Heat treatment of soybean meal and rapeseed meal suppresses rumen degradation of phytate phosphorus in sheep

The effect of heat treatment on rumen degradation of phytate in soybean meal and rapeseed meal was studied on three sheep fitted with rumen cannula. Soybean meal and rapeseed meal were roasted at 133°, 143° or 153°C for 3 h and the rumen degradation of phytate phosphorus in untreated and heat treated oilseed meals was examined using the nylon-bag technique. Effective degradability of phytate phosphorus in soybean and rapeseed meals, estimated at ruminal outflow rates of 0.02, 0.05 and 0.08 h⁻¹, was significantly (p < 0.05) reduced by heat treatment. The reduction was more marked in rapeseed meal than in soybean meal. These results suggest that heat processing of oilseed meals suppresses phytate degradation in the rumen and leads to a low availability of dietary phytate phosphorus.     

Biostable insect kinin analogs reduce blood meal and disrupt ecdysis in the blood-gorging Chagas’ disease vector,Rhodnius prolixus

Rhodnius prolixus is a blood-gorging hemipteran that takes blood meals that are approximately 10 times its body weight. This blood meal is crucial for growth and development and is needed to ensure a successful molt into the next instar. Kinins are a multifunctional family of neuropeptides which have been shown to play a role in the control of feeding in a variety of insects. In this study, two biostable Aib-containing kinin analogs were tested to see if they interfere with blood-feeding and subsequent development into the next instar. One of the analogs, 1729 (Ac-R[Aib]FF[Aib]WGa), had no effect on the size of the blood meal or on the subsequent molting of the insect into the next instar. This analog also did not interfere with either short-term or long-term diuresis. The second analog, 1728 ([Aib]FF[Aib]WGa), appeared to be an antifeedant. Insects feeding on blood containing this analog (15 μM) only consumed 60% of the blood meal taken by insects fed on blood without analog. Insects feeding on blood containing 1728 had a slower rate of rapid diuresis (diuresis in the first 3–5 h after feeding) leading to less urine being excreted by 5 days post feeding. The consequence of these effects was that insects fed on 1728 did not molt. This data indicates that the biostable Aib-containing analog 1728 disrupts normal growth and development in the blood-feeding insect, R. prolixus.     

The influence of feeding and fasting on plasma metabolites in the dogfish shark (Squalus acanthias)

Dogfish sharks are opportunistic predators, eating large meals at irregular intervals. Here we present a synthesis of data from several previous studies on responses in plasma metabolites after natural feeding and during prolonged fasting (up to 56 days), together with new data on changes in plasma concentrations of amino acids and non-esterified fatty acids. Post-prandial and long-term fasting responses were compared to control sharks fasted for 7 days, a typical inter-meal interval. A feeding frenzy was created in which dogfish were allowed to feed naturally on dead teleosts at two consumed ration levels, 2.6% and 5.5% of body weight. Most responses were more pronounced at the higher ration level. These included increases in urea and TMAO concentrations at 20 h, followed by stability through to 56 days of fasting. Ammonia levels were low and exhibited little short-term response to feeding, but declined to very low values during the extended fast. Glucose and β-hydroxybutyrate both fell after feeding, the latter to a greater and more prolonged extent (up to 60 h), whereas acetoacetate did not change. During prolonged fasting, glucose concentrations were well regulated, but β-hydroxybutyrate increased to 2–3-fold control levels. Total plasma amino acid concentrations increased in a biphasic fashion, with peaks at 6–20 h, and 48–60 h after the meal, followed by homeostasis during the extended fast. Essential and non-essential amino acids generally followed this same pattern, though some exhibited different trends after feeding: taurine, β-alanine, and glycine (decreases or stability), alanine and glutamine (modest prolonged increases), and threonine, serine, asparagine, and valine (much larger short-term increases). Plasma non-esterified fatty acid concentrations declined markedly through 48 h after the 2.6% meal. These data are interpreted in light of companion studies showing elevations in aerobic metabolic rate, urea production, rectal gland function, metabolic base excretion, and activation of ornithine–urea cycle and aerobic enzymes after the meal, and muscle N-depletion but maintenance of osmolality and urea production during long-term fasting.     

