the rumen, estimated total heat production increased, on average, by 1·73 kJ/min.

5. During the period 2–6 h after a meal of dried grass, portal venous temperature rose, on average, by 0·7°, visceral O2 consumption did not alter significantly, but total heat production rose by 1·19 kJ/min.

6. These initial results suggest that the heat of fermentation can be determined in vivo. In these experiments it was about 10 kJ per 100 kJ digestible energy consumed.
Dissimilation of 1,2-propanediol by rumen micro-organisms
Authors: Czerkawski J. W. , Breckenridge Grace
Published: September 2005

1. The main products of fermentation of 1,2-propanediol weren-propanol and propionic acid, but variable amounts of acetic acid and carbon dioxide were also formed. The concentrations of an intermediate propionaldehyde increased and then decreased.

2. A tentative scheme is suggested, showing that 1,2-propanediol is first dehydrated to propionaldehyde, which is then reduced ton-propanol. The scheme also explains the formation of propionic and acetic acids and shows how the metabolism of 1,2-propanediol is related to that of rhamnose.

3. Experiments with samples of rumen contents from animals on various diets showed that 1,2-propanediol was metabolized most rapidly when the animals were given molassed sugar-beet pulp. The rates of dissimilation of the diol increased with the concentration of rumen contents and with the concentration of substrate.

4. The dissimilation of 1,2-propanediol by rumen micro-organisms resulted in an increased uptake of hydrogen. The metabolic hydrogen, arising from the inhibition of methane production by chloroform, appeared to be better utilized than the gaseous hydrogen.

5. Oxygen gas did not affect the utilization of 1,2-propanediol, but the diol increased the uptake of oxygen by the rumen contents. The hydrogen and carbon balances were better when 1,2-propanediol was incubated anaerobically than in the presence of oxygen.
Changes in some physical characteristics of the digesta in the reticulo-rumen of cows fed once daily
Authors: Evans E. W. , Pearce G. R. , Burnett J. , Pillinger Susan L.
Published: September 2005

1. Three cows were given 3, 5 or 7 kg hay once daily in a Latin-square design, and samples of digesta from four sites in the rumen and one site in the reticulum were taken at six times within the 24 h period after the feed. Dry-matter content and distribution of particle size and of particle density were measured for each sample. The changes in these measurements with time were studied. The incidence of rumination was also recorded.

2. Dry-matter contents of samples ranged from 15 to 3%. Values for samples from the dorsal sacs of the rumen were considerably higher than those for samples from the ventral sites; they also changed more with time after feeding and with level of feeding.

3. Particles were fractionated by sieving into six size groups with mean dimensions (mm) of 9·3 × 0·8, 4·4 × 0·6, 2·6 × 0·3, 1·6 × 0·25, 0·5 × 0·1 and smaller than 0·5 × 0·1. Coarse particles occurred at highest concentrations in the dorsal sacs of the rumen and responded to effects of time and level of feeding; smaller particles showed less response.

4. Particle densities ranged from 800 g/l to 1500 g/l. The proportions of low-density particles were higher in samples from the dorsal sacs of the rumen than in samples from ventral sites; the latter samples had higher proportions of high-density particles than of low-density particles. The changes which occurred are discussed.

5. The density of coarse particles tended to be low and that of fine particles tended to be high.

6. Rumination started at the time of maximum concentration of particles of low density and minimum concentration of particles of high density. Conversely, rumination ended when the concentration of the low-density particles was a minimum and that of the dense particles a maximum.

7. The results are discussed in relation to the possible movement of particles within the reticulo-rumen and the kinetics of particle breakdown.
Concurrent studies on the flow of digesta in the duodenum and of exocrine pancreatic secretion of calves
Authors: Ternouth J. H. , Buttle H. L.
Published: September 2005

1. Two surgical techniques were developed in the calf to study the role of pancreatic secretion in digestion. The secretion was collected through a cannula placed in a small sac of duodenum into which the pancreatic duct drained. The continuity of the duodenum was re-established in the first technique by duodenal re-entrant cannulas, and in the second technique by end-to-end anastomosis of the duodenum with a cannula placed cranial to the anastomosis to return the pancreatic secretion. The accessory pancreatic duct was ligated.

