1. Iron deficiency was induced in albino rats by a milk-powder diet. Control groups were given milk powder plus an iron source.

2. The haemoglobin content of the blood was determined once each month. When the haemoglobin level fell to 10 g/100 ml or less in the deficient animals, determinations were made of the vitamin C content of 24 h urine as well as of liver, kidney, adrenals, brain and blood. Additional studies were made of in vitro synthesis of the vitamin by liver homogenate.

3. The urine and tissues of the deficient animals were found to have a higher concentration of the vitamin than those of the control animals. The difference in enzyme synthesis was in the same direction, but was not statistically significant.

4. The results are interpreted as suggesting an increased requirement, by rats, of the vitamin in iron deficiency; this increased requirement is met by increased synthesis.

1. Experiments were conducted with wether sheep in 1964 and 1965 fed pelleted or chopped mature Digitaria decubemes Stent (pangola grass) bay containing different crude protein contents. The voluntary intake of food, digestibility of dry matter and nitrogen, nitrogen retention and apparent time of retention of feed organic matter in the reticulo-rumen were measured. The different crude protein contents of the grass were obtained by applications of urea to the sward 14 and 28 days before cutting for hay in 1964 and 1965 respectively. This treatment increased the crude protein content of the dry matter from 4.9% to 8.7% in 1964 and from 3.7% to 7.2% in 1965. The size of the particles of the ground hay before pelleting is given.

2. The mean voluntary intake of chopped fertilized grass was 10% and 54% greater than that of the unfertilized; the voluntary intake of pellets made from fertilized grass was 35% and 75% greater than of those made from the unfertilized grass in 1964 and 1965 respectively.

3. The voluntary intake of pellets of unfertilized grass was 7% and 14% greater than that 30% greater than that of chopped fertilized grass in 1964 and 1965 respectively.

4. The digestibility of the pellets was less than that of the chopped grass.

5. The apparent digestibility of the feed nitrogen was increased by the fertilizer nitrogen, but grinding and pelleting had no consistent effect. Sheep eating chopped or pelleted fertilized hay were in positive nitrogen balance.

6. The apparent retention time of organic matter in the reticulo-rumen was longer when the sheep were eating chopped hay than when they were eating pellets. In 1964 the apparent retention time of organic matter in the reticulo-rumen was shorter for chopped and pelleted unfertilized grass than for chopped and pelleted fertilized grass, but in 1965 the order was reversed.

7. The relationship between voluntary intake, apparent retention time of organic matter in the rumen and the protein content of the food is discussed.

1. When weanling rats were given a vitamin E-deficient diet and 0.15% (w/v) silver acetate in their drinking water, there was a high incidence of liver necrosis and death after 2–4 weeks. This was prevented by 120 ppm D-α-tocopheryl acetate in the diet, was partially prevented by selenium at 1 ppm but not at 0.05 ppm and was only marginally prevented by 0.15% DL-methionhe.

2. All these effects were observed when the diet was free of fat and when it contained either methyl oleate or polyunsaturated methyl esters. The polyunsaturated lipid slightly increased the velocity of the terminal illness.

3. In spite of the ‘anti-vitamin E’ effect of Ag and the clear demonstration that α-tocopherol played a major part in preventing toxicity, experiments with tracer amounts of [5-Me-14C]-D-α-tocopherol showed that rather than there being any destruction of tocopherol in the critical period preceding the onset of disease, there was an increase in tocopherol in the liver due to Ag administation. The metabolism of tocopherol in the remainder of the animal was unaffected during the pre-necrotic phase.

4. The results are inconsistent with the view that the stress induced by Ag is caused by a pro-oxidant effect, either in the gastro-intestinal tract or in the tissues of the rat. They show that lipid peroxidation is not a causal factor in the aetiology of Ag-induced liver necrosis and suggest that stress in the vitamin E-deficient animal probably raises the requirement for tocopherol.

1. Eighty weanling albino rats, five from each of sixteen litters were distributed between five dietary groups in sixteen randomized blocks. Each block was formed from within a litter and each animal in the block received a different diet.

