1. Preschool children and schoolchildren from a rural area in the northeast of Thailand were compared with children from urban areas for prealbumin, albumin, transferrin, α1B-glycoprotein, the acute-phase reactants α1-acid glycoprotein, α1-antichymotrypsin. haptoglobin and the proteinase inhibitors α1-protease inhibitor (AlPI) as well as α1-macroglobulin (α2M). Urinary urea nitrogen: creatinine (U-C) as well as haemoglobin were also determined. Village preschool children were grouped according to their SD score for weight-for-height based on the (US) National Center for Health Statistics (1976) standard into a normal group with SD scores of ≥ −1.99 and an undernourished group with SD scores of ≤ −2.00.

2. There was no significant difference between the normal and the undernourished groups of preschool children for any of the factors measured.

3. Haemoglobin and prealbumin concentrations of preschool children were lower in the rural children than in the urban preschool children from Bangkok.

4. In rural schoolchildren haemoglobin was lower but albumin, transfemn, α1B-glycoprotein and haptoglobin were higher than in urban schoolchildren from the provincial town of Khon Kaen.

5. Serum concentrations of the proteinase inhibitors AlPI and α2M were significantly higher in the rural children than in the urban children.

6. U-C values were lower in rural schoolchildren compared with urban schoolchildren.

1. Duration of lactational amenorrhoea and interpreganancy interval were related to maternal body-weight in an urban low-income group population of 2250 women.

2. Breast-feeding practices were similar in all the women, none of whom had received any nutritional intervention.

3. In the study group the mean duration of lactation, lactational amenorrhoea and interpregnancy interval (months) were 20.7, 11.2 and 24.2 respectively.

4. Mean duration of lactation was significantly shorter in women whose body-weights were over 55 kg. Duration of lactational amenorrhoea increased with increasing duration of lactation (r 0.5164).

5. The duration of lactational amenorrhoea showed a progressive fall with increasing body-weight (r − 0.8139) even when duration of lactation was kept constant.

6. The mean duration of post-partum amenorrhoea in women who did not lactate remained unaltered irrespective of body-weight.

7. The findings suggest that maternal nutritional status modifies return of menstruation only in lactating women.

1. A group of 129 patients with chronic alcoholism were assessed for their nutritional status with respect to certain minerals and vitamins, and compared with control subjects.

2. In all subjects the plasma values were normal for calcium, magnesium and zinc.

3. As in other studies a seasonal variation was found in the plasma levels of 25-hydroxyvitamin D in the control subjects and the alcoholic subjects; in all seasons lower levels were found in the alcoholics than in the controls, but none of the alcoholic patients had results in the range found in osteomalacia.

4. The alcoholic subjects had low levels of ascorbic acid both in the plasma and in the leucocytes.

5. Although vitamin A and β-carotene levels were within the reference range, the results in alcoholics were found to be lower than in the control subjects.

6. We suggest that subclinical vitamin deficiencies other than thiamine deficiency contribute to the cerebral impairment frequently found in alcoholism.

1. Male Sprague-Dawley rats were allocated at 100 g into either an ad lib.-fed control group or a food-restricted group. The restricted group was fed for 9 d at 25% of ad lib. intake. Controls were killed at a body-weight of 100 g and 29 d of age and the restricted animlas were killed at 70 g and 38 d of age.

2. The effects of food restriction on muscle weight, fibre number, fibre diameter, DNA, and protein were examined in three skeletal muscles, the soleus, plantaris and extensor digitorum longus (EDL).

3. Acute dietary restriction caused body- and muscle-weight loss and a decrease in both the number and cross-sectional area of muscle fibres in each of the muscles.

4. The restriction halted growth-related increases in DNA in all muscles and decreased the protein: DNA value in the plantaris and EDL.

5. These results indicate that present theories describing cellular development are not adequate to define growth potential or growth retardation of skeletal muscle.

1. Detailed studies of variations in breast-milk fat concentrations were performed over 12 or 24 h periods on sixty rural Gambian women feeding on demand. The creamatocrit method (Lucas et al. 1978) was used.

