The study was conducted to provide reference values of anthropometry and dietary intakes of elderly Chinese aged ≥ 70 years and to investigate differences between urban and rural groups. A total of 441 subjects comprising 260 urban elderly (126 men and 134 women) and 181 rural elderly (83 men and 98 women) participated in the anthropometric study. One hundred subjects (50 men and 50 women) from both urban and rural locations were selected randomly from the anthropometric cohort for dietary survey using the method of diet recall. For both men and women, the urban elderly had significantly higher intakes of protein, fat, calcium, iron, retinol, thiamin, riboflavin and nicotinic acid than did the rural elderly. Significant sexual differences were also observed: men had higher intakes of total energy and three macronutrients than women. Both regional and sexual differences in anthropometry (but not blood pressure) seemed to be consistent with the results of the dietary survey. Positive correlations were found between systolic blood pressure and the ratio waist:hip circumference for both men and women. As a marker of adipose tissue distribution, it seemed that this ratio was more predictive of high blood pressure than body-weight.

Market baskets containing sixty food items included in the average Swedish diet were purchased from three shops in four major Swedish cities during autumn 1987. Food items were selected on the basis of food-balance-sheet data. Freeze-dried homogenates representative of each city were analysed for twelve essential or toxic mineral elements. The energy content of the market baskets (11.5 MJ) corresponded to the reference value for male adults. At this energy level the contents of calcium (1180 mg), magnesium (300 mg), iron (16 mg), zinc (12 mg) and selenium (44 μg) were above or close to the Swedish recommended daily intakes. The contents of manganese (3.7 mg) and molybdenum (150 μg) were within and that of copper (1.2 mg) was below the safe and adequate intake values given in the US recommended dietary allowance (Food and Nutrition Board, National Research Council, 1989). The content of nickel was 82 μg. The contents of lead (17 μg), cadmium (12 μg) and mercury (1.8 μg) in the daily diet were low compared with the provisional tolerable intakes set by the Joint Food and Agriculture Organization/World Health Organization Expert Committee on Food Additives (World Health Organization, 1972, 1989). The market-basket contents of Ca, Mg, Fe and Zn calculated from values in the Swedish food composition tables were close to the analysed values, indicating that the Swedish food tables provide relevant information for the estimation of the dietary supply of these elements.

As part of the Dutch Nutrition Surveillance System, cardiovascular risk factors and food consumption (24 h recall) as well as haematological, Fe and vitamin status (A, B6, C) were assessed in 126 Dutch boys aged 10–11 years (response 71 %). Body mass index (BMI) and the sum of four skinfolds were strongly associated (r 0.85, P < 0.01) and 8% of the boys were overweight (BMI > 20.1 kg/m2). Elevated serum total cholesterol levels (> 4.4 mmol/l) were observed in 38 %; total cholesterol and low-density-lipoprotein-cholesterol levels were strongly associated (r 0.88, P < 0.001). Intake of fat was high (38 % of energy) and too much fat was saturated (polyunsaturated: saturated 0.44, guideline: 0.5–1.0), whereas intake of carbohydrate (49% of energy) and dietary fibre was low. About 12% of the boys had insufficient Fe stores (plasma ferritin < 12.0 μg/l) and the mean Fe intake (9.0 mg/d) was below recommended daily allowance (10.0 mg/d). Plasma ferritin was, however, not associated with haematological indices and no frank anaemias were observed. No marginal values were observed for vitamins A, B6 and C status. In conclusion, the main nutritional risks in boys aged 10–11 years are cardiovascular risk factors and Fe nutrition.