2. The main features of the diets were: group 1, 72% sucrose; group 2, 72% uncooked wheat starch; group 3, 72% roll-dried wheat starch; group 4, 36% sucrose and 36% uncooked starch; group 5, 36% sucrose and 36% roll-dried starch.

3. The rats were killed after 20 days on the diets and assessed for dental caries. The rats consuming diets containing sucrose (groups 1, 4 and 5) had significantly more caries than animals receiving diets in which starch was the sole carbohydrate. The diet containing roll-dried wheat starch produced significantly more caries than uncooked starch. The mixture of uncooked starch and sucrose was more cariogenic than the mixture of roll-dried starch and sucrose.

1. The compositions of the fatty acids in ryegrass were determined in fresh samples, and in samples dried at room temperature for 26 h, at 50° and for 18 h or at 100° for 12 h. The drying of grass resulted in a small increase in palmitic acid and a decrease in linolenic acid in the total fatty acids.

2. Samples of grass dried at 50° and 100° were stored at three relative humidities (rh < 3%, 47% and 80%) for 13 months.

3. There were marked changes in the samples stored at 80% rh, with an onset of mould growth and a loss of dry matter. The samples stored at lower humidities had no mould.

4. There were two types of change in the fatty acids during storage. The deterioration brought about and mould was accompanied by a decrease in the concentration of linolenic acid and an increase in the concentrations of oleic and linoleic acids. The other type of change observed at the lower humidities resulted in a decrease in the content of linolenic and an increase in the content of palmitic, and did not affect the amounts of oleic and linoleic cells.

5. There was little difference between the changes that occurred in the composition of the total fatty acids of the grass dried at 50° and of that dried at 100°. The changes that were at all significant appeared to occur less rapidly, particularly in the early months of storage, in the grass dried at the higher temperature for the shorter time.

1. The activities of several lysosomal hydrolases were measured in the tissues of chicks suffering from nutritional muscular dystrophy, encephalomalacia or exudative diathesis.

2. In dystrophic breast muscle, β-glucuronidase was raised five- to six-fold, cathepsin fourfold and acid phosphatase 1.5-fold. No change was found in the subcellular distribution of β-glucuronidase.

3. Chicks with encephalomalacia showed no changes in the β-glucuronidase, β-galactosidase, acid phosphatase or β-acetylglucosaminase activities of cerebellum or brain. Subcellular distribution of β-glucuronidase and β-galactosidase in these tissues was also unchanged.

4. In exudative diathesis, hydrolases were found in the exudate, and there was increased activity in the subcutaneous tissue first showing haemorrhages. Increased hydrolytic activity was found in liver, spleen and kidney. Breast muscle was not always affected by the exudative condition, but, when it too degenerated, its hydrolase activity increased.

5. β-Glucuronidase activity was measured in the serums of chicks suffering from each of the three deficiency diseases. None of the diseases caused a rise in activity.

1. A survey of the incidence of goitre in Ceylon was carried out in the years 1947–9 and goitre was found to be endemic in the south-west sector of the Wet Zone of Ceylon.

2. In response to a request by the Ceylon Government to the World Health Organization for advice, Dr Dagmar Wilson in 1950 confirmed our earlier findings and as a short-term policy recommended the provision of iodine as KI tablets to the stress groups in the Wet Zone. This was initiated in August 1951.

3. A second survey was carried out in 1963 in nine of the villages in the Wet Zone that had been studied previously.

4. Statistical analysis showed that the incidence had significantly increased amongst the females in all nine villages and amongst the males in two villages.

5. A survey of the incidence amongst mothers attending antenatal clinics confirmed the existence of a strip of country where goitre was endemic.

6. The critical level of iodine intake from drinking water below which goitre becomes endemic has been shown to be 10 μg/1.

7. The low iodine content of the water in the Wet Zone has been shown to be due to the persistent heavy rainfall, associated with high drainage into the ocean, by which the soil is leached.

8. The mean annual escape of water per square mile of a river basin (the yield factor) has been shown to be directly proportional to the intensity of endemic goitre in that basin.

9. The aetiological factors related to the problem of goitre are discussed. The prophylactic method failed as it was not sustained.

