bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of calorie and protein deficiencies early in life on the subsequent learning ability of rats
Authors: Baird Angela , Widdowson Elsie M. , Cowley J. J
Published: June 2005

1. The effect of malnutrition early in life on the subsequent learning ability of male rats was studied when they were malnourished and after they had been rehabilitated. The HebbWilliams Test of animal intelligence was used.

2. Animals were malnourished from weaning, from birth, or from conception.

3. The rats used for tests were fed on a (1) low-protein, (2) low-calorie, or (3) stock diet.

4. The mean number of errors made by all groups of malnourished animals, tested when they were 13 weeks old, was always greater than that made by the corresponding controls. The same was true after rehabilitation for 5 weeks.
Rates of production of methane in the rumen and large intestine of sheep
Authors: Murray R. M. , Bryant A. M. , Leng R. A.
Published: June 2005

1. An isotope tracer method for estimating methane production in sheep is described.

2. The technique was used to estimate methane produced in both the upper and lower digestive tract and to determine the routes by which it was excreted.

3. Four Merino ewes given lucerne chaff (33 g every hour) were used.

4. Total methane production rate was 21±1.1 (se) ml/min; production in the rumen accounted for 87±1.2% of the total production; 95±1.4% of the methane produced in the rumen was excreted by eructation.

5. Of the methane produced in the lower digestive tract, 89±2.3% was excreted through the lungs and 11% through the anus.
Diets and living conditions of Asian boys in Coventry with and without signs of rickets
Authors: O'Hara-May Jane , Widdowson Elsie M.
Published: June 2005

1. The diets and living conditions of nine Asian boys with biochemical, and in most instances also radiological, signs of rickets were compared with those of nine other boys who appeared to be normal. The groups were matched according to age, religion, place of father's origin and boy's own place of birth.

2. There were no outstanding differences between the diets of the boys with, and of those without signs of rickets. All had adequate to high calcium intakes. Most of the boys had low intakes of vitamin D, and those with signs of rickets generally had lower intakes than the normal boys. The food tables used for making the calculations of vitamin D intakes report the amount of the vitamin in the lipid fraction of milk. If it proves to be true that most of the vitamin D activity of milk is in the aqueous fraction, the boys would have been getting considerably more vitamin D than the results suggested, and their average intake may have been about 3.5 μg/d.

3. It was not possible to make any quantitative measure of the exposure of the boys to sunlight. All Asian boys studied appeared to have their bodies more completely covered than British or West Indian boys.

4. The problem of why nine boys had signs of rickets and nine had none has not been solved. It is suggested that those with signs of rickets may have had higher requirements for vitamin D than the others. When the intake of vitamin D is low and exposure to sunlight is minimal, those with high requirements will be the ones to develop signs of rickets.
The site of magnesium absorption from the ruminant stomach
Authors: Tomas F. M. , Potter B. J.
Published: June 2005

1. A low-magnesium diet was fed to four sheep, each of which had been surgically prepared with a rumen fistula, a tube into the cranial one-third of the omasum, a tube to the cranial one-third of the abomasum and a re-entrant duodenal cannula. Mg, as gluconate or acetate, was continuously infused for 12–14 d in turn into (1) the caudal duodenal cannuia, (2) the abo-masum, (3) the omasum, (4) the rumen. A continuous infusion of the chromium-ethylene- diaminetetraacetic acid complex (CrEDTA) was maintained to the rumen. The abomasal effluent which flowed through the cranial duodenal cannula was continually sampled and the flow of Mg calculated from the concentrations of Mg and CrEDTA. Blood and rumen fluid samples were taken and urine and faeces collected during each period of Mg infusion.

2. The Mg infused to either the abomasum or omasum was completely recovered at the duodenum, indicating a lack of net absorption of Mg from these stomach compartments. In contrast, 13.7–18.7 mmol (36–61 %) of the Mg infused to the rumen was not recovered at the duodenum which suggested that a substantial net absorption of the infused Mg occurred from the reticulo-rumen. Absorption of Mg caudal to the pylorus was not related to the site of Mg infusion and averaged 3.28 ±0.56 (sem) mmol/d.

3. Compared with the intraruminal infusion, the post-ruminal infusion of Mg was associated with decreased plasma and rumen fluid Mg concentrations, decreased urinary Mg excretion, decreased Mg balance and increased faecal Mg excretion.

4. It is concluded that no significant absorption of Mg occurs from either the omasum or abomasum in sheep and that the reticulo-rumen is the principal site of Mg absorption before the pylorus. Absorption of Mg post-ruminally is insufficient to maintain normal Mg status in the animal.
Effect of feeding a carbohydrate-free diet on the growth and metabolism of preruminant kids
Authors: Tanabe S. , Kameoka K.
Published: June 2005

1. Experiments were done using 8-d-old kids to determine the metabolic effect of feeding a carbohydrate-free diet, and the effects of supplementation of this diet with a small amount of glycerol, sodium propionate or glucose.

2. The experimental (carbohydrate-deficient) diets permitted growth nearly equal to that with the control diet (cow's milk). The kids given the experimental diets generally had lower levels of blood glucose than those given the control diet.

3. With all experimental diets there were increases in the concentrations of plasma lipid and total liver lipid and a decrease in the concentration of liver glycogen; supplementation of the carbohydrate-free diet with glycerol, sodium propionate or glucose had no additional effect on these values.

