1. There was a significant increase in oxygen consumption in ten women after small intakes of alcohol.

2. No significant difference was found between the average increase in metabolic rate over 3 h after an isoenergetic meal of food or of food plus alcohol. However, during the last half of the 3 h postprandial period, the increased O2 consumption was significantly greater after the meal including alcohol.

3. Possible explanations for the contradictory results in the literature are discussed.

1. The voluntary ethanol consumption, ethanol elimination rate and blood acetaldehyde level after intraperitoneal injection of ethanol were studied in rats receiving diets with highly imbalanced proportions of dietary protein, carbohydrate and fat.

2. The rats, which received the low-protein diet containing 0.05 of the total energy as protein, 0.80 as carbohydrate and 0.15 as fat, drank only approximately half as much ethanol as did the control group, which received 0.30 of its total food energy from protein, 0.55 from carbohydrate and 0.15 from fat. Ethanol elimination rate in the low-protein group was decreased and the blood acetaldehyde level after ethanol injection was markedly increased.

3. On the high-fat diet, which contained 0.30 of the total energy from protein, 0.05 from carbohydrate and 0.65 from fat, the rats drank significantly more ethanol than did the rats on the control diet; their ethanol elimination rate was decreased but their blood acetaldehyde level was not affected.

4. In conclusion, the strong decrease in voluntary ethanol drinking by the low-protein group may have been caused by the increased acetaldehyde accumulation in the blood, but a particularly low blood acetaldehyde level was not one of the factors inducing excessive ethanol drinking in the high-fat group.

1. A method of estimating whole-body zinc, and Zn balances using a two-compartment model in combination with whole-body counting of 65Zn, is described. The method is applied to patients with rheumatoid and osteoarthritis.

2. The results suggested that there was not a wide variation in whole-body Zn and Zn turnover in individuals with these two diseases and no clearcut difference between patients with one or the other.

1. Adsorption of bile salts by dietary fibre is believed to promote their excretion and hence to reduce the serum cholesterol level in man and experimental animals.

2. We have tested a number of plant fibre fractions and other related materials for their ability to adsorb bile salts from aqueous solution. The ‘insoluble’ plant fractions were from ‘dry grain’ (a residue from brewing), apple, wheat bran, lucerne (Medicago sativa), soya beans, mung beans (Phaseolus mungo), chick peas (Cicer arietinum), rolled oats, spinach (Spinacia oleracea), sunflower seeds, sawdust and sheep faeces. The other materials were cholestyramine, pectin and lignins prepared from wheat bran and from sawdust.

3. Only cholestyramine and the fibre from lucerne, soya beans, mung beans, chick peas, spinach, and sunflower seeds adsorbed enough of either sodium cholate or sodium deoxycholate for adsorption to be detectable.

4. This result conflicts with a report that the lignin component of dietary fibre is responsible for adsorption of bile salts.

5. Adsorption of bile salts, when it occurs, may depend on the presence of saponins bound to the fibre.

1. Rabbit caecal segments in situ were used to measure absorption rates of volatile fatty acids (VFA) and inorganic ions from a saline solution comparable in composition to normal caecal fluid.

2. Results confirm the importance of VFA absorption from caecal material found by other workers.

3. Like the mammalian colon, the rabbit caecum conserved large amounts of sodium, chloride and water. Bicarbonate was also absorbed.

4. VFA replacement studies showed that net water absorption was reduced, net electrolyte absorption was hardly influenced.

5. Na replacement completely inhibited net water absorption and decreased net VFA and Cl absorption, HCO3 was heavily secreted.

6. These findings indicate that VFA absorption in the rabbit caecum is partly dependent on Na absorption and that in the absence of Na an anion-exchange mechanism occurs.

1. The lipolysis of cow's milk fat by salivary lipase (EC 3.1.1.3) in the preruminant calf has been studied in vitro by a simulated abomasal digestion, and also in vivo by examining the abomasal effluent collected over 12 h after giving whole milk to a calf.

2. In the in vitro experiment the liquid drained from the clot contained a higher proportion of short-chain fatty acids than the abomasal effluent in the in vivo experiment. This was considered to indicate the absorption of short-chain free fatty acids from within the abomasum.

3. Preferential release of short-chain fatty acids both in vitro and in vivo was observed.

4. The outflow of butyric acid from the abomasum of the calf was initially rapid, but had levelled off at approximately 6 h, whereas the outflow of a typical long-chain fatty acid (palmitic) was fairly constant over the 12 h.

Butyric acid predominated in the free fatty acids of abomasal effluent 0.5 h after feeding (668 mmol/mol total free fatty acids) but had become a minor component by 12 h (15 mmol/mol total free fatty acids).

