1. Ten pigs which had been undernourished for a year, and weighed about 5.5 kg at that time, were rehabilitated on an excellent dict. They grew fast, but no faster per kg body-weight than normal pigs, and they stopped growing at the same chronological age. Consequently, they did not attain the same adult size as the normally reared pigs.

2. The rehabilitated animals appeared to be fatter than the control animals, but the proportions of muscle to bone in the carcasses of the males and females were within the range to be expected in normal animals of the same fat-free weight, although the castrates may have been somewhat less muscular on this basis.

3. The weights of the organs per kg of fat-free body weight were within the limits found in normally reared animals of the same fat-free weight.

1. In two experiments with chicks given diets of different manganese content, the effects of vitamin D on the Mn contents of bone and liver and on the retention of 54Mn in bone, liver and the whole body were determined.

2. Vitamin D slightly increased the Mn content of dry fat-free bone but the proportion of Mn to ash remained unchanged and the Mn content of bone was influenced much more by the level of dietary Mn than by the presence of vitamin D.

3. Vitamin D, when given over a 3-week period, increased slightly the Mn content of the liver, but again the level of dietary Mn had a greater effect than the presence of vitamin D.

4. The retention of an oral dose of 54Mn was not uniformly influenced by vitamin D, but in birds given the hign-Mn diet retention was reduced by vitamin D, indicating a decrease in the turnover of Mn.

1. Young adult female albino rats were given 20, 40, 60, 80, and 100% raw egg white powder in their diet; controls were fed on laboratory chow. Daily clinical measurements were made for 2 weeks. The rats were then killed, and the weights and water contents of various organs were determined.

2. The experiment was repeated with groups of young male albino rats fed for 2 and 4 weeks.

3. Toxic signs caused by increasing intake of dried raw egg white powder were: decreased food intake, weight loss, soft stool, diarrhoea, glycosuria and death. Water intake and urine output rose with increasing raw egg white powder in the diet. In all groups the urine was alkaline and the urinary output of protein increased. At autopsy there was a decrease in the absolute weight and in the water content of most body organs with increasing amounts of raw egg white powder in the diet.

4. The toxicity syndrome was not prevented by a biotin supplement, but was largely prevented by heat denaturation of the egg white powder; 80% of denatured egg white was well tolerated, as was 80% of casein in the diet.

5. The syndrome was due to the direct toxic effects of large amounts of dietary raw egg white powder and not to biotin deficiency.

1. The meat of the Indian species of crab was assessed for the quality of its protein with the use of protein-depleted adult rats.

2. The crab meat and casein had the same biological value, 88.

3. Crab meat supported a higher growth rate than casein in rats.

1. Sixteen male cross-bred lambs were given four diets, which differed in the ratio of protein to energy. The protein contents of the diets (on a dry-matter basis) were: 6.1% (diet A), 11.9% (diet B), 17.5% (diet C) and 22.9% (diet D).

2. The experimental period of 7 weeks was divided into two 2-week periods (periods 1 and 2), and one 3-week period. The diets given to the lambs were changed between period 1 and period 2. In period 3 all the lambs were given the same dietary treatment as in period 2.

3. The daily feed intake of the lambs was regulated according to live weight. Adjustments were made at the beginning of period 1 and of period 2. The level of feeding was 121 kcal/kg live weight 24 h. In period 3 the intake was the same as in period 2.

4. Diet digestibility, live-weight gain, and nitrogen and sulphur balances were calculated for each lamb on each diet in all the periods. Wool growth on sample areas was measured over a 2-week and a 4-week period. These wool growth periods corresponded to treatment period 1, and treatment periods 2 and 3, respectively. At the end of the experiment the lambs were slaughtered and the composition of carcass and organs was determined.

5. The mean digestibilities of energy, N, ether extractives and dry matter increased significantly as the protein content of the diet increased.

6. The live-weight gain increased with increasing protein content of the diets, but only the difference between the means for diet A and all other diets was significant.

