Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude II. Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes to the diurnal fluctuation in ambient temperature during the hottest part of the year

1960 ◽  
Vol 55 (3) ◽  
pp. 295-302 ◽  
Author(s):  
R. B. Symington
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Skin Surface ◽  
Diurnal Fluctuation ◽  
Body Temperatures ◽  
Solar Insolation ◽  
Air Temperatures ◽  
Insensible Perspiration ◽  
Artificial Heat

Responses in body, skin and coat temperatures, cardio-respiratory frequencies and rate of moisture secretion of ewes of three breeds to the diurnal fluctuation in ambient temperature were recorded in the presence and absence of drinking water during the hottest part of the Rhodesian year.1. At 7.0 a.m. body temperatures were: Merino 102·8° F.; Persian 102·2° F. and Native 101·5° F. Between 7·0 a.m. and 1·0 p.m. body temperature rose almost equally in Persians and Natives and fell slightly in Merinos. Change in body temperature between 7.0 a.m. and 1.0 p.m. was not affected significantly by availability of water nor age of ewe, but varied with type of thermal burden (i.e. solar insolation only v. solar insolation plus artificial heat) when water was not available. Although air temperature fell towards late afternoon body temperature of Merinos and Natives rose appreciably, that of Persians only slightly.2. At 7·0 a.m. respiratory rates were (cyc./min.): Merino 59·6; Persian 43·0; Native 29·9. Increase in rate of respiration was the main thermolytic mechanism in all breeds. Merinos had a lower threshold of respiratory response to rising ambient temperature than either hair breed but increase in rate of respiration between 7.0 a.m. and 1.0 p.m. did not differ significantly with breed or age.3. No breed appeared to use the peripheral blood system in thermoregulation. Cardio-frequency, as a measure of this blood flow, remained almost constant with a slight tendency to fall with rise in ambient temperature.4. In all breeds skin temperature was related to ambient and body temperatures; consequently the diurnal fluctuation in skin temperature differed in wool and hair breeds. When thermal burden was greatest Merino skin temperature fell, that of hair breeds did not.Except at 11.0 a.m. there was a gradient between rectal, skin and air temperatures. Direct elimination of heat was thus possible for 23 hr. each day.5. In hair breeds moisture secretion depended on insensible perspiration; consequently, rate of moisture secretion changed with body and air temperatures. In Merinos moisture for skin surface evaporation was provided by sensible and insensible perspiration. Natives may be able to sweat at temperatures higher than those recorded but it is unlikely Persians have a sweating mechanism.6. In all breeds coat temperature was related closely to ambient temperature and changes in solar conditions evoked immediate response in coat temperature. Merino fleece apparently stabilized skin temperature whereas Persian and Native hair did not.

Body temperature regulation and oxygen consumption in young chicks fed thyroid hormone

1991 ◽  
Vol 69 (7) ◽  
pp. 1842-1847 ◽  
Author(s):  
Gregory K. Snyder ◽  
Joseph R. Coelho ◽  
Dalan R. Jensen
Keyword(s):  
Oxygen Consumption ◽  
Thyroid Hormone ◽  
Body Temperature ◽  
Ambient Temperature ◽  
Cold Exposure ◽  
Elevated Serum ◽  
Body Temperatures ◽  
Serum Thyroid Hormone ◽  
Regulate Body Temperature ◽  
Young Chicks

In chicks the ability to regulate body temperature to adult levels develops during the first 2 weeks of life. We examined whether the ability of young chicks to regulate body temperature is increased by elevated levels of the thyroid hormone 3,3′5-triiodothyronine. By 13 days following hatch, body temperatures of chicks were not significantly different from those expected for adult birds. Furthermore, at an ambient temperature of 10 °C, 13-day-old control chicks were able to maintain body temperature, and elevated serum thyroid hormone levels did not increase rates of oxygen consumption or body temperature above control values. Six-day-old chicks had body temperatures that were significantly lower than those of the 13-day-old chicks and were not able to regulate body temperature when exposed to an ambient temperature of 10 °C. On the other hand, 6-day-old chicks with elevated serum thyroid hormone had significantly higher rates of oxygen consumption than 6-day-old control chicks, and were able to maintain constant body temperatures during cold exposure. The increased oxygen consumption rates and improved ability to regulate body temperature during cold exposure were correlated with increased citrate synthase activity in skeletal muscle. Our results support the argument that thyroid hormones play an important role in the development of thermoregulatory ability in neonate birds by stimulating enzyme activities associated with aerobic metabolism.

