1. Salt is a convenient household commodity which is generally used as a vehicle for iodine in the prophylactic treatment of endemic goitre.

2. Iodization of salt depends on the normal requirements for iodine, the intensity of the environmental iodine deficiency, the presence of goitrogenic factors and the daily salt consumption per head of the population.

3. Although the intake of most nutrients has been worked out during the normal course of dietary surveys in the past, the daily salt consumption per head of the population has not been estimated.

4. In this survey a simple method has been described for evaluating salt consumption and this finding will be the basis for planning the iodization programme in Ceylon.

1. The use of deuterium oxide dilution to obtain an indirect estimate of body water in pregnant ewes was examined and the value of such an estimate in predicting body fat was investigated.

2. Deuterium oxide was infused intravenously into fourteen twin-bearing Blackface ewes and blood samples were taken 6–7 h later. The animals were subsequently slaughtered.

3. Deuterium oxide concentration was estimated by infrared spectroscopy and the deuterium oxide space was calculated. Studies on dose rates and equilibration times were made with the Blackface ewes and some non-pregnant Dorset ewes.

4. The amount of body fat in each ewe was estimated from the deuterium oxide space using a prediction equation relating body fat to body water in twenty-five pregnant and non-pregnant ewes which had been slaughtered.

5. Once satisfactory measurement of deuterium oxide concentration had been achieved, body fat predicted from deuterium oxide space differed from values obtained by analysis of the slaughtered animals by -0.8 to +1.7 kg in seven ewes containing 5.2–21.4 kg fat.

6. The standard deviation from regression of percentage of body fat estimated from deuterium oxide space on percentage of body fat measured after slaughter was ±1.2 percentage units. Thus deuterium oxide space was used to provide a useful measure of body fat in pregnant ewes.

1. The nature of the complexes of zinc, manganese and copper which occur in ryegrass has been examined as part of a study of the availability of these metals to ruminants.

2. Ryegrass labelled with 66Zn was produced by water culture. A large proportion of the Zn could be extracted with aqueous ethanol and with water. The remainder of the Zn was liberated on peptic digestion and on treatment with a fungal cellulase.

3. The aqueous ethanolic extract was examined by a combination of gel filtration and thin-layer chromatographic and electrophoretic techniques. The results showed the presence of closely related complexes of Zn of low molecular weight. These were of limited stability and their behaviour was dependent on pH.

4. The value of electrophoresis in free solution as a fractionation technique for the soluble forms of Cu, Zn and Mn from ryegrass was demonstrated. Soluble Mn from was found to exist in a single cationic, perhaps non-complexed form, whereas several anionic Cu and Zn complexes were present in closely related forms.

1. The time course of digestion of milk protein was studied in the 28-d-old pig given a test meal of homogenized cow's milk after a preliminary starvation period.

2. The milk was found to clot in the stomach 15–30 min after the meal. The soluble or ‘whey’ fraction of the stomach contents rapidly passed into the small intestine. Most of the clotted digesta had also left the stomach z h after the meal.

3. The distribution of digesta was studied in six equal segments of the small intestine. In general, there were no significant increases in the amount of intestinal contents at any time after the meal when compared with those in starved pigs, suggesting that digestion of milk at this age is a very efficient process.

4. Fractionation of the soluble digesta from the stomach and small intestine in Sephadex G-25 indicated that relatively little proteolysis occurred in the stomach, but in the small intestine digestion proceeded rapidly, producing a considerable increase in free amino acids in the mid-region.

5. The level of proteolytic enzyme activity in the stomach wall was elevated at 15 min after the meal, but thereafter returned rapidly to the prefeeding levels. Increasing the level of feeding increased the enzyme activity of the digesta and stomach wall. The enzyme activity appeared to be mainly adsorbed by the stomach clot.

6. The proteolytic enzyme activity in the pancreas was unaffected by the meal. However, the activity in the contents of the small intestine increased after the meal, reaching a maximum value at 45 min. Some accumulation of enzymes was found in the lower part of the small intestine, except in the region of the distal ileum where a marked decline in enzyme activity occurred. Increasing the level of feeding increased the proteolytic enzyme activity in the contents of the small intestine.

