1. The effect of drying and ensiling ryegrass on the site of digestion of the energy andcarbohydrate fractions was studied in sheep fitted with rumen cannulas and re-entrant can-nulas in the proximal duodenum and terminal ileum.

2. The sheep were given fresh (frozen) grass, dried grass, wilted and unwilted silage pre-pared from herbage harvested from the same sward. The grass diets were offered twice dailyto each animal and paper impregnated with chromium sesquioxide was administered twicedaily into the rumen. Twenty-four hour collections of duodenal and ileal digesta, adjusted togive 100 yo recovery of Cr2O3, were analysed to determine the extent of digestion in the fore-stomachs, the small intestine and the caecum and colon.

3. Total digestibility of the gross energy was similar for the fresh grass, dried grass andwilted silage diets (67·4,68·1 and67·5 %)but higher for the unwilted silage (72·0 %, P < 0·01).There was an increased flow of energy into the small intestine when the sheep were given driedgrass and unwilted silage. The proportion of the apparently digested energy lost within thesmall intestine was greater when the dried grass was given (302 yo) than when the fresh grasswas given (23·6 yo).

4. Drying or ensiling of wilted material affected digestion neither in the entire alimentarytract nor in the different sections of the tract, of some carbohydrate fractions. About 97 yo ofthe digested water-soluble carbohydrate, over 90 yo of the digested cellulose and over 70 yo ofthe digested hemicellulose were digested before reaching the small intestine. The increasedamount of energy entering the duodenum of the sheep given the dried grass was notaccounted for by changes in the fate of these carbohydrate fractions in the digestive tract. Withunwilted silage, digestibilities of the cellulose and hemicellulose fractions were higher, andlower proportions of the digested carbohydrates were lost before the small intestine.

1. The object was toinvestigate the importance of urea a source of ammonia in the large intestine of herbivores. Urea was present in small intestinal contents of slaughtered horses in concentrations similar to those in blood but, in the small intestine of salughtered sheep, the urea was less than in blooc.

2. There was little ammonia in small intestinal contents of slaughtered horses but consider-able ammonia was present in small intestinal contents of slaughtered sheep. The ammonia in small intestinal contents of the slaughtered sheep was probably formed from urea, as ileal con-tents taken from a sheep with an ileal cannula contained considerable urea and little ammonia.

3. The ammonia concentration in caecal contents of sheep was related to the concentration of urea in blood except when ileal contents were prevented from entering the caecum.

4. Ileal digesta of sheep contained more free amino nitrogen than did caecal digesta.

5. Ammonia was absorbed more rapidly than water from the caecum of sheep. The rate of absorption was related to the concentration of ammonia in the caecum.

1. An attempt was made to measure body volume and body fat in malnourished children using the same closed-circuit apparatus for both determinations. If these measurements were sufficiently accurate, they would enable total body protein to be calculated.

2. A helium dilution technique was used to estimate the volume of the child. Although highly reproducible measurements were obrained for the volume of inanimate objects by this techinque, the results with children were erratic.

3. The fat stores of the child were determind by measuring the amount of cyclopropane (C2H4) which would dissolve in the body. This technique gave acceptable answers with marasmic children who have little subcutaneous fat, but with obese children equilibrium could not be obtained in an acceptably short period of time. It is not practicable to calculate the equilibrium concentration by extrapolation of the uptake curve in obese children.

1. Lambs were removed form their dams at 2 d of age, and at 5 weeks of age eitht of one group were incoulated with a mixed rumen ciliate and seven in a second group were maintained ciliate-free throughout the 61 weeks of the experiment. Performance of the groups was compared when given a 2:1 roughage:concentrate diet as a set ration and with ad lib. roughage.

2. Mixed ciliate populations developed in all faunated lambs and average-sized populations were maintained. Large numbers of flagellate protozoa developed in the ciliate-free animals after flagellates had been introduced into the building with the ciliate-free animals after flagellates had been introduced into the building with the ciliate inoculum.

3. Higher numbers of rumen bacteria were found in the ciliate-free group.

4. Only between the 14th and 21st weeks was there a significant different between groups in weight gain and this was infavour of the faunated group. The only significant different in body measurements was greater girth in the ciliate-free lambs.

5. Only minor differences were found between the groups in calorimetric trials, digestibility and nitrogen balanes. There were no differences between groups in concentration of total protein N and soluble sugar in the rumen. The ammonis concentration was significantly higher in the faunated group.

