Daily Metabolic Energy Research Articles

Onset of zooplanktivory and optimal water flow rates for prey capture in newly settled polyps of ten Caribbean coral species

Zooplanktivory is an important source of nutrients in corals, providing up to 35% of daily metabolic energy requirements in some species. However, little is known about coral zooplanktivory shortly after larval settlement and metamorphosis. In most species it is unclear if, when and under which conditions newly settled polyps are able to capture and ingest prey. This remains a critical knowledge gap, as zooplanktivory could allow coral settlers to replenish energy reserves shortly after metamorphosis, possibly improving settler condition during one of their most vulnerable life stages. Here, we documented the onset of prey (Artemia salina nauplii) capture in ten Caribbean coral species and assessed optimal water flow rates (WFR) for prey capture in five of these species. All species initiated zooplanktivory within six days following metamorphosis, with the exception of Acropora palmata which was never observed capturing nauplii during our 20-day study. Optimal WFR for prey capture varied among species, with Favia fragum displaying maximum prey capture rates in zero flow and Diploria labyrinthiformis most effectively capturing nauplii under WFR of 5–20 cm s−1. Under each species’ optimum WFR, prey capture abilities varied considerably, with F. fragum capturing up to one nauplius every two minutes compared to one nauplius every nine minutes in Colpophyllia natans. Using these findings, we make species-specific recommendations to optimize coral husbandry and larval-based restoration practices for these ten coral species.

SAT-597 Hypothalamic ESR1 Gene Knockdown Elicits Intermittent Decrement in Postprandial Energy Expenditure Associated with Obesity Onset in Female Rhesus Monkeys

Declining serum estradiol (E2) levels during the menopausal transition are associated with increased central adiposity and heightened risk for metabolic disease. Estrogenic effects on adiposity and metabolism in female rodents are primarily mediated by estrogen receptor alpha (ESR1) activation in ventromedial (VMN) and arcuate (ARC) nuclei within the mediobasal hypothalamus (MBH). The role of hypothalamic ESR1 in the menopausal transition, and in regulating body weight, body composition and energy homeostasis in female primates, however, remains unclear. To investigate the involvement of ESR1 in regulating female primate body weight, we employed RNAi technology to assess ESR1 gene knockdown throughout the MBH of adult, full-grown, ovary intact female rhesus macaques. Using MRI-guided stereotaxic targeting, adeno-associated viral vector 8 (AAV8) expressing shRNA-ESR1 (ERαKD) (n=6), or a scrambled control sequence (n=4), were infused bilaterally into the MBH to knockdown ESR1 expression. Results: ERαKD females exhibited a ~22% (+2.0 ± 0.1 kg) increase in body weight to attain 10.4±0.9 kg after ~12-24 months (mo) (p<0.05), compared to ~12% increase in controls (+ 1.1±0.1 kg) attaining 9.1±1.0 kg body mass. The divergence in body weights between female groups, however, began at 6 mo. Daily calorie consumption at ~26 mo was comparable between groups. Assessments at ~28 months enabled customized metabolism cage analysis of energy expenditure (EE) corrected for fat-free mass and respiratory exchange ratio (RER). Postprandial EE (hours (h) 1-5 after once daily feeding) was inconsistently diminished in ERαKD compared to control females (1st day: ERαKD 0.087±0.001 vs. Control 0.104±0.002 kcal/min/kg, p<0.0002; 2nd day: ERαKD 0.092±0.0004 vs. Control 0.095±0.002 kcal/min/kg, NS). Overnight fasted RER (hours -1 to -2 prior to feeding) tended (p<0.06) to remain higher in ERαKD (1st day, 0.757±0.010, 2nd day, 0.732±0.031) compared to control females (1st day, 0.728±0.007, 2nd day, 0.728±0.060) suggesting constrained switching between lipids and other carbon sources for energy metabolism during fasting in ERαKD females. We found no significant differences in 24 hr, 12 hr light or 12 hr dark EE and RER. Overall, these findings highlight MBH ESR1 roles in regulating body weight, energy expenditure and carbon sources utilized in daily energy metabolism, and suggest a discrete MBH location for development of therapeutic targeting to combat female obesity.

