1. It has been observed previously that gastrocnemius muscles from rats rehabilitated after early nutritional stress have low endurance and oxidative capacity (Raju, 1974).

2. Exercise during rehabilitation reversed the effects of early malnutrition on muscle function and metabolism. The swimming performance of rehabilitated rats was poor and exercise during rehabilitation improved it.

3. The specific activity of gastrocnemius muscle myosin ATP phosphohydrolase (EC 3.6.1.3) was not altered by either early malnutrition or exercise.

1. Milk-substitute diets, in which 330-360 (L) or 610-700 (H) g/kg milk protein was replaced by protein from a thermo-alkali-treated soya-bean flour (SF) or from fish-protein concentrate (FPC), were compared in an experiment involving fifty Friesian calves, of which half were supplemented with a growth promoter, Grofas, known to have bacteriostatic properties. The liquid diets were fed ad lib. from 48 h of age until 136 kg live weight.

2. Seven calves, given non-milk protein, died or were removed from the experiment. There was little difference between treatments in the incidence of diarrhoea or in other observations on health of surviving calves, but those given non-milk protein maintained a lower mean rectal temperature.

3. Weight gain was reduced, especially during the first 3 weeks of life, by inclusion of non-milk protein. The reduction was greater for SF than for FPC, and greater at the H level. Supplementation with Grofas improved weight gain for calves given non-milk protein, but tended to reduce that for calves given milk protein.

4. Apparent digestibility of dry matter and protein was reduced when non-milk protein was used. The reduction was greatest at a young age, greater for SF than for FPC and greater at the H level. Apparent digestibility of fat was most markedly reduced with FPC, especially at 1 week of age, and was increased by Grofas supplementation. Digestibility of the carbohydrate in SF was low at 1 week but increased with age. Grofas supplementation caused a marked reduction in the disappearance of SF-carbohydrate in the alimentary tract. Apparent absorption of ash and calcium were reduced by non-milk protein, especially by FPC. The reduction in absorption of ash from SF was moderated by Grofas supplementation. Although Ca retention for calves given SF at the H level was very low, no bone defects were observed.

5. Nitrogen retention was slightly lower for calves given non-milk protein, but the efficiency of retention of apparently digested N was greater for calves given non-milk protein because of the much reduced urinary N excretion associated with a lower apparently digested N intake.

6. Dressed-carcass weight and ‘killing out’ percentage were lower for calves given non-milk protein, especially SF at the H level. Adrenal weights were markedly increased by feeding SF especially at the H level. Pancreas weight was greater for calves given SF than for those given FPC.

7. Weight of abomasal contents at slaughter was much lower for calves given non-milk protein. Weight of intestinal tissue and of total tissue in the alimentary tract were markedly increased by non-milk protein, especially by SF at the H level, and reduced by Grofas supplementation. The increased weight was associated with increased thickening of the walls of both the small and large intestine, which was possibly associated with hypertrophy of muscle cells.

8. It is concluded that up to 360 g/kg milk protein could be replaced by protein from this thermo-alkalitreated SF, and up to 610 g/kg milk protein from this FPC without markedly affecting performance, especially if an effective growth promoter is included in the diet. The beneficial effect of Grofas appeared to result from the reduction in the fermentation of the oligosaccharides of SF, which was reflected in higher digestibility particularly of fat and absorption of Ca and in reduced thickness of the intestines.

1. The nutritional value of fish protein oxidized with different levels of hydrogen peroxide, and the utilization of oxidized sulphur-amino acids in the rat were investigated.

2. The results showed that the biological value (bv) and protein efficiency ratio (per) of the fish protein were significantly decreased by the treatment with H2O2, and although there were no significant differences between samples treated with 20, 40 or 80 g H2O2/kg, there was a gradual decrease of BV at higher concentrations. Digestibility was not affected by the treatment.

3. Supplementation with 1 g L-methionine/kg or 1 g L-cystine/kg significantly increased the BV for all H2O2-treated samples. With the exception of the sample treated with 80 g H2O2/kg, the BV was increased by L-methionine supplementation to the level for the untreated fish protein.

4. Treatment with H2O2 led to the formation of methionine sulphoxide, methionine sulphone and cysteic acid. The availability of these compounds was studied as supplements to the untreated fish protein as well as to the H2O2-treated fish protein. The results showed that L-methionine DL-sulphoxide was as available as methionine, but that L-methionine sulphone and cysteic acid had no supplementary effect.

5. The availability of lysine in fish protein was not affected by treatment with 20 g H2O2/kg as judged by its effect as a supplement to wheat flour.