2. The complex pattern of within-feed and between-feed changes in fat concentration was largely explained by differences in volume per feed and time interval between feeds.

3. No consistent difference in fat production between the breasts of each individual was found despite the local custom of starting all feeds on the right breast.

4. A marked diurnal variation in the mean fat concentration per feed was noted. On average the highest values occurred in the early morning, the lowest values in the late afternoon.

5. There was significantly greater between-individual than within-individual variation in the mean fat concentration per feed over 12 h (P > 0.001).

6. A simple, rational and non-intrusive sampling procedure was devised for the estimation of whole-day mean fat levels based on the finding that the mean fat concentration of small samples of milk (0.25 ml) taken from both breasts before and after one specific feed of the day was closely correlated with 12 h and 24 h mean fat concentrations.

1. Long-term variations in breast-milk fat concentration of mothers feeding on demand were studied in 120 rural West African women over a 12-month period.

2. The over-all mean 12 h breast-milk fat concentration was 39.3 g/l.

3. Mean breast-milk fat concentrations were affected by season in a manner which was correlated with seasonal changes in maternal subcutaneous fat stores (P > 0.05) but which was unrelated to seasonal variations in maternal energy intake and breast-milk output.

4. Breast-milk fat concentrations were highest in early lactation, decreasing to a constant level during the first year.

5. There was significantly greater between-mother than within-mother variation in breast-milk fat concentrations measured in successive months, after correcting for season and stage of lactation (P > 0.001).

6. Breast-milk fat concentrations were highest for primiparous mothers, decreasing to a constant level at parity 4 and higher.

7. A mother's relative breast-milk fat concentration was not correlated with her levels of dietary energy intake and breast-milk output but was positively correlated with her relative subcutaneous fat deposits (P > 0.01).

1. The energy balance of eleven male and fourteen female adult farmers was measured for 6 d after the harvest, in December-January. Their energy intake was recorded by weighing their food consumption and their energy expenditure was determined using indirect calorimetry.

2. Body-weight, expressed as percentage of expected weight-for-height was 91 and 86% of the Inter-departmental Committee on Nutrition for National Development (1963) standard for women and men respectively.

3. The staple foods were sorghum (Sorghum vulgare) and millet (Pennisetum typhoïdes); carbohydrates, fat and protein supplied approximately 80, 13 and 12% of the total energy of the diet respectively.

4. In the male group, the mean energy intake (9.0 MJ (2148 kcal)) was in good agreement with the average energy output (8.91 MJ (2130 kcal)). By contrast, in the female group, the mean energy expenditure (8.11 MJ (1941 kcal)) exceeded the mean energy intake (6.3 MJ (1515 kcal)) and the deficit was statistically significant.

5. This study allows an evaluation of the adequacy of food intake for subjects living in a particular hostile environment, by using their actual energy output instead of current standard values. The energy deficit found for female farmers whose energy intake was similar to that reported in other developing countries emphasizes the need for a better understanding of the regulation of energy balance in such conditions.

1. A rumen bacterial culture containing specifically labelled nucleic acids was prepared using [8-14C]adenine.

2. The labelled preparation was given in a liquid diet to two preruminant lambs and via a rumen tube to two ruminant lambs. The radioactivity excreted in exhaled gases, faeces and urine and that incorporated into tissues was determined.

3 The preruminant lambs absorbed 58.3% of the total radioactivity measured after 24 h and the ruminant lambs 66.6% of the total activity measured after 48 h.

4. Of the total radioactivity absorbed the preruminant lambs exhaled 38%, excreted 34% in urine and retained 29% in tissues. The corresponding values for the ruminant lambs were 12,41 and 47% respectively.

5. There was a close relationship between total nucleic acid content and radioactivity per g of tissues of both preruminant and ruminant lambs.

6. Of the radioactivity in the urine, the ruminant and one preruminant lamb excreted most in the fraction containing allantoin, while the other lamb excreted most activity in the uric acid fraction.

7. The salvaging of the breakdown products of bacterial nucleic acids to make tissue nucleic acids appears to be an important synthesis in preruminant and ruminant lambs and of the likely precursors the purine base may be more important than the nucleoside.