7. The N and S balances increased with increasing intake of apparently digested N and S, and all differences between the means for individual diets were highly significant.

8. There was a significant correlation between N balance and live-weight gain for each diet. However, when compared at the same late of gain, N balance increased as the protein content or the diet increased.

9. Wool growth on the sample areas increased with an increase in the protein content of the diet and all differences between the means for individual diets were highly significant. There were no significant differences between the dietary treatments in their effect on the N and S contents of the wool. The mean values were 15.7% N and 2.87% S.

10. The retention of N in the wool grown did not account for the increased N retention on the diets of higher protein content. The lambs given diet A, retained more N and S in wool than was supplied by the diet.

11. The percentage of fat in the carcass decreased, and the percentage of protein increased as the protein content of the diet increased. The percentages of moisture and ash were not significantly affected by the dietary treatments.

12. The percentages of moisture in the liver, pancreas and muscle decreased and the percentages of protein in the liver and muscle increased as the protein content of the diet increased. The ratio of N in the organs (with the exception of the spleen and pancreas) to N in the carcass was highest for lambs given the diet with least protein (diet A).

1. Body-weight, skinfold thickness and food intake were measured at regular intervals in twenty-five young men while on an Antarctic expedition.

2. The mean calorie intake over the year was 3600 kcal/man per day; 12.1% of these calories were supplied by protein, 39.8% by fat, and 48.1% by carbohydrate.

3. The calorie intake was equivalent to that which would be expected in a moderately active worker living in a temperate climate. The chemical composition of the diets did not differ from average values for young men in the United Kingdom.

4. There was a significant fall in food intake during the winter months, when the outside temperatures were greatly reduced and there was polar night. During this period the men were largely confined to the limits of the base hut and the levels of physical activity showed a marked fall.

5. During the year there was a gain in body-weight of 2.7 kg. Of this gain 2.5 kg occurred in the first 2 months.

6. Skinfold thickness followed the trend of the body-weights except for the April-May increment which was unaccompanied by a weight change. This dissociation could not be explained.

1. In two experiments, involving 110 chicks up to 5 weeks of age, retention of an oral dose of 54Mn was always low; less than 5%.

2. There were no significant differences in retention by hybrid broiler cocks, hybrid layer cocks, and hybrid layer pullets, nor was retention affected by the period of fasting, i.e. 1 ½ or 24 h, before dosing.

3. Two-weeks-old birds retained 58% more radioactive manganese than 5-week-old birds, and retention in birds killed 24 h after the dose was only 64% of that in birds killed 4 h after the dose.

4. With the addition to a fixed dose of 54Mn of increasing quantities of non-radioactive Mn retention decreased only from 2.52% with no Mn added to 1.02% with 5000 μg Mn added, representing a very large increase in total retention of Mn.

1. An experiment was conducted with 4600 children in nine schools, in which an attempt was made to persuade a greater number of children to take school milk. The proportion taking the milk before the experiment ranged from about 25 to 65%.

2. Four methods of nutrition education were used: posters, lectures and films each in two schools, and pamphlets in one school. The remaining two schools acted as controls.

3. The material was used for one term in all seven ‘experimental’ schools, and again for the following term in one of the schools receiving each of the different forms of education.

4. Although it appears that there was a small increase in the number of children that said they would take milk, there was no significant increase in the number that did in fact do so, in either the first or the first or the second term.

5. The analysis of the possible causes for this failure to increase milk consumption suggests that nutrition education does not affect dietary behaviour if the factors that limit consumption are sufficiently strong.

1. Nine important varieties of groundnut (Arachis hypogaea Linn.) were analysed for amino acid composition by an ion-exchange chromatographic procedure. Cystine, as cysteic acid, and methionine and tryptophan were determined by colorimetric methods.

