Respiratory evaporation in panting fowl: Partition between the respiratory and buccopharyngeal pumps

1981 ◽  
Vol 145 (1) ◽  
pp. 63-66 ◽  
Author(s):  
John Brackenbury ◽  
Peter Avery ◽  
Michael Gleeson
Keyword(s):  
Respiratory Evaporation

Respiration in exercising fowl. II. Respiratory water loss and heat balance

1981 ◽  
Vol 93 (1) ◽  
pp. 327-332
Author(s):  
J. H. Brackenbury ◽  
M. Gleeson ◽  
P. Avery
Keyword(s):  
Rectal Temperature ◽  
Water Loss ◽  
Heat Balance ◽  
Domestic Fowl ◽  
Metabolic Energy ◽  
Air Temperatures ◽  
Respiratory Heat Loss ◽  
All Speeds ◽  
Body Heat ◽  
Respiratory Evaporation

1. Respiratory water loss and rectal temperature were measured in domestic fowl running for 10 min on a treadmill at speeds of 1.24-4.3 km h-1 in air temperatures of 20 +/− 2 degrees C or 32 +/− 2 degrees C. 2. At given speeds the water loss at 32 +/− 2 degrees C was approximately twice that at 20 +/− 2 degrees C and the end-exercise rectal temperature was 0.5-0.8 degrees C higher. 3. At 20 +/− 2 degrees C, respiratory evaporation accounted for 10–12% of the total metabolic energy used at all speeds. At 32 +/− 2 degrees C, the fractional respiratory heat loss fell from 26.5% at 1.24 km h-1 to 17% at 3.6 km h-1. The fraction of the total metabolic energy stored as body heat rose progressively with air temperature.

Oxygen Consumption and Respiratory Evaporation of the Emu and Rhea

The Condor ◽  
1968 ◽  
Vol 70 (4) ◽  
pp. 333-339 ◽  
Author(s):  
Eugene C. Crawford, ◽  
Robert C. Lasiewski
Keyword(s):  
Oxygen Consumption ◽  
Respiratory Evaporation

RESPIRATORY EVAPORATION IN BIRDS

1964 ◽  
Vol 39 (1) ◽  
pp. 113-136 ◽  
Author(s):  
GEORGE WILLIAM SALT
Keyword(s):  
Respiratory Evaporation

Temperature regulation in the new-born lamb. VI. Heat exchanges in lambs in a hot environment

1962 ◽  
Vol 13 (1) ◽  
pp. 122 ◽  
Author(s):  
G Alexander ◽  
D Williams
Keyword(s):  
Water Loss ◽  
Good Evidence ◽  
Sweat Glands ◽  
Second Phase ◽  
Ambient Temperatures ◽  
Respiratory Loss ◽  
Air Temperatures ◽  
Cutaneous Evaporation ◽  
Heat Exchanges ◽  
Respiratory Evaporation

At ambient temperatures below about 30°C, respiratory and cutaneous evaporation were constant in normal lambs and lambs without sweat glands. Above 30°C, respiratory water loss increased steeply. Cutaneous water loss also increased, but at a slower rate than respiratory loss and only in the lambs with sweat glands. The efficiency of evaporation in cooling the lamb was close to 100%. The contribution of cutaneous blood flow to facilitation of heat loss in lambs lying down appeared to be low. At low environmental humidity, respiratory evaporation at all rates of normal shallow panting was approximately 4 mg per respiration; but in "second phase" breathing this was increased up to 12 mg per respiration, and total respiratory evaporation was not reduced. Lambs showed no evidence of distress when exposed for 6–12 hr to air temperatures of 40°C and water vapour pressures of' less than I5 mm Hg. Cutaneous loss tended to fall and respiratory loss to increase. Maximum rates of cutaneous and respiratory evaporation were estimated by suppressing evaporation from the skin or respiratory tract at 43°C. These values tended to be higher in crossbred lambs then in Merinos, and Merinos tended to reach maximum "sweating" rates under less severe heat stress than the crossbreds. Homeothermic equilibrium was approached when evaporation from neither site was suppressed, but rectal temperatures increased rapidly when cutaneous evaporation was prevented, and more rapidly still when respiratory evaporation was much reduced. The results also illustrate how a high metabolic rate decreases heat tolerance. These experiments provide good evidence that sheep do sweat, but that respiratory evaporation is quantitatively more important than sweating.