The effect of feeding expeller-pressed canola meal on growth performance and diet nutrient digestibility in weaned pigs

The effects of feeding increasing levels of expeller-pressed (EP) canola meal in substitution for soybean meal as an energy and amino acid source were evaluated in 240 weaned pigs with an initial body weight of 7.3 ± 0.6 kg. Five pelleted wheat-based diets containing 0, 50, 100, 150 or 200 g EP canola meal/kg were formulated to contain 10.0 MJ net energy (NE)/kg and 1.18 g standardised ileal digestible (SID) lysine/MJ NE and were fed for 4 wk starting 1 wk after weaning at 19 days of age. Expeller-pressed canola meal was added at the expense of soybean meal and the diets were balanced for NE using canola oil and for amino acids using crystalline lysine, methionine, threonine and tryptophan. Increasing inclusion of EP canola meal linearly reduced (P<0.001) the apparent total tract digestibility of energy, dry matter and crude protein and the digestible energy content of diets. From 0 to 28 days on trial, increasing inclusion of EP canola meal did not affect body weight gain, feed intake and feed efficiency. In conclusion, up to 200 g EP canola meal/kg can replace soybean meal in diets formulated to equal NE and SID amino acid content and fed to nursery pigs starting 1 wk after weaning without reducing growth performance.     

A novel flexible method to split feeding behaviour into bouts

Before meal patterns can be analysed properly, a biologically relevant meal criterion must be determined in order to group short-term feeding behaviour into meals. Existing methodologies are based on modelling of the frequency distributions of intervals between feeding events but these methods cannot be used if the proper distributions cannot be clearly identified. For such cases we developed two new methods – (1) based on the analysis of the distribution of between-meal interval lengths only and (2) based on the analysis of changes in the probability of animals starting to feed with time since the last feeding event. Both methods were developed using a data set of over 700,000 records of visits to feeders obtained with broilers (Gallus gallus) aged between 2 and 5 weeks. The two methods resulted in meal criteria estimates of 20.1 and 17.5 min, respectively, which, when applied to the data set, gave statistically significant but very small differences in meal characteristics. The new methods were tested against an independent cow (Bos taurus) data set and the resultant meal criteria compared with those predicted by an existing method. The two novel methods estimated meal criteria for cows at 27.9 and 35.5 min, compared with 28.9 min for the existing method. Again, these differences in meal criteria resulted in only very small differences in meal characteristics. Even though meal criteria were relatively similar for birds and cows, characteristics such as average daily number of meals (10.9 and 5.9), meal size (12.5 g and 7.4 kg) and meal duration (7.7 and 31.4 min) were very different. The analyses show that, if the appropriate distributions of intervals cannot be identified, meal criteria can still be estimated for species as diverse as mature cows and young birds by the novel methodologies developed here.     

Antioxidant system response is modified by dietary fat in adipose tissue of metabolic syndrome patients

Metabolic syndrome (MetS) is associated with high oxidative stress, which is caused by an increased expression of NADPH-oxidase and a decreased expression of antioxidant enzymes in the adipose tissue. Our aim was to evaluate whether the quality and quantity of dietary fat can modify that process. A randomized, controlled trial conducted within the LIPGENE study assigned MetS patients to one of four diets for 12 wk each: (i) high-saturated fatty acid (HSFA), (ii) high-monounsaturated fatty acid (HMUFA), (iii) and (iv) two low-fat, high-complex carbohydrate diet supplemented with n-3 polyunsaturated fatty acids (LFHCC n3), or placebo (LFHCC). A fat challenge reflecting the same fatty acid composition as the original diets was conducted post-intervention. The intake of an HSFA meal induced a higher postprandial increase in gp91phox and p67phox mRNA levels than after the intake of HMUFA, LFHCC and LFHCC n-3 meals (all p-values < 0.05). The postprandial decrease in CAT, GPXs and TXNRD1 mRNA levels after the HSFA meal intake was higher than after the intake of HMUFA, LFHCC and LFHCC n-3 meals (all p-values < 0.05). The intake of an HSFA meal induced a higher postprandial increase in KEAP1 mRNA levels than after the consumption of the HMUFA (P = .007) and LFHCC n-3 (P = .001) meals. Our study demonstrated that monounsaturated fat consumption reduces oxidative stress as compared to saturated fat by inducing higher postprandial antioxidant response in adipose tissue, and thus, replacing SFA for MUFA may be an effective dietary strategy to reduce the oxidative stress in MetS patients and its pathophysiological consequences.     

