THE EFFECT OF AGE, AMBIENT TEMPERATURE, HYPOXIA AND HYPERCAPNIA ON THE BODY TEMPERATURE AND THERMOREGULATORY HEAT PRODUCTION IN THE GUINEA PIG

Author(s):  
MARIA FARKAS
1965 ◽  
Vol 20 (3) ◽  
pp. 405-410 ◽  
Author(s):  
Hermann Pohl

Characteristics of cold acclimation in the golden hamster, Mesocricetus auratus, were 1) higher metabolic rate at -30 C, 2) less shivering when related to ambient temperature or oxygen consumption, and 3) higher differences in body temperature between cardiac area and thoracic subcutaneous tissues at all ambient temperatures tested, indicating changes in tissue insulation. Cold-acclimated hamsters also showed a rise in temperature of the cardiac area when ambient temperature was below 15 C. Changes in heat distribution in cold-acclimated hamsters suggest higher blood flow and heat production in the thoracic part of the body in the cold. The thermal conductance through the thoracic and lumbar muscle areas, however, did not change notably with lowering ambient temperature. Marked differences in thermoregulatory response to cold after cold acclimation were found between two species, the golden hamster and the thirteen-lined ground squirrel, showing greater ability to regulate body temperature in the cold in hamsters. hibernator; oxygen consumption— heat production; body temperature — heat conductance; muscular activity — shivering; thermoregulation Submitted on July 6, 1964


In mammalian hibernation, the body temperature approaches that of the surroundings, allowing large savings in energy costs of basal metabolism and eliminating the need for heat production to compensate for heat loss. During entry into hibernation, heat production ceases while the body temperature set-point gradually decreases during slow-wave sleep. In the hibernating phase, the animal copes with problems concerning the maintenance of ion gradients, possible membrane phase transitions and the risk of ventricular fibrillation. In the arousal phase, the main part of the heat and practically all the necessary substrate comes from brown adipose tissue. The hibernation season is preceded by a preparatory phase. It may be concluded that hibernation is a practical, and perhaps even enviable, solution to a mammalian problem.


2018 ◽  
Vol 96 (suppl_3) ◽  
pp. 295-296
Author(s):  
A Morales Trejo ◽  
D Antoine ◽  
A Valle-Fimbres ◽  
H Bernal Barragán ◽  
L Camacho ◽  
...  

2020 ◽  
Vol 98 (Supplement_4) ◽  
pp. 192-193
Author(s):  
Sheyenne M Augenstein ◽  
Meredith A Harrison ◽  
Sarah C Klopatek ◽  
James W Oltjen

Abstract Heat stress continues to be a challenge for feedlot producers, forcing physiological adaptations in beef cattle that can have a negative impact on gain and carcass quality. Feedlots may want to incorporate systems that aid in mitigating heat stress, including sprinkler systems, which are commonly found on dairies. The objective of this study was to determine the impact of sprinkler systems on the body temperature of growing feedlot steers applied at three different temperature thresholds. Thirty-two Angus-cross beef steers (298 ± 15 SD days of age) were randomly assigned to 8 pens. Treatments were assigned to pens according to location to avoid drainage issues, with one replicate located on the eastern side of the feedlot and the other replicate located on the western side. Treatments including no sprinklers (C), high temperature threshold sprinklers (HT), moderate temperature threshold sprinklers (MT) or low temperature threshold sprinklers (LT). Sprinklers (flow rate: 5.11 L/min) were activated at 33°C (HT), 28°C (MT), and 23°C (LT) for five minutes at corresponding temperatures every thirty minutes for 57 days. Rectal temperature of steers in their pens was measured in the morning (0800 h), afternoon (1500 h), and evening (1900 h) three days each week (Monday, Wednesday, Friday) for a total of 19 experimental days. Weather measurements, including ambient temperature, windspeed, humidity and solar radiation were recorded at each measurement time along with the maximum values for each day. The change in body temperature (ΔBT) between the morning and afternoon was affected by ambient temperature (P < 0.01); MT (P = 0.02) and LT (P = 0.02) – different than C. There was no significant difference between sprinkler treatments and the control group (P > 0.05). Day affected (ΔBT) between the morning and afternoon (P < 0.05) and the afternoon and evening (P < 0.05). When averaged by day, the control group was significantly higher than MT (P = 0.04) between the morning and afternoon. The control group was also significantly higher than LT between the morning and afternoon (P = 0.03) and the afternoon and evening (P < 0.01). The change in steer body temperature between afternoon and morning was affected by ambient temperature, and averaged across days, lowering the temperature threshold for sprinkling decreased in the afternoon and evening body temperature increase in steers.


