1. Fifteen pieces of rectus abdominus muscle and fifteen pieces of taenia muscle were removed from patients undergoing various surgical procedures.

2. The muscles were extracted, hydrolysed and the content of Nτ-methylhistidine was measured.

3. The rectus muscles contained 3.13±0.7 μmols Nτ-methylhistidine/g fat-free dry solid andthe taenia muscles 2.4±0.6 μmols/g fat-free dry solid. There was a statistically significant difference (P < 0.05) between these values using the Student's unpaired t test, although this could have been due to contamination of the taenia muscles with connective tissue.

4. The muscle content of Nτ-methylhistidine was at least 40% higher than the only other reported value and therefore the method of calculating muscle protein breakdown based on Nτ-methylhistidine excretion requires revision.

1. The effect of varying energy and protein intake on nitrogen balance in adult men engaged in heavy manual labour was investigated.

2. Low protein and energy levels resulted in negative N balance and urea index (Waterlow, 1963) was decreased.

3. Urinary excretion of hydroxyproline was found to be sensitive to dietary protein level, but not to energy.

1. A study was carried out on 973 school children to find out any relationship between vitamin B-complex deficiency signs and defective vision, and the effect of supplementation of B-complex vitamins on visual acuity.

2. The results of the study showed a significant association between presence of clinical signs of vitamin B-complex deficiency and defective vision.

3. Supplementation with vitamin B-complex was found to have beneficial effect in improving the visual-acuity status of defective children and in preventing visual defects from developing.

4. It is concluded, therefore, that from the present study it appears that the relationship between vitamin B-complex deficiency and visual defects could be one of ‘cause and effect’.

1. Weanling rats were fed on purified-casein diets containing active and inactive (autoclaved) field bean (Vicia faba L.) proteinase inhibitors (PI) at levels of 1.25, 2.5, 5.0 and 10 g/kg. Diets containing raw-and autoclaved-field-bean meal (FBM) were also given. The body-weight gain, protein efficiency ratio (PER); i.e. the ratio of the live weight gain in g/g of protein consumed and apparent nitrogen digestibility were determined 7, 14 and 21 d after the start of the trial.

2. Significant growth depression (P < 0.001) was observed in rats given diets containing 2.5 g/kg PI (27–35%). In rats fed on raw FBM growth depression was severe after 7 d (57%).

3. Food intake was depressed at PI inclusion levels of 5 g/kg and higher between 14 and 21 d.

4. PER was depressed significantly (33–44%) in rats given diets containing the active PI at all levels after 7 d. The protein utilization of all casein diets was higher than that of the FBM diets.

5. Apparent N digestibility was depressed in rats fed on diets containing 10 g/kg PI by 9 and 7% at 14 and 21 d respectively. The N digestibility of both raw and heated FBM was similar at approximately 84%.

6. It was concluded that the PI are not the main factors responsible for the growth depression observed when raw FBM is fed to rats.

1. Male weanling rats were fed casein diets containing 1.25, 2.5, 5.0 and 10 g/kg active or autoclaved proteinase inhibitors (PI) from field bean (Vicia faba L.), and raw- and autoclaved-field-bean meal (FBM) diets. After 7, 14 and 21 d on the diets pancreas weights were measured and pancreas and intestinal trypsin (EC 3.4.4.4) and chymotrypsin (EC 3.4.4.5) assayed.

2. Pancreas weights increased on the raw FBM and active-PI-supplemented diets. Maximum pancreatic hypertrophy measured as the percentage increase above controls was observed after 14 d in rats fed on raw FBM. The same percentage increase in pancreas size compared with appropriate controls was obtained with rats fed casein diets supplemented with 5 g active PI/kg.

3. Pancreas trypsin and chymotrypsin levels decreased with increasing dietary PI level. Similarly, lower pancreas trypsin and chymotrypsin levels were observed in rats given raw FBM.

4. Intestinal trypsin and chymotrypsin increased with increasing dietary PI inclusion level. Although the magnitude of this response decreased with the period of feeding the differences in enzyme levels were still significant even after 21 d.