10. Iodization of kitchen salt is recommended for use by the general population. The amount of iodine added to the salt should not be great enough to produce any side-effects. Potassium iodate is suggested as the most suitable source of iodine for use in tropical regions with high humidity.

1. Activities of β-glucuronidase, β-galactosidase, acid phosphatase and cathepsin were measured in the uterine contents of normal rats during gestation and of vitamin E-deficient rats during foetal resorption.

2. β-Glucuronidase activity reached a peak value on days 11 and 12, falling to lower values by day 14. Deficient rats showed slightly greater mean values than normal rats on days 11 and 12, but not after that time.

3. Vitamin E deficiency did not affect the activities of β-galactosidase, acid phosphatase and cathepsin, all of which showed a slow decrease during pregnancy.

4. The supernatant fraction of homogenates of uterine contents from deficient rats showed increased β-glucuronidase and β-galactosidase activity from day 14 to 17, suggesting some degree of rupture of the lysosomal membrane.

5. β-Glucuronidase and acid phosphatase activities were raised in the uteruses of some deficient rats towards the end of pregnancy, but serum β-glucuronidase was unaffected.

6. Changes in lysosomal hydrolases were not so marked during gestation–resorption as in some other vitamin E deficiency states, such as muscular dystrophy in the chick and rabbit.

1. The entry rates of urea into the urea pool of the body fluids have been measured in sheep given rations varying in crude protein percentage from 3.5 to 27.3.

2. Results obtained with a single injection and with continuous infusions of [14C]urea were essentially the same.

3. The difference between the entry rate and the rate of excretion of urea in the urine was taken to indicate the quantity of urea degraded in the alimentary tract.

4. Plasma concentrations and urea entry rates were significantly and linearly related.

5. The relationship between excretion rate and plasma urea concentration was best described by a cubic equation.

6. Degradation of urea in sheep was found to be extensive in all the animals studied; as the protein intake increased, the quantity of urea degraded also increased but the percentage of urea entering the body pool that was degraded was decreased. Animals given a ration containing 3.5% crude protein degraded 76–92% of the urea entering the body pool.

7. A rectilinear relationship was found between pool size and plasma urea concentration. The urea space in animals given low-protein rations was significantly less than in animals on high-protein rations.

8. The effects of starvation for 2, 4 and 6 days on urea metabolism in sheep were investi-gated. In a11 the sheep starved for 2 days there was a significant increase in urea pool size, but the entry rate was markedly depressed indicating a retention of urea in the body pool on starvation.

9. A significant amount of nitrogen was found to go through the system: rumen ammonia → portal blood ammonia→blood urea→rumen ammonia.

10.Urea excretion rate, urea clearance by the kidney, urine flow rate and the ratio of the concentration of urea in urine to that in plasma (urea U:P ratio) were also examined.

11. There were significant correlations between urine flow rate and urea excretion and between plasma urea concentration and urine flow rate.

1. Analytical values are presented for body nitrogen, both on a fresh and dry carcass basis, body water and N to body water ratios for rats, of various ages, of the Sprague–Dawley Strain.

2. For 33- and 40-day-old animals, there were significant differences in body composition, including N:H2O ratio, between animals given a protein-free diet and those given protein at the 10% dietary level. For all age groups the N and water percentages were higher in the carcasses of animals given the non-protein diet.

3. For all age groups there were significant negative correlations between the percentage of N in the dry carcass and the net dietary protein value (NDpv) of the diet. For 33-, 37- and 40-day old animals there were significant negative correlations between the N content of the fresh carcass and the NDpv of the diet. For 33-day-old animals only, the correlation between N:H2O ratio and NDpv was also highly significant.

4. Body N values calculated from N:H2O ratio and from N:body-weight ratio were compared. At all ages, an equally good prediction was obtained from the N:body-weight ration as from the N:H2O ratio provided that the correct factors were used for animals given the non-protein and test diets.

1. Seventeen hooded female rats were given from weaning a retinol-free diet containing methyl retinoate. When 105 days old they were mated with normal bucks.