4. The ingestion of cow's milk produced hyperglycaemia 2 h after feeding, while in kids given the carbohydrate-free diet there was no increase in blood glucose level. The concentration of plasma free fatty acids in the kids given the carbohydrate-free diet was higher than that in control animals 24 h after feeding, suggesting that the kids given the experimental diet preferentially utilize free fatty acids as an energy source.
Gastric secretion and fermentation in the suckling pig
Authors: Cranwell P. D. , Noakes D. E. , Hill K. J.
Published: June 2005

1. The contribution to acidification of the stomach contents of pigs by hydrochloric acid secretion or by lactic acid produced by fermentation was studied in fifteen suckling pigs from six litters born and reared either in a ‘conventional’ environment or in an isolated ‘clean’ environment. Sequential samples of stomach contents obtained during periods of up to 24 h were analysed for their chloride and lactic acid contents, pH and total titratable acidity. These values gave a measure of organic and inorganic acids respectively.

2. Six pigs from two litters born and reared in a ‘clean’ environment had acid secretion in the stomach at 2 d of age, and the concentrations of lactic acid in stomach contents remained low (0-40 mmol/1) throughout the suckling period.

3. Eight pigs from three litters born and reared in a ‘conventional’ environment, and a ninth pig born in this environment but moved to the ‘clean’ environment at 24 h of age, had lactic acid in concentrations of up to 250 mmol/l in stomach contents within the 1st week of life. The pattern of lactic acid production (and hence the acidity of stomach contents) was governed by the frequency of suckling.

4. Both between- and within-litter variation in the age of onset of HCl secretion was evident in the group reared in a ‘conventional’ environment, and when HCl secretion did occur it was usually accompanied by a reduction in lactic acid production.

5. It is concluded: (I) that the environment at birth is important in determining the fermentative ability of the stomach flora; (2) that if lactic acid is produced in large amounts in the stomach, it may partly or completely inhibit acidification by HCl.
Amino acid metabolism in the piglet: influence of level of protein and of methionine in the diet on tissue uptake and in vivo oxidation
Authors: Newport M. J. , Chavez E. R. , Horney F. D. , Bayley H. S.
Published: June 2005

1. 14C-labelled lysine, glutamic acid and methionine were each administered as single infusions through catheters in the jugular veins of pigs between 28 and 42 d old, receiving either a low-protein (LP) (140 g protein/kg), or a high-protein (HP) (200 g protein/kg) diet. The pigs received 40 g diet/kg body-weight per d.

2. l-[U-14C]lysine and l-[U-14C]glutamic acid were both rapidly removed from the plasma; 3 min after completion of the infusion less than 10% of the activity from the [14C]-lysine, and between 10 and 20 % of the activity from the [14C]glutamic acid remained in the plasma.

3. In pigs killed 15 min after infusion of either [14C]lysine or [14C]glutamic acid 26% of the activity from the dose of lysine was in the liver of those receiving the LP diet, whereas the corresponding value was only 16% for those which had received the HP diet. The uptake of activity from [14C]glutamic acid by the liver was unaffected by the level of protein in the diet. More activity from [14C]lysine than from [14C]glutamic acid was recovered in the spleen, heart and brain.

4. The recovery of the activity from [14C]lysine as 14CO2 in the 6 h after the infusion of the dose was lower for the pigs on the LP diet (2.7 %) than for those on the HP diet (4.8%). The corresponding values for [14C]glutamic acid infusion were 34 and 52% respectively.

5. Supplementing the LP diet with five successive increments of 1.5 g DL-methionine/kg resulted in an increase from 8 to 17% dose in the recovery of activity as 14CO2 from a dose of l-[I-14C]methionine, whereas with the same supplementation of the HP diet the recovery increased from 8 to 24 % dose.
Studies on the appearance of a hepatic copper-binding protein in normal and zinc-deficient rats
Authors: Bremner I. , Davies N. T.
Published: June 2005

1. A study has been made by gel-filtration techniques of the soluble copper- and zinc-binding proteins in rat liver after both intraperitoneal injection of Cu and dietary Cu supplementation.

2. Liver Cu and Zn concentrations increased after injection of Cu, both metals accumulating in the cytosol, mainly in a fraction with an apparent molecular weight of (about 12 000)

3. When Zn-deficient rats were injected with Cu, there was little change in liver Zn concentration and the occurrence of Cu in the low-molecular-weight form (about 12 000) was more transient. At most periods after injection, Cu accumulated mainly in a fraction with a molecular weight greater than 65 000.

4. When the rats were Cu-loaded by dietary supplementation, virtually no Cu or Zn was found in the low-molecular-weight form in Zn-deficient rats, although they were found in the Zn-supplemented animals.

5. The results suggest that Zn is essential for the accumulation of Cu in this form, but not for Cu to stimulate production of the metal-binding protein by a process requiring active protein synthesis.
Comparative effects of fructose and glucose on the lipid and carbohydrate metabolism of perfused rat liver
Authors: Topping D. L. , Mayes P. A.
Published: June 2005

1. Livers from rats fed on a standard diet were perfused with whole blood, and infused continuously with glucose and fructose at equimolar rates.

2. Infusion of fructose increased both the secretion of very-low-density-lipoprotein (VLDL)-triglycerides and the incorporation of free fatty acids (FFA) from the perfusate into VLDL-lipids, but neither of these two processes was affected by infusion of glucose.

