Seasonal energy expenditures and thermoregulatory responses of moose

1986 ◽  
Vol 64 (2) ◽  
pp. 322-327 ◽  
Author(s):  
Lyle A. Renecker ◽  
Robert J. Hudson

Metabolic rates and thermoregulatory responses were studied in adult moose (Alces alces) exposed to various ambient temperatures during winter and summer. Resting energy expenditures followed a marked annual cycle with a maximum (940 kJ kg body weight−0.75 d−1) during spring – early summer and minimum (430 kJ kg body weight−0.75 d−1) during winter. The heat increment of feeding associated with a pelleted ration was 6–9 kJ kg body weight−0.75 h−1. The energy cost of standing was 4.2 kJ kg body weight−0.75 h−1, an increment of 25% over the lying posture. Although piloerection was observed between −25 and −30 °C, metabolic rates did not increase. In contrast to their cold tolerance, moose were easily heat stressed. During winter, moose increased respiration rates when ambient temperatures rose above −5 °C. Resistance to heat load was greater for standing moose during summer; respiration rate increased above 14 °C and open-mouthed panting began at 20 °C. Energy expenditure and heart rate followed a similar rise with increasing ambient temperature.

1979 ◽  
Vol 59 (3) ◽  
pp. 611-617 ◽  
Author(s):  
R. J. CHRISTOPHERSON ◽  
R. J. HUDSON ◽  
M. K. CHRISTOPHERSEN

The metabolic rates of two bison and four Hereford spring-born calves were measured at monthly intervals from December until the following November. Following adaptation at seasonal ambient temperatures, metabolic measurements were made while calves were exposed to controlled temperatures of +10, 0 and −30 °C. Exposure of the Hereford calves to −30 °C resulted in increased metabolic rates during the first 6 mo of the study but the magnitude of the response was greatly attenuated as the calves grew larger. At −30 °C, bison calves either maintained or reduced metabolic rates compared to expenditures at +10 °C. When the calves were about 17 mo of age, they were exposed to a combination of low temperatures and wind. Wind velocities of 4.7 km∙h−1 did not influence metabolic rates of either bison or Herefords at air temperatures of 0 °C. However, at −30 °C, metabolic rates increased from 650 and 700 KJ∙kg−.75∙d−1 to 835 and 950 KJ∙kg−.75∙d−1 in Hereford and bison calves, respectively. Neither respiratory frequencies nor heart rates were influenced significantly during cold exposure, but heart rates increased in response to wind. In general, metabolic rates and heart rates were lower in bison calves.


1971 ◽  
Vol 13 (2) ◽  
pp. 303-313 ◽  
Author(s):  
D. B. Stephens

SUMMARY1. The metabolic rates of 58 individual piglets kept either on a straw or on a concrete floor at ambient temperatures near to 10°, 20° or 30°C have been measured with ages ranging from newborn to 9 days, and body weight from 1·0 to 3·2 kg. The oxygen consumption was measured on each floor material at the chosen ambient temperature thus allowing paired comparisons for each animal.2. In comparison with the concrete floor, oxygen consumption on straw was reduced by 18% at 10°C, 27% at 20°C and by 12% at 30°C for pigs 2 to 9 days old. The regression coefficients of mean log (oxygen consumption) on log (body weight) were around 0·66 at 10° and 20°C. At 30°C the value was 0·99 ± 0·14. The regression coefficients were not significantly affected by the presence of a straw floor showing that its effect did not vary with body weight. Corresponding values foi piglets below 24 hours of age were 17% at 10°C, 27% at 20°C and 22% at 30°C ambient temperature.3. Moving a piglet on to a straw floor at 10°C had the same thermal effect as raising the ambient temperature to 18°C. Similar treatment at 30°C was equivalent to raising the ambient temperature to 32°C.4. Lowering ambient temperature to increase the temperature gradient between the homeothermic body of the piglet and the environment progressively increased heat loss in all cases. There was a concomitant decrease in the calculated conductance between core and environment which was more pronounced for the piglets lying on the concrete floor.


1987 ◽  
Vol 65 (6) ◽  
pp. 1377-1382 ◽  
Author(s):  
Graham A. J. Worthy

Metabolic rates and growth rates of juvenile harp and grey seals were monitored during the postweaning period after the onset of feeding. Growth rates varied from 0.03 to 0.32 kg d−1, depending on the level of energy intake and absolute body mass of the seal. Measurements of sculp mass (blubber with attached skin), as a percentage of total mass, indicated low rates of growth in the sculp and preferential growth in the core. When feeding started there was a 1.3- to 2.3-fold increase in standard metabolic rate, which was independent of the heat increment of feeding. Metabolic requirements of feeding seals, measured by indirect calorimetry, were between 1.2 and 7.2 W kg−1 in water and between 1.2 and 6.0 W kg−1 in air, similar to average daily metabolic rates calculated from net energy intake.