Effect of feeding schedule on apparent energy and amino acid digestibility by growing pigs

An experiment was conducted to investigate the effects of feeding schedule on dry matter (DM), gross energy (GE), crude protein (CP), and amino acid (AA) digestibility by growing pigs. Six growing castrates (initial body weight: 40.5 ± 2.25 kg) were equipped with a T-cannula in the distal ileum and allotted to a repeated 3 × 3 Latin square design with three animals and three periods in each square. A maize–soybean meal based diet (181 g CP/kg) was formulated and fed to the pigs in three different feeding schedules; i.e., one meal per day, two meals per day, or free access to feed. Pigs fed one or two meals per day were allotted a daily amount of feed equivalent to three times the maintenance energy requirement. Fecal and ileal samples were collected from all pigs in each period. The coefficients of ileal apparent digestibility (CIAD) for DM, GE, CP, and AA were calculated as were the coefficients of total tract apparent digestibility (CTTAD) of DM and GE. Results of the experiment showed that there were no differences in the CIAD for DM, GE, or for any of the AA among the three feeding schedules. In contrast, pigs given free access to the diet had lower (P<0.002) CTTAD for DM and GE compared with pigs fed a restricted amount of feed either once or twice daily. Therefore, the concentration of digestible energy in the diet was lower if calculated from pigs given free access to the diet compared with pigs fed the diet once or twice daily (14.38 MJ/kg versus 14.83 MJ/kg and 15.13 MJ/kg). It is concluded that the feeding schedule does not influence the CIAD for DM, GE, CP, or AA by pigs. Therefore, any of the three feeding schedules that were used in the current experiment may be used in experiments aimed at measuring CIAD in pigs. However, if the CTTAD of DM and GE are measured, it is recommended that pigs are given free access to feed.     

The effects of feeding on the swimming performance and metabolic response of juvenile southern catfish,Silurus meridionalis,acclimated at different temperatures

To test whether the effects of feeding on swimming performance vary with acclimation temperature in juvenile southern catfish (Silurus meridionalis), we investigated the specific dynamic action (SDA) and swimming performance of fasting and feeding fish at acclimation temperatures of 15, 21, 27, and 33 °C. Feeding had no effect on the critical swimming speeding (U_crit) of fish acclimated at 15 °C (p = 0.66), whereas it elicited a 12.04, 18.70, and 20.98% decrease in U_crit for fish acclimated at 21, 27 and 33 °C, respectively (p < 0.05). Both the maximal postprandial oxygen consumption rate (VO_2peak) and the active metabolic rate (VO_2active, maximal aerobic sustainable metabolic rate of fasting fish) increased significantly with temperature (p < 0.05). The postprandial maximum oxygen consumption rates during swimming (VO_2max) were higher than the VO_2active of fasting fish at all temperature groups (p < 0.05). The VO_2max increased with increasing temperature, but the relative residual metabolic scope (VO_2max? VO_2peak) during swimming decreased with increasing in temperature. The present study showed that the impairment of postprandial swimming performance increased with increasing temperature due to the unparalleled changes in the catfish's central cardio-respiratory, peripheral digestive and locomotory capacities. The different metabolic strategies of juvenile southern catfish at different temperatures may relate to changes in oxygen demand, imbalances in ion fluxes and dissolved oxygen levels with changes in temperature.     

Similar metabolic rate-temperature relationships after acclimation at constant and fluctuating temperatures in caterpillars of a sub-Antarctic moth

Temperature compensation in whole-animal metabolic rate is one of the responses thought, controversially, to characterize insects from low temperature environments. Temperature compensation may either involve a change in absolute values of metabolic rates or a change in the slope of the metabolic rate – temperature relationship. Moreover, assessments of compensation may be complicated by animal responses to fluctuating temperatures. Here we examined whole animal metabolic rates, at 0 °C, 5 °C, 10 °C and 15 °C, in caterpillars of the sub-Antarctic moth, Pringleophaga marioni Viette (Tineidae), following one week acclimations to 5 °C, 10 °C and 15 °C, and fluctuating temperatures of 0–10 °C, 5–15 °C, and 10–20 °C. Over the short term, temperature compensation was found following acclimation to 5 °C, but the effect size was small (3–14%). By comparison with caterpillars of 13 other lepidopteran species, no effect of temperature compensation was present, with the relationship between metabolic rate and temperature having a Q₁₀ of 2 among species, and no effect of latitude on temperature-corrected metabolic rate. Fluctuating temperature acclimations for the most part had little effect compared with constant temperatures of the same mean value. Nonetheless, fluctuating temperatures of 5–15 °C resulted in lower metabolic rates at all test temperatures compared with constant 10 °C acclimation, in keeping with expectations from the literature. Absence of significant responses, or those of large effect, in metabolic rates in response to acclimation, may be a consequence of the unpredictable temperature variation over the short-term on sub-Antarctic Marion Island, to which P. marioni is endemic.     