Quantitative characterization of the nutrition of the free-living horse (Equus caballus) on Vodnyi Island (Manych-Gudilo Lake)

The nutritional value of plant fodder, daily consumption, and digestibility of forage were assessed in an isolated group of free-living (wild) horses inhabiting the pastures of Vodnyi Island during different seasons of 2010–2011. The digestibility was determined by the proportion between inert food components (silicon, lignin) in the diet and the feces. The daily intake of food was calculated according to the weight of the daily feces and digestibility of food. Daily food consumption of the free-living horses during the snowless period is from 8 to 14 kg/ind. and 16 kg/ind. (dry weight) during the winter period. Food digestibility changes from 49 to 54% per year; the mean digestibility is 52%. The daily metabolic energy intake during the snowy period of the year (130.7 MJ/ind.) is almost twofold higher than in spring (67.4 MJ/ind.). In all the seasons, it exceeds the requirements for energy. The free-living horses of Vodnyi Island have parameters of digestibility and consumption of forage similar to other horses.

Effects of combined ‘all-fish’ growth hormone transgenics and triploidy on growth and nutrient utilization of Atlantic salmon (Salmo salar L.) fed a practical grower diet of known composition

Full-sibling, size-matched ‘all-fish’ growth hormone transgenic (TG; gene construct EO-1α) and non-transgenic (NTG) Atlantic salmon (Salmo salar L.) comprised of conventional diploid (DIP) and reproductively-sterile triploid (TRIP) fish were fed the same experimental grower diet in freshwater until they tripled their weight. The study was conducted to provide baseline data on growth performance, feed efficiency, nutrient digestibility, skeletal disorders, bone ash content and bone mineral composition of NTG/DIP, NTG/TRIP, TG/DIP and TG/TRIP fish and to determine if a practical grower diet for conventional NTG/DIP Atlantic salmon requires modification for TG/TRIP fish. TG fish consumed a significantly higher amount of feed on a daily basis but due to enhanced growth rates, better feed conversion ratios and higher nitrogen retention efficiency they achieved target weight gain in a considerably shorter period (40%) than NTG fish. Total feed required to produce the same fish biomass was reduced by 25%; representative of a significant reduction in overall feed intake. Of TG fish, TRIP had some significant effects on production traits primarily due to lower feed intake relative to DIP fish. Although feed intake was lower in TG/TRIP fish, feed efficiency, digestibility and nutrient retention efficiencies were equal to those of TG/DIP fish and, without exception; TG/TRIP fish out-performed their conventional NTG counterparts, regardless of ploidy. TG/DIP and TG/TRIP fish demonstrated a higher cellular capacity to direct dietary non-protein energy towards satisfying their daily metabolic energy requirements, allowing for a higher proportion of dietary amino acids to be directed towards protein biosynthesis; rather than catabolised as a dietary energy source. Since dietary protein is the largest and most expensive component of salmon feeds and also the major source of nitrogenous pollution from salmon farming, this could represent a highly beneficial alteration of energy metabolism which could result in more economical and ecologically-sustainable Atlantic salmon aquaculture, especially when conducted in closed-containment land-based systems. Although bone ash content of TG fish was slightly lower than NTG fish, no significant differences in key bone mineral composition were observed and the occurrence of skeletal disorders was low (<4%), regardless of transgenics or ploidy.