2. The flows of digesta through the duodenum of milk-fed calves were 5505, 6369 and 7709 ml/12 h at 7, 24 and 63 d of age respectively, similar to values reported previously in the literature. In a 12 h collection period 297, 441 and 602 ml pancreatic fluid were secreted by calves of 7, 24 and 63 d of age respectively. The secretion from the mucosa of the duodenal sac was 40 ml/12 h in two other calves.

3. The rate of secretion from the pancreas varied markedly in milk-fed calves, being lowest 2–3 h and highest 6–10 h after feeding. Changes in the concentration of chloride and bicarbonate with pancreatic secretion rate were indicative of a secretin stimulus to secretion.

4. The rates of inactivation of pancreatic enzymes collected from the duodenal sac were measured at 4°, 20° and 39°.
Artificial rearing of pigs
Authors: Braude R. , Newport M. J.
Published: September 2005

1. The butterfat in a whole-milk diet was replaced by either beef tallow, coconut oil or soya-bean oil. The diets contained 280 g fat and 720 g dried skim milk per kg and were supplemented with vitamins A, D, E and K.

2. These diets were offered as a milk, containing 200 g solids/Kg, to pigs weaned at 2 d of age during a 26 d experiment. The pigs were fed at hourly intervals to a scale based on live weight (scaleE).

3. The performance of the pigs and the apparent digestibility of the dietary fats indicated that soya-bean oil was equal to butterfat. Butterfat was slightly superior to coconut oil and markedly superior to beef tallow.

4. The amount and composition of the fatty acids were studied in the proximal, mid and distal portions of the small intestine. When the beef tallow diet was given there was an increased amount of total fatty acids in the digesta of the small intestine, mainly in the distal portion. The digesta contained the smallest quantity of fatty acids when the soya-bean oil diet was given. The fatty acid composition of the digesta indicated that the short- and medium chain fatty acids from all the diets were well utilized, but an increasing proportion of stearic acid occurred in the distal portion of the small intestine. The interpretation of changes in fatty acid composition in the digesta in relation to absorption is discussed.
Relative retentions of the nitrogen of urea and groundnut in isoenergenetic diets for growing heifers
Authors: Bines J. A. , Balch C. C.
Published: September 2005

1. Two experiments were conducted to compare the effect on nitrogen retention of three dietary levels of N given either as groundnut or as urea to growing heifers. Additions of maize starch or dextrose were made to the diets to equalize the inputs of digestible energy within and between experiments.

2. In the first experiment, in which the maximum level of N supplementation was 69·0 g/d, the response to additional N was linear, and was identical for both sources of N. Differences in faecal N between treatments were small; differences in urinary N were large and were entirely attributable to level of N intake.

3. In the second experiment, the maximum level of N supplementation was raised to 103·3 g/d. The response to additional N was again linear and identical for both sources of N; however, for a given level of N input, the amount of N retained was 4·6 g less than in Expt 1. This reduction in N retention may have been due to the change in the proportion of digestible energy derived from the fibrous components of the ration.

4. Live-weight changes calculated from the observed N retentions have been compared with published responses to the inputs of N and energy used in these experiments.
Concurrent studies of the flow of digesta in the duodenum and of exocrine pancreatic secretion of calves
Authors: Ternouth J. H. , Roy J. H. B. , Thompson S. Y. , Toothill Joyce , Gillies Catherine M. , Edwards-Webb J. D.
Published: September 2005

1. The flow of digesta through the duodenum and the concurrent secretion of the pancreas were studied in four Friesian calves given four milk-substitute diets. The diets were: reconstituted, ‘mildly’ pre-heated, spray-dried skim-milk powder with (SKF) or without (SK) margarine fat or with 50% of the skim-milk powder in diet SKF replaced by soya-bean flour (ASKF) or fish-protein concentrate (BSKF), together with dried whey. The diets were givenad lib.twice daily from 13 to 37 d of age, each diet being given for 6 consecutive days. Collections of duodenal digesta and pancreatic secretions, from cannulas, were made for 12 h after feeding the 6th and 12th meals (‘experimental’ meals) for each diet