5. It was concluded that the PI alone in raw-FBM diets could not entirely be responsible for the enlargement of the pancreas and the excess secretion of pancreatic enzymes since in synthetic diets PI levels of five times those in FBM were required to produce responses of similar magnitude.

1. The disaccharide lactulose (galactosyl-β-1,4-fructose) was poorly absorbed from rat small intestine in vitro and human mouth in vivo.

2. These results confirm indirect clinical evidence of poor absorption from the intestine.

3. The presence of calcium ions, or absence of sodium ions, had no effect on lactulose absorption from the buccal cavity.

4. The presence of ouabain, or absence of Na+, did not decrease the absorption of lactulose from small intestine.

5. It is thought that the mode of transport, in both instances, is by passive diffusion with the concentration gradient.

1. Longitudinal growth profiles contain much information but are difficult to incorporate into mathematical and statistical analyses.

2. A growth function, which is a weighed average of growth achievement at different ages, is proposed.

3. This function is a non-dimensional number with defined statistical properties, and emphasizes growth achievement in early life. It can be used to compare the growth of individuals and populations.

1. A flour was prepared from rhizomes of shoti (Curcuma zedoaria) in such a way that most of the protein was retained. The crude protein (nitrogen × 6.25) content in this product was 155 g/kg, compared with approximately 10 g/kg in commercial shoti flour.

2. The high-protein flour proved highly toxic to 5-week-old rats and caused 100% mortality within 6 d when given at 320 g/kg diet.

3. Fresh rhizomes were minced and dried, and the resulting meal was given to weanling rats at 400 g/kg diet. All the animals lost weight rapidly, and two of the five rats died within 4 d.

4. This same shoti meal was given to 1-d-old chicks at 100 and 200 g/kg diet. All the chick survived the test period (20 d), but body-weight, food intake and efficiency of food conversion decreased with increase in the level of shoti meal in the diet.

5. The traditional method of preparing shoti involves prolonged washing in changes of water, which removes most of the protein and other water-soluble nutrients and, presumably, a toxic constituent. Further investigation is needed to identify the toxic principle, and to discover a less wasteful procedure for removing it.

1. Male Sprague-Dawley rats were fed on diets containing either sucrose or starch as the carbohydrate component. In one experiment, the diets also contained 200 g either butter or polyunsaturated margarine/kg; in a second experiment, the diets contained less fat in the form of 20 g maize oil/kg.

2. Over a period of 11 months assays were made in the urine of several ions and of the activity of the enzyme N-acetyl-β-glucosaminidase (β-2-acetamido-2-deoxy-β-D glucoside acetamidodeoxygluco-hydrolase; EC 3.2.1.30); at 13 months, examination was made of some of the abdominal viscera, especially of the kidneys.

3. In rats fed on the higher amount of fat, dietary sucrose produced a higher activity of the enzyme than did dietary starch, and a greater excretion of inorganic phosphate.

4. With both the higher and lower amounts of dietary fat, sucrose led to an increase in the weight of the liver and of the kidneys, and an increase in the concentration of calcium and of phosphate in kidney tissue. With the higher amount of fat, sucrose also produced an increase in the concentration of magnesium in the kidney. There was no difference in the concentration of any of the ions assayed in the plasma or, apart from inorganic phosphate, in the urine.

5. The kidneys of the sucrose-fed rats showed nephrocalcinosis, mostly in the cortico-medullary region, and basophilic deposits in the tubules. Attention is drawn to this unusual occurrence of nephrocalcinosis in male rats.

1. Plasma concentrations of insulin, cortisol and growth hormone, and growth velocities have been measured in a group of Gambian village children up to 3 years of age. All three hormones showed changes in concentration with age, as did rates of growth.

2. Plasma insulin concentrations in the children were directly correlated with velocity of growth in height and weight, whereas cortisol concentrations showed inverse relationships. The values for insulin:cortisol concentration correlated more closely with growth velocity than did either hormone individually. Growth hormone values in plasma exhibited only marginal correlations with growth in height or weight, and these were negative.

3. Similar relationships between these hormones and growth were obtained from an animal experiment in which the rates of growth of rats were altered by restricting dietary intake of protein or energy or both.