Mass, temperature and metabolic effects on discontinuous gas exchange cycles in eucalyptus-boring beetles (Coleoptera: cerambycidae)

2000 ◽  
Vol 203 (24) ◽  
pp. 3809-3820 ◽  
Author(s):  
M.A. Chappell ◽  
G.L. Rogowitz
Keyword(s):  
Gas Exchange ◽  
Water Conservation ◽  
Life Stage ◽  
Resting Metabolic Rate ◽  
Metabolic Effects ◽  
Cycle Frequency ◽  
Ambient Temperatures ◽  
Terrestrial Arthropods ◽  
Frequency Changes ◽  
Respiratory Evaporation

Ventilatory accommodation of changing metabolic rates is a relatively little-studied aspect of the discontinuous gas exchange cycles (DGCs) that occur in a wide variety of terrestrial arthropods. We used correlation analysis of resting metabolic rate (RMR, measured as the rate of CO(2) emission; V(CO2)) and several components of the DGC to examine accommodation to both temperature-induced changes and individual variation in RMR in two wood-boring beetles (Phorocantha recurva and P. semipunctata; Coleoptera: Cerambycidae).At low to moderate ambient temperatures (T(a); 10–20 degrees C), Phorocantha spp. displayed a characteristic DGC with relatively brief but pronounced open (O) phase bursts of CO(2) emission separated by longer periods of low V(CO2), the flutter (F) phase. However, the V(CO2) never fell to zero, and we could not reliably differentiate a typical closed (C) phase from the F phase. Accordingly, we pooled the C and F phases for analysis as the C+F phase. At higher T(a) (30 degrees C), the duration of the combined C+F phase was greatly reduced. There were no differences between the two species or between males and females in either RMR or characteristics of the DGC. We found large variation in the major DGC components (cycle frequency, durations and emission volumes of the O and C+F phases); much of this variation was significantly repeatable. Accommodation of temperature-induced RMR changes was almost entirely due to changes in frequency (primarily in the C+F phase), as has been found in several other discontinuously ventilating arthropods. Frequency changes also contributed to accommodation at constant T(a), but modulation of emission volumes (during both O and C+F phases) played a larger role in this case.The DGC is often viewed as a water conservation mechanism, on the basis that respiratory evaporation is minimal during the C and F phases. This hypothesis assumes that the F phase is primarily convective (because of a reduction in tracheal P(O2) and total intratracheal pressure during the C phase). To test this, we measured the DGC in beetles subjected to varying degrees of hypoxia in addition to normoxia. As predicted for a largely diffusive F phase, we found an increase in the volume of CO(2) emitted during the C+F phase in hypoxic conditions (10.4 % oxygen). This finding, together with a reduced tendency to utilize a DGC at high T(a) (when water stress is greatest) and a natural history in which water availability is probably not limiting for any life stage, suggests that a reduction of respiratory evaporation may not have been critical in the evolution of the DGC of Phorocantha spp. Instead, selection may have favored discontinuous ventilation because it facilitates gas exchange in the hypercapnic and hypoxic environments commonly encountered by animals (such as Phorocantha spp.) that live in confined spaces.

Temperature Regulation and Heat Balance in Flying White-necked Ravens, Corvus Cryptoleucus

1981 ◽  
Vol 90 (1) ◽  
pp. 267-281 ◽  
Author(s):  
DENNIS M. HUDSON ◽  
MARVIN H. BERNSTEIN
Keyword(s):  
Steady State ◽  
Body Temperature ◽  
Wind Tunnel ◽  
Body Surface ◽  
Heat Balance ◽  
Metabolic Heat ◽  
Steady State Levels ◽  
Cutaneous Evaporation ◽  
Body Heat ◽  
Respiratory Evaporation

During level flight at 10 m.s−1 in a wind tunnel, white-necked ravens (Corvus cryptoleucus, mass 0·48 kg) exhibited an increase in body temperature to steady-state levels as high as 45°C, exceeding resting levels by nearly 3°C. This reflects the storage of up to half of the metabolic heat produced (Hp) during 5 min of flight. During steady-state flight, body heat was dissipated in part by respiratory evaporation and convection (13–40% of Hp) evoked by increases in ventilation proportional to body temperature. Remaining heat was lost by cutaneous evaporation (10% of Hp) as well as by radiation and convection from the external body surface. The results suggest strategies that might be used by ravens during flight under desert conditions.