5. The mean amounts of free and esterified fatty acids (mmol/mol fatty acid ingested) present in the abomasal effluent from the 12 h collection period were: triglyceride 465, diglyceride 215, monoglyceride 68, free fatty acid 252. These values showed that only one-third of esterified fatty acids ingested are lipolysed to absorbable products by salivary lipase.

1. In vitamin B12 deficiency the activity of tetrahydropteroylglutamate methyltransferase (EC 2.1.1.13) is depressed and the synthesis of methionine is reduced. Because the methyl group of methionine is largely utilized for the methylation of phosphatidylethanolamine, we investigated the effects of vitamin B12 deficiency on phosphatidylcholine synthesis.

2. The incorporation of injected [14Clformaldehyde into liver phosphatidylcholine was reduced by approximately 50% in vitamin B12-deficient rats. Also the corresponding incorporation of 5-[14C]methyl-tetrahydrofolic acid tended to decrease. The findings are consistent with a lower conversion of these precursors to methionine.

3. The effect of the deficient methyl-group supply on phosphatidylcholine synthesis was also investigated by the injection of [14C]ethanolamine. The amount (%) of lipid-14C recovered in phosphatidylcholine was significantly reduced in vitamin B12 deficiency.

4. Chemical analysis of liver phospholipids showed that the vitamin B12-deficient rats had a higher proportion of phosphatidylethanolamine and a lower proportion of phosphatidylcholine, indicating that the impaired synthesis of phosphatidylcholine by methylation leads to changes in membrane phospholipid composition.

1. Broilers were kept under environmental temperature regimens of 16, 21, 26 or 31° and given, 22–57 d of age, either a complete diet or free-choice of whole wheat and a higher-protein food containing either 252 or 516 g crude protein (nitrogen × 6.25)/kg.

2. Broilers maintained at 16 and 21° consumed food at a significantly higher rate than those kept at 26° and the latter had a significantly higher food intake rate than broilers kept at 31°, for each feeding treatment. Compared with 21° the 57 d body-weight of broilers kept at 26° and 31° was significantly reduced.

3. When kept under the 16, 21, 26 and 31° regimens, the amount of whole wheat in the food consumed by the broilers choice-fed with wheat and the 252 g crude protein/kg food was 56, 55, 48 and 46% respectively. The corresponding values for the broilers on the second choice-feeding treatment were 80, 76, 79 and 72%.

4. Except for a single instance the choice-fed broilers grew at a significantly slower rate than broilers given the complete diet.

1. Hypovitaminotic C guinea-pigs fed on a high-cholesterol diet for 5 weeks developed gallstones (810 mg cholesterol/g) whereas no concretements were observed in vitamin C-replete animals.

2. Scanning electron microscope studies of the three types of gallstone observed in the gallbladders of vitamin C-deficient animals showed them to be composed of randomly-arranged needle-shaped or laminated crystals of cholesterol.

3. The hepatic bile of gallstone-forming animals had a higher cholesterol concentration and lower bile acid content, the latter being principally due to a reduction in the chenodeoxycholic fraction, than the bile of vitamin C-replete animals.

4. No significant difference was observed between the volume of bile secreted by hypovitaminotic C and vitamin C-replete animals, but due to the qualitative changes in bile composition, gallstone formation was associated with an increased biliary secretion of cholesterol and a reduced secretion of bile acids.

1. Lysosomal stability was slightly increased in regenerating livers from rats receiving a zinc-deficient (< 0.5 mg/kg) diet for 10 d before surgery.

2. The activity of superoxide dismutase (EC 1.15.1.1) was significantly reduced in the same tissues.

3. The results do not support the view that increased lysosomal fragility represents a major biochemical consequence of nutritional Zn deficiency in animals.

1. Twenty-four Sprague-Dawley female rats were randomly assigned to three groups (groups A, B, C). Group A was given a folic acid-free diet and groups B and C received 0.0018 g folic acid/kg diet. Rats in group C were also given a supplement of 1 mg folic acid/d by intraperitoneal injection.

2. After 14 d of feeding the rats were mated. The diets were continued throughout gestation. On day 21, of gestation the dams were killed and their livers and products of conception assayed for RNA, DNA, protein and tetrahydrofolate dehydrogenase (5,6,7,8-tetrahydrofolate dehydrogenase; EC1.5.1.3) activity.

3. The foetuses, placentas and livers from supplemented rats (group C) were significantly larger than those from groups A and B and had a higher content of RNA, DNA and protein. Those tissues from group A dams were smaller than those from the other groups and had a correspondingly reduced nucleic acid and protein content.