Effect of High‐Fat Meal and High‐Carbohydrate Meal on Daily Total Energy Metabolism in Adults Japanese Men

IntroductionDiet‐induced Thermogenesis (DIT) is the increase in energy expenditure above resting associated with the consumption of a meal, accounts for approximately 10% of an individual fs total daily energy expenditure. The thermic effect of separate nutrients is highest for protein (20–30%), followed by CHO (5–10%), and fat (0–3%).ObjectiveThe objective of this study was to clarify the effect of high‐fat meal and high‐carbohydrate on daily energy metabolism in adult Japanese men using indirect human calorimeter.MethodsThe subjects were fourteen adults Japanese men (21.5 ± 0.3 years). We measured EE (energy expenditure), RQ (respiratory quotient), GOR (glucose oxide rate), LOR (lipid oxide rate), LF/HF (Low Frequency/High Frequency), HF (High Frequency). EE was measured using the IHC for 36 hours. The activity of sympathetic nervous system was assessed by real‐time analysis system of heart rate fluctuation.Results&amp; ConclusionTwenty‐four‐hours total energy expenditure was no different among three trial. On the other, RQ and GOR at supper time were significantly lower in HF trial than HCHO trial during the 120 minutes after ingestion (p &lt; 0.05). LOR at supper time was significantly higher in HF trial than HCHO trial during the 120 minutes after ingestion (p &lt; 0.05). Those results showed that high‐fat meal and high‐carbohydrate meal changed energy substrate.

Effects of Irregular Feeding under an 80% Energy Restricted Condition on the Growth and the Daily Energy Metabolism in Rats

Effects of Irregular Feeding under an 80% Energy Restricted Condition on the Growth and the Daily Energy Metabolism in Rats

Effects of Limited Dissolved Oxygen Supply on the Growth and Energy Allocation of Juvenile Chinese Shrimp, Fenneropenaeus chinensis

Abstract Information about the effect of hypoxia exposure on energy allocation is helpful for better understanding how aquatic animals tolerate and adapt to a hypoxic environment. The growth, molting, and energy allocation were investigated in juvenile Fenneropenaeus chinensis exposed to five different dissolved oxygen (DO) seawaters (2.09 ± 0.15, 3.10 ± 0.29, 4.13 ± 0.25, 4.73 ± 0.12, and 5.48 ± 0.09 mg/L DO) for 30 d. When DO was below 4.13 mg/L, the growth of shrimp was depressed. Feed ingestion and feed conversion efficiency decreased with the decrease of DO. Less feed ingestion was caused by lower daily metabolic energy. Higher proportion of ingested energy lost in metabolism, exuviations, and nitrogen excretion caused lower feed conversion efficiency. More energy lost in exuviations, lower survival rate, soft carapaces of dead shrimp, and cannibalism were found in oxygen deficient groups and it implicated that hypoxia could delay the shrimp recovering from molting and cause cannibalism and higher mortality. The results indicated that hypoxia was an important factor affecting the amount and fitness of shrimp stock because it could cause a high rate of mortality and growth depression.

Heterotrophic plasticity and resilience in bleached corals

Mass coral bleaching events caused by elevated seawater temperatures have resulted in extensive coral mortality throughout the tropics over the past few decades. With continued global warming, bleaching events are predicted to increase in frequency and severity, causing up to 60% coral mortality globally within the next few decades. Although some corals are able to recover and to survive bleaching, the mechanisms underlying such resilience are poorly understood. Here we show that the coral host has a significant role in recovery and resilience. Bleached and recovering Montipora capitata (branching) corals met more than 100% of their daily metabolic energy requirements by markedly increasing their feeding rates and CHAR (per cent contribution of heterotrophically acquired carbon to daily animal respiration), whereas Porites compressa (branching) and Porites lobata (mounding) corals did not. These findings suggest that coral species with high-CHAR capability during bleaching and recovery, irrespective of morphology, will be more resilient to bleaching events over the long term, could become the dominant coral species on reefs, and may help to safeguard affected reefs from potential local and global extinction.

Body weight gain in free-living Pima Indians: effect of energy intake vs expenditure.