4. Possible mechanisms for these observations are discussed in the light of recent knowledge concerning the hormonal control of growth rates.

1. Pigs were weaned at 2 d of age and fed on a milk substitute at hourly intervals. They were slaughtered at 28 d of age.

2. The diets contained 730 g dried skim-milk and 270 g fat/kg dry matter (DM). Three diets were compared in which the fat was supplied as soya-bean oil (SO) (diet A), equal amounts of SO and medium-chain triglyceride (MCT) (diet H), or 246 g MCT and 24 g SO (diet I)/kg DM. In the latter diet, SO ensured that the diet had an adequate content of essential fatty acids.

3. Growth rate (2–28 d of age) was reduced (P < 0.05) by the high-MCT diet (diet I) compared with the medium-MCT diet (diet H), but in comparison with diet A, the differences were not significant (P > 0.05). The feed: gain ratio (g DM consumed/g live-weight gain) was not affected by the type of dietary lipid.

4. Diet I increased the proportion of crude protein (nitrogen × 6.25) (g/kg wet weight) in the carcass but did not increase N retention (g/d per kg live weight). The proportion of fat in the carcass was reduced, particularly by diet I (P < 0.001), and was inversely related to an increase mainly in the water content, and to a lesser extent, in the crude protein content of the carcass. The liver weight (g/kg live wt) was greatly increased by MCT (P < 0.01 or P < 0.001).

5. Approximately 20, 44 and 80% of the fatty acids in the carcass of pigs on the SO, diet H and diet I respectively could not have been derived from direct deposition of the dietary fatty acids, but rather by de novo synthesis from carbohydrate or elongation of shorter-chain fatty acids.

MCT increased the concentrations in the blood, taken 1 h after feeding, of total lipid, phospholipid, cholesterol and cholesterol ester, indicating incomplete oxidation of the caprylic and caprylic and capric acids in MCT by the liver, and their incorporation, after chain elongation, into plasma lipids.

1. The requirement of the artificially-reared pig for crude protein (nitrogen × 6.38; CP) was estimated between 2 and 28 d of age. The pigs were given one of five diets, each containing 270 g soya-bean oil/kg and either dried skim-milk and dried whey in different proportions to supply 150, 180, 210 or 240 g CP/kg, or dried skim-milk alone which supplied 270 g CP/kg. The energy content of the diets was approximately 22 MJ digestible energy/kg.

2. The diets were obtained as spray-dried powders, reconstituted in water, and fed as a liquid containing 200 g DM/l. The pigs were fed at hourly intervals to a scale based on live weight.

3. N retention (g/d per kg live weight) and the proportion of CP in the carcass indicated a CP requirement of 240 g/kg for pigs from 2–28 d of age.There was no significant difference (P > 005)in performance between levels of dietary CP of 2.10, 240 or 270 g/kg. Although there was no increase in the proportion of CP in the carcass above a dietary CP level of 240 g/kg, a linear reduction in the proportion of lipid occurred as dietary CP level increased from 150 to 270 g/kg. Mortality, which was associated with scouring, was increased when the diet contained less than 210 g CP/kg.

4. There was a linear response in N retention to the level of CP in the diet at 7 d of age, whereas at 19 d of age, N retention reached a maximum with 240 g CP/kg diet, suggesting that the CP requirement may be greater during the first week of life.

5. Excretion of endogenous N in the urine was found to be 250 mg N/d per kg live-weight0.75 in pigs between 7 and 19 d of age (20–6.4 kg live weight).

1. Half (diet M) or total replacement (diet N) of dried skim-milk by fish-protein concentrate and dried whey was compared with a diet containing dried skim-milk (710 g/kg) as the only source of protein (diet A). All three diets were prepared as spray-dried powders, and contained 20 g starch and 270 g soya-bean oil/kg. The diets were calculated to be isonitrogenous, but upon analysis had crude protein (nitrogen × 6.25) contents (g/kg) of 230, 270 and 291 in diets A, M and N respectively.

2. The diets were reconstituted as liquids containing 200 g dry matter (DM)/l and given to pigs weaned at 2 d of age during a 26 d experiment. The diets were fed at hourly intervals to a scale based on live weight. Protein digestion was studied in pigs, 6 d of age, and killed 1 h after a feed.