7. The soluble marker polyethylene glycol was not entirely satisfactory as an indicator of the rate of passage of digesta. The concentration of the marker was found to be greater in the soluble stomach fraction than in the clot shortly after the milk had been ingested. The transit time of the marker from ingestion to the terminal ileum was 2–3 h.

1. The mean retention time of stained food residues was longer in sheep maintained on a chopped straw ration than in sheep maintained on a chopped lucerne ration.

2. Infection of sheep with 1500 infective Oesophagostomum columbianum juveniles was associated with increased mean retention times.

3. The extent to which the mean retention times were increased was associated with the diet and mode of infection of the sheep.

4. It was noted that an increase in mean retention time following infection was associated with a general decrease in food intake per kg live eight0.75.

5. The results are discussed in relation to the pathogenesis and survival of O.columbianum infections in sheep.

1. Children attending a boarding school in the New Guinea highlands, and receiving a protein-deficient diet of sweet potato and taro showed, when compared with village children, a progressive retardation of growth which was related to the number of years at school.

2. Feeding of supplementary protein resulted in a dramatic acceleration of growth in both height and weight, whereas the feeding of extra calories produced an increase in only weight and skinfold thickness.

3. This response to protein feeding appears to be greater than previously reported in the literature.

1. The interaction between nitrogen and water intake was studied in two ewes and two red deer hinds. They were given pelleted diets, at maintenance level, containing equal amounts of roughage but either rich or poor in nitrogen. The deer received 50 % more food than the sheep. Water was given either in large amounts (sheep 5.01, deer 7.0 1 daily) or in small amounts (sheep 1.1 l, deer 2.4 l daily).

2. Nearly three-quarters of the nitrogen of the high-nitrogen rations but less than half of that of the low-nitrogen rations was excreted in the urine. Restriction of water intake reduced urinary nitrogen excretion by only about 1 g daily, mainly as a result of decreases in the excretion of urea and ammonia, but did not affect the excretion of nitrogen in the faeces.

3. The urinary excretions of creatinine, creatine, hippuric acid, uric acid and allantoin were also examined. The excretion of creatinine was not related to either nitrogen or water intake. The excretion of uric acid and of allantoin was greater in the sheep than in the deer.

4. The concentrations of urea in the plasma and of ammonia in the rumen fluid were measured before and after feeding. The plasma urea value was related to dietary nitrogen intake and was higher on the low- than on the high-water regime. The rumen ammonia value also was related to the nitrogen intake but, while it generally increased after feeding when the high-nitrogen diet was given, it fell almost to zero 2 h after feeding when the low-nitrogen diet was given.

5. The sheep digested dry matter, cellulose and nitrogen a little more fully than the deer. The high-water regime slightly increased the digestibility of dry matter and cellulose but did not affect the digestibility of nitrogen.

1. Regular estimations of dietary intake, body-weight, skinfold thickness, blood pressure and pulse rate, and serum lipids were made in twenty-four members of an Antarctic expedition over 1 year.

2. The mean levels of serum total cholesterol, phospholipids, and triglycerides were 198.5 ±4.85 mg/100 ml, 221.4±5.73 mg/100 ml and 120.9±13.53 mg/100 ml respectively.

3. A positive correlation was found between the total intake of fat expressed as calories and the following serum lipid levels: total cholesterol, β-cholesterol, and the cholesterol:phospholipid ratio. Significant positive correlation was also found between the latter serum levels and fat when expressed as a percentage of the total food intake.

4. This correlation has not been found in small groups before, and is due to the fact that each estimation was the result of several assessments made over 1 year.

5. The survey suggests that the personal serum cholesterol level may be dependent upon the habitual total intake of dietary fat and the percentage of the total calories supplied by fat.

1. Bovine plasma albumin (BPA) containing approximately 14% moisture, when heated for 27 h at 115° suffered an appreciable loss of cystine and a small loss of lysine; at 145° all the amino acids except glutamic acid and those with paraffin side-chains, showed considerable losses. Isoleucine also showed some loss through racemization to alloisoleucine.

2. BPA heated at 115° evolved H2S; at 145° other sulphur compounds were released as well, all coming from the breakdown of cystine. Possible mechanisms for this are discussed.

3. Ammonia was also liberated from BPA heated at 115°. The degree of correlation of lysine binding in different proteins with ammonia liberation and amide changes has led us to suggest that the main reaction of ε-amino lysine groups is with amide groups of asparagine and glutamine. Reaction of ε-amino groups with carboxylic groups is thought to be less important.