The thermoregulatory mechanism of melatonin-induced hypothermia in chicken

1998 ◽  
Vol 274 (1) ◽  
pp. R232-R236 ◽  
Author(s):  
I. Rozenboim ◽  
L. Miara ◽  
D. Wolfenson
Keyword(s):  
Blood Pressure ◽  
Heart Rate ◽  
Heat Stress ◽  
Body Temperature ◽  
Heat Losses ◽  
Induced Hypothermia ◽  
White Leghorn ◽  
Evaporative Water ◽  
Dose Dependent ◽  
Respiratory Evaporation

The involvement of melatonin (Mel) in body temperature (Tb) regulation was studied in White Leghorn layers. In experiment 1, 35 hens were injected intraperitoneally with seven doses of Mel (0, 5, 10, 20, 40, 80, or 160 mg Mel/kg body wt) dissolved in ethanol. Within 1 h, Mel had caused a dose-dependent reduction in Tb. To eliminate a possible vehicle effect, 0, 80, and 160 mg/kg body wt Mel dissolved in N-methyl-2-pyrrolidone (NMP) was injected. NMP had no effect on Tb, with Mel again causing a dose-dependent hypothermia. In experiment 2 ( n= 30), Mel injected before exposure of layers to heat reduced Tb and prevented heat-induced hyperthermia. Injection after heat stress had begun did not prevent hyperthermia. Under cold stress, Mel induced hypothermia, which was not observed in controls. In experiment 3 ( n= 12), Mel injection reduced Tband increased metatarsal and comb temperatures (but not feathered-skin temperature), respiratory rate, and evaporative water loss. Heart rate rose and then declined, and blood pressure increased 1 h after Mel injection. Heat production rose slightly during the first hour, then decreased in parallel to the Tbdecline. We conclude that pharmacological doses of Mel induce hypothermia in hens by increasing nonevaporative skin heat losses and slightly increasing respiratory evaporation.

Sweating in cattle. I. Cutaneous evaporative losses in calves and its relationship with respiratory evaporative loss and skin and rectal temperatures

1958 ◽  
Vol 50 (1) ◽  
pp. 73-81 ◽  
Author(s):  
G. C. Taneja
Keyword(s):  
Skin Temperature ◽  
Air Temperature ◽  
Water Loss ◽  
The Other ◽  
Sweat Glands ◽  
Water Losses ◽  
Evaporative Loss ◽  
Cutaneous Evaporation ◽  
The University ◽  
Respiratory Evaporation

Three calves (Australian Illawara Shorthorn, Shorthorn and Zebu × Australian Illawara Shorthorn) were exposed to different combinations of wet- and dry-bulb temperatures in a psychrometric chamber at the Physiology Department of the University of Queensland. These animals were 2–3 months old when first exposed to heat.Measurements were made on these animals for cutaneous and respiratory water losses, and skin and rectal temperatures.Cutaneous water losses in all the animals studied increased with increases in air temperature. Comparing these results with those on men with congenital absence of sweat glands exposed to high air temperature below the sweat point, suggests that the cutaneous evaporative losses in cattle are more than those that can be accounted for by diffusionmoisture alone.Increase in cutaneous evaporation under hot conditions is accompanied by increase in skin and rectal temperatures. In the Zebu cross, however, the skin temperature did not rise with rise in air temperature.Keeping the humidity constant, rise in dry-bulb temperature caused increase in respiratory water loss. On the other hand, rising humidity at a constant dry-bulb temperature resulted in decrease in respiratory evaporation. Respiratory evaporative loss was, therefore, greater in hot-dry than in hot-wet conditions.

Sign in / Sign up

Export Citation Format

Share Document