scholarly journals Body Temperatures in Some Australian Mammals II.Peramelidae

1962 ◽  
Vol 15 (2) ◽  
pp. 386 ◽  
Author(s):  
PR Morrison
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Active Phase ◽  
Temperature Measurements ◽  
Temperature Cycle ◽  
Body Temperatures ◽  
Ambient Temperatures ◽  
Diurnal Temperature

Body temperature measurements on the short-nosed bandicoot (Thylacis obeaulus) have shown a nocturnal cycle with a range of 1� 2�C and a short active phase at 2200-0400 hr. The bilby or rabbit bandicoot (Macrotis lagoti8) had a sharply defined temperature cycle, with a range of almost 3�C after several months of captivity, during which the day-time resting temperature was progressively lowered from 36� 4 to 34� 2�C. Forced activity raised the diurnal temperature substantially but not to the nocturnal level. Forced activity did not raise the nocturnal level which was similar in the two species (37' O�C). Both species could regulate effectively at an ambient temperature of 5�C, but only Thylaci8 showed regulation at ambient temperatures of between 30 and 40�C.

Effect of continuous cold exposure on nocturnal body temperatures of man

1959 ◽  
Vol 14 (1) ◽  
pp. 43-45 ◽  
Author(s):  
M. B. Kreider ◽  
P. F. Iampietro ◽  
E. R. Buskirk ◽  
David E. Bass
Keyword(s):  
Body Temperature ◽  
Cold Stress ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
Cold Exposure ◽  
Control Period ◽  
Cold Period ◽  
Body Temperatures ◽  
Temperature Responses

Effects of continuous cold stress on 24-hour patterns of body temperature were studied in five men. Cold stress consisted in living at 15.6℃ (60℉) for 14 days wearing only shorts. The cold period was preceded and followed by 2 weeks at 26.7℃ (80℉). Activity (minimal) and diet were the same for all periods. One blanket was used at night. Rectal temperature (Tr) and skin temperature (Ts) were measured. Tr during sleep fell more rapidly and to lower values during cold exposure (35.6℃) than during the control period (36.1℃). Ts during sleep was slightly lower in the cold than in the control period; also, Ts did not exhibit the gradual drop characteristic of sleep in the control period. Comparison of Tr and Ts between early and later cold days revealed the following differences: a) nocturnal Tr fell to lower levels on the later cold days; b) nocturnal toe temperatures were 15℃ (27℉) higher on the later cold days. The arch temperatures followed the same pattern as the toes. No significant differences were found in daytime temperatures between early and later cold days. The data suggest that evidence for acclimatization to cold in terms of altered body temperature responses may be fruitfully sought in responses during rewarming and/or sleep. Submitted on September 19, 1958

Studies on the adaptability of three breeds of sheep to a tropical environment modified by altitude IV. Role of the fleece in thermoregulation in German Merino ewes

1960 ◽  
Vol 55 (3) ◽  
pp. 311-315
Author(s):  
R. B. Symington
Keyword(s):  
Thermal Stress ◽  
Body Temperature ◽  
Respiratory Rate ◽  
Skin Temperature ◽  
Rectal Temperature ◽  
High Heat ◽  
Diurnal Fluctuation ◽  
Body Temperature Regulation ◽  
Southern Rhodesia

The influence of fleece on thermoregulation in German Merino ewes was investigated in Rhodesia. Comparative heat tolerances of Persian Blackhead, indigenous Native and shorn and unshorn Merino ewes were obtained during the hottest month of the year in Northern Rhodesia. The main thermolytic responses in unshorn, partially shorn and completely shorn Merino ewes were measured at 7.0 a.m.; 10.0 a.m.; 1.0 p.m. and 4.0 p.m. during April in Southern Rhodesia.1. Unshorn Merino ewes showed more and shorn Merino ewes less effective body temperature regulation than Persian or Native ewes. High heat tolerance in unshorn Merinos was due primarily to insulation by the fleece and not to more efficient physiological thermolysis than in hair breeds. No ewe showed signs of undue thermal stress and feed intake was not affected by heat.2. Increases in rectal temperature and respiratory rate between 7.0 a.m. and 1.0 p.m. of Merinos in Southern Rhodesia were related inversely to fleece length. Body temperature did not differ significantly at 1.0 p.m. owing to differential rates of increase in respiratory rate.3. Magnitude of the diurnal fluctuation in skin temperature was also related inversely to fleece length. Partially shorn ewes, however, began with and maintained highest skin temperature through the heat of the day. In all groups skin temperature fell after 10.0 a.m. although ambient temperature continued to rise. This fall could not be attributed to sweating since moisture secretion declined simultaneously.