4. Model experiments have shown that a reaction between amide groups and the e-amino group of lysine in proteins can occur at practical drying temperatures.

5. Reactions of the ε-amino group of lysine with destruction products of cystine is also considered to be partially responsible for the lysine binding in heated proteins.

1. Information was obtained on the activity and food intake of ninety-two boys and 186 girls aged 16–19 years over a period of 7 days. Seventy-four boys and 132 girls were students, and eighteen boys and fifty-four girls were employed.

2. Each subject recorded daily activity on a chart divided into squares corresponding to 5 min, using a code letter for each type of activity. The amounts of all foods and beverages consumed each day were recorded in a food diary.

3. The energy expenditure of each subject was estimated from selected values for the energy cost of each activity. The intakes of calories and nutrients were calculated from tables of food composition.

4. It was found that the subjects spent very little time in strenuous physical exertion. There were slight differences between the age-group and the occupation groups, but between 78 and 80% of the total time was spent in bed or seated, 14–20% in very light to light physical activity and only 1.5–4.4% in any activity greater than walking at an even pace.

5. The group means for estimated energy expenditure in kcal, with their standard deviations, were: schoolboys aged 16–17, 2780 ± 250; employed boys aged 16–17, 2890±240; schoolboys aged 18–19, 2710±280; employed boys aged 18–19, 2749±270; schoolgirls aged 16–17, 2030±170; employed girls aged 16–17, 2140±240; schoolgirls aged 18–19, 2040±190; trainee teachers aged 18–19, 1900±140; employed girls aged 18–19, 2070±160.

6. Group means for the intake of kcal were: schoolboys aged 16–17, 3040±540; employed boys aged 16–17, 2730±520; schoolboys aged 18–19, 3110±450; employed boys aged 18–19, 2700–170; schoolgirls aged 16–17, 2140±420; employed girls aged 16–17, 1910±310; schoolgirls aged 18–19, 2400 ± 310; trainee teachers aged 18–19, 2020 ± 330; employed girls aged 18–19, 2030±440

7. The employed girls aged 16–17 had lower intakes of calories and all nutrients than the schoolgirls of the same age.

8. No correlation was found between the weight and calorie intake of individual subjects, nor between their calorie intake and energy expenditure during the time interval studied. The results indicated that for these Australian subjects, calorie balance was not achieved over a period of a few days. This is in accord with evidence of workers in other countries.

9. The findings suggest the need for further studies on the nutritional status of Australian employed girls aged 16–17.

1. Assessments were made of the energy expenditure and food intake of five boys and four girls aged between 16 and 20 years.

2. The subjects recorded their activity over a 7-day period and weighed and recorded their food intake over the same period. The energy expended by them in performing specific activities, such as sitting, standing and walking, was measured by indirect calorimetry. The total daily energy expenditure of each subject was then counted. (Values were selected from the litera ture for the energy cost of the activities which we did not measure.)

3. The following range of values was obtained for the energy cost per min of various activities: sitting, 1.0–1.8 kcal, standing, 1.2–2.0 kcal; walking, 2.0–7.5 kcal; office work 1.1–1.9 kcal; laboratory work 1.4–2.3 kcal; playing table tennis, 4.6 kcal; riding a bicycle, 3.6–6.0 kcal; running, 5.2–7.5 kcal.

4. The means and standard deviations for daily energy expenditure and for calorie intake, respectively, expressed in kcal, of the individual subjects were: for the boys 2677±184 and 3348±668, 2285±91 and 2652±418, 2730±263 and 2985±625, 2638±338 and 2379±204, 2594±244 and 3150±692; for the girls 1939±234 and 2340±524, 2261±175 and 2064±376, 2131±148 and 2011±389, 2104±171 and 2454±469.

5. There was no correlation between the daily energy expenditure and calorie intake of any subject, nor was there any relation between the weight of individual subjects and either their total energy expenditure or calorie intake.

6. It is concluded that more precise methods of measuring the energy expenditure and calorie intake of individual subjects would need to be used in order to determine if there is any correlation between these two variables over short periods.

7. The results of this study tend to confirm the findings of other workers that calorie balance is only achieved over periods longer than 7 days.