3. Infusion of fructose decreased the oxidation and increased the esterification of FFA, but glucose infusion had no effect on these processes. When fructose and glucose were infused together there was a further decrease in oxidation.

4. When fructose was infused alone or together with glucose, blood concentrations rapidly became stabilized at those found in the hepatic portal vein in vivo, with similar rates of hepatic uptake to those found in the intact animal. Infusion of glucose alone resulted in continuously increasing perfusate glucose concentrations, and rates of uptake which were only 20 % of those for fructose. Blood glucose concentrations were reduced, and lactate concentrations were increased by fructose infusion, and when glucose and fructose were infused together there was a greatly increased rate of glucose uptake.

5. Liver glycogen was not affected by the infusion of fructose or glucose alone; however, their combined addition significantly increased its concentration.

6. Uptake of perfusate FFA was not affected by either fructose or glucose infusions.

7. The results are discussed in terms of the differences in nutrition and metabolism between glucose and fructose, with particular reference to the development of hyper- triglyceridaemia.
Milk-substitute diet composition and abomasal secretion in the calf
Authors: Williams V. J. , Roy J. H. B. , Gillies Catherine M.
Published: June 2005

1. The effect of different protein sources in milk-substitute diets on abomasal acidity and proteolytic activity was studied in Friesian calves, aged 20–58 d (Expt 1). The diets contained ‘mildly’ preheated, spray-dried skim-milk powder (MHM), ‘severely’ preheated, spray-dried skim-milk powder (SHM), fish-protein concentrate (FPC) or solvent-extracted soya-bean flour (SF) as the main protein source.

2. Gastric juice was collected from abomasal pouches before feeding and at 15 min intervals for 8 h after the morning feed. Samples of digesta were obtained from the abomasum at 1 h intervals during the same period.

3. Digesta pH was lower and titratable acidity higher 0-3 h after giving the diet containing MHM than when any of the other three diets was given.

4. Acid secretion from the pouches for the different diets was in the order: FPC > MHM > SHM ≥ SF.

5. Protease secretion from the pouches, assayed at pH 2.1, was in the order: MHM > SHM = FPC > SF.

6. The effect of dry matter (dm) intake and concentration on abomasal acidity was also studied in calves given diets which contained MHM (Expt 2). This diet was reconstituted at either 100 or 149 gdm/kg liquid diet and fed at either 32.5 or 49.0 g DM/kg live weight0.75per d. Samples of abomasal digesta were collected as in Expt 1.

7. A high intake ofdmat a lowdmconcentration resulted in low acidity of the digesta in the first 3 h after feeding, which suggested a dilution effect. Comparison of two diets of differentdmconcentration, which were fed in the same volume of liquid, indicated that the greater thedmintake, the greater was the amount of acid secreted.

8. It is concluded that the protein sources varied in their ability to stimulate abomasal acid and protease secretion and it is suggested that this may relate to calf performance.
The utilization of dietary protein by Nigerian men
Authors: Nicol B. M. , Phillips P. G.
Published: June 2005

1. The excretion of urinary and faecal nitrogen by young Nigerian men of a low income group was found to vary significantly between subjects, but was not significantly different in the same subject, when they were given a mixed diet composed of rice, vegetables and fish on two separate occasions. At the levels of energy and protein supplied by this diet the men gained or lost small amounts of weight, mean values indicating N equilibrium, the variation around the mean being high.

2. The correlation between the urinary and faecal N of these men was significantly negative at and below the level of N equilibrium, becoming positive 2–3 weeks after they had consumed the above diet supplemented by 400 g of lean beef per day, and had already established considerable rates of gain in body-weight and N retention. The diets were made isoenergetic by adding the beef at the expense of cassava flour and red palm oil.

3. The physiological processes involved in the adaptation, by young Nigerian men of low income, to a highly efficient use of low-protein diets are discussed in relation to the biological value and true digestibility of those diets, and to the ‘safe level of protein intake’ and protein-energy ratios proposed by FAO/WHO (1973, 1975).

4. It is concluded that the protein requirements of apparently healthy men can only be established in the context of their ecological, socio-economic and nutritional backgrounds.
Amino acid metabolism in the piglet
Authors: Chavez E. R. , Bayley H. S.
Published: June 2005

1. Supplementing a lysine-deficient diet (5 g lysine/kg) with five increments of lysine, each of 2 g/kg, resulted in increases in growth rate of Yorkshire piglets, aged between 3 and 7 weeks, up to the highest level of lysine (15 g/kg).

2. The free lysine concentration of plasma tended to increase as the dietary lysine level increased from 13 to 15 g/kg, and plasma threonine concentration decreased significantly as the lysine content of the diet was increased from 11 to 15 g/kg indicating that threonine was the second limiting amino acid in the diet.

3. Oxygen consumption and carbon dioxide production of the piglets were not influenced by supplementing the diets with lysine. The heat production was 0.313 kJ/min per kg body-weight in the 6 h experimental period.

4. Supplementation of the diet with lysine had no consistent effect on the recovery of 14C as 14CO2 from a single dose of l-[U-14C]lysine.