2. Small, but statistically significant, differences in the contents of nitrogen, serine, glutamic acid, proline, alanine, leucine, phenylalanine, tyrosine, lysine, methionine and cystine were found in the varieties.

3. A positive correlation (P < 0.05) between methionine any cystine was observed.

4. There was, however, no indication that selection from the varieties studied would permit development of a variety of superior protein quality.

1. The nutrient contents of diets consumed by families in the lower income groups in Lagos are compared with published values for diets consumed by Nigerians in rural areas.

2. Qualitatively, the dietary patterns of urban dwellers tended to resemble those of the regions from which they had migrated; attention is drawn to certain exceptions.

3. Quantitatively, urban diets resembled those in rural areas in (a) providing a lower proportion, in relation to requirements, of calories rather than of protein; and (b) allowing children lower intakes of all nutrients, in relation to requirements, than adults.

4. Restriction of calorie intake resulted in diversion of dietary protein to energy production, and this in turn led to low mean body-weights of children and of adults.

1. A series of experiments was carried out to determine the minimum essential amino acid requirements of the adult rat.

2. After testing four amino acid patterns taken from the literature, a basal pattern was formulated in which each amino acid appeared at the lowest level at which it was presented in any of the original diets.

3. Nitrogen balance was the main criterion used to judge any benefit arising from modest increases in individual amino acids tested in a modified Latin-square design. They were given at a protein level of 3.6% of the diet. Non-essential amino acids were in the same proportions as in whole egg.

4. It appeared that three amino acids, namely tryptophan, threonine and isoleucine, brought about more favourable balances when presented at concentrations higher than basal.

5. Reduced levels of each amino acid were then tested in order to ensure that no surpluses were present.

6. N retentions indicated that lysine, phenylalanine plus tyrosine, leucine and valine could be reduced below the basal level and still meet the needs of the rat for these amino acids.

7. When the pattern of amino acids arising from these latter trials was tested in combination, rather than as trios, pairs, or single changes, positive N balances gave confidence that these were minimal levels of the essential amino acids required for meeting the maintenance needs of adult rats.

8. Plasma proteins from the rats on the evolved pattern were found to be in no way different from those found for normal animals. This gave further support to the belief that the pattern was adequate for the rats.

1. In expt 1 daily supplements of 0 or 27–28 g potassium, with 0 or 7·5 1. water, were given to each of eight fistulated wether sheep on a hay and concentrate diet in two 4 × 4 latin square experiments. Faeces were collected for the last 4 days of, and urine throughout, 10-day treatment periods.

2. Adding K to the diet decreased the urinary output of magnesium by 33% (P < 0·001) and significantly increased those of phosphorus, sodium and calcium by 98, 76 and 150%, respectively. Faecal outputs of Mg and K were increased, whereas that of P was decreased. The retentions of P and Na tended to be decreased, whereas that of K was increased (P < 0·001). Mg in serum was decreased by 0·4 mg/100 ml (P < 0·05) and K increased by 4·9 mg/100 ml (P < 0·001).

3. Increasing the water intake increased the urinary outputs of Mg, P, Na and Ca by 33, 165, 47 and 200%. The faecal output of Ca was increased and the retentions of Mg, P and Ca were decreased (P < 0·01).

4. The effects of water and K were generally independent, but interactions affected the urinary outputs of P and K and the retention of K.

5. The increases in urinary Na output were three- and eight-fold greater during the first 3 days of increased water and K intakes than during the balance study.

6. In expt 2, mineral balance studies were conducted before and after supplementing the diet with potassium acetate, using five wethers from Expt 1. K intakes were similar to those of Expt 1. The effects of potassium acetate and KCl were generally similar qualitatively but the acetate produced greater decreases in urinary Mg and faecal P outputs and greater increases in urinary Na and K outputs than KCl. K in serum was increased by 28 mg/100 ml but Mg was not affected.

