scholarly journals Improvement of cold resistance and performance of broilers by acute cold exposure during late embryogenesis

2011 ◽  
Vol 90 (3) ◽  
pp. 633-641 ◽  
Author(s):  
D. Shinder ◽  
M. Ruzal ◽  
M. Giloh ◽  
S. Druyan ◽  
Y. Piestun ◽  
...  
Keyword(s):  
Cold Exposure ◽  
Cold Resistance ◽  
Acute Cold Exposure ◽  
Late Embryogenesis ◽  
And Performance

EFFECT OF COLD ADAPTATION AND HIGH-FAT DIET ON COLD RESISTANCE AND METABOLIC RESPONSES TO ACUTE COLD EXPOSURE IN RATS

1974 ◽  
Vol 24 (3) ◽  
pp. 277-292 ◽  
Author(s):  
Akihiro KUROSHIMA ◽  
Masashi KURAHASHI ◽  
Katsuhiko DOI ◽  
Tomie OHNO ◽  
Ikuko FUJITA
Keyword(s):  
Cold Exposure ◽  
High Fat Diet ◽  
Cold Adaptation ◽  
Cold Resistance ◽  
Metabolic Responses ◽  
High Fat ◽  
Acute Cold Exposure

Cold exposure of Southdown and Welsh Mountain sheep. 1. Effects of breed, plane of nutrition and acclimatization to cold upon resistance to body cooling

1969 ◽  
Vol 11 (1) ◽  
pp. 65-75 ◽  
Author(s):  
A. R. Sykes ◽  
J. Slee
Keyword(s):  
Cold Exposure ◽  
Cold Resistance ◽  
Temperature Treatment ◽  
Cold Temperature ◽  
Acute Exposure ◽  
Acute Cold Exposure ◽  
Similar Temperature ◽  
Body Cooling ◽  
Female Sheep

SUMMARY1. Twenty-four Southdown and 24 Welsh Mountain year-old female sheep, half on high plane and half on low plane nutrition, were closely shorn and given two short acute cold exposures (−20°C, 4 mph wind) in climate chambers. For two weeks before the first acute exposure half the sheep were kept at a moderately cold temperature (+8°C) and the remainder at a thermoneutral temperature (+30°C). During the next two weeks between acute exposures these temperatures were reversed for each group of sheep.2. Resistance to body cooling during acute cold exposure was significantly greater after exposure to + 8°C. This was attributed to acclimatization. No further acclimatization resulted from acute cold exposure in addition to chronic moderate cold exposure.3. Sheep which had been kept at +8°C cooled 33% more slowly than those which had been at + 30°C. High plane sheep cooled 34 % more slowly than low plane sheep. Southdowns cooled 32 % more slowly than Welsh sheep, but the Welsh sheep showed relatively greater acclimatization on low plane nutrition.4. Compared with Scottish Blackface sheep given similar temperature treatment in an earlier experiment, the Southdowns and Welsh showed less initial cold resistance and less capacity for acclimatization.

Tolerance of estrogen-treated rats to acute cold exposure

1979 ◽  
Vol 47 (1) ◽  
pp. 59-66 ◽  
Author(s):  
M. J. Fregly ◽  
D. L. Kelleher ◽  
D. J. Black
Keyword(s):  
Oxygen Consumption ◽  
Cold Exposure ◽  
Previous Experiment ◽  
Female Rats ◽  
Control Group ◽  
Maximal Rate ◽  
Acute Cold Exposure ◽  
Exposure To Cold ◽  
Rate Of Oxygen Consumption ◽  
Rate Of Cooling

Female rats treated chronically with ethynylestradiol (36 micrograms/kg per day) alone, and in combination with the progestational agent, norethynodrel (253 micrograms/kg per day), cooled significantly faster than controls when lightly restrained and exposed to air at 5 degrees C. Rate of cooling of rats given only norethynodrel was similar to that of the control group. In other studies, rate of oxygen consumption was determined for all groups during acute exposure to cold (14 degrees C). All estrogen-treated groups achieved the same maximal rate of oxygen consumption as control and norethynodrel-treated groups during cold exposure, but cooled significantly faster. Two groups of female rats were treated chronically with ethynylestradiol at two separate doses (36 and 61 micrograms/kg per day). An untreated group served as controls. Rate of oxygen consumption of all animals were measured during restraint and exposure to cold (18 degrees C). The estrogen-treated groups again achieved the same maximal rate of oxygen consumption as the control group, but also cooled significantly faster despite the fact that the cold stress was less severe than in the previous experiment. That estrogen-treated rats cooled faster than controls in both studies despite achieving a maximal rate of heat production which did not differ from controls suggests that reduced cold tolerance of estrogen-treated rats may be related to increased heat loss.

Responses of cold- and warm-adapted dogs to infused norepinephrine and acute body cooling

1965 ◽  
Vol 209 (1) ◽  
pp. 227-230 ◽  
Author(s):  
Tetsuo Nagasaka ◽  
Loren D. Carlson
Keyword(s):  
Heart Rate ◽  
Oxygen Consumption ◽  
Cold Exposure ◽  
Nonshivering Thermogenesis ◽  
Mechanically Ventilated ◽  
Cold Adapted ◽  
Pentobarbital Sodium ◽  
Acute Cold Exposure ◽  
Increased Sensitivity ◽  
Body Cooling

Oxygen consumption, heart rate, and colonic, pinna, and paw temperatures were recorded continuously in warm-adapted (W-A) and cold-adapted (C-A) dogs anesthetized with pentobarbital sodium (30 mg/kg), paralyzed with Flaxedil (5 mg/kg per hr), and mechanically ventilated. The dogs were infused with norepinephrine (1.25 µg/kg per min) for 20 min at 30 C and after 45 min of acute cold exposure to 5 C. Oxygen consumption of C-A dogs increased with a slight increase in the heart rate during the initial 18–20 min of body cooling. O2 consumption decreased continuously during cold exposure in W-A dogs. Calorigenic effects of infused noradrenaline were similar in C-A and W-A dogs at 30 C and 5 C. Heart rate increased in W-A dogs at 30 and 5 C. These results show that nonshivering thermogenesis is well developed by cold acclimation in dogs, and suggest that the increase may be due to an increase in noradrenaline in blood rather than to increased sensitivity of the animals to the calorigenic effects of noradrenaline.

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