The effectiveness of guar gum in reducing post-prandial blood glucose and plasma insulin levels in human subjects seems to depend mainly on its ability to increase the viscosity of digesta in the small intestine. However, the precise relationship between the rheological properties of guar gum (either in vitro or in vivo) and the changes in blood metabolites and hormones is unknown. The aim of the present study, therefore, was to investigate the effects of wheat breads containing guar gum samples varying in molecular weight (Mw) and particle size (characteristics that strongly influence the rheological properties of guar gum) on post-prandial blood glucose and plasma insulin levels in healthy subjects. The sensory qualities of breads containing guar-gum flours of different Mw were also evaluated using a hedonic scoring technique. No significant differences in the post-prandial blood glucose responses were found between the control and guar breads. However, all the guar breads elicited significant (P < 0.05) decreases in the post-prandial rise in plasma insulin, an effect that did not appear to be influenced by large variations in Mw or particle size of guar gum. Moreover, the sensory qualities of guar bread were markedly improved by using low Mw grades of guar gum.

A diet questionnaire was developed in association with a computer program to provide rapid nutritional feedback to the general public. The questionnaire was validated against 16 d of weighed diet records and biochemical variables in blood and urine. The highest Pearson correlation coefficients obtained between the questionnaire and the weighed records were for alcohol, fibre, iron, riboflavin (r 0.74, 0.67, 0.66, 0.66 respectively). Striking sex differences were shown in the results; the trend for higher correlations persisted in females. At least 65% of subjects were classified by questionnaire to within one quintile of the classification by weighed record for the majority of nutrients.

Treatment of lactating rats with the anti-progestin Mifepristone or Onapristone adversely affects growth of their litters. The present studies aimed to elucidate the underlying mechanism. The treatment did not interfere with the behavioural interactions between mothers and pups, which are required for normal litter growth. Treatment with the antagonists had a stimulatory action on ovarian oestrogen production. However, ovarian hormones did not play a role in litter growth impairment, as this also occurred with lactating ovariectomized rats. Treatment with anti-progestins did not affect the concentrations of the macronutrients in milk (protein, lactose and lipid), nor did it change the fatty acid composition of lipid. Reduced litter growth was not related to a possible direct effect of exposure of the suckling young to the drugs via the milk. Direct injections into them unequivocally affected adrenal gland and testicular development, but did not affect their body-weight development. Milk secretion, as measured by the milk weight accumulating during 6 or 24 h following sudden removal of litters in advanced lactation, was not impaired by the treatments. However, the ingestion of food and water by dams treated with Mifepristone was significantly below that of control animals. It is concluded that litter growth impairment during treatment of lactating rats with anti-progestin results from the reduction of the intake of food and water by the mother.

Four lactating Friesian cows with permanent cannulas in the rumen and proximal duodenum were given early (EC)- or late (LC)-cut grass silage ad lib., each with either 3 or 9 kg concentrate dry matter (DM)/d in a 4 x 4 Latin square design starting about 10 weeks after calving. Feed was offered twice daily at 08.30 hours and 15.30 hours. Periods lasted 5 weeks and measurements were made in the last 15 d. The higher amount of concentrates increased total DM intake but reduced silage DM intake and the fractional rate of degradation of silage-fibre DM. Later cutting date of silage had no effect on DM intake or the fractional rate of degradation of silage-fibre DM but reduced potential degradability of silage fibre. Dilution rate of CoEDTA in rumen fluid was greater during the day (eating period) than during the night (resting period). Dilution rates measured at the duodenum were lower than those measured in the rumen, but neither was affected by diet. Silage-particle passage rates were measured by use of ytterbium-labelled silage fibre (Yb-fibre) and chromium-mordanted faecal particles (Cr-faeces) and samples were taken at the duodenum and in the faeces. Values for slower rate constant (k1) and transit time were higher and for faster rate constant (k2) were lower for Yb-fibre than for Cr-faeces, but differences in total mean retention time were inconsistent. Values for k1 for both markers and k2 for Yb-fibre only were similar at both sampling sites, but values for k2 for Cr-faeces were lower in the faeces. No diet effects were established with Yb-fibre but, with Cr-faeces, k1 was reduced by more concentrates and EC-silage. Daily mean weights of wet digesta, liquid, neutral-detergent fibre (NDF) and indigestible NDF in the rumen were greater with LC-silage but were unaffected by the amount of concentrates whereas weight of rumen DM was increased by the amount of concentrates only. Maximum rumen fill occurred at 18.00 hours with all diets. Particle-size distribution of rumen contents did not vary markedly during the day. Mean particle size was generally greater with LC-silage than EC-silage. Very small particles, passing through the 0.3 mm screen, constituted about half the rumen DM. It is concluded that rumen fill could have limited intake of LC-silage but not EC-silage. The reduced silage intake with greater concentrate intake was associated with a reduction in fibre degradation rate and an increase in rumen DM fill but no other consistent effects on weight or kinetics of rumen fractions were established.