2. The diets fed as ‘experimental’ meals contained polyethylene glycol (PEG) as a fluid (whey) marker and goat's milk containing [3H]lysine as a marker for total protein; β-carotene was added as a lipid marker to the three diets containing margarine fat

3. Over the 12 h postprandial period, the patterns of duodenal digesta flow and secretion of pancreatic fluid did not differ markedly between the four diets. The abomasal outflow of both nitrogen and lipid in a 12 h postprandial period was related to their intakes from the ‘penultimate’(5th and 11th) meals for diets SKF and SK but to their intakes at the ‘experimental meals’ for diets ASKF and BSKF. Secretion of pancreatic enzyme activity was highest during the 1st hour after feeding but the main outflow from the abomasum of total N and lipid occurred 5–10 h after feeding

4. The time required for all the whey marker (PEG) to pass through the duodenum was similar for diets SKF and SK, but only 53 and 42% respectively of the ingested protein marker passed through the duodenum in the 12 h after feeding. More acid appeared to be secreted by the abomasum when diet SK was given; also less undigested protein passed out of the abomasum after giving this diet. It is concluded that the physical absence of fat globules in the abomasal clot increases the degree of proteolysis

5. The secretions of pancreatic fluid and pancreatic enzyme activity were all markedly lower for diet SK than for diet SKF

6. With diets containing non-milk proteins (ASKF and BSKF), abomasal proteolysis was less efficient and the ingested protein passed out of the abomasum more rapidly than for diet SKF. There was no difference in the rate of abomasal outflow of the whey fluids between diets SKF, ASKF and BSKF

7. In comparison with diet SKF, diets ASKF and BSKF tended to induce less pancreatic enzyme secretion over a 12 h postprandial period, with the exception of lipase

8. There appeared to be no direct relationship between the quantities of any of the pancreatic enzymes secreted during a postprandial period and either the concurrent flow of duodenal digesta or the total quantities of dietary constituents passing through the duodenum.
Nutritional studies on East African herbivores
Authors: Arman Pamela , Hopcraft D. , McDonald I.
Published: September 2005

1. A series of nitrogen-balance trials was done using groups of four animals of various species of wild and domesticated ruminants using pelleted diets (Arman & Hopcraft, 1975)

2. Various herbivores were given grass or grass hays, legumes, herbs and shrubs. Food and faecal samples were analysed for N

3. With the pelleted diets, the N content of the faecal dry matter (DM) was low for eland (Taurotragus oryx Pallas), high for sheep and cattle (Bos taurus and Bos indicus) and intermediate for the three small antelope species (hartebeest (Alcelaphus buselaphus cokei Günther), Thomson's gazelle (Gazella thomsonii Günther) and duiker (Sylvicapra grimmia L.)). With the natural fodders, similar relationships were found, together with variations associated with the type of diet

4. Three forms of equation were used to express the relationship between faecal N and food N. One of the forms, the linear regression of g faecal N/kg DM intake v. g food N/kg DM intake, fitted the results less well than did the other two and was not used to estimate metabolic faecal N (MFN) losses

5. MFN was calculated by extrapolation of linear regressions of g faecal N/kg faecal DM v. g N intake/kg faecal DM for the pelleted diets. The range of values was (g N/kg faecal DM): Friesians 7·6, eland 8·1, zebu cattle 11·0 and small antelope and sheep 11·5–12·6. There were significant differences (P < 0·001) between species in slopes and intercepts

6. MFN was calculated from linear regressions of g faecal N/kg faecal DM v. g food N/kg food DM for all diets. This method gave the best fit for the pelleted diets. Values for these diets were (g N/kg faecal DM): eland 8·3, cattle and sheep 9·3–11·0 and small antelope 11·6–12·3. Species differences were significant (P < 0·001). With grasses, values ranged from 5·9 for non-ruminants (rabbit (domesticated), warthog (Phacochoerus aethiopicus Pallas) and hippopotamus (Hippopotamus amphibius L.)) plus eland and wildebeest (Connochaetes taurinus Burchell), to 8·4 for the other ruminants (sheep, goat, hartebeest, gazelle, duiker, buffalo (Syncerus caffer Sparrman)), kob (Adenota kob thomasi Sclater), reedbuck (Redunca redunca Pallas) and topi (Damaliscus korrigum Ogilby). For ruminants (sheep, hartebeest, duiker and kob), excluding eland, given legumes the value was 8·6, and for sheep and duiker given herbs the value was 14·7. With shrubs, faecal-N losses were variable and sometimes high