2. Six of these rats were subsequently given dietary supplements of 100 μg retinol daily and another six were given 100 μg 3-dehydroretinol daily. All twelve rats had litters.

3. The five rats that received only methylretinoate during pregnancy resorbed their foetuses.

4. One of the litters from the female rats given 3-dehydroretinol consisted of six male pups. These young rats had never had access to retinol. They were maintained on a retinol-free diet supplemented with methyl retinoate. Two of these rats were given daily supplements of 3-dehydroretinol and another pair were given daily an equal amount of retinol.

5. The six rats were killed when 195 days old. The testes and the retina of the rats given either 3-dehydroretinol or retinol were normal. The testes and the retina of the rats given methylretinoate only were degenerate.

1. The activities of several lysosomal hydrolases have been measured in tissues of rats with nutritional liver necrosis. Incipient or actual liver necrosis did not alter total, free or unsedimentable activities of cathepsin, β-glucuronidase, β-galactosidase or acid phosphatase of liver and kidney. Free hydrolytic activity towards p-nitrophenyl phosphate was slightly raised in liver, and serum β-galactosidase and β-glucuronidase were moderately elevated. These results suggest that lysosomal hydrolases are not directly implicated in the causation of liver necrosis.

2. Testicular degeneration was studied with reference to changes in β-giucuronidase activity. This enzyme activity, total, free and unsedimentable, was raised in deficient rat testis at 6 months old and did not decline even after a year. Raised values were also found in serum.

1.The oral administration of sodium molybdate caused a rapid rise of molybdenum in the milk of cows and goats fed on a low-molybdenum diet, but did not affect the xanthine oxidase activities of the milk of either species.

2.In the milks of cows not dosed with sodium molybdate, the regression of the xanthin oxidase activity (y) on the molybdenum content (x) was found to be y = 170.7x+43.86 (r = +0.9386; P < 0.0001), suggesting that all the molybdenum of such milk is bound to enzymically active xanthine oxidase.

3.The molybdenum contents of the milk of goats not does with sodium molybdate varied from animal to anumal and the xanthine oxidase activites were much lower than those of cow' milk. there was no correlation between xanthine oxidase activity and the molybdenum contend of the milks of the goats.

4. These results are discussed in relation to previous work of the authors and others.

1. The excretions of magnesium, calcium, potassium and faecal dry matter (DM) by sheep grazing the same pasture have been determined at intervals throughout two grazing seasons. Two groups of four wethers, 2 and 7 years old, were used. Collections of faeces were total and of urine only partial; creatinine was used as an indicator of urine volume.

2.The overall mean outputs of DM in the faeces of the young and old sheep were 509 and 387 g/day respectively.

3. The values for the percentage digestibility of herbage DM ranges from 81.1 in spring to 63.2 in winter. The overall means for the estimated intake of DM by the young and old sheep were 1859 and 1405 g/day respectively and the difference was highly significant (P < 0.001).

4. The mean values for overall excretion of Mg by the young and old sheep were respectively 0.452 and 0.292 g/day in the urine and 2.70 and 2.21 g/day in the faeces. For all sheep there was a highly significant rectilinear relationship between the amount in urine and in faeces, but there were significant differences between the regression coefficients for the individual sheep.

5. The values for the excretion of Ca in urine and faeces were significantly higher for the young than for the old sheep; the respective means were 0.385 and 0.306 g/day for urinary Ca and 13.02 and 10.8 g/day for faecal Ca.

6.The mean values for the excretion of K by the young and old sheep were respectively 28.2 and 29.1 g/day in the urine and 7.1 and 3.9 g/day in the faeces, the latter differences being highly significant.

7.High values for the total excretion of Mg, Ca and K occurred in June and low values in winter.

8. Intakes of Mg, Ca and K by the sheep have been calculated from the information on intake of DM and chemical composition of the cut herbage and compared with total excretion in urine and faeces. Good agreement between the two sets of values was obtained for Mg, but not for either Ca or K. The possible causes of these findings have been discussed and it was concluded that the sheep selected herbage with concentrations of Ca and K different from those in the samples of cut herbage.