5. Adjustment of the determined recoveries of the tracer dose of lysine for the differences in the plasma concentrations of free lysine for the pigs receiving the graded levels of dietary lysine simplified the relationship between recovery and dietary lysine level: it was linear for the first four increments in dietary lysine and then increased sharply for the fifth increment. This indicated that a marked change in the rate of lysine catabolism occurred as the level of dietary lysine was increased from 13 to 15 g/kg.

6. The results of this experiment indicate that the piglets' requirement for lysine is between 13 and 15 g lysine/kg in a diet which contained 181 g crude protein (nitrogen × 6.25)/kg.
The effect of RNA supplementation of rat diets on the composition of body fluids
Authors: Heaf D. J. , Davies J. I.
Published: June 2005

1. In a number of separate experiments, yeast RNA, mixtures of its constituent nucleosides, its constituent bases and ribose were administered orally to rats. In each instance, the resultant changes in the composition of body fluids were monitored using sensitive methods.

2. Ingestion of RNA (100g/kg diet) caused detectable increases in intestinal ribose, inorganic phosphate, uridine, pseudouridine, uracil, inosine, uric acid and probably other purine bases. Their accumulation did not detectably affect the rate of passage of food along the digestive tract, even though some nucleosides are known to affect gut motility.

3. Although plasma levels of uric acid and uridine were higher when RNA was administered in the diet, these changes were very slight compared with those in plasma uracil, which in some experiments were increased more than 20-fold compared with control levels (300μmol/l). Analysis of erythrocytes indicated that the internal environment of at least some cells of the body are similarly altered.

4. Analyses indicated that all dietary RNA-phosphate passed into the urine from the gut but most of the RNA-ribose was probably metabolized. Uracil and uric acid levels in the urine reflected plasma composition.

5. The effect of orally administered mixed nucleosides on blood and urine composition was similar to that of RNA, but the response to an equivalent mixture of free bases differed in several respects; cytosine, adenine and hypoxanthine appeared in urine only under these circumstances.
A study of the age of onset, diet and the importance of infection in the pattern of severe protein-energy malnutrition in Ibadan, Nigeria
Authors: Laditan A. A. O. , Reeds P. J.
Published: June 2005

1. Fifty unselected consecutive cases of protein-energy malnutrition (PEM) presenting at the General Out-patient Clinic of the University College Hospital, Ibadan were classified as marasmus (twenty), kwashiorkor (nineteen) marasmic-kwashiorkor (seven) and undernutrition (four) according to the Wellcome Classification of PEM (Lancet, 1970; Waterlow, 1972).

2. The mean age of the children with marasmus (22.4 months) and of the children with kwashiorkor (25.4 months) were not significantly different. The children with marasmickwashiorkor (27.8 months) were significantly older than the children with marasmus.

3. The deficits in weight- and length-for-age were similar to values previously reported (Waterlow, 1972) even though the children with marasmus tended to be older and the children with kwashiorkor younger than has been reported. Values obtained for the deficit in length-for-age suggested that the children with marasmus had been undernourished from birth whereas the children with kwashiorkor had apparently grown normally until they were 10 months old. It is possible that the history of growth in the first year of life influences the final form of PEM in these two groups of children.

4. Forty-nine of the fifty children had been breast-fed for at least 9 months and nine children had been breast-fed for 2 years. Of the twenty children with marasmus nine were still receiving some breast milk. The diets fed to weaned children with marasmus and to children with kwashiorkor were identical and consisted solely of a maize-starch gruel with no supplementation of protein or vitamins. The similarity in the dietary histories of the two main groups of children suggests some uncertainty concerning a specific role for protein deficiency in the development of kwashiorkor.

5. All the children had had similar infections. The most common of these were measles (morbilli) (40% of all cases) and gastrointestinal infections. However the children with marasmus had a history of chronic diarrhoea whereas the children with kwashiorkor had had more acute diarrhoea.

6. The similar dietary histories but dissimilar histories of infection given by the mothers of the children with marasmus as opposed to those with kwashiorkor suggest that recurrent diarrhoea was at least partially responsible for the chronic undernutrition in the group of children with marasmus. Furthermore although the weaning diets were inadequate the final deterioration in nutritional status was precipitated by gastroenteritis, often following measles.
The effect of different diets including those containing soya-bean products, on digesta movement and water and nitrogen absorption in the small intestine of the pre-ruminant calf
Authors: Sissons J. W. , Smith R. H.
Published: June 2005

1. Preruminant calves, fistulated in the abomasum and distal ileum, were given by infusion into the abomasum, at intervals of 2–3 d, single experimental feeds of cow's milk or a synthetic milk diet in which the protein source was casein or a soya-bean product. Polyethylene glycol (PEG) and phenol red were included as markers.

2. After infusion of the experimental feed, measurements were made of transit time from proximal duodenum to distal ileum and mean ileal flow-rates for the first 3 and 21 h after food residues reached the distal ileum. PEG recoveries for these two periods and net nitrogen absorption up to the distal ileum were also determined. In some experiments sodium, potassium and magnesium concentrations and numbers of viable bacteria in ileal digesta were determined.

3. Measurements of passage of digesta, recovery of marker and net N absorption did not differ greatly between calves given cow's milk and the synthetic milk diet containing casein. Compared to the casein-based diet, a diet based on heated soya-bean flour given to a calf for the first or second time produced a somewhat higher ileal flow-rate and a significantly lower net N absorption. Net N absorption was even lower when a calf received a diet containing unheated soya-bean flour.

