scholarly journals The thermogenic effects of noradrenaline in new-born and infant kittens and other small mammals. A possible hormonal mechanism in the control of heat production

1963 ◽  
Vol 168 (2) ◽  
pp. 290-317 ◽  
Author(s):  
R. E. Moore ◽  
Mary C. Underwood
Keyword(s):  
Small Mammals ◽  
Heat Production ◽  
New Born ◽  
Hormonal Mechanism

scholarly journals Adipose tissue and heat production in the new-born ox (Bos taurus)

1968 ◽  
Vol 195 (3) ◽  
pp. 639-646 ◽  
Author(s):  
D. McEwan Jenkinson ◽  
R. C. Noble ◽  
G. E. Thompson
Keyword(s):  
Adipose Tissue ◽  
Heat Production ◽  
Bos Taurus ◽  
New Born

SEASONAL CHANGES IN INSULATION OF THE FUR

1956 ◽  
Vol 34 (1) ◽  
pp. 53-57 ◽  
Author(s):  
J. S. Hart
Keyword(s):  
Small Mammals ◽  
Heat Production ◽  
Seasonal Changes ◽  
Temperate Zone ◽  
Seasonal Acclimatization

Seasonal changes in insulation of the fur have been compared in nine species of arctic and North temperate zone mammals. Relative seasonal changes ranged from 12 to 52% of the winter value. Absolute changes were greatest in the larger mammals with thickest fur. The limited seasonal insulative change in small mammals suggests that changes in heat production may be important in seasonal acclimatization.

Temperature regulation in the new-born lamb. III. Effect of environmental temperature on metabolic rate body temperatures, and respiratory quotient

1961 ◽  
Vol 12 (6) ◽  
pp. 1152 ◽  
Author(s):  
G Alexander
Keyword(s):  
Body Temperature ◽  
Heat Loss ◽  
Heat Production ◽  
Temperature Regulation ◽  
Low Temperatures ◽  
Environmental Temperature ◽  
Body Temperatures ◽  
Normal Body Temperature ◽  
Ambient Temperatures ◽  
New Born

Studies were made on temperature regulation of lambs in a closed circuit indirect calorimeter. Dry new-born lambs were able to maintain normal body temperature in ambient temperatures as low as -5°C. This was accomplished by increasing heat production to 2–3 times "basal" levels, apparently by increased oxidation of fats, and by reducing heat loss through the extremities by vasoconstriction. The lower limit of the zone of thermal neutrality was about 29°C. In unsuckled lambs within 24 hr of birth, the heat produced in response to cold appeared to be independent of pre-natal nutrition and age. It was considerably lower in lambs with hairy coats than in lambs with fine coats. Milk intake increased heat production, and this increase was abolished after 12 hr of fasting in lambs up to 3 days old, but the increase persisted in older lambs. The increase was accompanied by, and was apparently due to, elevated heat loss from the extremities, which persisted even at low temperatures. The maximal thermal insulation of the tissues, calculated from these results, was about 1 Clo; that of the fleece plus air was only 1 to 2 Clo.

Temperature regulation in the new-born lamb. IV. The effect of wind and evaporation of water from the coat on metabolic rate and body temperature

1962 ◽  
Vol 13 (1) ◽  
pp. 82 ◽  
Author(s):  
G Alexander
Keyword(s):  
Metabolic Rate ◽  
Heat Loss ◽  
Heat Production ◽  
Temperature Regulation ◽  
Tap Water ◽  
High Heat ◽  
Cooling Efficiency ◽  
Experimental Conditions ◽  
Ambient Temperatures ◽  
New Born

The study of temperature regulation in new-born lambs has been extended from dry lambs in "still air" at various ambient temperatures to dry lambs in a wind of 550 cm sec-l, and to lambs whose coats are drying. Exposure to wind resulted in an increased slope of the line relating heat production to ambient temperature, but under the experimental conditions evaporation of water from the coat added approximately the same increment at all ambient temperatures. The effects of wind and evaporation at any one temperature appeared additive. The heat loss from naturally wet new-born lambs less than 1 hr old, in a wind, was greater than in slightly older lambs wetted with tap water. Lambs with hairy coats were able to conserve heat more readily than lambs with fine coats. The cooling efficiency of evaporation from the coat was about 25%. The elevation in temperature of the extremities which follows feeding and persists under conditions of moderate heat loss, appears to be almost abolished under conditions of high heat loss. During the studies on drying lambs, beat loss in many lambs exceeded heat production, and rectal temperature fell, which thus indicated the maximum possible heat production (summit metabolic rate) of which lambs are capable. Lambs from ewes on low or medium levels of feeding during pregnancy cooled more readily than lambs from well-fed ewes.

scholarly journals Heat production in new-born infants under normal and hypoxic conditions

1957 ◽  
Vol 138 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Hugh R. Brodie ◽  
K. W. Cross ◽  
T. R. Lomer
Keyword(s):  
Heat Production ◽  
New Born ◽  
Hypoxic Conditions
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