The effect of supplementing grass silage with fishmeal on growth, muscle composition and the rate of muscle protein synthesis was investigated in young Friesian steers with and without oestradiol implants. The effect of the β-adrenergic agonist cimaterol was simultaneously investigated in animals fed on silage alone. Treatments lasted for 9 or 10 weeks. Fishmeal supplementation significantly increased animal growth rates (P < 0.001) and the weights of three dissected muscles (P < 0.001) compared with the silage-fed controls. These effects were further enhanced in animals also implanted with oestradiol. Muscle weights expressed as a proportion of body-weight were increased by fishmeal, suggesting that protein deposition had been enhanced. No further increase in the proportional muscle weights was obtained with oestradiol. Muscle dry matter content tended to be increased in both implanted and non-implanted animals receiving fishmeal compared with controls, but the proportions of protein, fat and ash were relatively constant. The intramuscular lipid composition was slightly altered by fishmeal. Muscle protein fractional synthetic rates (FSR), measured by continuous infusion of [3H]tyrosine, were increased by fishmeal in all three muscles of both implanted and non-implanted animals. There were no differences, however, due to oestradiol, over non-implanted fishmeal animals. This suggests that oestradiol may increase muscle accretion by reducing protein degradation rate. Cimaterol significantly increased longissimus dorsi (P < 0.05) and vastus lateralis (P < 0.01) muscle weights but had no effect on semitendinosus muscle weight or live-weight gain. The proportion of protein was increased (P <0.001) and the fat content reduced (P < 0.05) in all three muscles but intramuscular lipid composition was not markedly affected. Whilst methylhistidine: creatinine excretion was reduced by cimaterol, FSR were increased in the I. dorsi and v. lateralis muscles suggesting β-agonists have effects on both protein synthesis and protein degradation.

The mean retention time (MRT) of stained hay through the whole digestive tract and its digestibility were measured in Japanese sika deer (Cervus nippon) and were compared with those in sheep when lucerne (Medicago sativa) hay was fed at 10, 20 and 30 g/kg body-weight. The recoveries in faeces of plastic particles with five specific gravities were also measured in deer. MRT for deer was significantly shorter than that for sheep at 10 and 20 g/kg feeding levels. The digestibilities of dry matter, organic matter, and neutral-detergent fibre were significantly lower for deer than for sheep at 30, 30 and 10 g/kg feeding levels respectively. The recovery rates of plastic particles were increased, but the ruminated rates were decreased, with increasing specific gravity in deer. These results suggest that the lower digestibility of lucerne hay in Japanese deer may be due to a shorter MRT compared with sheep.

