The metabolic rate of Merino rams bred for high or low wool production

1968 ◽  
Vol 19 (5) ◽  
pp. 821 ◽  
Author(s):  
N McCGraham
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Metabolic Rates ◽  
Wool Production ◽  
Skeletal Size ◽  
Body Weights ◽  
Free Body ◽  
Fasting Heat Production

Five rams from a flock bred for high wool production at pasture and six rams from another flock bred for low production were studied. The two groups had also grown differing amounts of wool when rationed to 800 g food per day in pens. The high producers were somewhat larger and heavier than the low producers and had greater fat-free body weights. Both groups had higher metabolic rates (fasting heat production) than ewes and wethers of the same weight, in whatever units metabolism was expressed. The high producers were judged to have higher metabolic rates than the low producers; some of this difference may have been due to the larger skeletal size of the high producers.

scholarly journals Effects of altitude, ambient temperature and solar radiation on fasting heat production in yellow cattle (Bos taurus)

2003 ◽  
Vol 89 (3) ◽  
pp. 399-407 ◽  
Author(s):  
Xing-Tai Han ◽  
Ao-Yun Xie ◽  
Xi-Chao Bi ◽  
Shu-Jie Liu ◽  
Ling-Hao Hu
Keyword(s):  
Solar Radiation ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
High Altitude ◽  
Heat Production ◽  
Bos Taurus ◽  
Starvation Period ◽  
Adaptation Period ◽  
Yellow Cattle ◽  
Fasting Heat Production

Growing yellow cattle (Bos taurus, n 30, 1·0–3·5 years old and 75–240 kg) from their native altitude (2000–2800 m) were used to evaluate the effects of altitude, ambient temperature (Ta) and solar radiation on the basal energy metabolism in this large mammal. Fasting heat production (FHP) was measured at altitudes of 2260, 3250 and 4270 m on the Tibetan plateau both in the summer and winter respectively, after a 90 d adaptation period at each experimental site. The gas exchanges of the whole animal were determined continuously for 3 (2260 and 3250 m) or 2 (4270 m) d after a 96 (2260 and 3250 m) or 48 (4270 m) h starvation period, using closed-circuit respiratory masks. Increasing altitude from 2260 to 3250 m at similar Ta in the summer significantly elevated FHP for all animals (P<0·01), and from 3250 to 4270 m for young cattle (P<0·05); increasing altitude from 2260 to 3250 m in the winter also significantly elevated FHP (P<0·05), but the increase was mainly due to the decrease of Ta and the increase in wind speed. No results were obtained at 4270 m in the winter, due to the problems of the animals, adaptating to the altitude. The magnitude of FHP elevation caused by increasing altitude was greater with summer sunshine or winter wind than without them. Increase of Ta from 10·0 to 22·0°C, in the presence of solar radiation, slightly (2260 m) or significantly (3250 and 4270 m, P<0·01) elevated FHP, but slightly reduced it in the absence of solar radiation; decrease of Ta from 0·0 to −30·0°C linearly increased FHP. At 3250 and 4270 m, FHP at the same Ta was higher with summer sunshine or winter wind (3250 m) than without them, but this did not occur at 2260 m. In conclusion, high altitude elevates FHP in yellow cattle in the warm season, and the summer solar radiation and winter wind at high altitude significantly increase metabolic rate. It may be also concluded that the effects of solar radiation on metabolic rate depend on the altitude and the environmental temperature.

scholarly journals Effect of previous nutrition on body composition and maintenance energy costs of growing lambs

1986 ◽  
Vol 56 (3) ◽  
pp. 595-605 ◽  
Author(s):  
C. L. Ferrell ◽  
L. J. Koong ◽  
J. A. Nienaber
Keyword(s):  
Body Composition ◽  
Body Weight ◽  
Small Intestine ◽  
Large Intestine ◽  
Heat Production ◽  
Intact Male ◽  
Period 2 ◽  
Similar Weight ◽  
Free Body ◽  
Fasting Heat Production

