Effects of body mass and huddling on resting metabolic rates of post-weaned European rabbits under different simulated weather conditions

2009 ◽  
Vol 23 (6) ◽  
pp. 1070-1080 ◽  
Author(s):  
Martin W. Seltmann ◽  
Thomas Ruf ◽  
Heiko G. Rödel
Keyword(s):  
Body Mass ◽  
Weather Conditions ◽  
Metabolic Rates ◽  
European Rabbits

scholarly journals Dietary Intake, Hydration Status, and Body Composition of Three Belgian Military Groups

2020 ◽  
Vol 185 (7-8) ◽  
pp. e1175-e1182
Author(s):  
William De Bry ◽  
Patrick Mullie ◽  
Eva D’Hondt ◽  
Peter Clarys
Keyword(s):  
Body Composition ◽  
Dietary Intake ◽  
Body Mass ◽  
Fat Mass ◽  
Military Training ◽  
Weather Conditions ◽  
Urine Specific Gravity ◽  
Hydration Status ◽  
Dietary Intakes ◽  
Negative Consequences

Abstract Introduction Malnutrition, suboptimal hydration, and inadequate body composition can have negative consequences on soldiers’ performance and health. A recent consensus statement concerning “soldiers’ physical performance” points to the scarcity of data in specific military populations. Therefore, the aim of the present study was to assess and compare dietary intake, hydration status, and body composition of three military groups during their specific military training. Materials and Methods Eighty-five soldiers (ie, 21 in a qualification course to join the Special Forces [SF], 22 Infantrymen [Chasseurs Ardennais, CA], and 42 Recruits [REs]) participated in this 3- to 4-day study. Body mass was assessed before and after each study period. All soldiers self-reported their dietary intakes, from which energy and macronutrient intakes were calculated. In addition, their morning urine samples were collected daily to assess urine specific gravity (USG) as a measure of hydration status. Fat mass was estimated at the end of the study using bioelectrical impedance analysis. Results All groups lost significant amounts of body mass (ie, mean losses ranging between 1.3 and 1.7 kg). Macronutrient intakes were not fully met in respect to the recommendations. Most notably, REs’ fat intake was high (ie, 42.3 [±1.6] energy percent [E%]), while their carbohydrate intake was low (ie, 44.5 [±2.1] E%). Furthermore, saturated fat intakes were high among all groups (ie, group means ranging between 13.6 and 21.4 E%). USG values indicated suboptimal hydration status was prevalent in all groups. Most noteworthy, for SF, only 5.4% of the USG values indicated optimal hydration. The average fat mass (%) for SF, CA, and RE was 11.2 (±3.1), 18.8 (±5.1), and 19.4 (±5.0), respectively. Conclusion The present study showed that military men are not always adequately fed nor hydrated. These issues should be resolved by creating nutritional packages, and individual dietary and hydration strategies, all in function of military planning and weather conditions.

scholarly journals Allometry of mitochondrial efficiency is set by metabolic intensity

2019 ◽  
Vol 286 (1911) ◽  
pp. 20191693 ◽  
Author(s):  
Boël Mélanie ◽  
Romestaing Caroline ◽  
Voituron Yann ◽  
Roussel Damien
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Coupling Efficiency ◽  
Energy Output ◽  
Scaling Exponent ◽  
Metabolic Rates ◽  
Mammal Species ◽  
Skeletal Muscle Mitochondria ◽  
Metabolic Intensity ◽  
Mitochondrial Efficiency

Metabolic activity sets the rates of individual resource uptake from the environment and resource allocations. For this reason, the relationship with body size has been heavily documented from ecosystems to cells. Until now, most of the studies used the fluxes of oxygen as a proxy of energy output without knowledge of the efficiency of biological systems to convert oxygen into ATP. The aim of this study was to examine the allometry of coupling efficiency (ATP/O) of skeletal muscle mitochondria isolated from 12 mammal species ranging from 6 g to 550 kg. Mitochondrial efficiencies were measured at different steady states of phosphorylation. The efficiencies increased sharply at higher metabolic rates. We have shown that body mass dependence of mitochondrial efficiency depends on metabolic intensity in skeletal muscles of mammals. Mitochondrial efficiency positively depends on body mass when mitochondria are close to the basal metabolic rate; however, the efficiency is independent of body mass at the maximum metabolic rate. As a result, it follows that large mammals exhibit a faster dynamic increase in ATP/O than small species when mitochondria shift from basal to maximal activities. Finally, the invariant value of maximal coupling efficiency across mammal species could partly explain why scaling exponent values are very close to 1 at maximal metabolic rates.

scholarly journals Body-mass Changes in Female Collared Flycatchers: State-dependent Strategy

The Auk ◽  
2001 ◽  
Vol 118 (2) ◽  
pp. 550-552 ◽  
Author(s):  
Mariusz Cichoń
Keyword(s):  
Mass Loss ◽  
Body Mass ◽  
Weather Conditions ◽  
Adaptive Strategy ◽  
Ficedula Albicollis ◽  
Prolonged Incubation ◽  
Collared Flycatcher ◽  
State Dependent ◽  
Adverse Weather ◽  
Body Mass Changes

Abstract Collared Flycatcher (Ficedula albicollis) females experimentally were forced to prolong their incubation to address the question whether mass constancy during incubation and subsequent mass loss after hatching is actually related to breeding stage. Compared to unmanipulated control females a week after expected hatching, experimental females did not show any significant mass loss during prolonged incubation, whereas control females that successfully hatched their eggs dropped their mass significantly. Results show that body mass in females is associated with the reproductive stage and may reflect an adaptive strategy. High and stable incubation mass can be a fasting endurance in case of adverse weather conditions when females stay on the nest instead of foraging.