6. The concentrations of total rumen volatile fatty acids (VFA) were higher in the faunated group. Differences, between groups, in proportions of VFA were attributed to the activity of the rumen bacteria rather than the ciliates per se.

7. No differences between groups were found in the concentrations of blood sugar and haemoglobin.

8. It was concluded that the changes due to the presence of rumen ciliates were not great enough to be reflected in animal performance under the conditions of this experiment.

1. Experiments in children and in animals seem to demonstrate that in marasmic malnutrition there is a reduction in the secretion of growth hormone. To study this problem the fasting, resting plasma concentrations of growth hormone were determined, before, and 45 and 60 min after, stimulation with an intravenous dose of arginine, in six infants with marasmus, in six infants with kwashiorkor and in five normal infants.

2. The values of plasma growth hormone (4·5 ± 0·97 ng/ml) in marasmic infants were significantly (P < 0·001) lower than those of the controls (7·8 ± 2·6 ng/ml), and responded little to stimulation with arginine (5·1 and 5·8 ng/ml at 45 and 60 min respectively), in contrast to those in the control group, which rose to 16·4 and 14·6 ng/ml. In children with kwashiorkor the values were very variable, but generally high, and showed little response (25·6 ± 13·3 before and 25·0 ± 17·6 and 14·2 ± 5·3 ng/ml at 45 and 60 min after stimulation respectively).

3. These results demonstrate that the responses of the hypophysis to deprivation of calories and protein (marasmus) and to protein deprivation (kwashiorkor) are different: in marasmus there is a progressive adaptation, with low secretion and poor reaction to stimulation, whereas in kwashiorkor the process is acute with high basal values of plasma growth hormone.

1. Sour maize pap fortified with soya (Soy-Ogi), developed at the Federal Institute of Industrial Research, Oshodi, Nigeria has been evaluated chemically for its nutrient composition, biologically for protein quality and toxicity, and therapeutically on patients with kwashiorkor.

2. The indications are that it is a complete protein food suitable for feeding to children after weaning, and it compares favourably and economically with milk foods.

3. It was successfully used to restore normal health to children suffering from kwashiorkor.

1. Constant intravenous (3 h) infusions of a fructose solution were given on a rate for body-weight basis (0·6 g/kg per h) to thirty patients who had no evidence of diabetes mellitus or liver disease. Concentrations of blood fructose, pyruvate and lactate formed a plateau during the last 1–1·5 h of the infusion period.

2. Although the numbers were small, the individual pyruvate and lactate concentrations at plateau varied greatly and assumed a bi-modal distribution, suggesting two distinct groups. The group to show a lower pyruvate and lactate rise (group A) contained more males of a lower age and more patients who had ischaemic cardiac disease than the other group (B); none of these differences was, however, statistically significant. The fructose concentrations at plateau were not significantly different between the groups. Serum triglyceride glycerol concentration during the infusions rose markedly in three patients in group A but in none in group B. Minor changes in concentration of blood glucose, insulin, inorganic phosphate and uric acid during the infusions were not significantly different between the groups and did not fall into a bi-modal pattern.

3. Constant intravenous (3 h) infusions of 0.15M-sodiurn lactate at the same infusion rate in eight of the patients (four from group A and four from group B) did not produce a significant difference in the blood lactate concentrations at plateau between patients from the two groups.

4. These results reflect qualitative differences in fructose metabolism in the patients studied. The difference in pyruvate and lactate production may be associated with total carbohydrate intake. However, the bi-modal distribution strongly suggests a genetically determined difference in metabolism between the two groups.

1. The distribution of copper, zinc and manganese in seven regions of the brain, liver, heart, muscle from the abdominal wall, and skin of children was determined by means of atomic absorption spectrophotometry.

2. The results showed significantly lower levels of Cu, Zn and Mn in livers of children with kwashiorkor compared with control subjects. The concentrations of these three elements were higher in livers of children with marasmus than in livers of children suffering from kwashiorkor and not significantly different from those of control subjects.

3. The Cu concentration in muscle obtained from the abdominal wall of subjects with kwashiorkor and the Mn concentration in heart muscle of all groups with protein-calorie malnutrition were significantly lower than the respective values for the control group.

4. There was no significant difference between Cu, Zn or Mn concentration in brain tissues of control subjects and in those with protein-calorie malnutrition.