Insulin Injections in Relation to Meals in the Hospital Medicine Ward: Comparison of 2 Protocols

ObjectiveTo investigate whether changing the prandial regular insulin to rapid-acting insulin analogue in hospital medicine wards improves the timing of insulin delivery in relation to meals and improves patient safety and glucose control.MethodsThis open-label randomized controlled trial in type 2 diabetic patients compared insulin lispro with meals and basal insulin glargine (intervention) vs regular insulin before meals and basal neutral protamine Hagedorn insulin twice daily (control). The primary endpoint was the rate of targeted timing of insulin to meals (target time). In the intervention group, target time was defined as insulin administered from 15 minutes before to 15 minutes after the patient started a meal. For the control group, target time was defined as insulin administered from 30 minutes before to 30 minutes after the patient started a meal. Hypoglycemic, hyperglycemic, and severe hyperglycemic patient-days were compared between groups.ResultsTwenty-seven patients in the intervention group and thirty-three patients in the control group were studied. The percentage of times that the insulin was given within target time was significantly higher in the intervention group as a whole (88.9% vs 70.1%, P < .001) and was higher for lunch and the evening meal (90% vs 66.7% and 94.7% vs 70.1%, P < .001). The rate of hypoglycemia was lower in the intervention group (1.85% vs 15%, P < .001). The rate of hyperglycemia was similar in both groups (68.2% vs 59.8%, P = .224), but the intervention group had a higher rate of severe hyperglycemia (28.9% vs 12.9%, P = .003).ConclusionsThe use of prandial insulin analogues in medicine wards allows better timing with meals than regular insulin and results in better hypoglycemic outcomes. Higher rates of hyperglycemia with prandial analogues may need adjustment in insulin doses. (Endocr Pract. 2011:17:737-746)     

Postprandial hepatic protein expression in trout Oncorhynchus mykiss a proteomics examination

Following a meal, a series of physiological changes occurs in animals as they digest, absorb and assimilate ingested nutrients, the kinetics of these responses depends on metabolic rate and nutrient quality. Here we investigated the hepatic proteome in the ectothermic teleost, the rainbow trout, following a single meal to define the postprandial expression of hepatic proteins. The fish were fed a high marine fishmeal/fish oil single meal following a period of 24 h without feeding. Liver protein profiles were examined by 2D gel electrophoresis just before feeding (time 0 h) and at 6 and 12 h after feeding. Of a total of 588 protein spots analysed in a temporal fashion, 49 differed significantly in abundance between the three time groups (ANOVA, p<0.05), before and after feeding, 15 were increased and 34 were decreased in abundance after feeding. Amino acid metabolism-regulated proteins such as phenylalanine-4-hydroxylase and proliferating cell antigen were increased in abundance 12 and 6 h following the meal, suggesting by this time that the fish were increasing their protein turnover to utilize efficiently their dietary protein consumption. Overall, these results highlight some specificity of the trout metabolism and identify postprandial response of metabolism-related proteins 6–12 h after feeding a single meal.     

Tracking aphid predation by lycosid spiders in spring-sown cereals using PCR-based gut-content analysis

Detection of prey DNA-remains in arthropod predators by polymerase chain reaction (PCR) is useful when investigating food webs. In this study we estimated how long after a feeding event it was possible to detect mitochondrial COII DNA (331 bp) from an important aphid pest, Rhopalosiphum padi (Homoptera: Aphididae), in spiders of the genus Pardosa (Araneae: Lycosidae). Following laboratory evaluations we tested spiders collected in spring-sown cereals for aphid predation during two seasons. Aphids were digested rapidly in laboratory-fed predators and the time point when prey DNA could be amplified from 50% of the spiders was estimated to be 3.7 h. A total of 372 field- collected predators were analyzed by PCR and despite low aphid densities many spiders (26% in 2004 and 19% in 2005) tested positive for R. padi, indicating consumption of at least one aphid within a few hours before capture. The percentage of spiders that tested positive for R. padi DNA varied considerably between fields and logistic regression analysis revealed that the probability of detecting aphid DNA was significantly influenced by location and year. We conclude that Pardosa spiders, under certain conditions, frequently feed on R. padi and deserve special attention in conservation biological control.     