7. The nature of these responses in discussed with particular reference to the aetiology of hypomagnesaemic tetany.

1. The ‘landing’ and ‘swimming’ tests have been used to detect the onset of the neurological manifestations of toxicity of β,β-iminodipropionitrile (IDPN) in rats.

2. Rats on diets of net percentage of dietary protein calories (NDpCal%) of 10.1, 6.2 or 4.6 developed the syndrome later than those on diets of lower protein value.

3. L-Thyroxine did not prevent the development of the ECC-syndrome, but only delayed the onset of the action of IDPN.

1. An experiment was undertaken to determine whether high rates of sweating in a tropical climate affect protein requirements by increasing the total nitrogen losses from the body.

2. Six fully acclimatized volunteers were given a diet supplying 50 g protein (= 8 g N) daily. They performed strenuous physical work of a normal nature for an average of 6½ h a day for two 5-day periods. During control periods the subjects took minimal exercise and lived in a cool environment. N balance was measured throughout.

3. Rates of sweating were measured by weighing. Whole body sweat was collected and the concentrations were measured of nitrogen, sodium and potassium. During 6½ h work approximately 3 l. of sweat were lost, containing on average 0·49 g N, 64 m-equiv. Na and 22 m-equiv. K.

4. The N concentration in sweat was 0·20 mg/g, which is lower than that found by most other workers. It is suggested that acclimatization is an important factor in reducing N loss by sweating.

5. There was a marked decrease in urinary Na excretion during sweating, which compensated fully for the loss of Na in sweat. Renal compensation for loss of K was less efficient.

6. Because the total N loss in sweat was small, it was not possible to establish with certainty whether it was compensated for by a reduced renal excretion of N. However, after the initial period the subjects were in N balance in spite of the relatively low protein intake.

7. It is concluded that there is no evidence to suggest that heavy sweating under natural conditions in a tropical climate causes a significant increase in protein requirements.

1. The protein efficiency ratio of three protein sources was determined with rats by a depletion-repletion method. The sources were: a groundnut product, a methionine-supplemented groundnut product and lactalbumin.

2. Livers obtained from the test animals were assayed for arginase activity, and kidneys for transamidinase activity (glycine amidinotransferase).

3. The measurements indicated that there was an inverse relationship between arginase activity and the nutritive value of the dietary protein.

4. Transamidinase activity was also influenced by nutritive value. Only the unsupplemented groundnut product, which had the lowest nutritive value, failed to produce a significant increase of transamidinase activity over basal levels.

5. The findings are discussed from the standpoint of physiological function and needs. It is suggested that observed levels of arginase activity are not necessarily related to amounts of urea excreted; similarly, transamidinase activity may be well in excess of physiological requirements.

1. Vitamin B12 nutrition was studied in normal, coprophagy-prevented and antibiotic-treated rats on Vitamin B12-deficient diets with and without a vitamin B12 supplement; the indices used were excretion of total urinary ether-soluble acid (TUESA) and methylmalonic acid, and vitamin B12 assays on the liver and intestinal tract.

2. A significant positive correlation (r = 0.61) was found between TUESA excretion and weight of rats, and a significant negative correlation (r = −0.89) between TUESA excretion and liver vitamin B12 contents.

3. Although prevention of coprophagy reduced the contents of vitamin B12 in the stomach and small intestine, no effect on vitamin B12 nutrition, as assessed by TUESA excretion and liver vitamin B12 contents, was found. Rats in which coprophagy was permitted became vitamin B12-deficient, when given a diet in which vitamin B12 was low.

4. The amounts of TUESA and methylmalonic acid excreted indicated that streptomycin and erythromycin administered orally prevented vitamin B12 deficiency in rats on a diet deficient in vitamin B12. Liver vitamin B12 contents were, however, very low in these rats. this anomaly was thought to be due to the non-specificity of the Euglena gracilis assay for vitamin B12.

5. It was concluded that, under the conditions of these experiments, coprophagy was not necessary to the vitamin B12-sparing action of antibiotics.