7. With the pelleted diets, true digestibilities of crude protein (N×6·25) varied from 0·84 to 0·91

8. The results are discussed in relation to the digestive physiology and feeding habits of the various species, and there is an examination of the feasibility of using linear regressions of crude protein in the diet v. N in the faecal DM for evaluating the quality of the diets selected by free-ranging East African herbivores.
The effect of dietary lipids on lipolysis in rat adipose tissue
Authors: Larking P. W. , Nye E. R.
Published: September 2005

1. Rats were fed for 8 weeks on one of five diets differing in the amount of fatty acids 18:1, 18:2 and 18:3. Lipolysis, in vitro, of epididymal fat from fed and fasted rats was measured both basally and in the presence of noradrenaline with and without prostaglandin E1

2. Lipolysis was markedly influenced by the type of dietary fat. In particular, lipolysis in adipose tissue from rats given diets rich in the fatty acid 18:3 was higher than in the rats given diets containing 18:2

3. Results showing the effects of fasting on adipose tissue lipolysis are also presented

4. The results are discussed in relation to the known effects of unsaturated fats on hyper-plasia and protein synthesis in adipose tissue and on the possible role of prostaglandins.
Endogenous nitrogen excretion and utilization of dietary protein
Authors: Nicol B. M. , Phillips P. G.
Published: September 2005

1. The endogenous nitrogen losses of men of different ethnic, ecological and socio-economic backgrounds are similar when calculated per unit body-weight or per unit basal energy consumption. The hypothesis that endogenous N losses, adjusted upwards by a factor of 0.30 to equate them with N equilibrium, can be used to derive man's physiological requirements for proteins of high quality, e.g. those of egg and milk, was studied..

2. Men living in Nigeria, accustomed to eat diets which provided mixtures of protein only slightly higher than the ‘safe level of intake’ proposed by the Joint FAO/WHOad hocExpert Committee on Energy and Protein Requirements (FAO/WHO, 1973), were found to use absorbed N more efficiently than University of California students who habitually consume diets which supply a great excess of protein over that ‘safe level’..

3. The greater protein-sparing effect of carbohydrates than of fats and oils may play a part in this more efficient use of protein by men living in developing countries. Also, man possesses mechanisms in intermediary metabolism which allow him to adjust to low levels of protein intake..

4. Thus it appears that all apparently healthy men cannot be considered equal in regard to their requirements for protein.
Serum protein fractions from children of differing nutritional status analysed by polyacrylamide gel electrophoresis and electroimmunoassay
Authors: Schelp F. P. , Migasena P. , Saovakontha S. , Pongpaew Praneet , Supawan Venus
Published: September 2005

1. The nutritional status of children showing no clinical signs of malnutrition, from the University School of Khon Kaen, Khon Kaen province, north-east Thailand and from two villages nearby, was tested. The children were grouped according to their body-weight expressed as a percentage of expected weight-for-height (Harvard standards (Stuart & Stevenson, 1959), as given by Jelliffe (1966))..

2. The differing prealbumin concentrations indicated that nutritional status differed between the groups..

3. The urinary urea: creatinine ratio was significantly lower in the village children compared with the children from Khon Kaen, indicative of the higher dietary protein intake of the latter..

4. α1-Acid glycoprotein and the first ‘post-albumin peak’ (obtained by polyacrylamide gel electrophoresis of serum and containing mainly Gc-globulin, α1-antichymotrypsin and α1-B-glycoprotein) were found to be significantly higher in the village children compared with children from Khon Kaen..

5. The three main proteins of the first ‘post-albumin peak’ from polyacrylamide gel electrophoresis of serum were tested separately using the electroimmunoassay method. There was no significant difference in Gc-globulin between the children from Khon Kaen and the village children. The concentration of α1-B-glycoprotein from those Khon Kaen children whose body-weight was more than 95% expected weight-for-height was significantly lower compared with that of village children. α1-Antichymotrypsin concentration was significantly higher in serum from Khon Kaen children than in serum from village children.