Digestibility coefficients (DC) of protein, dry matter, energy, starch, and dietary fibre in individual feedstuffs were used to predict the DC in feed mixtures. Digestibility studies with growing rats involved six feed sources: soya-bean meal, barley, rapeseed meal, peas, wheat bran and wheat, given individually and in various combinations, i.e. fourteen diets in total. True digestibility of protein (TD) and apparent digestibility of starch could be predicted in feed mixtures from their respective DC values for the individual ingredients, except in the diet composed of peas+barley. Dry matter (DM) and insoluble dietary fibre digestibilities in the mixtures could also be calculated from their individual DC values. Energy digestibility could be predicted in all mixtures except for barley+wheat and peas + wheat. Although the discrepancies were significant, the differences were not great. The digestibility of soluble dietary fibre in the mixtures could be predicted as for the individual ingredients in all but three diets: rapeseed meal + barley, peas + barley and peas + wheat. The results confirm that DC values for TD, DM, energy, starch and dietary fibre in mixtures can be calculated with high precision from DC determined from individual ingredients. Caution should be taken though when mixtures contain a high amount of dietary fibre, especially of the soluble type.

The aim of the experiment was to test the theory that accustoming pigs to a high-fat diet causes exaggerated gastric inhibitory polypeptide (GIP) secretion in response to a high-fat meal, and to determine whether hypersecretion of GIP could be related to an increase in the GIP content of the small intestine. Twenty-four pigs were fed one of three dietary regimens for 11 weeks: a high-carbohydrate diet (CL), or a high-fat diet (FL), both fed at 1.46 MJ gross energy (GE)/kg live weight0.75 per d, or a high-fat diet (FH) fed at 2.10 MJ GE/kg live weight0.75 per d. At the end of the period two acute tests were performed. For acute test 1 the accustomed meal (diets CL FL and FH) and for acute test 2 a standard high-fat meal (diet FL) were given; blood samples were taken during the next 5 h and analysed for GIP, insulin and glucose. Integrated increases in hormone and glucose levels were compared by analysis of variance (0–300 min). In acute test 1 there were significantly different plasma GIP concentrations between groups (CL > FH > FL; P < 0.05). Plasma insulin concentrations were significantly higher in group CL compared with groups FL and FH (P < 0.002). There were no differences in glucose levels. In acute test 2 integrated increases in plasma GIP (0–300 min) concentrations were not significantly different; however, GIP (0–45 min) concentrations were significantly higher in group FH than in groups CL and FL (P < 0.05). There were no differences in plasma insulin concentrations. Plasma glucose (0–300 min) concentrations were significantly higher in groups FL and FH compared with group CL (P < 0.05). The GIP content of tissue samples taken at the end of the experiment from the duodenum, jejunum, upper and lower ileum decreased significantly in a proximal to distal direction (P < 0.001). Diet FH significantly increased the average GIP content of the small intestine compared with diets CL and FL (P < 0.05). It is concluded that fat meal-stimulated GIP secretion was enhanced by increased feeding level during a pre-treatment phase, possibly due to an increase in GIP synthesis in the small intestine. The high-fat diet caused glucose intolerance after a high-fat meal. This may be due in part to the action of dietary fat on glucose transport and metabolism.

Digestible energy (DE) values were measured in a selection of feedstuffs for the tilapia (Oreochromis niloticus Linn.) and used to develop equations for predicting DE values of a wider range of feedstuffs from chemical analyses. Preliminary work examined the influences of substitution level in a reference diet and adaptation over time on DE values for soya-bean meal. Length of adaptation period significantly affected DE values (P < 0.01), but substitution level, over the range 200–600 g soya-bean meal/kg reference diet, did not. The DE values of sixteen feedstuffs, thirteen derived from plant sources and three animal by-products, were subsequently determined. DE values for plant-derived feedstuffs were found to be higher than those quoted in the literature for trout (Oncorhynchus mykiss) and catfish (Ictalurus punctatus), whereas DE values for animal-derived feedstuffs were lower than those for trout and pigs. It was concluded that energy values quoted in tables of feed composition for other species are inaccurate when used as proxy values for tilapia. Regression equations were therefore computed using data from the present study to provide a rapid means of predicting DE values of feedstuffs for tilapia. Equations using neutral-detergent fibre as an independent variable were found to predict DE values of plant-derived feedstuffs reliably. Where fibre values were not used as independent variables, available carbohydrate and crude protein (nitrogen × 6.25) were found to be useful predictors of DE values. These equations offer the possibility of reducing the need for time-consuming digestibility trials with tilapia when formulating least-cost production diets for this species.