Effects of feeding crambe meal upon intake,gain, health and meat quality of broiler chicks

True metabolizable energy of crambe meal was determined with adult cecectomized turkeys to be 11.8 kJ(2.8 kcal)g⁻¹. Amino acid digestibilities were 90% or greater, indicating that protein quality of crambe meal was high. Growing broilers were fed diets containing 0, 50, 100 or 150 (g crambe meal) kg⁻¹ diet (control, 50C, 100C and 150C, respectively) for 56 days. Feed intake for the 150C birds was lower than the other treatments initially; at the end of the experiment, intake of the 150C birds compensated and was similar to the control birds. Weight gain patterns were similar to intake responses. Birds on the 150C treatment had reduced tibial ash content and locomotor difficulties in the first half of the experiment; these effects were absent in the second half of the experiment. Meat quality and serum chemistries were unaffected by feeding crambe meal. Broilers fed the 150C diet had increased liver and kidney weights. Broilers can be fed diets containing up to 50 (g crambe meal) kg⁻¹ diet with no adverse effects on gain and health and up to 100 g kg⁻¹ diet with minimal adverse effects on gain and health.     

Identification of the economics,composition, and supplementation of maggot meal in broiler production

The primary goal of this study was to conduct a preliminary assessment of maggot meal protein supplements in broiler production. Maggot meal comprises 55 percent crude protein (CP), 27.65% ether extract, 8.33% Ash, 3.37 crude fiber (CF), 2.14 NFE, 94.7 percent Dry Matter, 5702 kcal/kg gross energy, and 3955 kcal/kg metabolizing energy, according to proximate analysis. Maggot meal supplementation affected broiler meat feed intake, body weight gain, FCR, dressing %, mortality, antibody titer against ND, and organoleptic features. The cost-effectiveness of maggot supplementation was also evaluated. Birds were put into four experimental groups after a week of adaptation:Control group (M0), the first experimental group (M1), the second experimental group (M2), and the third experimental group (M3), which received supplements of 0, 2, 3, and 4 g/kg, respectively. A plane ratio was given to the control group as well. The overall feed intake findings were inversely proportional to the supplementation rate. Thus, the highly supplemented group (M3) showed the lowest feed intake than the control group (M0). Bodyweight gain was directly proportional to the supplementation rate, as evident by a considerable increase in the highly supplemented group (M3) compared to the control group.     

The influence of circadian rhythms on pre- and post-prandial metabolism in the snake Lamprophis fuliginosus

Measuring standard metabolic rate (SMR) and specific dynamic action (SDA) has yielded insight into patterns of energy expenditure in snakes, but less emphasis has been placed on identifying metabolic variation and associated energy cost of circadian rhythms. To estimate SMR, SDA, and identify metabolic variation associated with circadian cycles in nocturnally active African house snakes (Lamprophis fuliginosus), we measured oxygen consumption rates (VO2) at frequent intervals before and during digestion of meals equaling 10%, 20% and 30% of their body mass. Circadian rhythms in metabolism were perceptible in the VO2 data during fasting and after the initial stages of digestion. We estimated SMR of L. fuliginosus (mean mass=16.7+/-0.3 g) to be 0.68+/-0.02 (+/-SEM) mL O2/h at 25 degrees C. Twenty-four hours after eating, VO2 peaked at 3.2-5.3 times SMR. During digestion of meals equaling 10-30% of their body mass, the volume of oxygen consumed ranged from 109 to 119 mL O2 for SMR, whereas extra oxygen consumed for digestion and assimilation ranged from 68 to 256 mL O2 (equivalent to 14.5-17.0% of ingested energy). The oxygen consumed due to the rise in metabolism during the active phase of the daily cycle ranged from 55 to 66 mL O2 during digestion. Peak VO2, digestive scope, and SDA increased with increasing meal size. Comparisons of our estimates to estimates derived from methods used in previous investigations resulted in wide variance of metabolic variables (up to 39%), likely due to the influence of circadian rhythms and activity on the selection of baseline metabolism. We suggest frequent VO2 measurements over multiple days, coupled with mathematical methods that reduce the influence of undesired sources of VO2 variation (e.g., activity, circadian cycles) are needed to reliably assess SMR and SDA in animals exhibiting strong circadian cycles.     

