The significance of the coat in heat tolerance of cattle. II. Effect of solar radiation on body temperatures

1960 ◽  
Vol 11 (5) ◽  
pp. 871 ◽  
Author(s):  
DF Dowling

An experiment was performed to test the effect of solar radiation on the body temperatures of cattle, both clipped and with hair coat, in a clear transparent plastic covering as compared with cattle in a white reflective plastic covering. The mean body temperature of the animals in white plastic coats was 0.15°F lower than that of animals in clear plastic coats. This difference was highly significant statistically (P< 0.001). Animals in both clear and white coats had higher body temperatures than controls without plastic coats. The difference was highly significant, and was about 1.5°F in the clipped animals.

1984 ◽  
Vol 5 (1) ◽  
pp. 37-41 ◽  
Author(s):  
David Stubbs ◽  
Adrian Hailey ◽  
Elizabeth Pulford

AbstractThe mean body temperature of T. hermanni in woodland in France was 28.5 °C (August 1981). Body temperatures were elevated above air temperature and indirect evidence for basking and selection of an optimal microenvironment is discussed.


PLoS ONE ◽  
2021 ◽  
Vol 16 (1) ◽  
pp. e0244458
Author(s):  
Sarah Hews ◽  
Zahkeyah Allen ◽  
Adrienne Baxter ◽  
Jacquline Rich ◽  
Zahida Sheikh ◽  
...  

Behavioral thermoregulation is an important defense against the negative impacts of climate change for ectotherms. In this study we examined the use of burrows by a common intertidal crab, Minuca pugnax, to control body temperature. To understand how body temperatures respond to changes in the surface temperature and explore how efficiently crabs exploit the cooling potential of burrows to thermoregulate, we measured body, surface, and burrow temperatures during low tide on Sapelo Island, GA in March, May, August, and September of 2019. We found that an increase in 1°C in the surface temperature led to a 0.70-0.71°C increase in body temperature for females and an increase in 0.75-0.77°C in body temperature for males. Body temperatures of small females were 0.3°C warmer than large females for the same surface temperature. Female crabs used burrows more efficiently for thermoregulation compared to the males. Specifically, an increase of 1°C in the cooling capacity (the difference between the burrow temperature and the surface temperature) led to an increase of 0.42-0.50°C for females and 0.34-0.35°C for males in the thermoregulation capacity (the difference between body temperature and surface temperature). The body temperature that crabs began to use burrows to thermoregulate was estimated to be around 24°C, which is far below the critical body temperatures that could lead to death. Many crabs experience body temperatures of 24°C early in the reproductive season, several months before the hottest days of the year. Because the use of burrows involves fitness trade-offs, these results suggest that warming temperatures could begin to impact crabs far earlier in the year than expected.


1975 ◽  
Vol 39 (2) ◽  
pp. 226-230 ◽  
Author(s):  
J. Timbal ◽  
J. Colin ◽  
C. Boutelier

Sweat rates and body temperatures of human subjects were measured at 0200, 1000, and 1800 h during a heat exposure of 90 min. The latent period of sweating was not significantly altered in the evening but significantly shortened during the night. Mean body temperature corresponding to the onset of sweating was nearer to the basal body temperature during the night, while during the day the difference between these two temperatures became larger. This phenomenon seems related to the circadian cycle of vasomotor adjustment, since during the night body conductance was higher than during the day and corresponded to a state of a vasodilatation similar to that observed at the onset of sweating. During the day, this situation was reversed. During steady state, the following changes were observed: sweating rate, night less than morning less than evening; skin temperatures, night less than morning less than evening; and rectal temperature increase, morning less than evening less than night. It is hypothesized that these changes are due to either different metabolic rates or an imbalance between heat gains and losses which preserve the circadian rhythm of the body temperature, even under thermal loads.