Rumen nitrogen metabolism values were estimated by the use of a single injection of 15(NH4)2SO4 into the rumen of sheep and consecutive 15N enrichment measurements in the rumen ammonia pool, rumen non-NH3-N (NAN) pool, rumen purine pool and blood urea-N (BUN) pool for a period of 24 h. Synthesis and degradation of N compounds in the rumen and passage of N to and from the rumen were evaluated on a chemical rather than a microbial basis; microbial fractions were not separated. This model was examined in two experiments. In Expt 1 a ram (55 kg) was given a semi-synthetic diet (1067 g dry matter (DM), 22.8 g N) in which soya-bean meal provided over 90% of the N. In Expt 2, two rams (45 kg) were given in three consecutive periods a semi-synthetic basal diet containing: (1) roasted soya-bean meal (SBM, 725 g DM, 14.8 g N/d); or (2) fishmeal (FM, 728 g DM, 15.5 g N/d); or (3) raw soya-bean meal (RSBM, 724 g DM, 13.8 g N/d). In all these rations, the main protein source provided over 90% of the N. In Expt 1, 68.3% of N intake was degraded directly to NH3 in the rumen, 21.2% escaped rumen degradation and 10.5% was incorporated into stable N compounds in the rumen. Net NH3 transfer to the blood was 30.4%, NH3 flow from the rumen was 6.6% and rumen NAN output was 63% of N intake. In Expt 2, rumen NAN output was larger (7.67, 14.36 and 8.89 g N/d for diets containing SBM, FM and RSBM respectively; P < 0.05) and net NH3 loss to the blood was smaller (6.1, 0.39 and 4.17 g N/d for diets SBM, FM and RSBM respectively; P < 0.05) for diet FM as compared with the soya-bean diets. The percentage of rumen NAN that was synthesized from NH3 was larger for diet RSBM (36.4, 40.3 and 49.1 for diets SBM, FM and RSBM respectively; P < 0.05) than for the other two rations. NH3 pool sizes (g N) were 0.463, 0.385 and 0.301 for diets SBM, FM and RSBM respectively (P < 0.05), while their hourly turnover rates were 15.8, 26.1 and 5.12 for diets SBM, FM and RSBM respectively (P < 0.01), indicating no correlation between pool size and its turnover rate. The existence of a small and rapidly turning over NAN pool to which NH3 is first bound (SNAN1) was indicated by the difference in the shape of the NAN and purines 15N-enrichment curves in the first 3 h after label injection. The fact that the rate of NH3 initial binding to SNAN1 pool was related neither to ammonia pool size nor to SNAN1 pool size suggests the existence of an unknown control mechanism at this site.

Experiments were carried out to study the digestibility of a cassava (gari) diet and its effect on growth in young male dogs. Three groups of dogs were fed on diets with rice (control), cassava (gari), and rice+cyanide respectively as the carbohydrate source. Each diet contained 130 g crude protein (nitrogenx6.25)/kg, was supplemented with vitamins and minerals, and was fed for 14 weeks. Variables measured were body-weight gain, bone growth, plasma alkaline phosphatase (EC 3.1.3.1) activity, total serum 3,5,3'-triiodothyronine (T3) and some plasma free amino acids. The apparent digestibilities of dry matter, protein and fat were not significantly different in the three groups, but the digestibility of gari fibre was significantly lower than the digestibility of rice fibre when fed to dogs (P < 0.05). Proximate analysis of the faeces showed that the group of dogs fed on the gari diet had faeces which had a significantly higher moisture content than the faeces of the other groups (P < 0.05), and also a significantly higher fibre content (P < 0.05). There was no significant difference in body-weight gain and bone growth between the control and gari-fed groups of dogs, but these variables were significantly lower in the dogs fed on the rice+cyanide diet (P < 0.05). At the end of the 14-week experimental period total serum T3 and plasma alkaline phosphatase activity were not significantly different between the control group of dogs and the gari-fed group, but were significantly lower in the rice+cyanide group. Plasma free methionine, leucine, isoleucine and valine concentrations were higher in the rice+cyanide group of dogs than in the control group and the gari group, indicating that these amino acids were accumulating and not being utilized for protein synthesis and growth to the same extent in the rice+cyanide group of dogs as in the other groups. It was concluded that the digestibilities of cassava starch and rice starch were the same in the dog but that rice fibre was more digestible in the dog than cassava fibre. It was also concluded that growth proceeded normally when a balanced gari diet or a balanced rice diet containing 130 g crude protein/kg was fed to dogs, but growth was retarded when a balanced rice+cyanide diet containing 130 g crude protein/kg was fed to dogs because total serum T3 concentration became greatly depressed.