6. The plasma amino acid pattern for rats given a diet with H2O2-treated fish protein was identical to that for rats given an untreated fish protein, with the exception of the presence of the two isomers of L-methionine DL-sulphoxide and L-methionine sulphone. The oxidized S-amino acids were also found in liver, kidney and gastrocnemius muscle from the rat.

7. Only traces of L-methionine DL-sulphoxide were found in the urine. About half the ingested L-methionine sulphone was found in the urine and almost all was present as an acid-labile conjugate.

1. Mixed bacteria were obtained from the rumen contents of steers and were taken at different times after the animals had been given different feeds. The feeds contained [15N]urea and in some experiments Na235SO4 so that the bacteria were labelled with these isotopes.

2. Samples of labelled bacteria were subjected to a simulated abomasal digestion with pepsin and the digests were infused with a non-absorbed marker, polyethylene glycol, into the duodenums of test steers equipped with re-entrant ileal cannulas. Except for samples taken after a 24 h fast, which sometimes gave somewhat lower values, mean values for digestibilities of 15N and 35S in the small intestine were 0.79 and 0.85 respectively.

3. The corresponding value for the digestibility of 15N in similarly-treated wheat-leaf protein concentrate was 0.86.

4. Net digestibilities of total N in the small intestine of the test steers when they were given either a mainly protein-free diet of straw, tapioca and urea or a diet of flaked maize and hay were approximately 0.62.

5. From these and other values it was calculated that approximately 5.2g intestinally-secreted endogenous N/d flowed through the ileum of a 100 kg steer.

1. Serial estimations of plasma (PAA) and leucocyte (LAA) ascorbic acid concentrations were made in geriatric patients in a stable phase of their illness, and compared with a similar (‘unstable’) group suffering from acute illness.

2. In the ‘unstable’ group, though PAA levels were unchanged, LAA levels were reduced.

3. In the ‘follow-up’ period of 7-8 d there was much greater variation in both PAA and LAA levels in the ‘unstable’ group.

4. Acute illness was often accompanied by an increase and then a decrease in LAA levels. Recovery was associated with an increase in LAA levels.

1. The galactolipids of heat-treated, 14C-labelled rye grass S24 administered intraruminally to a sheep fed on an autoclaved diet were rapidly catabolized.

2. When grass was homogenized with rumen contents devoid of higher plant lipases the grass galactolipids were rapidly metabolized, but were not metabolized when the rumen contents were boiled to destroy microbial galactolipases.

3. 14C-labelled monogalactosyldiglyceride, digalactosyldiglyceride and triolein were metabolized, with the release of 14C-labelled fatty acids when incubated with a homogenate (100 g/l) of grass or clover in rumen fluid from a starved sheep, but not when the rumen fluid was heat-treated to destroy microbial enzymes.

4. It is concluded that in the sheep the lipases of rumen micro-organisms play a major part in the ruminal degradation of ingested complex lipids of pasture.

1. Rat pups developed chronic protein insufficiency resulting from malnutrition diet in utero while their dams received 40 g protein/kg diet.

2. Before weaning they were found to have decreased salivary amylase (EC 3.2.1.1) and aminopeptidase activities.

3. A complete diet (250 g protein/kg) rapidly restored salivary amylase activity before weight normalization. However, renourished pups (malnourished pups given 250 g protein/kg for 14 d) still had increased numbers of Streptococcus mutans in their plaque.

1. Parenchymal cells were isolated from the liver of rats that had been deprived of dietary protein for 3 weeks.

2. The cells were two-thirds the diameter of those derived from livers of normal animals and consumed oxygen at a rate of 16.2±2.7 μl/h per 106 viable cells, half the normal value.

3. Albumin and transferrin were synthesized at rates of 0.94±0.12 and 0.60±0.07 μg/h per 106 viable cells respectively and urea at a rate of 0.77±0.12 μg/h per 106 cells. This represents a 25-50% decrease in the rates of synthesis measured in cells isolated from normal livers.

4. The results are discussed in relation to the long-term effects of malnutrition on liver cell function.

1. The feasibility of improving iron nutrition by fortifying cane sugar with ascorbic acid was studied.

2. The absorption of Fe added to maize-weal porridge was measured in 116 volunteer multiparous Indian women using the radio-Fe erythrocyte utilization method. The meals were fed with and without tea or coffee and with and without varying amounts of ascorbic acid.

3. The mean absorption of Fe from maize-meal porridge was very low (3.8 %), being even further reduced (2.1 %) when tea was drunk with the meal.

4. The addition of 50 or 100 mg ascorbic acid to maize-meal porridge caused approximately a 10-fold increase in Fe absorption. The increase was much less when tea was present, being 2-fold and 5-fold with 50 and 100 mg ascorbic acid respectively. The inhibitory effect of tea on Fe absorption could, however, be overcome by giving larger doses of ascorbic acid (250 and 500 mg).