1. Forty-eight intact male lambs (30 kg) were fed to gain 16 (H), 5 (M) or –6 (L) kg during a 42 d interval (period 1). Lambs from each of the H and M groups were fed to gain either 16 (HH, MH), 5 (HM, MM) or –6 (HL, ML) kg and lambs from the L group were fed to gain 27 (LS), 16 (LH) or 5 (LM) kg during the ensuing 42 d (period 2).2. Fasting heat production (FHP) of four lambs from each treatment was determined at the end of period 2.3. Weights and compositions of the carcass, offal and digesta-free body as well as weights of major internal organs were determined for four lambs of each treatment at the end of periods 1 and 2.4. Within groups of lambs of similar weight at the end of period 2, body composition was, in general, similar, but FHP was greater in lambs that had been on higher planes of nutrition during period 2.5. Within groups of lambs of similar weight, lambs that were fed at higher planes of nutrition during period 2 had greater weights or proportions of liver, small intestine, large intestine and stomach.6. Neither weight of the liver, kidney, stomach, small intestine, large intestine nor daily fasting heat production were constant functions of body-weight. Relations of these traits to body-weight changed with rate of gain.7. Regression analysis indicated that the feeding of lambs at higher planes of nutrition during period 1 resulted in higher maintenance requirements of those lambs during period 2.

METABOLIC AND ENDOCRINE ASPECTS OF THE WHIRLER MUTATION IN MALE MICE

1970 ◽  
Vol 64 (2) ◽  
pp. 347-358
Author(s):  
A. Stanley Weltman ◽  
Arthur M. Sackler
Keyword(s):  
Locomotor Activity ◽  
Endocrine Function ◽  
Metabolic Rates ◽  
Heterozygous Female ◽  
Endocrine Organ ◽  
General Body ◽  
Adrenocortical Activity ◽  
Body Weights ◽  
Seminal Vesicle Weight ◽  
Eosinophil Counts

ABSTRACT Body weight, metabolic rate, locomotor activity and alterations in endocrine organ activity were noted in recessive homozygous male whirler mice and the phenotypically »normal« heterozygotes. Representative populations of the two types were studied at different age levels. In general, body weights of the whirler mice were consistently and significantly lower. Open-field locomotion studies similarly indicated heightened locomotor activity. Total leukocyte and eosinophil counts were either markedly or significantly lower in the homozygous vs. heterozygous whirler groups. Evaluation of relative organ weights showed significantly increased adrenal weights in whirler mice sacrificed at 14 weeks and 11 months of age. These changes were accompanied by involution of the thymus. Thus, the varied data indicate persistent increased metabolism and adrenocortical activity during the life-span of the whirler mice. Seminal vesicle weight decreases in the whirler males at 11 months suggest lower gonadal function. The findings are in accord with previous studies of alterations in metabolic rates and endocrine function of homozygous whirler vs. heterozygous female mice.

scholarly journals Metabolic traits in brown trout (Salmo trutta) vary in response to food restriction and intrinsic factors

2020 ◽  
Vol 8 (1) ◽  
Author(s):  
Louise C Archer ◽  
Stephen A Hutton ◽  
Luke Harman ◽  
W Russell Poole ◽  
Patrick Gargan ◽  
...  
Keyword(s):  
Life History ◽  
Metabolic Rate ◽  
Intraspecific Variation ◽  
Brown Trout ◽  
Environmental Conditions ◽  
Food Restriction ◽  
Metabolic Rates ◽  
Intrinsic Factors ◽  
Metabolic Traits ◽  
Food Conditions

