scholarly journals Heat increment of feeding in double-crested cormorants (Phalacrocorax auritus) and its potential for thermal substitution

2008 ◽  
Vol 211 (1) ◽  
pp. 49-57 ◽  
Author(s):  
M. R. Enstipp ◽  
D. Gremillet ◽  
D. R. Jones
Keyword(s):  
Phalacrocorax Auritus ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Thermal Substitution

scholarly journals Thermal substitution and aerobic efficiency: measuring and predicting effects of heat balance on endotherm diving energetics

2007 ◽  
Vol 362 (1487) ◽  
pp. 2079-2093 ◽  
Author(s):  
J.R Lovvorn
Keyword(s):  
Heat Balance ◽  
Breath Holding ◽  
Biomechanical Models ◽  
Energy Needs ◽  
Direct Measurements ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Different Depths ◽  
Thermal Substitution ◽  
Present Understanding

For diving endotherms, modelling costs of locomotion as a function of prey dispersion requires estimates of the costs of diving to different depths. One approach is to estimate the physical costs of locomotion ( P mech ) with biomechanical models and to convert those estimates to chemical energy needs by an aerobic efficiency ( η = P mech / V o 2 ) based on oxygen consumption ( V o 2 ) in captive animals. Variations in η with temperature depend partly on thermal substitution, whereby heat from the inefficiency of exercising muscles or the heat increment of feeding (HIF) can substitute for thermogenesis. However, measurements of substitution have ranged from lack of detection to nearly complete use of exercise heat or HIF. This inconsistency may reflect (i) problems in methods of calculating substitution, (ii) confounding mechanisms of thermoregulatory control, or (iii) varying conditions that affect heat balance and allow substitution to be expressed. At present, understanding of how heat generation is regulated, and how heat is transported among tissues during exercise, digestion, thermal challenge and breath holding, is inadequate for predicting substitution and aerobic efficiencies without direct measurements for conditions of interest. Confirming that work rates during exercise are generally conserved, and identifying temperatures at those work rates below which shivering begins, may allow better prediction of aerobic efficiencies for ecological models.

scholarly journals Obesity and the Heat Increment of Feeding

Nature ◽  
1969 ◽  
Vol 223 (5202) ◽  
pp. 213-213 ◽  
Author(s):  
M. J. STOCK
Keyword(s):  
Heat Increment Of Feeding ◽  
Heat Increment

scholarly journals Heat increment of feeding in Brunnich's guillemot

1997 ◽  
Vol 200 (12) ◽  
pp. 1757-1763 ◽  
Author(s):  
P Hawkins ◽  
P Butler ◽  
A Woakes ◽  
G Gabrielsen
Keyword(s):  
Oxygen Consumption ◽  
Energetic Cost ◽  
Uria Lomvia ◽  
Deep Body Temperature ◽  
Common Murre ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Rate Of Oxygen Consumption ◽  
Free Ranging ◽  
Persistent Elevation

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.

Hormonal factors in reduced postprandial heat production of exercise-trained subjects

1984 ◽  
Vol 56 (3) ◽  
pp. 772-776 ◽  
Author(s):  
J. LeBlanc ◽  
P. Diamond ◽  
J. Cote ◽  
A. Labrie
Keyword(s):  
Exercise Training ◽  
Heat Production ◽  
Human Subjects ◽  
Resting Metabolic Rate ◽  
Glucose Disposal ◽  
Plasma Norepinephrine ◽  
Trained Subjects ◽  
Enhanced Sensitivity ◽  
Heat Increment Of Feeding ◽  
Heat Increment

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.