Postprandial profiles of CCK after high fat and high carbohydrate meals and the relationship to satiety in humans

ContextCCK is understood to play a major role in appetite regulation. Difficulties in measuring CCK have limited the potential to assess its profile in relation to food-induced satiety. Improvements in methodology and progress in theoretical understanding of satiety/satiation make it timely for this to be revisited.ObjectiveFirst, examine how physiologically relevant postprandial CCK8/33(s) profiles are influenced by fat (HF) or carbohydrate (HCHO) meals. Second, to examine relationships between postprandial CCK and profiles of satiety (hunger/fullness) and satiation (meal size).Participants and designSixteen overweight/obese adults (11 females/5 males) participated in a randomised-crossover study (46 years, 29.8 kg/m²) in a university research centre. Plasma was collected preprandially and for 180 min postprandially. Simultaneously, ratings of hunger/fullness were tracked for 180 min before an ad libitum lunch was provided.ResultsCCK8/33(s) levels increased more rapidly and reached a higher peak following HF compared to HCHO breakfast (F_(1,15) = 14.737, p < 0.01). Profiles of hunger/fullness did not differ between conditions (F_(1,15) = 0.505, p = 0.488; F_(1,15) = 2.277, p = 0.152). There was no difference in energy intake from the ad libitum meal (HF-3958 versus HCHO-3925 kJ; t₍₁₄₎ = 0.201, p = 0.844). CCK8/33(s) profiles were not associated with subjective appetite during early and late phases of satiety; nor was there an association between CCK8/33(s) and meal size.ConclusionsThese results demonstrate CCK levels were higher after HF meal compared to HCHO isocaloric meal. There was no association between CCK levels and intensity of satiety, or with meal size. Under these circumstances, CCK does not appear to play a unique independent role in satiety/satiation. CCK probably acts in conjunction with other peptides and the action of the stomach.     

Diet selection and eating behaviour of lactating goats subjected to time restricted feeding in choice and single feeding system

This study was carried out to investigate diet selection and eating behaviour of lactating German Fawn × Hair Crossbred goats in different feeding methods and levels. Twenty German Fawn × Hair first backcross does (B₁) were allocated into 4 treatment groups (2 feeding methods single (TMR) and choice feeding × 2 feeding levels ad libitum and restricted) with 5 replicates. Restricted feeding was applied only 4 h feed allocation during day. Barley, corn, soybean meal, corn gluten meal, wheat bran and alfalfa hay were feed ingredients for single and choice feeding. Eating patterns, milk yield and composition were determined for 8 weeks. The following results were obtained: (1) the meal criteria for goats restricted single and choice-fed, ad libitum single and choice-fed were determined as 1.00 and 0.63, 12.88 and 10.23 min, respectively. (2) Ad libitum feeding increased meal size, meal length, intermeal interval, total eating duration and decreased eating rate and meal number, compared to restricted feeding (P < 0.01). Choice feeding decreased meal size (P < 0.05), meal length (P < 0.01) and increased eating rate and meal number (P < 0.01), compared to single feeding. Restricted fed goats decreased intermeal interval in single feeding compared to choice feeding (P < 0.01), but increased meal number in choice feeding (P < 0.01). (3) Ad libitum choice-fed does made a diet containing 12.79% corn, 35.41% barley, 13.21% wheat bran, 5.35% soybean meal, 1.28% corn gluten meal and 29.80% alfalfa meal while restricted choice-fed does made a diet having more corn (27.69%), corn gluten meal (5.62%) and wheat bran (16.17%) and less barley (14.37%) and soybean meal (4.51%). (4) Choice feeding decreased RUP intake (P < 0.05) without affecting milk protein, irrespective to feeding levels, while having a tendency to increase in milk yield (14.2%) and 4% FCM (8.8%). (5) Restricted feeding decreased DM, ME, ADF and NDF intakes (P < 0.05) with concomitant decreases in 4% FCM, total milk solid, ash and fat compositions (P < 0.05), irrespective to feeding methods. (6) Choice-fed goats changed their preferences for a possible synchronized nutrient intake during a daytime, as sorted barley, soybean meal and alfalfa hay from early morning to late afternoon.It could be concluded that choice-fed goats have the ability to make their diet to meet nutrient requirements and had a tendency to increase in milk yield. Restriction in feeding time resulted in lower feed intake and milk yield, although the animal changed their feed preference in favour of high quality ingredients and eating pattern with lower meal criterion and intermeal interval.     