Thermal homeostasis in rats after intrahypothalamic injections of 6-hyroxydopamine

1976 ◽  
Vol 230 (4) ◽  
pp. 932-939 ◽  
Author(s):  
JG Van Zoeren ◽  
EM Stricker
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Thermal Balance ◽  
Local Injection ◽  
Noradrenergic Neurons ◽  
Body Temperatures ◽  
Hypothalamic Region ◽  
Electrolytic Lesions ◽  
Noradrenergic Fibers ◽  
Effector Mechanisms

Specific destruction of at least 90% of the noradrenergic neurons in the preoptic/anterior hypothalamic region (PO/AH) by local injection of 9-hyroxydopamine (6-HDA) did not disrupt thermoregulation by rats either in the heat or the cold. Examination of the multiple effector mechanisms suggested that thermal balance was maintained in a normal fashion, and that compensatory adjustments did not conceal individual dysfunctions. In contrast with the ineffectual 6-HDA lesions of the PO/AH were the outstanding impairments seen in rats following electrolytic lesions of this area. All the latter animals became severely hyperthermic during the 1st h of exposure to an ambient temperature of 40 degrees C, and half of them were additionally unable to maintain body temperatures when exposed to an ambient temperature of 6 degrees C. The electrolytic lesions reduced norepinephrine levels in the PO/AH, but the 50-70% depletions were substantially smaller than those found in 6-HDA-treated rats. These results raise new doubts about whether central noradrenergic fibers have an important role in the regulation of body temperature by rats.

scholarly journals Heart rate reveals torpor at high body temperatures in lowland tropical free-tailed bats

2017 ◽  
Vol 4 (12) ◽  
pp. 171359 ◽  
Author(s):  
M. Teague O'Mara ◽  
Sebastian Rikker ◽  
Martin Wikelski ◽  
Andries Ter Maat ◽  
Henry S. Pollock ◽  
...  
Keyword(s):  
Heart Rate ◽  
Body Temperature ◽  
Metabolic Rate ◽  
Ambient Temperature ◽  
The Body ◽  
Metabolic Rates ◽  
Body Temperatures ◽  
Wide Range ◽  
Save Energy ◽  
Molossus Molossus

Reduction in metabolic rate and body temperature is a common strategy for small endotherms to save energy. The daily reduction in metabolic rate and heterothermy, or torpor, is particularly pronounced in regions with a large variation in daily ambient temperature. This applies most strongly in temperate bat species (order Chiroptera), but it is less clear how tropical bats save energy if ambient temperatures remain high. However, many subtropical and tropical species use some daily heterothermy on cool days. We recorded the heart rate and the body temperature of free-ranging Pallas' mastiff bats ( Molossus molossus ) in Gamboa, Panamá, and showed that these individuals have low field metabolic rates across a wide range of body temperatures that conform to high ambient temperature. Importantly, low metabolic rates in controlled respirometry trials were best predicted by heart rate, and not body temperature . Molossus molossus enter torpor-like states characterized by low metabolic rate and heart rates at body temperatures of 32°C, and thermoconform across a range of temperatures. Flexible metabolic strategies may be far more common in tropical endotherms than currently known.

scholarly journals Thermal biology of Amphisbaena munoai (Squamata: Amphisbaenidae)

2018 ◽  
Vol 35 ◽  
pp. 1-9 ◽  
Author(s):  
Nathalia Rocha Matias ◽  
Laura Verrastro
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Thermal Environment ◽  
Rio Grande ◽  
The Body ◽  
Rio Grande Do Sul ◽  
Body Temperatures ◽  
Physiological Mechanisms ◽  
Thermal Biology ◽  
The Relationship

Studies on the thermal biology of fossorial reptiles that examine the relationship between the body temperature and thermal environment are needed to determine the extent of their thermoregulation abilities. This study assessed the thermal biology of Amphisbaena munoai Klappenbach, 1969 in the rocky fields of the Rio Grande do Sul and in the laboratory. The body temperature of most individuals was between 24 and 30 °C, both in the field (n = 81) and laboratory (n = 19). More individuals were caught in winter (n = 55) and spring (n = 60) than in summer (n = 25) and fall (n = 45), and in spring, individuals showed similar nocturnal and diurnal activities. In the laboratory, we found individuals with body temperatures up to 5 °C higher than the ambient temperature (n = 4), suggesting that some physiological mechanisms participate in the thermoregulation of these animals. Amphisbaena munoai is a thigmothermic species that is capable of actively regulating its temperature by selecting microhabitats such that its various activities occur within an ideal temperature range. This study is the first to evaluate the effect of seasonality and diurnal and nocturnal variations on the thermoregulation of an amphisbaenid.