Obesity results from a chronic imbalance between energy intake and energy expenditure. However, experimental evidence of the relative contribution of interindividual differences in energy intake and expenditure (resting or due to physical activity) to weight gain is limited. To assess prospectively the association between baseline measurements of daily energy metabolism and weight changes by studying free-living adult Pima Indians, one of the most obese populations in the world. A study of the pathogenesis of obesity in the Pima Indians living in Southwestern Arizona. The participants were 92 nondiabetic Pima Indians (64M/28F, 35+/-12 y, 35+/-9% body fat; mean+/-s.d.). At baseline, free-living daily energy metabolism was assessed by doubly labeled water and resting metabolic rate (RMR) by indirect calorimetry. Data on changes in body weight (5.8+/-6.5 kg) over a follow-up period of 4+/-3 y were available in 74 (49M/25F) of the 92 subjects. The baseline calculated total energy intake (r=0.25, P=0.028) and RMR (r=-0.28, P=0.016) were significantly associated with changes in body weight. The baseline energy expenditure due to physical activity was not associated with changes in body weight. Using state-of-the-art methods to assess energy intake and expenditure in free-living conditions, we show for the first time that the baseline calculated total energy intake is a determinant of changes in body weight in Pima Indians. These data also confirm that a low RMR is a risk factor for weight gain in this population.

Seasonal energy utilization in bamboo by the red panda (Ailurus fulgens)

Seasonal energy intake and digestion of bamboo by red pandas were measured in energy balance trials at the field station at an altitude of 3,100 m in Yele Natural Reserve, Mianning County of Sichuan Province, Peoples Republic of China. Two-week trials were conducted at monthly intervals by feeding animals with only natural bamboo browse, Bashania spanostachya, from May to November 1995. Results demonstrated that energy intake, digestible energy, and digestibility differed significantly among seasons and diets. Energy digestibilities were high in summer-autumn, intermediate in spring, and low in winter. These variations correlated positively with the nutrient contents of bamboo. The daily metabolic energy requirement measured varied from 2,603.3 kJ in the spring to 3,139.8 kJ in the summer-autumn to 2,740.8 kJ in the winter. The results also showed that shoots were more easily digested than leaves and exhibited the highest digestibility. Restricted by the capacity of digestive tracts, red pandas poorly utilized the energy provided by bamboo as indicated by the lower energy digestibility (averaging 26.47% for leaves and 44.08% for shoots among the seasons). To fulfill their daily energy requirements, red pandas ingested a large amount of energy from bamboo leaves, which varied from 10,145.8 kJ in the spring, 12,045.1 kJ in the summer-autumn, and 12,276.9 kJ in the winter to maximize the rate of energy intake. Zoo Biol 19:27–33, 2000. © 2000 Wiley-Liss, Inc.

Influence of Thyroid Status on Water Metabolism and Survival of Normal and Dehydrated Desert RodentsMeriones libycus

The relationship between thyroid status and resistance to water deprivation in a desert rodent,Meriones libycus,has been studied in normal, radiothyroidectomized (Tx), and thyroidectomized T4-supplemented (1.5 μg T4/day) (Tx+T4) animals. In animals given free access to water, 1 month after thyroidectomy water influx and efflux decreased 3-fold. This decrease was partially corrected after 5 days of T4 administration. Thyroidectomy did not modify urinary osmolality nor affect survival. In dehydrated animals, the body weight decreased (about 15%) over 2 weeks in all groups and then stabilized. Water flux decreased sharply in normal or Tx + T4 animals during the 1st week and then stabilized. A further decrease of water flux occurred in hypothyroid animals, which continued over 4 weeks, when fluxes were half those of normal or Tx + T4 animals. The urinary osmolality increased equally sharply in the three groups, at least during the first 5 days of dehydration when sampling was possible. Whereas dehydrated normal and Tx + T4 animals survived at least 7 weeks, 70% of Tx animals had died after 4 weeks and none survived more than 7 weeks. The daily metabolic energy intake was estimated from water flux and metabolic water of the dietary barley. After 4 weeks, when water influx represented only metabolic water from food, metabolic energy intake decreased 2.5-fold in hypothyroid compared with normal or Tx + T4 animals. This low metabolic energy intake led to a trend of body dehydration, hypothermia, and death. Thus, although an effect of thyroidectomy on survival of hydrated animals beyond 4 weeks cannot be excluded, we infer that thyroid hormones play a significant role in the survival of desert rodents under conditions of hydric stress.

Daily energy metabolism in patients with type 1 diabetes mellitus.