Abstract Metabolic rates vary hugely within and between populations, yet we know relatively little about factors causing intraspecific variation. Since metabolic rate determines the energetic cost of life, uncovering these sources of variation is important to understand and forecast responses to environmental change. Moreover, few studies have examined factors causing intraspecific variation in metabolic flexibility. We explore how extrinsic environmental conditions and intrinsic factors contribute to variation in metabolic traits in brown trout, an iconic and polymorphic species that is threatened across much of its native range. We measured metabolic traits in offspring from two wild populations that naturally show life-history variation in migratory tactics (one anadromous, i.e. sea-migratory, one non-anadromous) that we reared under either optimal food or experimental conditions of long-term food restriction (lasting between 7 and 17 months). Both populations showed decreased standard metabolic rates (SMR—baseline energy requirements) under low food conditions. The anadromous population had higher maximum metabolic rate (MMR) than the non-anadromous population, and marginally higher SMR. The MMR difference was greater than SMR and consequently aerobic scope (AS) was higher in the anadromous population. MMR and AS were both higher in males than females. The anadromous population also had higher AS under low food compared to optimal food conditions, consistent with population-specific effects of food restriction on AS. Our results suggest different components of metabolic rate can vary in their response to environmental conditions, and according to intrinsic (population-background/sex) effects. Populations might further differ in their flexibility of metabolic traits, potentially due to intrinsic factors related to life history (e.g. migratory tactics). More comparisons of populations/individuals with divergent life histories will help to reveal this. Overall, our study suggests that incorporating an understanding of metabolic trait variation and flexibility and linking this to life history and demography will improve our ability to conserve populations experiencing global change.

Metabolic Rate and Energy Expenditure of the Spiny Dogfish, Squalus acanthias

1978 ◽  
Vol 35 (6) ◽  
pp. 816-821 ◽  
Author(s):  
J. R. Brett ◽  
J. M. Blackburn
Keyword(s):  
Energy Expenditure ◽  
Metabolic Rate ◽  
Key Words ◽  
Swimming Performance ◽  
Squalus Acanthias ◽  
Spiny Dogfish ◽  
Metabolic Rates ◽  
Performance Curve ◽  
Power Performance ◽  
General Energy

The metabolic rate of spiny dogfish, Squalus acanthias, was determined in both a tunnel respirometer and a large, covered, circular tank (mass respirometer). Swimming performance was very poor in the respirometer, so that a power–performance curve could not be established. Instead, resting metabolic rates were determined, with higher rates induced by causing heavy thrashing (active metabolism). Routine metabolic rates were measured for the spontaneous activity characterizing behavior in the circular tank. For fish of 2 kg mean weight, the metabolic rates at 10 °C were 32.4 ± 2.6 SE (resting), 49.2 ± 5.0 SE (routine), and 88.4 ± 4.6 SE (active) mg O2∙kg−1∙h−1. Assuming that the routine rate represents a general energy expenditure in nature, this is equivalent to metabolizing about 3.8 kcal∙kg−1∙d−1 (15.9 × 103 J∙kg−1∙d−1). Key words: dogfish, metabolic rates, energetics, respiration

scholarly journals Feeding plasticity more than metabolic rate drives the productivity of economically important filter feeders in response to elevated CO2 and reduced salinity

2018 ◽  
Vol 75 (6) ◽  
pp. 2117-2128 ◽  
Author(s):  
Samuel P S Rastrick ◽  
Victoria Collier ◽  
Helen Graham ◽  
Tore Strohmeier ◽  
Nia M Whiteley ◽  
...  
Keyword(s):  
Metabolic Rate ◽  
Biological Effects ◽  
Absorption Efficiency ◽  
Environmental Stressors ◽  
Elevated Pco2 ◽  
Combined Effects ◽  
Metabolic Rates ◽  
Scope For Growth ◽  
Filter Feeders ◽  
Feeding Plasticity