1. The effect of varying dietary levels of casein (40–140 g/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase (EC 1.1.1.49; G6PD), malic enzyme (EC 1.1.1.40; ME), citrate cleavage enzyme (EC 4.1.3.8;CCE), acetyl CoA carboxylase (EC 6.4.1.2; AcCx), glucokinase (EC 2.7.1.2; GK), and pyruvate dehydrogenase (PDH) was examined in young, growing rats.

2. The activities of AcCx, FAS, G6PD and in vivo fatty acid synthesis were generally found to increase with increased dietary protein.

3. The levels of GK and PDH were not related to dietary protein.

4. ME decreased with increasing dietary protein.

5. The results demonstrate a dissociation between hepatic fatty acid synthesis and ME and suggest that when rats consume low-protein diets the NADPH needed for fatty acid synthesis is generated primarily by ME but that as the level of dietary protein is increased the contribution of ME is reduced while that of the phosphogluconate pathway becomes more important.

1. The relationships between the intakes of protein and of non-protein energy (NPE), nitrogcn retention and body protein synthesis have been studied in female pigs weighing 30 and 35 kg.

2. Four animals were assigned to three regimens and given a conventional (basal) diet supplemented with fat, carbohydrate or protein. After 1 week, measurements of N excretion in urine and faeces (7 d collection) and gaseous exchange (3–4 d) were made. At the end of the balance period a solution of [l-14C]leucine was infused at a constant rate. Body protein synthesis was then calculated as the difference between the apparent irreversible loss of blood leucine and the loss of 14C in expired air.

The animals were then offered the basal diet without supplement for 10 d and the measurements of N retention, energy retention and protein synthesis were repeated.

3. The intakes of metabolizable energy (ME; MJ/kg body-weight (W)0.75per d) were 1.75 for fat, 1.58 for carbohydrate, 1–25for protein and 1.18 for the basal diet; corresponding intakes of apparently digestible N (ADN; g N/kgW0.75 per d) were 2.30,2.31,4.35 and 2–17. Daily N retention, which during the period of basal feeding was 13.6 g was increased by between 3.4 and 7.2 g by the supplements. Daily fat deposition was also increased in the animals that received the diets supplemented with carbohydrate and fat.

4. The rate of leucine catabolism was significantly reduced in the animals receiving the diets that were supplemented with W Eand increased by the addition of protein to the diet.

5. When based on the specfic radioactivity of blood leucine both the synthesis and breakdown of body protein (per unit metabolic body-weight) were increased by 30% in the animals receiving the high-protein diet but the increases in protein synthesis associated with the addition of carbohydrate (+14%) and fat (+12%) were much less marked. Consideration of these results together with previous observations (Reeds et al. 1980) suggested that body protein synthesis(g N/d) increased by 0.88 for each g increase in daily ADN and by 0.93 for each MJ increase in daily ME intake.

6. Comparison of the results obtained with the animals given high-carbohydrate diets and those given high-protein diets suggested an increase in heat production of 14 KJ/g of additional fat deposition. A similar comparison of animals receiving the high-protein and basal diets suggested a heat increment of 23.5KJ/g additional protein deposition. The changes in heat production and protein synthesis in the animals given the protein supplement were compatible with a heat increment of 5.3 KJ/g additional protein synthesized. Because of the large proportion of heat production associated with the deposition of fat this could not be confirmed with either of the other supplements, but it is possible that the energy cost of protein accretion varies with the relative proportions of protein and NPE in the diet.

1. In two experiments measurements were made of food intake, live-weight change, milk yield and milk composition in early lactation when dairy cows were given diets containing varying proportions of protein as fish meal (low rumen degradability) or as groundnut meal (high rumen degradability). In a preliminary trial measurements were also made with cows given supplements of either fish meal or barley and fed at a restricted level of feeding.

2. When metabolizable energy (ME) intake exceeded 160 MJ/d there was no evidence of responses to changes in protein degradability, but at ME intakes below 135 MJ/d increases in the supply of undegradable protein led to increases in fat-corrected milk yield, protein content and live-weight loss.