1. Twenty pigs were reared to a weight of 90 kg on various dietary regimens so that their lipid content varied from 16 to 38%;. They were injected intravenously with ~ 400 μCi of 42KCl. The animals were killed ~ 28 h after injection and their contents of water, lipid, sodium and potassium were determined.

The specific activity of plasma reached equilibrium 10–12 h after injection, that of urine not until 20 h after.

Losses of activity in urine, faeces and gut contents in the 24 h after injection amounted to 3·1, 0·3 and 1·5% of the injected dose, respectively.

Total body K was more accurately estimated from urine specific activity than from plasma specific activity.

Exchangeable K, estimated from urine specific activity Ke(u), was highly correlated with the weight of fat-free tissue (r = 0·93), the residual standard deviation of the regression being 1·8 kg fat-free tissue.

Percentage extractable fat was equally well correlated with Ke(u) (r = −0·92).

1. A combination of balance and isotope techniques has been used to study the effects of age and dietary calcium content on Ca metabolism in forty-two wether sheep.

2. The amount of Ca absorbed by young growing animals varied significantly with intake. The percentage of the dietary Ca absorbed, however, remained unchanged. In older animals the amount of Ca absorbed was not altered by changes in intake, but decreased slightly with age.

3. Retention of Ca was directly related to the amount of Ca absorbed and was independent of age or breed. Furthermore, nearly all the Ca absorbed above the minimum mean amount required for maintenance was retained.

4. Faecal endogenous loss of Ca also was related to the amount of Ca absorbed. Values for faecal endogenous Ca were much lower than those used in the calculation of dietary require-ments by the Agricultural Research Council (1965).

5. Urinary Ca excretion was variable, and was not related to age or changes in dietary Ca intake.

6. Increased absorption of Ca in young growing animals was accompanied by a decreased rate of bone resorption, but the rate of bone accretion remained unchanged. Changes in dietary Ca in older animals had no effect on either of these two processes. Results indicate that bone resorption is the main pathway governing Ca homoeostasis. Both the rates of Ca accretion into bone and resorption from bone decreased with age.

7. Neither the rapidly exchangeable Ca pool (P) nor the slowly exchangeable bone pool (E) was altered by changes in dietary intake in young or mature animals. Both, however, decreased in size with age.

8. The size of the slowly exchangeable pool (E) was directly related to the rate of Ca accretion into bone. 9. The results were used to calculate dietary Ca requirements of sheep gaining weight at different rates, and these values have been compared with values recommended by the Agricultural Research Council (1965).

1. The plasma and blood volumes of twenty-eight Iraqi children were measured. Twenty-four of them were malnourished in varying degrees and four were normal children who acted as controls. None of the children was anaemic.

2. There was an increase in the plasma and blood volumes per unit body-weight correlating with the degree of malnourishment (P < 0·001).

3. There was little variation in the values for plasma and blood volumes when calculated per unit body length; the values were less constant when calculated per unit body surface.

4. The effect of age on the plasma and blood volumes per unit body-weight was less than the effect of the degree of malnutrition.

5. There was no correlation between the plasma volume of malnourished children and their corrected venous haematocrit, if children with severe anaemia were excluded.

1. The Knoop test of hardness of materials has been used to test the hardness of human nail.

2. The range of hardness of nails was found to be small in healthy persons and large in malnourished children.

3. Nails from malnourished children were in general much harder than those from healthy persons. The nails of a small group of three children became softer while they were recovering from malnutrition.

1. Four young Friesian bulls with rumen fistulas were given four isocaloric all-concentrate diets containing different amounts and sources of nitrogen in a Latin square arrangement. Diet HP (high-protein) contained 2·31% plant nitrogen; diet MPU (medium-protein with urea) 1·67% plant nitrogen and 0·69% urea nitrogen (total 2·36%); diet LPU (low-protein with urea) 0·95% plant nitrogen and 0·69% urea nitrogen (total 1·65%); diet HPU (high-protein with urea) 2·28% plant nitrogen and 0·69% urea nitrogen (total 2·97%), calculated on an air-dry basis.

2. The rumen pH varied between 5·8 and 6·1 with diets HP, MPU and HPU, but was significantly lower with diet LPU with values between 5·4 and 5·8.

3. The results showed no differences between the isonitrogenous diets HP and MPU except that replacement of plant nitrogen with urea was followed by an increase in the concentration of ammonia in the rumen. With the diets containing urea, the concentrations of rumen ammonia varied inversely with the amount of dietary plant nitrogen supplied, indicating a negative effect of plant nitrogen on urea utilization.