We evaluated the daily energy balance and main substrate utilization in Type 1 insulin dependent diabetic patients and healthy volunteers. Ten patients with Type 1 diabetes mellitus and eight healthy volunteers were studied. Diabetic patients were well controlled under intensive insulin treatment (0.6 UI/kg body weight, HbA1c = 5.5 +/- 0.7%). During the 30 hours each subject spent in the respiration chamber VO2, VCO2, respiratory quotient, daily energy intake, 24-hour, day-time, night-time and basal energy expenditure as well as energy expenditure during exercise (at 40% maximal exercise capacity), main substrate oxidation (carbohydrates, lipids and proteins) and overall diet-induced thermogenesis, were measured. The results were corrected for 24-hour urinary nitrogen loss. Diet-induced thermogenesis, expressed as percent of energy intake, was found to be significantly lower in diabetic patients than in control subjects (6.69 +/- 1.29% vs 11.8 +/- 4.71% of energy intake, p < 0.05). A negative correlation was found between diet-induced thermogenesis and daily average glycemia for diabetic patients (r = -0.65, p < 0.01). Energy expenditure during exercise, calculated in terms of net work efficiency, was not different between the two groups. In conclusion, since diet-induced thermogenesis is highly correlated with the theoretical cost of glucose storage and since no difference was found in carbohydrate oxidation, glucose storage in diabetic patients is probably reduced when hyperglycemia occurs. Diabetic patients in good metabolic control are able to perform mild exercise with a work efficiency very similar to that of control subjects.

Interactive effects of temperature and photoperiod on the daily activity and energy metabolism of pouched mice (Saccostomus campestris: Cricetidae) from southern Africa.

The daily activity and energy metabolism of pouched mice (Saccostomus compestris) from two localities in southern Africa was examined following warm (25 degrees C) and cold (10 degrees C) acclimation under long (LD 14:10) and short (LD 10:14) photoperiod. There was no differential effect of photoperiod on the daily activity or metabolism of pouched mice from the two localities examined, which suggests that reported differences in photoresponsivity between these two populations were not the result of differences in daily organisation. Nevertheless, there was a significant increase in metabolism at 10 degrees C, irrespective of photoperiod, even though seven cold-acclimatized animals displayed bouts of spontaneous torpor and saved 16.4-36.2% of their daily energy expenditure. All but one of these bouts occurred under short photoperiod, which suggests that short photoperiod facilitated the expression of torpor and influenced the daily energy metabolism of these individuals. As expected for a nocturnal species, the amount of time spent active increased following acclimation to short photoperiod at 25 degrees C. However, there was a reduction in mean activity levels under short photoperiod at 10 degrees C, possibly because the stimulation of activity by short photoperiod was masked by a reduction in activity during bouts of spontaneous torpor. Cold temperature clearly had an overriding effect on the daily activity and metabolism of this species by necessitating an increase in metabolic heat production and eliciting spontaneous torpor which over-rode the effect of short photoperiod on activity at an ambient temperature of 10 degrees C.

Energieumsatz von küken bei niedriger umgebungstemperatur

The daily energy metabolism of growing chickens for meat production (origin T 82) fed ad libitum was measured from the 5th up to the 65th day of life at environmental temperatures decreasing in the course of development (25, 20, 15, 15, 15, 10, 10, 5 and 5 degrees C, resp.). Further in each period the heat production was measured through a wide range of temperatures (Maximum 40 degrees C to 5 degrees C in steps of 5 K) by 30-minute short time measurements. The mean live weight of the chickens was 75 g at the beginning of the experiment and 3416 g (male) or 2952 g (female) at the end of the experiment. The digestibility of energy and nutrients was independent of the stage of development. On average the total efficiency of utilization of metabolizable energy was 39.2 +/- 4.8% and the partial efficiency of utilization was 69.7 +/- 2.1%. 15-38% of the produced heat, caused by thermoregulation. The thermoneutral temperature decreased in the course of development from 35 to 18 degrees C and in the same way the thermoregulatory heat production decreased from 23 to 12 kJ/kg LW0.75.d.K. In the 2nd period the thermoregulatory heat production was extraordinarily high at an amount of 28 kJ/kg LW0.75.d.K.