3. The interaction between energy intake and protein degradability is unexpected because net protein:net energy requirement increases as milk yield increases, but may be explained in terms of differential effects of changing rumen outflow rates on degradabilities.

1. An experiment was designed to provide information on the alterations in body metabolism which would account for the loss of body-weight in cattle due to the specific effect (factors other than reduced food intake) of the tick Boophilus microplus.

2. Two groups of British (Shorthorn × Hereford) and Africander × British calves, each approximately 6 months old, were used: one group (treated) of each breed was tick-infested and the other (control) was tick-free. Within breeds, calves in the control group were pair-fed to calves in the treated group.

3. In both breeds, the effect of ticks: (a) depressed packed cell volume, serum alkaline phosphatase (EC 3.1.3.1) and amylase (EC 3.2.1.1) activities, plasma cholesterol and phospholipid levels, serum iron and albumin levels. (b) increased the plasma levels of urea-nitrogen and γ-globulin (c) increased rectal temperature, water intake, urine volume, urinary and faecal total N, urinary urea-N and α-amino acids, the excretion of water, sodium and potassium in the faeces and (d) reduced N balance, N and dry-matter digestibilities.

4. In the British breed, ticks increased the excretion of K with a corresponding decrease in the excretion of Na in the urine and inreased the plasma clearance of bromsulphthalein.

5. A second experiment showed that the specific effect of tick infestation increased the flow of organic matter (OM) from the abomasum and the fractional turnover of rumen fluid of Hereford steers. It was also shown that the decrease in OM digestibility in the gastrointestinal tract was largely due to a decrease in OM digestibility in the rumen and that the increased urinary urea excretion and plasma urea concentration was caused by higher production rates of urea despite a tendency for lowered urea degradation in the gastroinestinal tract.

1. The effects of a methane inhibitor, ICI 111075, and a propionate enhancer, monensin, were studied using in vitro continuous fermenters.

2. Both compounds increased the yield of substrate energy, carbon and hydrogen in volatile fatty acids (VFA). This was mainly due to an increase in the molar proportion of propionic acid.

3. Improved yields of VFA were accompanied by reductions in methane production and microbial yield.

4. Since published information showed that monensin reduced rumen dilution rate in vivo an analogous in vitro system was proposed in which a high dilution rate control fermenter was compared with a monensin treated fermenter set to run at a low dilution rate.

5.Results showed that the general intrinsic microbial activity of the chemical manipulators was not affected by changes in dilution rate. Changing dilution rate in addition to chemical treatment however resulted in substantial modifications in the net effect on the fermentation.

6. The practical implications of reducing rumen dilution rate as a side effect of chemically manipulating the rumen fermentation could involve changes in food intake, increased importance of secondary fermentations and a reduced effect of nutrients not degraded in the rumen.

1. Studies were conducted to measure the influence of perinatal undernutrition of twin-bearing ewes on ewe milk yields and lamb performance in early lactation. Comparative studies were conducted with lambs to measure the effects of postnatal nutrition on lamb performance and carcass composition. The major objective of this work was to determine the extent of the influence of postnatal nutritional deprivation of lambs.

2. From 8 weeks prepartum to 4 weeks postpartum each of forty twin-bearing ewes was given daily 0.30 MJ of ME/kg body-weight (W)0.75. Measurements were made of ewe body-weight changes, milk yields during the first 4 weeks of lactation, and of lamb performance.

3. There were three postnatal experiments with lambs of ‘light’ and ‘normal’ birth weights, wcaned from the ewes at 72 h. One hundred and four lambs were used and they were individually reared on separate allowances of lamb milk-substitute for 8 weeks. They were subsequently given a lamb concentrate ration. In Expts 1 and 2 the lamb concentrate was fed ad lib. to ‘slaughter’ live weight. In Expt 3 the concentrate was restricted for 8 weeks post weaning and then fed ad lib. A carcass analysis (bone, muscle, fat content) was conducted on all lambs after slaughter. In the first experiment, half the lambs were slaughtered at 8 weeks of age on being weaned off the milk substitute, and a carcass analysis was carried out.