1957 ◽  
Vol 188 (3) ◽  
pp. 435-438 ◽  
Author(s):  
M. J. Fregly ◽  
N. B. Marshall ◽  
J. Mayer

Goldthioglucose-obese mice cannot adjust their food intake to meet the increased energy requirements due to cold. At all ambient temperatures above 15°C the spontaneous running activity of these animals is less than that observed for nonobese controls. Activity of obese mice is maximal at 19°C and minimal at 15°C or lower. Body weights decrease during exposure to cold. In contrast to that of obese mice, running activity of nonobese controls is maximal at an ambient temperature of 25°C but nearly ceases at 15°C or lower. The food intake of these animals increases in the cold and remains elevated even at temperatures at which activity decreases. The body weight of nonobese controls is either maintained constant or increases during exposure to cold air.


Nature ◽  
1969 ◽  
Vol 223 (5202) ◽  
pp. 213-213 ◽  
Author(s):  
M. J. STOCK

1997 ◽  
Vol 200 (12) ◽  
pp. 1757-1763 ◽  
Author(s):  
P Hawkins ◽  
P Butler ◽  
A Woakes ◽  
G Gabrielsen

The rate of oxygen consumption (O2), respiratory quotient (RQ) and deep body temperature (TB) were recorded during a single, voluntary ingestion of Arctic cod Boreogadus saida (mean mass 18.9+/-1.1 g, s.e.m., N=13) by five postabsorptive Brunnich's guillemots (thick-billed murre, Uria lomvia). The birds were resting in air within their thermoneutral zone, and the fish were refrigerated to 0-2 degreesC. The rate of oxygen consumption increased by a factor of 1.4 during the first few minutes after ingestion, but there was no significant change in TB. Mean rate of oxygen consumption returned to preingestive levels 85 min after the birds ate the fish. The telemetered temperature of one fish reached TB within 20 min. This suggests that the persistent elevation in O2 over the next hour corresponded to the obligatory component of the heat increment of feeding (HIF) and was not related to heating the fish. Abdominal temperature increases after diving bouts in free-ranging common guillemots (common murre, Uria aalge) are possibly achieved through the HIF, since meals are processed at sea. Of the increase in O2 measured in the laboratory, it is calculated that 30 % is required to heat the fish, while 70 % is due to the HIF. In free-ranging birds, the excess heat provided by the HIF could contribute 6 % of the daily energy expenditure. This suggests that the HIF augments heat production in Uria spp. and thus reduces the energetic cost of thermoregulation.


1984 ◽  
Vol 56 (3) ◽  
pp. 772-776 ◽  
Author(s):  
J. LeBlanc ◽  
P. Diamond ◽  
J. Cote ◽  
A. Labrie

The influence of exercise training on postprandial heat production was investigated in human subjects. Whereas resting metabolic rate was comparable for trained and nontrained subjects, the heat increment of feeding (HIF) after subjects consumed a meal containing 755 kcal was approximately 50% smaller in the trained subjects. Measurements of respiratory quotient also indicated a reduction of about 50% in glucose oxidation associated with exercise training. The levels of plasma norepinephrine increased significantly (P less than 0.01) from 200 to 300 pg/ml in the sedentary subjects, but the changes observed in trained subjects were not significant. During the early phase of the meal, plasma levels of insulin were increased, even before nutrients appeared in the blood. Throughout the study the enhanced sensitivity to insulin of the trained subjects was confirmed. the postprandial heat production was diminished in exercise-trained subjects, and it is suggested that this could be related to a reduced activity of the sympathetic nervous system. Another possibility is that this reduction in HIF is related to a facilitation of glucose disposal in the form of glycogen rather than in the form of lipids.


The Condor ◽  
2005 ◽  
Vol 107 (1) ◽  
pp. 151-155 ◽  
Author(s):  
Sheldon J. Cooper ◽  
James A. Gessaman

AbstractWe measured body temperature of Mountain Chickadees (Poecile gambeli) and Juniper Titmice (Baeolophus ridgwayi) at different times of day and under a range of ambient temperatures in order to determine the use of nocturnal hypothermia in seasonally acclimatized small passerines. Our findings show both species used nocturnal hypothermia year-round. Depth of hypothermia was inversely correlated to body mass in Juniper Titmice but not in Mountain Chickadees. In both species, depth of hypothermia did not vary seasonally but nocturnal body temperature was regulated 3–11°C lower than daytime values. Nocturnal energy savings range from 7%–50% in chickadees and from 10%–28% in titmice. These nocturnal energy savings translate into ecologically important reductions in daily energy expenditures for these two species.Hipotermia Nocturna en Individuos de Poecile gambeli y Baeolophus ridgwayi Aclimatados EstacionalmenteResumen. Medimos la temperatura corporal de Poecile gambeli y Baeolophus ridgwayi a diferentes horas del día y en un rango de temperaturas ambientales para determinar el uso de hipotermia nocturna en pequeñas aves paserinas aclimatadas estacionalmente. Nuestros resultados muestran que ambas especies presentaron hipotermia nocturna durante todo el año. La profundidad de la hipotermia estuvo inversamente correlacionada con la masa corporal en B. ridgwayi, pero no en P. gambeli. En ambas especies, la profundidad de la hipotermia no varió estacionalmente, pero la temperatura corporal nocturna estuvo regulada 3–11°C por debajo de los valores diurnos. El ahorro nocturno de energía varió entre 7%–50% en P. gambeli y entre 10%–28% en B. ridgwayi. Estos ahorros nocturnos de energía se tradujeron en reducciones ecológicamente importantes en los gastos diarios de energía para ambas especies.


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