Seasonal and diurnal variations in body temperatures of Hereford and Brahman cross cattle in a cool temperate environment

Kendall (1948) suggested that the ability of cattle to thrive in tropical regions could be better indicated by the diurnal variation in body temperature rather than actual body temperature. However, Bligh & Lampkin (1965) found little difference in the nychthemeral variation in deep-body temperature of East African Zebus and Herefords grazing under conditions where the atmospheric shade temperature varied from 71 to 40 °F.

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

Journal of Applied Physiology ◽

10.1152/jappl.1987.63.6.2189 ◽

1987 ◽

Vol 63 (6) ◽

pp. 2189-2194 ◽

Cited By ~ 4

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.

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A comparison of the deep-body temperature of Hereford and zebu cows recorded continuously by radio-telemetry under similar field conditions

The Journal of Agricultural Science ◽

10.1017/s0021859600064790 ◽

1965 ◽

Vol 64 (2) ◽

pp. 221-227 ◽

Cited By ~ 8

Author(s):

J. Bligh ◽

G. H. Lampkin

Keyword(s):

Body Temperature ◽

Radio Telemetry ◽

Field Conditions ◽

Muscular Tissue ◽

East African ◽

Deep Body Temperature ◽

Probe Technique ◽

Telemetric System ◽

Deep Body ◽

Zebu Cows

1. A radio-telemetric system linked to a thermistor- probe embedded in deep muscular tissue has been used to record continuously variations in deep-body temperature during 46–66 hr. in three Hereford (temperate) and three East African zebu (tropical) cows under similar temperate field conditions.2. The limitations of the ‘probe’ technique for measuring deep-body temperature are discussed.

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Induced hyperthermia in sedated humans and the concept of critical thermal maximum

AJP Regulatory Integrative and Comparative Physiology ◽

10.1152/ajpregu.1978.235.5.r228 ◽

1978 ◽

Vol 235 (5) ◽

pp. R228-R236 ◽

Cited By ~ 24

Author(s):

G. D. Bynum ◽

K. B. Pandolf ◽

W. H. Schuette ◽

R. F. Goldman ◽

D. E. Lees ◽

...

Keyword(s):

Body Temperature ◽

Exposure Time ◽

Serum Enzymes ◽

Critical Thermal Maximum ◽

Body Temperatures ◽

Mathematical Technique ◽

Deep Body Temperature ◽

Equivalent Time ◽

Thermal Maximum ◽

Deep Body

The concept of critical thermal maximum (CTM) has been defined in the literature as the minimal high deep-body temperature that is lethal to an animal. In man the CTM has been estimated at 41.6--42.0 degrees C. Data are presented for sedated, unacclimatized, well-hydrated men heated 1 h at esophageal temperatures of 41.6--42.0 degrees C, without sequelae, except for modest elevation of serum enzymes in two of five patients. These data when combined with other observations in the literature suggest that CTM be redefined as the particular combination of exposure time at elevated body temperatures that results in either subclinical (CTM)s) or clinical (CTMc) injuries. Also presented is a mathematical technique, equivalent time at 42 degrees C (Teq 42 degrees), for expressing hyperthermia in terms of body temperature and exposure time.

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