3. Live-weight gain was slightly improved when half the dried skim-milk was replaced, but the feed: gain ratio (g DM consumed/g live weight gain) was unaltered. Total replacement of dried skim-milk, markedly reduced performance and increased the incidence of scouring and mortality.

4. Increasing the proportion of fish protein reduced the apparant digestibility (AD) and the retention of N (g/d per kg live weight). N retention, but not AD, decreased with age.

5. Total replacement of dried skim-milk decreased the amount of digesta in the stomach, its pH value, and the proportion of DM and total N in the digesta, but non-protein N as a proportion of total N was increased.

6. The total pepsin activity in the stomach digesta was decreased by the substitution with fish protein, but there was no change in the activity of the stomach tissue. Trypsin and chymotrypsin activities in the pancreas were not affected by the source of dietary protein, but in the digesta of the small intestine the activity of these two enzymes was markedly reduced when the diet contained fish protein.

7. Total replacement of dried skim-milk with fish-protein concentrate and dried whey may increase the rate of flow of digesta through the small intestine, which together with the reductions in the apparent digestibility of N and amounts of trypsin and chymotrypsin in the digesta could reduce the efficiency of protein digestion and adversely affect performance.

1. Food intake and rates of protein, lipid and energy deposition were measured for lean and obese (fatty) Zucker rats offered to appetite from 34 d of age to slaughter at 66 d of age, one of sixteen semi-synthetic diets. Measurements were also made of the digestibility of dietary protein and the metabolizability of dietary energy. Total carcasses were analysed for protein and lipid, and body energy was calculated thereby. Changes in body constituents were calculated by the comparative-slaughter technique.

2. In Expt 1, four rats of each phenotype and sex were offered one of four diets, each of which contained either 150 or 300 g casein (150 C and 300 C respectively)/kg and either 150 or 300 g cellulose (150 CELL and 300 CELL respectively)/kg (diets 150 C/150 CELL, 150 C/300 CELL, 300 C/150 CELL and 300 C/300 CELL. As expected, males ate more and had higher rates of protein deposition than female animals of the same phenotype on all diets. These sex differences were greater for the lean phenotype. The results for animals in this experiment are presented with, and discussed in relation to, those obtained previously for animals of both sexes fed on cellulose-free diets having these two levels of casein.

3. In Expt 2, four female animals of each phenotype were fed one of twelve semi-synthetic diets, each of which contained casein, gluten or zein at one of the following levels (g crude protein (nitrogen × 6.25)/kg diet): 93, 132, 267 or 627. On all diets containing zein both fatty and lean rats had similar, low food intakes and failed to grow. Fatty rats fed on diets containing casein or gluten had higher rates of food intake, weight gain, lipid and energy deposition than leanrats, but similar rates of protein deposition. Rats fed on diets having the two lower levels of casein ate more and grew better than animals of the same phenotype fed on the two corresponding diets containing gluten but at higher protein levels differences in food intake and growth attributable to differences in protein quality disappeared and furthermore, the rate of protein deposition became similar and maximal for both phenotypes.

4. The results from both experiments are discussed in relation to previous work on appetite control in the Zucker rat. It appears that fatty and lean rats eat during growth to attain the maximal rate of protein deposition of which they are capable. The rate of lipid deposition would appear to be of no importance in the food intake regulation of animals depositing protein maximally.

5. Rats given diets that fail to support maximal rates of protein deposition appear to regulate their intake of digestible energy rather than that of digestible protein. They do not overeat protein-deficient diets in order to acquire sufficient protein for maximal growth although the factors that induce satiety in these animals are unknown.

1. To investigate the effects of sulphur intake on molybdenum metabolism in sheep, ewes were given intakes of 0.3 or 3.5 mg Mo and 0.98, 1.33, 1.73 or 3.23 g S/d in a 2 × 4 factorial experiment with two replicates lasting 35 d. 99Mo with 0.1 mg carrier Mo was infused intravenously for the last 14 d and, when 99Mo concentrations in urine and faeces had attained plateaux (days 11–14), stable Mo and 99Mo balance trials were conducted; samples of blood and rumen contents were taken principally for studies of Mo distribution.