1. Among a series of 343 children with severe primary malnutrition there were 248 for whom, on admission, there were reliable records of age, weight, height, liver size, severity of oedema, skin lesions and angular stomatitis, and concentration of total serum protein, haemoglobin and sodium. For eighty-four of these children the serum bilirubin concentration was also known.

2. The correlations of these characteristics of the children on admission, with mortality, and with the rate of recovery were investigated.

3. Age, weight, oedema and haemoglobin concentration were not significantly related to mortality or to rate of recovery. A multiple regression analysis showed that an increased serum bilirubin concentration and a decreased serum sodium concentration indicated a bad prognosis, and these two factors contributed almost the whole of the multiple correlation coefficient of 0.63 with respect to mortality and 0.59 with respect to speed of rccovery.

4. We conclude that in our series of children death was more closely associated with liver failure or overhydration than with protein depletion, and suggest that the administration of ton much protein or water to an acutely ill malnourished child may precipitate death.

5. This analysis shows that the mortality observed in our series cannot be adequately explained by any combination of the characteristics considered above; there must, therefore, be other factors of importance for which we do not have suitable measurements.

1. In two experiments, 100 pigs were fed from age 4 or 5 weeks to age 16–19 weeks on practical-type diets containing 10% of meat meal (15–17% lipid) of either low (3–17) or high (114–150 μmoles/g lipid) peroxide value. The cereal basis of the diet in the first experiment was wheat and maize and in the second barley. Other variants were the inclusion of a stabilized vitamin E supplement in the diet of one of the groups in Expt 1, the presence of 100 (Expt1) or 250(Expt 2)ppm of copper, and storage of a diet containing oxidized meat meal for 6–21 weeks before feeding to one of the groups in Expt 2.

2. Apart from an unusually high incidence of stomach ulcers which, however, were almost equally distributed between the control and oxidized fat groups and did not appear to affect the health and nutrition of the animals, the pigs grew well, with no significant difference between the groups in weight gain, food conversion ratio, liver weight, vitamin A storage in the liver, and aspartate aminotransferase and alanine aminotransferase activities in the serum.

3. Changes in the lipids of the diets during storage were studied and samples of back fat from the carcasses examined for fatty acid composition, tocopherol content and susceptibility to autoxidation. Moisture content appeared to be a major factor influencing the oxidative stability of the meat meals used. Tocopherol content and oxidative stability of the pig fat were highest in the group given a vitamin E supplement, and generally lower in Expt 2 than in Expt 1.

1. The effects have been compared of log-term administration of similar amount of ethanol given either diluted in drinking water or spaced out in the form of intoxicating doses.

2. The effect of ethanol on the development of liver lesions produced by a marginal diet was examined. The measurements of growth rate, water balance, plasma glucose and electrolytes, rate of ethanol elimination, and some behavioural tests for the detection of tolerance and possible signs of neurological disturbance were also included.

3. Isocalorically pair-fed growing male rats were subjected to three different regimens for 6 months: (A) ethanol solution as the sole drinking fluid with 2 days' intake adjusted to approximately 5 mg/g body-weight; (B) a similar quantity of ethanol give as a single intoxicating dose per os on alternate days; (C) oleic acid isocaloric with the ethanol per os on alternate days.

4. All the regimens caused fatty liver. Hepatic fibrosis, as judged macro- and micro- scopically, was equally severe after treatments A and C, but milder after treatment B.

5. Growth was retarded by intoxication, which also brought about a large increase in water consumption, without exerting other clear effects on water balance or on plasma electrolytes. The rate of ethanol elimination was increased by repeated intoxication. Behavioural tolerance of the effects of ethanol was also found in the animals subjected to intoxication.

1. After a preliminary period on pelleted perennial ryegrass hay (0.28% sodium in dry matter) groups of sheep were fed on timothy hay (0.04% Na) with and without added sodium chloride or sodium bicarbonate.

2. When the sheep were fed on timothy hay, the Na content of urine and faeces fell and balances were negative. Na content of saliva fell markedly and potassium content increased.

3. Supplementary N a prevented these changes.

4. The low levels of dietary Na appeared to have no effect on the well-being of the sheep.