Abstract Climate change driven alterations in salinity and carbonate chemistry are predicted to have significant implications particularly for northern costal organisms, including the economically important filter feeders Mytilus edulis and Ciona intestinalis. However, despite a growing number of studies investigating the biological effects of multiple environmental stressors, the combined effects of elevated pCO2 and reduced salinity remain comparatively understudied. Changes in metabolic costs associated with homeostasis and feeding/digestion in response to environmental stressors may reallocate energy from growth and reproduction, affecting performance. Although these energetic trade-offs in response to changes in routine metabolic rates have been well demonstrated fewer studies have investigated how these are affected by changes in feeding plasticity. Consequently, the present study investigated the combined effects of 26 days’ exposure to elevated pCO2 (500 µatm and 1000 µatm) and reduced salinity (30, 23, and 16) on the energy available for growth and performance (Scope for Growth) in M. edulis and C. intestinalis, and the role of metabolic rate (oxygen uptake) and feeding plasticity [clearance rate (CR) and absorption efficiency] in this process. In M. edulis exposure to elevated pCO2 resulted in a 50% reduction in Scope for Growth. However, elevated pCO2 had a much greater effect on C. intestinalis, with more than a 70% reduction in Scope for Growth. In M. edulis negative responses to elevated pCO2 are also unlikely be further affected by changes in salinity between 16 and 30. Whereas, under future predicted levels of pCO2C. intestinalis showed 100% mortality at a salinity of 16, and a &gt;90% decrease in Scope for Growth with reduced biomass at a salinity of 23. Importantly, this work demonstrates energy available for production is more dependent on feeding plasticity, i.e. the ability to regulate CR and absorption efficiency, in response to multiple stressors than on more commonly studied changes in metabolic rates.

Leptocephalus energetics: metabolism and excretion

1999 ◽  
Vol 202 (18) ◽  
pp. 2485-2493
Author(s):  
R.E. Bishop ◽  
J.J. Torres
Keyword(s):  
Metabolic Rate ◽  
Energy Budget ◽  
Citrate Synthase ◽  
Sea Water ◽  
Negative Slope ◽  
Ion Pump ◽  
Metabolic Rates ◽  
Energy Reserves ◽  
Developmental Strategy ◽  
Juvenile Form

Leptocephali are the unusual transparent larvae that are typical of eels, bonefish, tarpon and ladyfish. Unlike the larvae of all other fishes, leptocephali may remain in the plankton as larvae for several months before metamorphosing into the juvenile form. During their planktonic phase, leptocephali accumulate energy reserves in the form of glycosaminoglycans, which are then expended to fuel metamorphosis. The leptocephalus developmental strategy is thus fundamentally different from that exhibited in all other fishes in two respects: it is far longer in duration and energy reserves are accumulated. It was anticipated that the unusual character of leptocephalus development would be reflected in the energy budget of the larva. This study describes the allocation of energy to metabolism and excretion, two important elements of the energy budget. Metabolic rates were measured directly in four species of leptocephali, Paraconger caudilimbatus, Ariosoma balearicum, Gymnothorax saxicola and Ophichthus gomesii, using sealed-jar respirometry at sea. Direct measurements of metabolic rates were corroborated by measuring activities of lactate dehydrogenase and citrate synthase, two key enzymes of intermediary metabolism, in addition to that of Na(+)/K(+)-ATPase, a ubiquitous ion pump important in osmotic regulation. Excretion rates were determined by subsampling the sea water used in the respiratory incubations. The entire premetamorphic size range for each species was used in all assays. Mass-specific oxygen consumption rate, excretion rate and all enzyme activities (y) declined precipitously with increasing mass (M) according to the equation y=aM(b), where a is a species-specific constant and −1.74&lt;b&lt;-0.44. In leptocephali, the highly negative slope of the familiar allometric equation describing the relationship between mass-specific metabolic rate and mass, normally between −0.33 and 0, showed that a massive decline in metabolic rate occurs with increasing size. The result suggests that the proportion of actively metabolizing tissue also declines with size, being replaced in large measure by the metabolically inert energy depot, the glycosaminoglycans. Leptocephali can thus grow to a large size with minimal metabolic penalty, which is an unusual and successful developmental strategy.