Compensatory effect of the heat increment of feeding on thermoregulation costs of white-tailed deer fawns in winter

1999 ◽  
Vol 77 (9) ◽  
pp. 1474-1485 ◽  
Author(s):  
Paul G Jensen ◽  
Peter J Pekins ◽  
James B Holter
Keyword(s):  
Metabolic Rate ◽  
Heat Production ◽  
Resting Metabolic Rate ◽  
Energetic Cost ◽  
Critical Temperatures ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Minor Portion ◽  
A Minor

For northern white-tailed deer (Odocoileus virginianus) fawns, the energetic cost of thermoregulation (HcE) during severe winters can result in substantial catabolism of body-tissue reserves. The heat increment of feeding (HiE) has the potential to offset thermoregulatory energy expenditure that would otherwise require the catabolism of these reserves. During winters 1996 and 1997, we conducted 18 fasting and 18 on-feed heat-production trials using indirect respiration calorimetry in a metabolic chamber. Nonlinear regression analysis was used to estimate the lower critical temperatures (Tlc) and determine the fasting metabolic rate (FMR) and resting metabolic rate (RMR). Resulting models were used to calculate HiE, HcE, and percent substitution of HiE for HcE. For fawns fed a natural browse diet, estimated FMR and RMR were 352 and 490 kJ·kg body mass (BM)-0.75·d-1, respectively; this 40% increase in thermoneutral heat production reduced Tlc from -0.8 to -11.2°C between the fasted and fed states, respectively, and reduced HcE by 59% for fed fawns. For fawns fed a concentrate diet, estimated FMR and RMR were 377 and 573 kJ·kg BM-0.75·d-1, respectively. Level of browse intake had a significant effect on RMR andTlc. RMR was 12% higher for fawns on a high versus a low level of intake, and estimated Tlc was -15.6 and -5.8°C, respectively. Our data indicate that the energetic cost of thermoregulation is probably a minor portion of the energy budget of a healthy fawn consuming natural forage.

The heat increment of feeding and its thermoregulatory implications in the short-tailed shrew (Blarina brevicauda)

2003 ◽  
Vol 81 (8) ◽  
pp. 1445-1453 ◽  
Author(s):  
Allyson G Hindle ◽  
Ian W McIntyre ◽  
Kevin L Campbell ◽  
Robert A MacArthur
Keyword(s):  
Oxygen Consumption ◽  
Body Temperature ◽  
Nutritional Status ◽  
Blarina Brevicauda ◽  
Open Flow ◽  
Metabolic Chamber ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Rate Of Oxygen Consumption ◽  
Excretion Rates

The nature and potential thermoregulatory benefits of the heat increment of feeding (HIF) were investigated in short-tailed shrews (Blarina brevicauda). At thermoneutrality, the postprandial rate of oxygen consumption ([Formula: see text]O2) of shrews increased by an average of 18% beyond fasting levels for ca. 2 h following the consumption of 3.5 g of earthworms. Over the same period, body temperature increased by an average of 0.6 °C. The digesta-retention time calculated from nickel alloy tracer excretion rates (168.1 ± 11.4 min (mean ± SE); n = 7) exceeded the duration of HIF (117.5 ± 10.4 min; n = 6) by 43%. This finding suggests that the mechanical costs of feeding may be a relatively mi nor component of HIF in this species. Regression of resting [Formula: see text]O2 on ambient temperature (Ta) below thermo neutrality yielded similar slopes (P = 0.71) and intercepts (P = 0.33) for fed and fasted animals, suggesting that HIF substitutes, at least partially, for facultative thermogenesis at low Ta. We found no evidence that HIF enhanced microclimate warming of an insulated, open-flow metabolic chamber occupied by recently fed shrews. Occupancy of this chamber by shrews increased microclimate Ta from 5 to 9.0–9.5 °C regardless of their nutritional status.

Seasonal energy expenditures and thermoregulatory responses of moose

1986 ◽  
Vol 64 (2) ◽  
pp. 322-327 ◽  
Author(s):  
Lyle A. Renecker ◽  
Robert J. Hudson
Keyword(s):  
Body Weight ◽  
Early Summer ◽  
Metabolic Rates ◽  
Ambient Temperatures ◽  
Energy Expenditures ◽  
Respiration Rates ◽  
Thermoregulatory Responses ◽  
Heat Increment Of Feeding ◽  
Heat Increment ◽  
Resistance To Heat

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.

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