Metabolic rate does not scale with body mass in cultured mammalian cells

2007 ◽  
Vol 292 (6) ◽  
pp. R2115-R2121 ◽  
Author(s):  
Melanie F. Brown ◽  
Tyson P. Gratton ◽  
Jeffrey. A. Stuart
Keyword(s):  
Metabolic Rate ◽  
Body Mass ◽  
Oxygen Delivery ◽  
Mammalian Cells ◽  
Cultured Cells ◽  
Mammalian Species ◽  
Cellular Respiration ◽  
Metabolic Rates ◽  
Respiration Rates ◽  
Species Specific

The allometric scaling of metabolic rate with organism body mass can be partially accounted for by differences in cellular metabolic rates. For example, hepatocytes isolated from horses consume almost 10-fold less oxygen per unit time as mouse hepatocytes [Porter and Brand, Am J Physiol Regul Integr Comp Physiol 269: R226–R228, 1995]. This could reflect a genetically programmed, species-specific, intrinsic metabolic rate set point, or simply the adaptation of individual cells to their particular in situ environment (i.e., within the organism). We studied cultured cell lines derived from 10 mammalian species with donor body masses ranging from 5 to 600,000 g to determine whether cells propagated in an identical environment (media) exhibited metabolic rate scaling. Neither metabolic rate nor the maximal activities of key enzymes of oxidative or anaerobic metabolism scaled significantly with donor body mass in cultured cells, indicating the absence of intrinsic, species-specific, cellular metabolic rate set points. Furthermore, we suggest that changes in the metabolic rates of isolated cells probably occur within 24 h and involve a reduction of cellular metabolism toward values observed in lower metabolic rate organisms. The rate of oxygen delivery has been proposed to limit cellular metabolic rates in larger organisms. To examine the effect of oxygen on steady-state cellular respiration rates, we grew cells under a variety of physiologically relevant oxygen regimens. Long-term exposure to higher medium oxygen levels increased respiration rates of all cells, consistent with the hypothesis that higher rates of oxygen delivery in smaller mammals might increase cellular metabolic rates.

Environmental and genetic influences on body mass and resting metabolic rates (RMR) in a natural population of weaselMustela nivalis

2012 ◽  
Vol 21 (5) ◽  
pp. 1283-1293 ◽  
Author(s):  
KAROL ZUB ◽  
STUART PIERTNEY ◽  
PAULINA A. SZAFRAŃSKA ◽  
MAREK KONARZEWSKI
Keyword(s):  
Natural Population ◽  
Body Mass ◽  
Genetic Influences ◽  
Metabolic Rates

scholarly journals Accounting for body mass effects in the estimation of field metabolic rates from body acceleration

2021 ◽  
pp. jeb.233544
Author(s):  
Evan E. Byrnes ◽  
Karissa O. Lear ◽  
Lauran R. Brewster ◽  
Nicholas M. Whitney ◽  
Matthew J. Smukall ◽  
...  
Keyword(s):  
Body Mass ◽  
Predictive Models ◽  
Scale Dependence ◽  
Metabolic Rates ◽  
Body Acceleration ◽  
Mass Effects ◽  
Order Of Magnitude ◽  
Field Metabolic Rates ◽  
Free Ranging ◽  
Modelling Process

Dynamic Body Acceleration (DBA), measured through animal-attached tags, has emerged as a powerful method for estimating field metabolic rates of free-ranging individuals. Following respirometry to calibrate oxygen consumption rate (MO2) with DBA under controlled conditions, predictive models can be applied to DBA data collected from free-ranging individuals. However, laboratory calibrations are generally performed on a relatively narrow size range of animals, which may introduce biases if predictive models are applied to differently sized individuals in the field. Here, we tested the mass dependence of the DBA-MO2 relationship to develop an experimental framework for the estimation of field metabolic rates when organisms differ in size. We performed respirometry experiments with individuals spanning one order of magnitude in body mass (1.74–17.15 kg) and used a two-stage modelling process to assess the intraspecific scale dependence of the MO2-DBA relationship and incorporate such dependencies into the coefficients of MO2 predictive models. The final predictive model showed scale dependence; the slope of the MO2-DBA relationship was strongly allometric (M1.55), whereas the intercept term scaled closer to isometry (M1.08). Using bootstrapping and simulations, we evaluated the performance of this coefficient-corrected model against commonly used methods of accounting for mass effects on the MO2-DBA relationship and found the lowest error and bias in the coefficient-corrected approach. The strong scale dependence of the MO2-DBA relationship indicates that caution must be exercised when models developed using one size class are applied to individuals of different sizes.

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