2. Increases in S intake caused the following changes in Mo metabolism; absorption decreased, urinary and faecal endogenous excretion decreased and retention increased; Mo concentrations in rumen contents decreased but the predominant association with the solid phase was unaffected; Mo concentrations in plasma decreased, but a higher proportion was associated with the protein fraction; Mo in protein-free plasma became apparently less ultrafiltrable at the glomerulus.

3. The pattern of response to S for each factor was generally curvilinear, the first increment in S intake having by far the greatest effect. The effect of S was generally greatest at the higher Mo intake.

4. It is suggested that the manifold effects of S on Mo metabolism are related to a common interaction in the rumen leading to the formation of Mo-complexes, possibly thiomolybdates, which are poorly absorbed but even more poorly excreted.

1. Digesta were collected from twenty-three pigs, initially of 30 kg live weight, and fitted with single Ash re-entrant cannulas in either the duodenum, jejunum or ileum. A further twenty-four pigs were used in a conventional digestibility trial.

2. Three approximately isonitrogenous diets were used; they contained: barley, fine wheat offal, white fish meal, minerals and vitamins (diet BWF), starch, sucrose, maize oil, cellulose, minerals, vitamins and either groundnut (diet SSG) or casein (diet SSC).

3. The flow-rates of nitrogen (N), liquid-fraction N (LN) and non-protein liquid-fraction N (NPLN) were measured hourly in the duodenum and jejunum and every 6 h in the ileum during 24 h collection periods. Faeces were collected during 5 d periods.

4. Marked increases in flow of N, LN and NPLN were seen in the duodenum and jejunum after feeding each diet, but not in the ileum.

5. Values for, N output: intake from the duodenal, jejunal or ideal cannulas and in faeces in 24 h periods were respectively: 0.98, 0.88, 0.25 and 0.21 for diet BWF; 1.00, 0.97, 0.22 and 0.24 for diet SSG; 0.98, 0.73, 0.09 and 0.03 for diet SSC. The corresponding values for LN in the duodenum, jejunum and ileum respectively were: 0.53, 0.53 and 0.12 for diet BWF; 0.46, 0.60 and 0.13 for diet SSG; 0.57, 0.50 and 0.06 for diet SSC. The corresponding values for NPLN in the duodenum, jejunum and ileum respectively were: 0.41, 0.38 and 0.09 for diet BWF; 0.35, 0.36 and 0.08 for diet SSG; 0.46, 0.38 and 0.04 for diet SSC.

6. The results are discussed in relation to similar studies, particularly in pigs with duodenal cannulas, in which widely different observations were made.

1. Digesta were collected from seventeen pigs initially of 30 kg live weight 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. The pigs received three types of diet containing: barley, fine wheat offal, white fish meal, minerals and vitamins (diet BWF); starch, sucrose, maize oil, cellulose, minerals and vitamins and either groundnut (diet SSG) or casein (diet SSC).

3. Amino acids were measured in samples representative of the digesta flow in 24 h periods and in the faeces collected in 5 d periods.

4. For each diet the total flow in 24 h periods in the duodenum for aspartic acid, threonine, serine and glycine exceeded or equalled intake, while the amounts of the other amino acids were usually rather less than intake.

5. For each diet in the jejunum, the amounts of glycine and cystine exceeded intake in 24 h periods, while methionine, arginine and tyrosine were the most rapidly absorbed amino acids anterior to the cannula site. On average 0.22, 0.25 and 0.31 of the dietary amino acids were absorbed anterior to the cannula site for diets BWF, SSG and SSC, respectively.

6. For each diet in the ileum, the least apparently absorbed dietary amino acids were glycine and cystine. On average 0.81, 0.83 and 0.95 of the dietary amino acids were absorbed anterior to the cannula site for diets BWF, SSG and SSC, respectively.

7. There was net disappearance of most amino acids in the large intestine, but some net accumulation occurred in this region.

8. The results are discussed in relation to the amino acid composition of endogenous secretions (particularly glycine in bile), protease and peptidase specificity, free amino acid absorption and the role of the microflora in the large intestine.