4. The activity of tetrahydrofolate dehydrogenase, the first and rate-limiting enzyme in the metabolism of folate, was increased in the folate supplemented rats (group C) and reduced in the rats given a folic acid-free diet (group A). These changes in enzyme activity could explain the differences in nucleic acid biosynthesis and growth shown by the different groups.

1. Twelve sheep fitted with abomasal cannulas were given ad lib. access to a diet of chopped lucerne (Medicago sativa) hay to ascertain if the amount of digesta being transported by the intestines was limiting intake. If this was the situation, pumping a solution of the bulk-laxative methylcellulose (100 g/kg; MC) into the abomasum should have reduced intake in proportion to the mass of digesta attributable to the MC and associated water. In preliminary experiments faecal water and wet matter ouptuts increased by 6.2 and 7.4 g/g MC powder respectively.

2. The infusion of 2.95 kg MC/d did not affect food intake even though wet faecal output increased from a control value of 2.436 to 4.616 kg/d. The transit time of 51Cr-EDTA through the intestines decreased only slightly during the infusion indicating that MC produced a marked increase in the mass of intestinal contents. Increasing the rate of infusion to 5.336 kg/d increased wet faecal output to 5.437 kg/d, did not change transit time but significantly decreased food intake presumably to protect the intestines from overdistension. After stopping the infusion, food intakes and faecal outputs returned to control values but transit time remained unchanged. The intake of chopped lucerne hay by sheep was not limited by the capacity of the small and large intestines to transport bulk as intake was maintained even though wet faecal output was doubled and the intestines apparently became markedly distended.

1. Rats given diets containing freshly-irradiated wheat showed significantly lower mean antibody titres to four different antigens, decreased numbers of antibody-forming cells in the spleen and rosette-forming lymphocytes as compared to rats given either unirradiated wheat or irradiated wheat stored for a period of 12 weeks.

2. The immune response in rats given 90 g protein/kg diet was essentially similar to that seen in animals given 180 g protein/kg diet.

1. Using male rats, the availability of fluoride from five by products of the aluminium smelting industry was tested. This was done by considering the balance between fluoride administered in controlled diets and the total fluoride content of waste products eliminated over an experimental period of 1 week.

2. Results indicated that yields of available fluoride expressed as percentage weight of original material were cryolite (Na3ALF8), 45.9%; sodium fluoride (NaF), 41.7%; aluminium fluoride (ALF3.H2O), 9.1%; mist eliminator grid solids (with CaF2), 9.4%; reclaimed alumina with adsorbed F, 0.27%.

3. Of the various tissues analysed for fluoride content, only the kidney and femur showed any significant correlation with the amounts of fluoride absorbed or retained.

1. The rate of transfer of plasma urea-nitrogen to rumen ammonia was measured by infusion of 15NH4Cl and [15N]urea into sheep given brome grass (Bromus inermis) or lucerne (Medicago sativa) pellets. Urea was infused into the rumen or abomasum of two sheep given brome grass in order to increase the concentration of rumen ammonia.

2. From 6.2 to 9.8 g/d of plasma urea-N were transferred to the rumen of sheep given brome grass pellets and a measurement of 1.3 g nitrogen/d was obtained for a sheep given lucerne pellets. When urea was infused into the rumen of sheep given brome grass pellets the transfer was only 2.8–3.7 g N/d.

3. There was a significant negative correlation between the rate of transfer of plasma urea-N to the rumen and the concentration of rumen ammonia.

1. Early-weaned lambs were used to estimate the concentration of urea required to give the maximum intake and utilization of maize or barley with either a high (HPB) or low (LPB) protein content.

2. Approximately the same concentration of urea (7–11 g urea/kg feed) was required for maximum intake and feed utilization of both HPB and LPB. With maize there was no increase in intake, live weight gain, digestion and feed conversion as a result of adding more than 7 g urea/kg.

3. The proportion of protein degraded in the rumen was estimated by the synthetic fibre bag technique to be 0.69, 0.82 and 0.54 for HPB, LPB and maize respectively. The similarity in concentration of urea required for the optimum utilization of LPB and HPB might be explained by differences in the extent of degradation of protein in the rumen, but the lower concentration of urea required for maize cannot be similarly explained.

4. From estimates of yield of microbial protein in the rumen, the extent of rumen fermentation and the measured extent of protein degradation, theoretical requirements for urea were calculated and compared with other predictions and with the experimentally determined values. For barley, predicted values agreed reasonably well with experimental ones, but for maize all values, including those derived by a new system adopted by the Agricultural Research Council (ARC) Working Party, were too high.

1. Guinea-pigs were growth-retarded in early life by feeding their mothers a restricted quantity of food during the second half of pregnancy. After birth, all animals were fed ad lib. Body-weights were recorded weekly and behavioural tests were made on adult males. The animals were then killed and their brains dissected into forebrain, cerebellum and brain stem. These regions were weighed and DNA-phorphorus content measured.