4. The mean net body-weight loss per ewe from commencement of late pregnancy to 28 d post partum was 23.8 kg. The over-all mean daily milk yield was 843 g/d. The mean growth rate of the lambs was 97 g/d during the 4-week measurement of ewe milk yields.

5. Live weight gain of lambs subjected to restricted milk-substitute allowance (125 g/dry matter (DM) per d) was low, irrespective of lamb birth weight. The average daily gain over the 8-week postnatal period was 86.5 g/d on restricted milk allowance compared with 244 g/d for those fed ad lib. Conversely, the food intake and growth rate of these lambs were almost identical during feeding on ad lib. concentrates. This clearly reflected a response to compensatory food intake which was independent of either birth weight or postnatal milk allowance. The average daily gain of lambs, before weaning, on the restricted milk allowance was very similar to that of the lambs being suckled by ewes subjected to perinatal undernutrition. The effects of postnatal undernutrition of lambs was particularly reflected in the time required to reach ‘slaughter’ live weight. The period of time varied from 117 d for those on ad lib. food intake to 169 d for lambs on restricted food intake.

6. The major effect of postnatal undernutrition on carcass composition was evident in the lambs slaughtered at 8 weeks in Expt 1. The percentage carcass fat was 4.7 for those on the low milk allowance. The carcass composition of all lambs at ‘slaughter’ live weight was similar. It would appear that lambs on a restricted milk intake before weaning deposited more fat during the subsequent period of compensatory food intake.

7. It is evident from the present results that postnatal growth retardation in lambs reflects either perinatal undernutrition of twin-bearing ewes, or postnatal undernutrition of the lambs due to inadequate milk availability from the dam.

1. In a randomized block design, four sheep were given 800 g daily of diets containing: chopped lucerne (L), chopped lucerne–rolled barley (2:1; LB), rolled barley–chopped lucerne (2:1; BL), rolled barley (B); each diet was supplemented with minerals, vitamins and urea as considered necessary. Chromic oxide was included in the diets as a flow marker.

2. Flows of organic matter (OM) and non-ammonia-nitrogen (NAN) to the small intestine (SI) were measured and microbial protein was identified by a 35S-incorporation procedure.

3. OM disappearance in the rumen increased linearly with increasing inclusion of barley in the diet but there was no significant change in microbial NAN flow to the SI so that the yield of microbial NAN (g)/kg fermented OM (FOM) decreased from 29.6 (diet L) to 22.7 (diet B). Changes in the energetic efficiency of microbial protein synthesis appeared to be unrelated to alterations in rumen fluid volatile fatty acid (VFA) proportions or in rumen fluid dilution rate (D).

4. The degradability of dietary protein (non-urea-N), estimated using the 35S procedure, was 0.72, 0.76, 0.86 and 0.86 for diets L, LB, BL and B respectively. Similar values were obtained from concurrent polyester-bag experiments when the fractional outflow rate of undergraded protein from the rumen (k) was assumed to be 0.046.

1. The maximum capacity of the bovine liver to excrete manganese in bile was determined in three Friesian-cross steers surgically prepared to allow bile flow-rate to be measured and samples collected. Plasma Mn concentrations were increased by infusing manganese chloride solutions into a jugular vein and the biliary excretion rates of Mn, copper, zinc and iron were measured.

2. The maximum capacity of the liver to excrete Mn in bile was exceeded at an infusion rate of approximately 4000 μg Mn/min, and at this rate there was a significant decrease in the concentration of Cu, Fe and Zn in bile. The maximum concentration (mean ± SE) of Mn in bile was 193 ± 19 μg/ml, and the maximum excretion rate (mean ± SE) was 1210 ± 130 μg/min for the three animals. There was no reduction in bile flow or evidence of liver damage as a result of the infusions.

1. The effects of dietary supplements of ω 3 polyunsaturated fatty acids on the fatty acid composition of platelets and plasma choline phosphoglycerides were studied in vegans and in omnivores.

2. A supplement of 18:3ω3 led to an increase in 20:5 ω3 but was less effective than one of 20:5ω3+22:6ω3.