2017 ◽  
Vol 4 (12) ◽  
pp. 171359 ◽  
Author(s):  
M. Teague O'Mara ◽  
Sebastian Rikker ◽  
Martin Wikelski ◽  
Andries Ter Maat ◽  
Henry S. Pollock ◽  
...  

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.


2012 ◽  
Vol 90 (1) ◽  
pp. 79-84 ◽  
Author(s):  
Feng Yue ◽  
Xiao-Long Tang ◽  
De-Jiu Zhang ◽  
Xue-Feng Yan ◽  
Ying Xin ◽  
...  

The body temperature (Tb) and standard metabolic rate (SMR) of female Eremias multiocellata Günther, 1872, a viviparous lizard, were measured at 25, 30, and 35 °C during pregnancy and after parturition to assess energy requirement of reproduction. The results showed that the Tbs of female lizards were slightly higher than actual ambient temperature in the 25 and 30 °C groups, while they were slightly lower than ambient temperature in the 35 °C group. Ambient temperature significantly affected SMR and gestation period of females. Energy requirement was constant in nonpregnant females, whereas it was increased in pregnant females. The maximal estimates of maintenance costs of pregnancy (MCP) were 4.219, 4.220, and 4.448 mg CO2·min–1, which accounted for 19.40%, 14.15%, and 12.32% of the total metabolic rate in the 25, 30, and 35 °C group, respectively. The results indicated the MCP was an important component of total energy cost for the lizard E. multiocellata and the MCP in this lizard incurs a relative fixed energetic cost irrespective of ambient temperature.


2021 ◽  
Vol 43 ◽  
pp. 153-159
Author(s):  
Emma Quirosa

La biología térmica es uno de los aspectos más necesarios para entender la distribución y los patrones de actividad de las especies, sobretodo de los organismos ectotermos. El presente estudio aporta información sobre temperatura corporal de seis ofidios ibéricos y temperatura ambiental para el lugar donde habitan. Para tres de las especies, Coronella girondica (Daudin 1803), Macroprotodon brevis (Günter 1862) y Hemorrhois hip­pocrepis (Linnaeus 1758), estos son los primeros datos publicados en España. En el caso de Natrix maura (Linnaeus 1758) los datos de este estudio incluyen temperatura tanto en medio acuático como en medio terrestre. En total se han obtenido 31 registros de temperatura corporal y 30 registros de temperatura ambiente. También se aportan datos sobre temperatura corporal y ambiental de Malpolon monspessulanus (Hermann 1804) y Zamenis scalaris (Schinz 1822). Thermal biology is one of the most necessary aspects in understanding the distribution and activity patterns of species, above all of ectothermal organisms. The present study provides data on body temperature of six Iberian ophidians and the environmental temperature of the place they inhabit. For three species, southern smooth snake Coronella girondica (Daudin 1803), western false smooth snake Macroprotodon brevis (Günter 1862), and horse-shoe snake Hemorrhois hippocrepis (Linnaeus 1758), these are the first data published in Spain. In the case of Natrix maura (Linnaeus 1758), the present data include its temperature on land as well as in aquatic environments. In total, 31 body temperature records and 30 ambient temperature records were obtained. Additionally, data is given on body and environmental temperature for the ophidian species Malpolon monspessulanus (Hermann 1804) and Zamenis scalaris (Schinz 1822).


2018 ◽  
Vol 35 ◽  
pp. 1-9 ◽  
Author(s):  
Nathalia Rocha Matias ◽  
Laura Verrastro

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.


Sign in / Sign up

Export Citation Format

Share Document