2. At 14 weeks each male was paired with another male for 10 min on four consecutive days and their social behaviour scored. Tests 1 and 2 were on like-treatment pairs and tests 3 and 4 on unlike-treatment pairs. At 25 weeks the same animals were subjected to six graded series of brief, unavoidable shocks and their responses recorded. After 3 d, thresholds of aversion to electric shock were measured by recording the period of time spent on the ‘safe’ side of a rectangular box at five shock levels.

3. Undernourished guinea-pigs were significantly lighter than controls at birth but not at adulthood. Regional brain weights and DNA-P content of previously-undernourished guinea-pigs were significantly lower than those of controls, with the greatest deficit in brain stem.

4. Pairs of previously-undernourished guinea-pigs began to interact more quickly and threatened and nosed each other more often than pairs of controls. In mixed pairs previously-undernourished animals chased controls more than their control partners chased them. There were no differences between groups in responsiveness to unavoidable shock or in aversion thresholds.

1. Comparisons were made between castrated male Scottish Blackface sheep and red deer (Cervus elaphus) of voluntary forage intake (VFI), digestibility and the mean retention time (MRT) of a particulate-phase marker (103Ru-phenanthroline) in the alimentary tract, when a range of forages: dried-grass pellets, chopped dried grass, fresh-frozen Agrostis-Festuca spp. and heather (Calluna vulgaris, L. Hull) were given at different times of the year.

2. On both the dried-grass-pellet and chopped dried-grass diets the red deer and sheep ate similar quantities. Both species had a higher VFI of dried-grass pellets in July than in November. The sheep digested the dried-grass-pellet diet better than the red deer and this was associated with a longer MRT of the particulate-phase marker in the alimentary tract.

3. The VFI of Agrostis-Festuca spp. and heather by the red deer was twice that of the sheep. The VFI of heather by the sheep increased by 32 % between January and April, and the VFI of both the Agrostis-–Festuca spp. and heather diets by the red deer increased by 65–70 %. The sheep digested the Agrostis–Festuca spp. better than the red deer but the red deer digested the heather slightly better than the sheep. MRT of the particulate-phase marker was greater for the sheep than for the red deer on both diets. The digestibility and MRT of both diets in the red deer did not decrease with the seasonal increase in VFI, suggesting a possible hypertrophy of the alimentary tract.

1. Rats were fed on either a diet deficient in essential fatty acid (EFA) or one supplemented with dihomo-γ-linolenic acid (20:3,n-6) at levels that represented 0.25, 0.5, 1.0 and 2.0% of the dietary energy.

2. Supplementation of the diet of EFA-deficient animals with 20:3,n-6 reversed most of the fatty acid changes induced in the liver phospholipid fraction.

3. The EFA potency of 20:3,n-6 was found to be similar to that of γ-linolenic acid (18:3,n-6) which has been shown to be higher than that of linoleic acid (18:2,n-6).

1. The effects of bucket- v. teat-feeding and warm- v. cold-milk feeding on the flow of duodenal digesta and the concurrent pancreatic secretion were studied in two experiments in preruminant Ayrshire calves (28–43 d of age), fitted with duodenal re-entrant and pancreatic sac cannulas.

2. As measured by the time interval taken for total recovery of the polyethylene glycol fed in the milk, the whey fluids had a more rapid passage through the abomasum when the calves were given warm milk by teat rather than by bucket (Expts 1 and 2). The duodenal digesta contained less sodium ions and more ‘Cl-Na+’ when the calves were fed by teat even though the volumes of milk drunk and duodenal flow were similar. It was concluded that more abomasal acid was secreted when calves were fed by teat.

3. When the calves were fed by teat rather than by bucket, the protein-nitrogen : N (PN : N) in the duodenal digesta was lower, especially during the first 6 h after feeding and there was a tendency for more pancreatic proteases to be secreted.

4. In Expt 1, when the calves were given warm milk the total flow of N and lipid in the duodenal digesta was 22 and 19% greater than that ingested. This was considered to be due to the coagulum from the penultimate meal plus the experimental meal passing more readily through the duodenum when sampling and to endogenous secretion of N and lipid.

5. When four Ayrshire calves were bucket-fed cold, rather than warm milk there was a reduced secretion of abomasal and pancreatic fluids and abomasal acid. There were no differences in the time interval required for the whey fluids to leave the abomasum or the PN : N value.

6. There was a positive correlation between the total duodenal flow of non-whey fluids and the pancreatic secretion regardless of the method of feeding.

7. The completeness of digestion and susceptibility of calves to diarrhoea when fed by teat and bucket is discussed.