4. Concentrations of alkali-labile nitrogen (amide) were not increased with diets containing urea except with diet HPU, which produced the highest concentrations of ammonia in the rumen.

5. The concentration of true protein in the rumen and the amino acid distribution were similar with all four diets, indicating the ability of the microflora to adapt to qualitative and quantitative differences in dietary nitrogen intake.

6. Ration acceptability was lower with diets LPU and HPU than with diets HP and MPU.

7. Large differences between individual animals in rumen pH, percentage of dry matter and total nitrogen concentration in the rumen were noted.

1. Free amino acid entry rates, rates of portal uptake of amino acids and rates of glucose synthesis from amino acids have been measured during the continuous intravenous infusion of [U-14C]-labelled mixed amino acids in six sheep receiving diets that supplied different amounts of protein.

2. In four of these sheep and in one other, total rates of glucose production have been measured using continuous intravenous infusions of [U-14C]-labelled glucose.

3. A signiiicant correlation was found between total amino acid entry rate ( Y mg/min.kg) and daily protein intake ( X g/kg): Y = 2·14+ 1·38X (r = 0·878, 0·02 > P > 0·01).

4. A significant correlation was found between the rate of absorption of amino acids into the portal system ( Y mg/min.kg) and the daily protein intake ( X g/kg): Y = 0·58 + 0·58X (r = 0·884, 0·02 > P > 0·01).

5. A highly significant correlation was found between total glucose production rates ( Y mglmin. kg) and daily protein intake ( X g/kg): and daily protein intake ( X g/kg): Y = 2.14+ 1.38X (r = 0·878, 0·02 > P > 0·01). Y = 0·375f0·702X (r = 0·866, 0·005 > P > 0·001).

6. The mean proportional contribution to total amino acid entry made by portal absorption was 33·5 f 1·8 yo (six animals).

7. A significant correlation was found between the rate of glucose production from amino acids (Y mg/min.kg) and the rate of entry of amino acids ( X mg/min.kg): Y = 0-189X-0·414 ( r = 0·84, 0·01 > P > 0·005).

8. The best approximation of the proportion of glucose derived from amino acids was 28·16 f 5·1 % (six animals).

9. The specific radioactivities of amino acids in liver, kidney and muscle did not approach those found in plasma during infusions of [U-14C]-labelled mixed amino acids of up to 6·75 h.

1. Two experimental groups, each of thirteen boarding schoolboys, were given either 400 mg α-tocopheryl acetate or placeboes daily in addition to their normal diet during training in swimming and various athletic activities over a period of 6 weeks. Evaluation of the experimental treatments was made from tests of anthropometric status, cardiorespiratory efficiency and motor fitness and performance, which were administered at the beginning and end of the experimental period.

2. Whereas training significantly improved physiological function and performance in both groups (P < 0·05), vitamin E did not.

1. NaH14CO3, was infused at a constant rate either subcutaneously or intraperitoneally into sheep kept in a uniform environment and consuming a standard amount of food each hour. After 3 h of infusion the specific radioactivity (SR) of COe obtained by acidification of samples of blood taken from the right atrium showed no significant change with time until after 22 h when the infusions were stopped.

2. Entry rates of COa (I/h) in sheep were estimated from the ratio of rate of infusion of 14CO2, as NaH14C08 (µCi/h) to the SR of CO2 (µCi/l) in samples of jugular venous blood, urine and exhaled gas taken after infusions had been in progress for at least 3 h. Concurrently, rates of energy expenditure were calculated from the gaseous exchanges over periods of 60–90 min which were determined for grazing sheep by use of re-entrant tracheal cannulation and meter-ing and analysis of exhaled gas, or for housed sheep by measurement in respiration chambers.

3. Significant positive relationships were found between entry rate, the independent variable, and the contemporary energy expenditure. Equations obtained for grazing sheep were not significantly different from those obtained for other, housed, sheep when both groups were infused subcutaneously and COz for assay of radioactivity was obtained in all instances from blood, or in all instances from urine.

4. With subcutaneous infusion the equation relating energy expenditure to entry rate estimated from the SR of urinary COa differed significantly from that where entry rate was derived from radioactivity assays of blood or exhaled CO2. There was also a significant differ-ence between two equations where entry rates were determined from the SR of blood CO2 but route of infusion was in the one instance intravenous and in the other was sub-cutaneous. Reasons for the differences between equations are discussed.