4. Calves given the diet containing heated soya-bean flour on several occasions appeared to develop a sensitivity to the flour, and after further feeds containing it they had significantly higher rates of ileal flow (accompanied by correspondingly high rates of Na and K flow), lower small intestine transit times and lower net N absorption values than similarly fed unsensitized calves. They also had significantly lower rates of passage of marker in the first few hours after food residues reached the ileum, indicating inhibition of abomasal emptying. Over all, the changes indicated a severe disturbance in digestive function which was not caused by abnormal bacterial growth and may have been due to a gastrointestinal allergy.

5. Diets prepared from water-extracted flour and from soya-bean-protein isolate also led to digestive disturbances in sensitized calves, but those containing concentrates prepared by extracting soya-bean meal with hot aqueous ethanol did not.
Studies on lipid digestion in the preruminant calf. The source of lipolytic activity in the abomasum
Authors: Toothill Joyce , Thompson S. Y. , Edwards-Webb J. D.
Published: June 2005

1. Lipolytic and proteolytic activities and pH values were determined in secretions collected from innervated abomasal pouches and in abomasal contents from preruminant calves given liquid diets.

2. No lipolytic activity was detected in pouch secretions collected during 1 h after feeding, though lipolytic activity was present in abomasal contents; pepsin (EC 3.4.23.1) and rennin (EC 3.4.23.4) were present in both pouch secretions and abomasal contents. The pH values of pouch secretions ranged from 1.2 to 1.8 and those of abomasal contents from 4.2 to 5.9.

3. When diet was placed directly into the abomasal pouch soon after feeding, the pH values of pouch and abomasal contents decreased similarly (i.e. from 6.3 to approximately 5). Protease activity (U/ml) of pouch contents ranged from 0.1 to 0.8 and that of abomasal contents from 0.1 to 0.2. No lipolytic activity was detected in pouch contents, though abomasal contents contained 0.6 to 1.2 U/ml and when the diet contained milk-fat as the dietary fat source considerable lipolysis of triglycerides containing shorter-chain fatty acids was found.

4. It is concluded that there is no significant secretion of lipolytic enzymes by the fundal mucosa and that the lipolysis of triglycerides in the abomasum of the preruminant calf is due predominantly to a lipolytic enzyme in saliva.
Nutritional evaluation of the protein of dried tomato pomace in the rat
Authors: Drouliscos N. J.
Published: June 2005

1. Nutritional evaluation of dried tomato pomace (DTP-20) as a source of protein was carried out using weanling rats. Comparisons were made with casein (CS), soya-bean meal (SOM-45) and the hydrocarbon-grown yeast Toprina (BP-T). The growth-promoting effects of the diets were evaluated over a period of 28 d ofad lib.feeding.

2. The unsupplemented DPT-20 had a protein efficiency ratio (per) of 2.18±0.13 and a net protein utilization (npu) of 0.55. The addition ofdlmethionine (5 g/kg) resulted in aperof 1.74±0.15 (t2.99,P< 0.01) and anpuof 0.40, while the addition of an amino acid mixture resulted in aperof 2.33±0.08 (t1.84,P< 0.1) and anpuof 0.70.

3. The reason for the decrease in growth and the reducedperandnpuvalues recorded for the methionine-supplemented group of rats is not clear and it is discussed in connexion with an imbalance or a slight toxicity caused by the added amino acid.
Regulation of food intake during growth in fatty and lean female Zucker rats given diets of different protein content
Authors: Radcliffe J. D. , Webster A. J. F.
Published: June 2005

1. Food intake, and the rates of protein, lipid and energy deposition during growth were measured for lean and congenitally obese (fatty) female Zucker rats given diets of different protein content ad lib. Six semi-synthetic diets were used, which contained 40, 100, 150, 300, 500 and 700 g casein/kg (diets 40C, 100C, 150C, 300C, 500C and 700C).

2. Dietary treatments began when the rats were 34 or 35 d old. Collections of urine and faeces were analysed for energy content. The total carcasses of all the rats were analysed individually for protein, lipid and energy.

3. In the first experiment, twelve rats of each phenotype were given diets 150C or 300C. Four fatty and four lean rats were killed at 50, 66 and 98 d of age. In the second experiment groups of four fatty and four lean rats were given diets 40C, 100C, 500C and 700C ad lib. until they were killed at 66 d of age. Other groups of fatty rats were pair-fed from 35 to 67 d of age on diets 100C and 500C. Rats were also killed at 24 and 34 d of age to provide initial samples for the comparative slaughter procedure.

4. When given food ad lib., fatty and lean rats had identical rates of protein deposition at all ages and for all diets, but lipid and energy deposition were always much greater in the fatty rats. Food intake was also much greater for the fatty rats (except on diet 40C). Differences in food intake and growth rate attributable to diet were most pronounced for the range of diets 40C-150C.

5. Fatty rats pair-fed to lean rats deposited less protein but about twice as much energy and lipid as lean rats on the same diets.