5. When contaminating Fe (2.5 mg) in the form of labelled rust (Fe2O3) or ferric hydroxide was added to maize-meal porridge it was poorly absorbed (mean values were 0.01 % and 1.5 % respectively). The addition of 100 mg ascorbic acid increased the mean Fe absorption rates to 0.5 % and 6.7 % with Fe2O3 and Fe(OH)3 respectively. Fe(OH)3 was found to be absorbed about half as well as the intrinsic Fe present in maize-meal porridge.

6. It is concluded that ascorbic acid is capable of improving Fe absorption from a cereal source. It can partially overcome the inhibitory effect of tea and might be expected to facilitate the absorption of at least some forms of Fe that may contaminate food.

1. Body-weight, height, skinfold thickness and body density measurements were made on 245 men and 324 women aged between 17 and 72 years. The body fat content of each individual was calculated from his density measurement using equations similar to that of Siri (1956) but appropriate to age, muscular development, and extent of obesity. Regression equations were then derived for separate age-groups for the prediction of body fat from (1) weight–height (W–H) relationships (W:H, W:H2 W:H3, W0.33:H, H:W0.33), (2) ‘percentage overweight’ (body-weight:mean body-weight; W:W;) and ‘percentage desirable weight’ body-weight: ‘desirable weight’ (mean weights for men and women aged 20-24 years); (W:DES), (3) the independent variables weight and height incorporated in a regression equation, (4) skinfold measurements.

2. The correlations between height and indices, W:H, W:H3, W0.33:H and H:W0.33: were substantially different from those between height and body fat estimated by densitometry.

3. The method having the highest correlation with body fat estimated by densitometry was the skinfold method, although in the older groups of women other methods sometimes gave equally good correlations. The index H:W0.33 had a negative correlation with body fat, and the indices W:H, W0.33:H and W:H3 had a lower correlation with body fat estimated by densitometry than did the other indices. These indices are therefore unsuitable measures of obesity, and this is in agreement with the findings of other workers.

4. The correlations betweeen body fat estimated by densitometry and the indices W:H2, W:W, W:DES and the equations incorporating the independent variable weight and height are all very similar, although it is not appropriate to use the index W:W; as a measure of obesity in groups of people of widely different ages.

5. The standard error of prediction of body fat from skinfold measurement may be of the same order of magnitude as the standard error of prediction of body fat by densitometry. It is therefore probably inappropriate to assess the accuracy of the skinfold method by comparison with the density method alone.

6. From the distribution patterns obtained, it was evident that compared with the density method, all methods tended to over-estimate body fat in very lean individuals. The skinfold method however showed this tendency to only a relatively small extent.

1. A high-protein yeast cake, based on ovalbumin and lactalbumin, and containing 200 g sucrose/kg was baked and toasted as previously described by Block, Cannon, Wissler, Steffe, Straube, Frazier & Woolridge (1946). This caused a severe reduction in its protein quality for rats, and in its fluorodinitrobenzene (FDNB)-reactive lysine content. The damage appeared to be caused by inversion of sucrose to glucose and fructose during fermentation by the yeast followed by Maillard reactions. Processing an albumin-sucrose mixture in a similar way but without fermentation caused no loss in nutritional value for rats and a small reduction in FDNB-reactive lysine.

2. Sucroselysine solutions were prepared and heated as previously described by El-Nockrashy & Frampton (1967). Contrary to their findings, we detected no loss of lysine after storage for 16 h at 35° or after heating for 2 h at 100°, although after heating for 4 h at 121° about 0.7 of the original lysine remained. At an alkaline pH, sucrose hydrolyses only slowly even at 121°, and this is catalysed to some extent by the presence of lysine.

3. A ‘dry’ albumin-sucrose mixture (10-200 mg moisture/g) was heated in sealed glass ampoules under a range of conditions. The loss of FDNB-reactive lysine was stongly dependent on the processing conditions; in particular it was decreased by an increase in pH. After 2 h at 121°, lysine damage caused by sucrose was similar to that caused by glucose. Lysine damage due to sucrose was believed to follow on from its breakdown to glucose and fructose.

4. Although the presence of sucrose does not make proteins highly sensitive to Maillard reactions and loss of nutritive value, it must not be considered entirely inert. Our results confirm earlier work indicating that its presence at relatively high levels in oil seeds may be largely responsible for the damage to protein quality observed when they are severely processed.

1. Male, adult guinea-pigs received a scorbutogenic diet and a daily supplement of 1.0 mg ascorbic acid/100 g body-weight.

2. Restriction of food intake for a period of 17 d resulted in a 25 % loss in body-weight and a significant reduction in the retention of ascorbic acid by the spleen, liver and adrenal glands.