5. Changes in the rates of energy expenditure of sheep effected by intermittent exercise on a treadmill were reflected in changes in CO2 entry rates. Values for the energy cost of hori-zontal locomotion by the sheep were derived from the entry rates and were similar in magni-tude to those reported by other workers.

6. I t is suggested that the method of determining energy expenditure from COz entry rate may be adapted for use on many species of animal in a variety of environments.

1. The winged bean (Psophocarpus palustris Desv.) has been grown successfully for several seasons, on an experimental basis, in the forest belt of Ghana, where earlier attempts to grow the soya bean had proved unsatisfactory.

2. Although botanically different, the composition of the dry seeds was found to be very similar to that of the soya bean, containing 37·3% protein, 18·1% fat, 13·9 ppm thiamin and 1·8 ppm riboflavin. The oil of the seeds contained 125·9 mg tocopherol (γ + β) per 100 g. The amino acid composition of the protein was very similar to that of the soya bean, with methionine as the first-limiting amino acid. The content of unsaturated fatty acids and that of poly-unsaturated essential fatty acids were satisfactory.

Active trypsin inhibitor found in the raw seeds could be destroyed satisfactorily by moist heat. No urease activity was detected.

The protein efficiency ratio (PER) and net protein utilization (NPU) of the beans determined with rats, were superior to those of groundnuts. The supplementary value of the protein was shown by mixing two parts of the winged bean and three parts of maize flour. When adjusted to either 10% or 16% protein, the PER values of these mixtures were similar to those of skim milk. At the 16% protein level, addition of skim milk or 0·3% DL-methionine to this mixture produced only an insignificant improvement in PER value.

The pleasant, sweet taste even when in the raw state is one of the advantages of the winged bean. Although, it is a climber, and should be staked, its cultivation on a small scale in selected areas of Ghana is recommended.

1. Gastric motility was studied in a young bull and two sheep which had retained their sucking behaviour. Pressure tracings or electromyograms were recorded from all compart-ments of the stomach.

2. During the sucking of milk or water reticulum contractions either became more fre-quent but weak, or ceased altogether. After sucking, or after the introduction of fluid directly into the abomasum, reticulum contractions slowed down but retained their strength. The rumen and omasum were more fully inhibited than the reticulum.

3. It is concluded that the inhibitory response to sucking has two phases, a cephalic phase dependent upon the eagerness of sucking which mainly influences the strength of the contractions of the forestomach, and an abomasal phase dependent on the degree of distension of the abomasum which mainly affects the frequency of the contractions.

1. Freeze-dried cod muscle and casein were subjected to various conditions of heat treat-ment. Diets containing the different products, or the unheated materials, were given to a group of four adult male rats during successive 48 h periods, and urine was collected during the second 24 h of each 48 h period. A further collection of urine was made from the rats after they had been given protein isolated from heated skim-milk powder. The content and amino acid composition of the ‘peptide’ and ‘free amino acids’ in the urines were determined.

2. Heat damage to the cod-fillet protein increased the total urinary excretion of peptide-bound amino acids, from 18·6 to 48·8 µmol/rat.d. The composition of the peptide also changed, and in particular there was a marked increase in lysine, from 2·98 to 20·30 µmol %. Three amino acids - lysine, aspartic acid and glutamic acid - together comprised nearly 70 % of the total amino acid residues. There was a corresponding increase in urinary excretion of free amino acids, from 53·7 to I 14·4 µmol/rat.d. The combined losses of lysine in urinary peptide and free amino acids were 1·5 % of the total lysine ingested, as against 0·3 % for the unheated cod fillet.

3. The effects of similar heat treatment of casein on the composition of the urinary peptide and free amino acids were less marked. There was no increase in total urinary peptide excretion and there was a smaller increase in the lysine content of the peptide.

4. In urine of rats given protein isolated from heated skim-milk powder, the peptide hydro-lysate was rich in lysine and in furosine, which together comprised 41 mol % of the total amino acid composition. These compounds were presumably formed, together with a smaller quantity of pyridosine, from lysine-carbohydrate complex in the urine. It is probable that, as compared with free lysine, the lysine-carbohydrate complex was absorbed relatively in-efficiently from the rat intestine.

5. The findings are discussed in relation to the wider question of the metabolism of the ‚unavailable peptide’ that is released in the course of digestion of heat-damaged protein.