6. The results are discussed in relation to existing theories of appetite control. It appears that food intake is precisely regulated in the congenitally obese Zucker rat. This regulation is intimately linked with the impetus for protein deposition and the rates of retention of lipid and energy appear to be of no importance in relation to appetite control.
Studies on the nutrition of marine flatfish. The effect of different dietary fatty acids on the growth and fatty acid composition of turbot (Scophthalmus maximus)
Authors: Cowey C. B. , Owen J. M. , Adron J. W. , Middleton C.
Published: June 2005

1. Five groups of juvenile turbot (Scophthalmus maximus) which had been given a diet free of fat for 12 weeks were given diets in which the lipid component (g/kg) was: oleic acid alone 50, oleic acid 40+linoleic acid 10, oleic acid 40+linolenic acid 10, oleic acid 40+arachidonic acid 10 or oleic acid 40+cod-liver oil 10. These five experimental diets were given for 16 weeks.

2. Weight gains were highest in the group given the diet containing cod-liver oil and lowest in the groups given diets containing oleic acid alone or oleic acid+linoleic acid. Weight gains in the groups given oleic acid+arachidonic acid or linolenic acid were markedly inferior to those of the group given oleic acid+cod-liver oil. It is concluded that arachidonic acid is inferior to polyunsaturated fatty acids of the ω3 series in maintaining growth rate in turbot.

3. Fatty acid analyses of neutral lipids and phospholipids of liver and extrahepatic tissues did not suggest any evidence of desaturation of dietary oleic acid, linoleic acid or linolenic acid by the turbot. These experiments confirm previous isotopic evidence that turbot lack the necessary microsomal desaturases to perform this metabolic transformation.
Studies on digestion and absorption in the intestines of growing pigs. Measurements of the flow of digesta and pH
Authors: Braude R. , Fulford Rosemary J. , Low A. G.
Published: June 2005

1. Thirty-five pigs were fitted with single re-entrant cannulas in either the duodenum, jejunum or ileum. A further twenty-four pigs were used in a conventional digestibility trial.

2. Methods for collecting, sampling and returning digesta were developed.

3. A ‘practical-type’ diet and two purified diets were used, fed twice daily.

4. Flow and pH of digesta were measured hourly in the duodenum and jejunum, and every 6 h in the ileum.

5. In the duodenum and jejunum there were clear flow responses to feeding, while such an effect was not found in the ileum where the flow-rate was much lower and more uniform than in the former sites.

6. In the duodenum and jejunum, and within 6 h periods in the ileum, there was considerable variation in the flow-rate between different pigs within each hour but there was less variation in pH.

7. The pattern of flow in the duodenum and jejunum was similar for each of the diets but the total flow and the average pH in 24 h differed significantly between diets. There were more digesta of a lower pH from the ‘practical-type’ diet than the purified diets.

8. The pH in the duodenum was highest after feeding and decreased with increasing time after feeding. In the jejunum and ileum the pH varied over a much smaller range than in the duodenum.

9. Collections for 6 h periods appeared to be insufficiently long to predict the values obtained in 24 h collections with reasonable accuracy.
Effect of dietary nitrogen source on carbohydrate metabolism in the rumen of the young steer
Authors: McAllan A. B. , Smith R. H.
Published: June 2005

1. Steers, fitted with simple rumen and duodenal cannulas, were given diets of approximately equal parts of flaked maize and hay (A) (containing 16 g nitrogen/kg dry matter (dm)) or diets of flaked maize and straw supplemented with decorticated groundnut meal (B), fish meal (C), or heated (D) or unheated (E) soya-bean meal (containing 24 g N/kg dm). Chromic oxide was given as a marker with the feeds, and flows of different combined sugars at the duo denum estimated from the values for sugars: marker at this site. Contributions of bacterial constituents to these flows were estimated from amounts of RNA present.

2. Rumen bacteria from steers receiving diet A contained approximately 110 g α-dextran-glucose/kg dm and contributed about 60 g α-dextran-glucose/d at the duodenum; bacteria from steers receiving diets B, C, D or E contained 25–40 g α-dextran-glucose/kg dm and contributed about 20–30 g α-dextran-glucose/d at the duodenum. There were no significant differences between different N supplements. About half the α-dextran-glucose, varying amounts of the mannose and galactose, and nearly all the rhamnose and ribose in duodenal digesta were contributed by the bacteria. Almost all the arabinose, xylose and cellulose-glucose was of dietary origin.

3. For steers receiving diet A, mean coefficients of digestibility between mouth and duodenum, corrected where necessary for bacterial contribution, were 0.96, 0.73, 0.58, 0.22 and 0.53 for starch-glucose, galactose, arabinose, xylose and cellulose-glucose respectively. Corresponding mean values when diets B, C, D and E were given, which did not differ significantly amongst themselves, were 0.98, 0.79, 0.81, 0.59 and 0.58. Most values for galactose, arabinose and xylose were significantly higher than the diet A values.
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. , Shotton Susan M.
Published: June 2005

1. The effect of age on the flow of duodenal digesta and of pancreatic secretion was studied in preruminant calves fitted with duodenal re-entrant and pancreatic sac cannulas. In Expt 1 a comparison was made at 7, 24 and 63 d of age of Ayrshire calves given whole milk, and in Expt 2 Friesian calves given milk-substitute diets were studied during the period 16–37 d of age.

2. For the Ayrshire calves, ad lib. whole-milk intake increased with age, but whole-milk intake on a per kg metabolic body-weight (W0.75) basis did not alter. As the intake increased with age, the whey fluids were passed out of the abomasum more rapidly.