A randomized cross-over study of the effects of macronutrient composition and meal frequency on GLP-1, ghrelin and energy expenditure in humans

ObjectiveLittle is known about human postprandial increase of energy expenditure and satiety-associated hormones in relation to both meal frequency and macronutrient composition.DesignRandomized cross-over study with four conditions for each participant.MethodsSeven men and seven women (mean age 23 ± 1.5 years) were randomly assigned to the order of intake of a 750 kcal drink with the same protein content while having either 20 energy-percent (E%) or 55 E% from carbohydrates and the remaining energy from fat. Participants were also randomized to consume the drinks as one large beverage or as five 150 kcal portions every 30 min, starting in the fasting state in the morning. Energy expenditure (EE) was determined every 30 min by indirect calorimetry. Hormonal responses and suppression of hunger (by visual-analogue scales) were also studied. A p < 0.013 was considered statistically significant following Bonferroni-correction.ResultsThe area under the curve (AUC) for EE was higher during the 2.5 h after the high-carbohydrate drinks (p = 0.005 by Wilcoxon) and also after ingesting one drink compared with five (p = 0.004). AUC for serum active GLP-1 was higher after single drinks compared with five beverages (p = 0.002). Although GLP-1 levels remained particularly high at the end of the test during the low-carbohydrate meals, the AUC did not differ compared with the high-carbohydrate occasions (low-carbohydrate: 58.9 ± 18 pg/ml/h, high-carbohydrate: 45.2 ± 16 pg/ml/h, p = 0.028). Hunger sensations were suppressed more after single beverages compared with five small drinks (p = 0.009).ConclusionsWe found higher EE during 2.5 h following one large drink compared with five smaller beverages. Since hunger was also suppressed more efficiently, and serum GLP-1 levels were higher after one compared with five smaller drinks, our findings do not support nibbling to avoid hunger or to keep up EE from morning to noon.     

The role of nest surface temperatures and the brain in influencing ant metabolic rates

Thermal limits of insects can be influenced by recent thermal history: here we used thermolimit respirometry to determine metabolic rate responses and thermal limits of the dominant meat ant, Iridomyrmex purpureus. Firstly, we tested the hypothesis that nest surface temperatures have a pervasive influence on thermal limits. Metabolic rates and activity of freshly field collected individuals were measured continuously while ramping temperatures from 44 °C to 62 °C at 0.25 °C/minute. At all the stages of thermolimit respirometry, metabolic rates were independent of nest surface temperatures, and CT_max did not differ between ants collected from nest with different surface temperatures. Secondly, we tested the effect of brain control on upper thermal limits of meat ants via ant decapitation experiments (‘headedness’). Decapitated ants exhibited similar upper critical temperature (CT_max) results to living ants (Decapitated 50.3±1.2 °C: Living 50.1±1.8 °C). Throughout the temperature ramping process, ‘headedness’ had a significant effect on metabolic rate in total (Decapitated V̇CO₂ 140±30 µl CO₂ mg⁻¹ min⁻¹: Living V̇CO₂ 250±50 CO₂ mg⁻¹ min⁻¹), as well as at temperatures below and above CT_max. At high temperatures (>44 °C) pre- CT_max the relationships between I. purpureus CT_max values and mass specific metabolic rates for living ants exhibited a negative slope whilst decapitated ants exhibited a positive slope. The decapitated ants also had a significantly higher Q₁₀:25–35 °C when compared to living ants (1.91±0.43 vs. 1.29±0.35). Our findings suggest that physiological responses of ants may be able to cope with increasing surface temperatures, as shown by metabolic rates across the thermolimit continuum, making them physiologically resilient to a rapidly changing climate. We also demonstrate that the brain plays a role in respiration, but critical thermal limits are independent of respiration levels.