1958 ◽  
Vol 193 (3) ◽  
pp. 539-540 ◽  
Author(s):  
A. H. Hamdy ◽  
C. R. Weaver

The body temperatures of 37 Merino and Shropshire lambs were recorded for the first 100 days of life. Mean temperature of Merino lambs was found to be 102.8°F with a range of 100.2°– 104.0°F while the mean temperature of Shropshire lambs was 102.7°F with a range of 101.2°–104.4°F. There was no relation between the internal and atmospheric temperatures. Again, the correlation between the body and atmospheric temperatures within limited age groups was not statistically significant. The temperature of older lambs was less variable than that of younger lambs.


1968 ◽  
Vol 71 (1) ◽  
pp. 61-66 ◽  
Author(s):  
M. E. D. Webster ◽  
K. G. Johnson

SummarySkin temperatures, deep body temperatures and respiratory rates have been measured in Southdown and Merino sheep following feeding, and during infra-red irradiation, rumen infusions of hot and cold water, and cold exposure induced by shearing. The increases in respiratory rate and skin temperatures induced by infra-red heating and the heat increment of feeding were reversed by addition of iced water to the rumen and were suppressed by shearing. These responses could not be systematically related to particular body temperatures in the sheep and appeared to be continuously variable rather than ‘all-or-none’ phenomena. Considerable overlap was observed between respiratory and vasomotor mechanisms of thermoregulation. Measurements of the surface area and weight of ears and legs showed that these regions contribute approximately 23% of the surface area and 8% of the body weight in Merino sheep. Calculations suggested that up to 70% of the additional heat produced in the 2 h after feeding in sheep may be stored in the tissues through increase in mean body temperature. Sheep kept in short wool throughout the winter appeared to establish a new thermoregulatory ‘set-point’ associated with lower rectal temperatures than those in sheep with a full fleece.


1987 ◽  
Vol 8 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Benoit Heulin

AbstractMean body temperature (TC) of Lacerta vivpara ranges from 26°8 to 32° at Paimpont (France). There is a highly significant correlation between environmental temperatures (TS) and body temperatures (TC). The mean body temperature of pregnant females is lower than that of males and non-pregnant females. Also, the regression line TC = f(TS) calculated for pregnant females is different from those calculated for males and non-pregnant females. The possible relations between pregnancy and body temperature are discussed.


2018 ◽  
Vol 66 (4) ◽  
pp. 235 ◽  
Author(s):  
Luh P. E. K. Yuni ◽  
Susan M. Jones ◽  
Erik Wapstra

Body temperatures in ectotherms are strongly affected by their thermal environment. Ectotherms respond to variation in the thermal environment either by modification of behavioural thermoregulation to maintain their optimal body temperature or by shifting their optimal body temperature. In this study, the body temperatures of males of three populations of spotted snow skinks, Niveoscincus ocellatus, living along an altitudinal gradient (low, mid, and high altitude) were studied in the field and laboratory in spring, summer, and autumn, representing the full activity period of this species. The environmental variation across both sites and seasons affected their field active body temperatures. At the low and mid altitude, N. ocellatus had a higher mean body temperature than at the high altitude. Animals achieved their thermal preference at the low and mid altitude sites in all seasons. At the high altitude, however, N. ocellatus struggled to reach its preferred body temperatures, especially in autumn. The lower body temperature at the high-altitude site is likely due to limited thermal opportunity and/or an effect of avoiding the costs associated with increased intensity of basking.


1993 ◽  
Vol 71 (11) ◽  
pp. 2152-2155 ◽  
Author(s):  
Geoffrey R. Smith ◽  
Royce E. Ballinger ◽  
Justin D. Congdon

The thermal ecology of a high-altitude lizard, Sceloporus scalaris, was investigated in the Chiricahua Mountains of southeastern Arizona, where the lizards are active on sunny days throughout the year. Mean body temperature was 32.6 °C (range 12.6–39 °C) and mean air temperature was 20.2 °C (range 5.2–36.4 °C). The slope of the body temperature versus air temperature regression was 0.23. Monthly differences in body temperature were observed, with the highest body temperatures observed in early summer. Lizards at three study sites with differing slope and vegetative cover had different mean body temperatures. Males had higher body temperatures than both nongravid and gravid females. Maintenance of elevated body temperatures even during winter lengthens the activity and growing season, permitting early maturity with potentially important life-history consequences.