3. As judged by the mean duodenal pH values and the values for ‘chloride ion minus sodium ion’ concentration in the digesta, and for apparent secretions (total quantity recovered at duodenal cannula during 12 h after feeding minus intake) the duodenal digesta became more acid as the Ayrshire calves became older. There was no change with age in the extent of degradation of the milk proteins as indicated by the protein-nitrogen: total N values for duodenal digesta.

4. The volume of pancreatic fluids secreted by the Ayrshire calves increased markedly with age, but when expressed on a per kg W0.75 the volume did not increase after 24 d of age. In absolute terms and also in relation to whole-milk intake or W0.75 there was a large increase in secretion of total protease, a very large increase in α-amylase (EC 3.2.1.1) but no change in trypsin (EC 3.4.4.4) activities with age.

5. In the Friesian calves secretion of pancreatic fluid and activities of α-chymotrypsin (EC 3.4.4.5), α-amylase, lipase (EC 3.1.1.3) and ribonuclease (EC 2.7.7.16, 2.7.7.17) but not trypsin or total protease increased with age.

6. The extent of the increase in secretion of pancreatic enzymes during the first hour after the Friesian calves were fed milk-substitute diets differed between enzymes.

7. The changes in the quantities of pancreatic enzymes secreted are discussed in relation to the changes in the digestibility of milk-substitute diets.
The effect of cortisone acetate on the course of development of experimental protein-energy malnutrition in rats
Authors: Lunn P. G. , Whitehead R. G. , Baker B. A. , Austin S.
Published: June 2005

1. The role of corticosteroids in determining which clinical features of protein-energy malnutrition develop on a deficient diet has been studied by the administration of cortisone acetate to experimentally malnourished rats fedad lib.on a mixture containing 31 g protein/kg.

2. Daily administration of 1.25 mg cortisone acetate did not affect dietary intake, which remained the same as in saline (9 g sodium chloride/l)-injected controls. Plasma albumin concentrations, however, increased from a low value of 25.7 g/1 to 47.2 g/l and this was accompanied by an increase both in liver weight and protein content. On the other hand, the protein content of muscle decreased.

3. These changes in the protein contents of liver and muscle were associated with alterations in the corresponding free amino acid pools. The free amino acid content of muscle generally decreased, but in liver many amino acids were increased.
Protective effect of zinc supplementation against copper toxicosis in sheep
Authors: Bremner I. , Young B. W. , Mills C. F.
Published: June 2005

1. A study has been made of the effects of dietary zinc supplementation on the development of copper toxicosis in three groups each of eight 12-week-old lambs.

2. None of the lambs receiving 420 mg Zn/kg diet developed Cu toxicosis in the 24-week experimental period, compared with three in the control group receiving 43 mg Zn/kg and possibly one in the group receiving 220 mg Zn/kg.

3. Liver Cu concentrations were reduced by up to 40% in the Zn-supplemented animals, with concomitant reductions, especially in the early stages of the experiment, in the extent of liver damage, as assessed by measurement of plasma aspartate aminotransferase (EC 2.6.1.1) and arginase (EC 3.5.3.1) activities.

4. Plasma and liver Zn concentrations were increased only slightly in the lambs receiving the Zn-supplemented diets, and the only indication of possible toxic effects of the Zn supplements was the development of a slight anaemia in those animals receiving 420 mg Zn/kg diet.

5. The results suggest that the incidence of Cu toxicosis in sheep may be controlled by increasing their dietary Zn intake.
The biphasic nature of protein metabolism during pregnancy in the rat
Authors: Naismith D. J. , Morgan B. L. G.
Published: June 2005

1. Additional protein given to malnourished rats early in pregnancy was found to increase substantially the weight and cellularity of their foetuses and placentas at term.

2. This observation confirms the hypothesis that protein is stored in early pregnancy for use during the period of rapid foetal growth.
The rapid determination of carcass fat by the Foss-Let specific gravity technique
Authors: Woodward C. J. H. , Trayhurn P. , James W. P. T.
Published: June 2005

1. Carcass fat was determined by extraction with tetrachloroethylene and measurement of the solvent's change in density. The results were comparable in precision to those of a reference method; the new method extracted storage lipid but little structural lipid.

2. The technique is simple, rapid and appropriate for many nutritional studies.
Sulphur and cystine incorporation into rumen microbial protein
Authors: McMeniman N. P. , Ben-Ghedalia D. , Elliott R.
Published: June 2005

1. In three series of experiments, Na235SO4was infused into the rumen of sheep consuming a variety of diets. The specific activity of the sulphur in the rumen H2S pool, rumen bacteria and of the S in bacterial cystine were determined.

2. The results showed that, depending upon the diet, the proportion of total sulphur and cystine sulphur in rumen bacteria originating in the rumen H2S pool could be as low as 0.557 and 0.280 respectively.
Protein turnover in rats treated with Trienbolone acetate
Authors: Vernon Briman G. , Buttery Peter J.
Published: June 2005

1. The anabolic agent Trienbolone acetate (3-oxo-17-β-hydroxy-4,9,11-estratriene acetate) given subcutaneously to female rats increased their growth rate compared with untreated controls (P < 0.001).