The urease (EC 3.5.1.5) inhibitor, phenylphosphoryldiamidate (PPDA), was given by continuous infusion into the rumen of two sheep nourished by intragastric infusion and into either the rumen or abomasum of four sheep given a pelleted diet containing 119 g crude protein (nitrogen x 6.25)/kg dry matter. PPDA was given at 1 g/d in infusion sheep and 1.5 g/d in the normally-fed sheep. Measurements of urea kinetics were made using single injections of [14Clurea. Urease inhibition was complete within 24 h of starting PPDA infusions to the rumen; in this time-period, urea concentration in rumen contents reached equilibrium with that in plasma and this situation persisted until infusions were terminated. Relative to the control periods, plasma urea and rumen ammonia concentrations were unchanged but urea irreversible loss rate decreased by 26% in infusion sheep and 33% in fed sheep when PPDA was given. Urinary urea excretion was not affected, hence urea degradation, measured by difference, decreased by 77 and 58% respectively in response to urease inhibition. Administration of PPDA to the abomasum resulted in a reduction in rumen urease activity to about 40% of control values but had no effect on urea metabolism. Differences between treatments in daily nitrogen retention were not significant, indicating that under the dietary conditions imposed in these experiments, even substantial changes in urea recycling had only minor effects on the overall N economy of the animal.

Two experiments were carried out with piglets, 3–5 kg live weight, to evaluate the effects of feeding a tryptophan (TRP)-deficient diet for 2 weeks on protein synthesis rates measured in vivo 2 h after a meal. In the first experiment on twenty piglets fed on 250 g protein/kg diets, TRP deficiency (0.77 g/16 g nitrogen) as compared with adequacy (1.17 g/16 g N) significantly decreased feed intake, growth performance and fractional protein synthesis rates (FSR), without variation of RNA in longissimus dorsi (LD) and with parallel increases in RNA in semitendinosus (ST) muscle and liver. In the second experiment thirty-two piglets were tube-fed deficient and adequate diets at the two feeding levels (LF) previously achieved. Both TRP and LF significantly increased growth performance and FSR, but not RNA, in LD and ST muscle, with a trend to a synergy between the two factors (TRP x LF interaction). In another muscle, trapezius (TR), the same interaction was only apparent in RNA content. Among the three muscles it was in LD that FSR was the most responsive to dietary TRP (significant muscle x TRP interaction). In the liver the TRP x LF interaction on FSR and not RNA was the major significant effect, indicating that higher TRP and higher LF were both required to get the maximum protein synthesis rate. At 30 min after a meal the same significant interaction effect was shown on plasma glucose, whilst the higher LF increased plasma insulin with both diets. After a further 30 min the appearance of a similar significant effect of the TRP x LF interaction on plasma insulin resulted from its abatement when the deficient diet had been fed at high LF. These results suggest that dietary TRP deficiency decreased muscle and liver protein synthesis rates in relation to a decrease in the post-prandial release of insulin following a decreased rate of nutrient absorption.