Effects of obesity on insulin sensitivity and responsiveness in sheep

1989 ◽  
Vol 257 (5) ◽  
pp. E772-E781 ◽  
Author(s):  
E. N. Bergman ◽  
S. S. Reulein ◽  
R. E. Corlett
Keyword(s):  
Insulin Sensitivity ◽  
Insulin Receptors ◽  
High Energy ◽  
Response Curves ◽  
Peripheral Tissues ◽  
Glucose Clamp Technique ◽  
Body Weights ◽  
Tissue Sensitivity ◽  
Free Body ◽  
The Right

To assess the mechanisms of insulin resistance in the ruminant, severe and adult-onset obesity was produced in Dorset ewes by overfeeding a high-energy ration over a 1- to 2-yr period. Body weights increased to 100 kg compared with 50 kg in lean control sheep; significant hyperinsulinemia (40 +/- 4 vs 10 +/- 1 microU/ml) also developed as did a moderate hyperglycemia (62 +/- 2 vs. 52 +/- 1 mg/100 ml). Tissue sensitivity and responsiveness to insulin were then determined in both obese and lean sheep by the euglycemic glucose-clamp technique. Insulin was infused at eight different rates from 0.2 to 50 mU.kg-1.min-1 and [6-3H]-glucose was infused for measurement of glucose kinetics. The mean dose-response curves for glucose utilization and clearance rates were displaced to the right in obese compared with lean sheep. As a result, the half-maximally effective insulin concentrations usually were elevated two- to fourfold, indicating decreased insulin sensitivity in obese sheep, and this is consistent with decreased insulin receptors in peripheral tissues. On the basis of fat-free body weight, the maximal glucose responses, however, were not significantly different between obese and lean sheep, indicating that postreceptor defects do not exist in muscle tissue. Furthermore, lean ruminants are more resistant to insulin than are humans, but this resistance seems only because of the sheep's decreased responsiveness to insulin and thus only because of postreceptor insulin effects in peripheral tissues.

Torpor patterns in food-deprived Myotis lucifugus (Chiroptera: Vespertilionidae) under simulated roost conditions

1991 ◽  
Vol 69 (1) ◽  
pp. 255-257 ◽  
Author(s):  
Allen Kurta
Keyword(s):  
Metabolic Rate ◽  
Myotis Lucifugus ◽  
Metabolic Rates ◽  
Laboratory Studies ◽  
Insectivorous Bats ◽  
Wet Weather ◽  
Single Night ◽  
Little Brown Bats

Temperate insectivorous bats are commonly prevented from foraging by cold or wet weather. This study examines the effect of missing a single night of foraging on the energetics of pregnant and lactating little brown bats (Myotis lucifugus) under simulated roost conditions. After not foraging, the day-roosting metabolic rate of pregnant M. lucifugus was reduced by 61% and that of lactating bats by 46%. Although previous laboratory studies predicted that food-deprived bats should remain in torpor throughout the day-roosting period, M. lucifugus consistently aroused from torpor between 11:00 and 15:00 and maintained elevated metabolic rates for the rest of the day.

Effect of altitude on dietary-induced thermogenesis at rest and during light exercise in man

1978 ◽  
Vol 45 (3) ◽  
pp. 345-349 ◽  
Author(s):  
M. J. Stock ◽  
N. G. Norgan ◽  
A. Ferro-Luzzi ◽  
E. Evans
Keyword(s):  
Metabolic Rate ◽  
Specific Dynamic Action ◽  
Metabolic Rates ◽  
Postprandial Metabolism ◽  
Interindividual Differences ◽  
Liquid Meal ◽  
The Mean ◽  
Monte Rosa ◽  
Hypoxic Exercise ◽  
Made In

Measurements of metabolic rate and the thermic response (specific dynamic action) of a 400-kcal liquid meal were made in six subjects at rest and during light exercise. The tests were conducted before (LA1) and after (LA2) a 3-wk sojourn (HA1, HA2, HA3) at 3,650 m on the Monte Rosa. Fasting metabolic rate at rest increased inittally and then fell, as did fasting and fed exercising metabolic rates. The fall in metabolic rates, but not the initial increases, can be ascribed to the change in body weight. Resting thermic responses at altitude were only slightly lower than normal, although peak values were significantly depressed at HA2 (P less than 0.05). The mean exercising thermic response was also significantly lower at HA2 (P less than 0.05) but recovered in HA3 and LA2. In the time taken for thermic responses to decrease and recover there were interindividual differences that were best explained by the previous altitude experience of the subjects. The possibility of a cardiovascular shift during hypoxic exercise causing depression of postprandial metabolism is discussed.

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