2. The compound had little androgenic activity.

3. The fractional synthetic and fractional degradative rates of the mixed muscle proteins were smaller in the treated rats than in the control rats.
Changes in adipose tissue of the rat due to early undernutrition followed by rehabilitation
Authors: Harris Patricia M.
Published: June 2005

1. Male Black and White Hooded rats were allocated at birth to foster mothers in litters of three, nine or sixteen. At weaning animals from each of these litter sizes weread lib.-fed on a stock diet forming threead lib.-fed control groups. At weaning further animals from litters of nine and sixteen were fed on the stock diet in restricted amounts until 12 weeks of age. These undernourished animals were then rehabilitated by being allowedad lib.access to the stock diet.

2. Five animals from each group were killed at various stages of the experiment, their bodies analysed for fat and nitrogen, and the size and number of cells determined in four specific fat depots.

3. The previously undernourished rats failed to make a complete recovery and were significantly smaller thanad lib.-fed animals from the same litter size at 32 weeks of age when the experiment was terminated.

4. The previously undernourished rats from litters of nine deposited a significantly greater proportion of fat in their bodies during rehabilitation thanad lib.-fed animals from litters of nine over the same gain in body-weight. The previously undernourished rats from litters of sixteen deposited the same proportion of fat in their bodies during rehabilitation asad lib.-fed animals from litters of three, nine and sixteen over the same gain in body-weight.

5. There were no significant differences in apparent or total fat cell numbers betweenad lib.-fed animals and undernourished-rehabilitated animals at any of the four sites studied at 32 weeks of age.
Changes in adipose tissue of the rat due to early undernutrition followed by rehabilitation
Authors: Harris Patricia M.
Published: June 2005

1. Male Wistar rats were allocated at birth to foster mothers in litters of three, nine or sixteen. At weaning animals from each litter size weread lib.-fed on a stock diet. Further animals from litters of nine and sixteen were fed on the stock diet in restricted amounts until 12 weeks of age and then rehabilitated by being allowedad lib.access to the stock diet.

2. Five animals from each group were killed at 24 weeks of age and the size and number of cells determined in four specific fat depots.

3. Animals reared in litters of sixteen and further undernourished from 3 to 12 weeks (group L16/U) had significantly fewer fat cells at all sites studied than animals reared in litters of three andad lib.-fed. Group L16/U animals also had significantly fewer observable fat cells at the epididymal site thanad lib.-fed animals reared in litters of nine. These results differ from those found in the Black and White Hooded rat where, after similar treatments, no significant differences in observable fat cell number were found.
Changes in adipose tissue of the rat due to early undernutrition followed by rehabilitation
Authors: Kirtland Janet , Harris Patricia M.
Published: June 2005

1. Well-nourished rats were injected with tritiated thymidine at 15, 22, 28 or 84 d of age. At 1, 6, 11 and 16 d after injection animals from each group were killed, samples of adipose tissue were removed from two subcutanecus sites (abdominal and scapular) and separated, using collagenase (EC3.4.24.3), into ‘fat cell’ and ‘stromal cell’ fractions. The specific (radio)activity of DNA isolated from each fraction was measured. The specific activity of DNA isolated from two ‘deep body’ sites (perirenal and epididymal) was measured only in the animals injected at 84 d of age.

2. Animals undernourished from birth up to 84 d of age were injected with tritiated thymidine at 22, 28 or 84 d of age. Animals were killed 1 and 11 d after injection, adipose tissue removed, and the specific activity of DNA measured. Other undernourished animals were rehabilitated from 84 to 107 d and injected at 91 d of age with tritiated thymidine. The animals were killed 1, 6, 11 and 16 d after injection, adipose tissue was removed from the subcutaneous and deep body sites and the specific activity of DNA determined as before.

3. In well-nourished animals fat cell replication had largely ceased by 12 weeks of age in the subcutaneous depots. There were differences between the various sites of adipose tissue regarding the period of hyperplastic growth, its timing or rate of replication or both.

4. In undernourished animals replication was slow in the subcutaneous depots compared with well-nourished animals of the same age. Rehabilitation from undernutrition stimulated replication which resulted in higher rates in all four depots examined compared with those in well-nourished animals.

5. The findings are discussed in relation to the concept of a finite period of hyperplasia for adipose tissue.
The use of common salt (sodium chloride) fortified with iron to control anaemia: results of a preliminary study
Authors: Nadiger H. A. , Krishnamachari K. A. V. R. , Naidu A. Nadamuni , Narasinga Rao B. S. , Srikantia S. G.
Published: June 2005

1. Iron-deficiency anaemia continues to be a major public health problem in all developing countries. Fortification of commonly consumed food items has been suggested as an effective method of preventing anaemia. Common salt (sodium chloride) has been identified as a suitable vehicle to be fortified with Fe in India.

2. Common salt was fortified with ferric orthophosphate (3500 mg/kg) and sodium hydrogen sulphate (5000 mg/kg) to provide an additional 1 mg elemental Fe/g common salt consumed.

3. After ascertaining the acceptability of the fortified salt with respect to its colour, taste and bioavailability a pilot feeding trial was conducted among residential schoolchildren in Hyderabad. Feeding of the fortified salt for a period of 1 year resulted in a significant increase in the haemoglobin level of these children. There was also a significant reduction in the prevalence of anaemia among children given the fortified salt.

4. Before the same fortified salt is recommended as a public health measure to prevent Fe-deficiency anaemia among our population it is necessary that further large-scale community trials with this fortified salt are carried out particularly among the rural population.