Differential effects of hypoxia on sleep of warm- and cold-acclimated rats

1987 ◽  
Vol 63 (6) ◽  
pp. 2189-2194 ◽  
Author(s):  
M. J. Pollard ◽  
D. Megirian ◽  
J. H. Sherrey
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Neural Mechanism ◽  
Body Temperatures ◽  
Deep Body Temperature ◽  
Neutral Temperature ◽  
State Changes ◽  
Different Levels ◽  
Deep Body ◽  
Maximum Minimum

We studied the effect of different levels of hypoxia (10, 12 or 13, 15, and 18% O2) on the sleep-waking pattern (SWP) and the maximum-minimum core temperature of warm-acclimated (WA) and cold-acclimated (CA) rats at their neutral temperature, 29 degrees C. Whereas the SWP of WA rats showed a trend toward increasing disruption as the degree of hypoxia increased, CA rats exhibited no such trend. The effect was chiefly on the frequency of state changes and less on epoch durations. The SWP of WA rats was more vulnerable to hypoxia than that of CA rats. Maximum and minimum body temperatures of WA and CA rats were not significantly affected by O2 lack down to 10% inspired O2. We conclude that in the rat 1) hypoxia primarily affects the neural mechanism that governs the frequency of changes in sleep-waking states; 2) the extent of alterations in SWP's depends on the ambient temperature to which the rats are acclimated; and 3) hypoxia does not significantly affect deep body temperature at the animal's neutral temperature.

Peripheral body temperature and thermogenic drinking in cold-treated rats

1975 ◽  
Vol 39 (6) ◽  
pp. 965-968 ◽  
Author(s):  
E. L. Nelson ◽  
M. J. Fregly ◽  
P. E. Tyler
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Skin Temperature ◽  
Water Intake ◽  
Abrupt Change ◽  
Rapid Change ◽  
Specific Pattern ◽  
Colonic Temperature ◽  
Peripheral Temperature

Transfer of rats abruptly from air at 5 degrees C to air at 26 degrees C was accompanied by a significant increase in water intake (thermogenic drinking) during the first hour after transfer. A possibility existed that the increased water intake observed under these conditions was attributable to the rapid change in skin temperature. Thus, the objective of this study was to determine the effect on thermogenic drinking of a slow, as opposed to an abrupt, change in ambient temperature. The results indicated that warming room air rates of either 0.5 or 1.0 centigrade deg/min had no effect on thermogenic drinking when compared with the water intake of rats removed abruptly from cold. Thermogenic drinking does not appear to be initiated by a specific pattern of changes in peripheral temperature relative to colonic temperature.

scholarly journals Behavioral adaptations in Ameivula ocellifera (Squamata: Teiidae) in response to thermal environmental changes

2019 ◽  
Vol 18 (2) ◽  
pp. 225-240
Author(s):  
Raul Fernandes Dantas Sales ◽  
Eliza Maria Xavier Freire
Keyword(s):  
Body Temperature ◽  
Rainy Season ◽  
Environmental Changes ◽  
Northeastern Brazil ◽  
Body Temperatures ◽  
Thermal Environments ◽  
Behavioral Adaptations ◽  
Air Temperatures ◽  
External Sources ◽  
Regulate Body Temperature

Behavioral adaptations in Ameivula ocellifera (Squamata: Teiidae) in response to thermal environmental changes. Lizards rely on external sources to regulate body temperature, but in many species, it is not known whether lizards are able to change their thermoregulatory behaviors in response to variations in thermal environments. The seasonal thermal ecology of three populations of the Brazilian whiptail lizard, Ameivula ocellifera, in northeastern Brazil (two Caatinga sites and one in the Atlantic Forest) was investigated. The relationships between body temperature and microhabitat temperatures (substrate and air), and between body temperature and thermoregulatory behavior (i.e., time of exposure to sunlight classes and time spent basking) were explored. The average body temperatures of the lizards were 38–39°C; these neither varied seasonally nor among populations. Substrate and air temperatures are lower at the natural Caatinga site, and lizards in there spent less time in the shade and more time exposed to the sun. Microhabitat temperatures vary seasonally in natural Caatinga; they are lower in the rainy season, when lizards spent more time exposed to sun and less time in fltered sun. Lizard body temperatures exceeded microhabitat temperatures in the rainy season in all three populations; however, they did not exceed substrate temperature in the dry season. In each of the populations, lizards with low body temperatures during cloudy conditions spent more time basking. Thus, A. ocellifera adjusts its body temperature behaviorally to compensate for seasonal changes in environmental temperatures, as well as geographic thermal variation throughout its range.

Sign in / Sign up

Export Citation Format

Share Document