1956 ◽  
Vol 33 (2) ◽  
pp. 348-357
Author(s):  
C. R. AUSTIN

The chilling of rats to body temperatures down to 4-7° C. before and during the time of ovulation had little effect upon the subsequent penetration of the eggs by spermatozoa. With a hypothermia of 0-1° C, however, there was almost complete and apparently permanent inhibition of spermatozoon entry. There seemed to be no reason to ascribe this effect to direct influence of cold on eggs or spermatozoa. Probably the failure of penetration arose largely from delay of ovulation, coupled perhaps with some derangement of the tubal environment. Hypothermia after ovulation but before and during the time of spermatozoon entry into the eggs temporarily but completely inhibited penetration when the body temperature was kept below 33° C. The likely explanation appears to be that ‘capacitation’ is prevented or greatly slowed by such temperatures. Hyperthermia, induced before and during the time of ovulation, somewhat reduced the mean number of eggs ovulated (from 10.5 to 7.5) and the proportion penetrated by spermatozoa (from 97 to 66%). The proportion of eggs penetrated by two or more spermatozoa was increased (from 19 to 28%), but the frequency of polyspermic fertilization did not change significantly. Hyperthermia after ovulation but before and during the time of spermatozoon entry also led to a greater proportion of eggs containing two or more spermatozoa (31%), but in addition it increased the incidence of polyspermy (from 2.5 to21.2%). Larger rats (170-200 g.) subjected to hyperthermia showed a higher frequency of polyspermy (34%) than smaller rats (100-130 g.; 13% polyspermy). Evidently the processes involved in the ‘zona reaction’ are reduced in efficiency by hyperthermia whether applied before or after ovulation. On the other hand, the block to polyspermy depends on processes that are much more sensitive to heat after ovulation. It is considered that the slowing down of the block to polyspermy is associated with ageing of the egg, that the ageing is accelerated by hyperthermia and that this effect is promoted in older rats.


2020 ◽  
Author(s):  
Sarah Hews ◽  
Zahkeyah Allen ◽  
Adrienne Baxter ◽  
Jacquline Rich ◽  
Zahida Sheik ◽  
...  

AbstractBehavioral thermoregulation is an important defense against the negative impacts of climate change for ectotherms. In this study we examined the use of burrows by a common intertidal crab, Minuca pugnax, to control body temperature. To understand how body temperatures respond to changes in the surface temperature and explore how efficiently crabs exploit the cooling potential of burrows to thermoregulate, we measured body, surface, and burrow temperature data during low tide on Sapelo Island, GA in March, May, August, and September of 2019. We found that an increase in 1°C in the surface temperature led to a 0.70-0.71°C increase in body temperature for females and an increase in 0.75-0.77°C in body temperature for males. Body temperatures of small females were 0.3°C warmer than large females for the same surface temperature. Female crabs used burrows more efficiently for thermoregulation compared to the males. Specifically, an increase of 1°C in the cooling capacity (the difference between the burrow temperature and the surface temperature) led to an increase of 0.42-0.50°C for females and 0.34-0.35°C for males in the thermoregulation capacity (the difference between body temperature and surface temperature). The body temperature that crabs began to use burrows to thermoregulate was estimated to be around 24°C, which is far below the critical body temperatures that could lead to death. Many crabs experience body temperatures of 24°C early in the reproductive season, several months before the hottest days of the year. Because the use of burrows involves fitness trade-offs, these results suggest that warming temperatures could begin to impact crabs far earlier in the year than expected.


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