Contrasts in energy intake and expenditure in sit-and-wait and widely foraging lizards.

Daily energy metabolism and water flux were measured with doubly labeled water in the free-living insectivorous lizards Cnemidophorus tigris (mean body mass 15.7 g) and Callisaurus draconoides (8.6 g) in June 1979 in the Colorado Desert of California. C. tigris was an active forager; it spent 91% of its 5-h daily activity period in movement. C. draconoides was a sit-and-wait predator; it spent less than 2% of its 10-h activity period in movement. C. tigris had significantly higher rates of field energy metabolism and water influx (210 Jg-1 day-1, 36.8 ul H2O g-1 day-1, N=19) than C. draconoides (136, 17.1, N=18). There were no significant differences between the sexes within either species.The extra costs of free existence were calculated from differences between field metabolic rates and maintenance costs estimated from laboratory respirometry. Rates of energy metabolism during the field activity period were about 1.5x resting levels at 40° C (∼field active body temperature) for C. draconoides and 3.3 x resting levels at 40° C (∼field active body temperature) for the more active C. tigris. Feeding rates calculated from water influx data were 13.3 mg g-1 day-1 for C. tigris and 5.8 mg g-1 day-1 for C. draconoides. Though C. tigris had a high rate of energy expenditure, its foraging efficiency [Formula: see text] was higher than C. draconoides'.

An evaluation of heart rate as an indirect measure of daily energy metabolism of the American kestrel

1. 1. The average daily heart rate ( HR) of eight kestrels was used with O 2 consumption ( V ̇ O 2 )- HR relationships measured on each individual to estimate their daily energy metabolism. Hea rate provided a good index of daily metabolism (i.e. less than 10% error) in some individuals. The unpredictable shifts that occur in the resting VO 2- HR relationship over periods of days, weeks or months is a major shortcoming of the heart rate method. 2. 2. Heart rate, when sampled for l min every 10 min throughout a 24-hr period provides a very good measure of the true average daily HR of some kestrels. 3. 3. Suggestions for potential users of the heart rate method are given.

Daily Energy Metabolism of Two Rodents (Peromyscus leucopus and Tamias striatus) in Their Natural Environment

Daily energy metabolism of Peromyscus leucopus and Tamias striatus was measured in three natural seasonal temperature regimes by gas analysis. Average daily metabolic rates (ADMR) were calculated from these daily metabolic patterns. Polynomial multiple regression analyses were conducted to examine the relative influence of body mass, ambient temperature, and time of day on metabolic rates. Several predictive equations are derived from regression analyses which are compared with both the observed data and similar predictive equations of other authors. In both species, ADMRs are approximately double the estimated resting metabolic rates under the same environmental conditions. The $D_{2}^{18}O$ method was used to estimate free-living daily energy metabolism of these species in their natural environment. Based on results of the $D_{2}^{18}O$ method, there is no significant difference in either species in the metabolic rates of free-living animals and animals living in large, field-located metabolism chambers...

Oxygen consumption in the prosobranch snail Viviparus contectoides (Mollusca: Gastropoda)—III. Effects of light

Abstract o 1. Daily metabolic energy demand and weight specific daily metabolic energy demand of male and female Viviparus contectoides is dependent on the number of hours of light. 2. Weight specific daily metabolic energy demand of Viviparus contectoides is dependent on weight. 3. Variation in the number of hours of light caused no apparent pattern in the absolute value or occurrence of the peaks or troughs in the weight specific oxygen consumption in either males or females and no consistent effect of light cycle on these variables was observed. 4. Daily metabolic energy demand for both males and females increased with decreasing hours of light. The energy demand of females increased more rapidly than males. Daily metabolic caloric requirements of both sexes were nearly equal during days with 18 and 24 hr of light. 5. Mean weight specific daily metabolic energy demand of males is greater than females during all light cycles. Mean weight of females is greater than mean weight of males.