1997 Fiscal Year Final Research Report Summary
Specific Characters of Thermoregulation for Environmental Management in Farm Animals
| Project/Area Number |
07456124
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| Research Category |
Grant-in-Aid for Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Applied animal science
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| Research Institution | HIROSHIMA UNIVERSITY |
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Principal Investigator |
YAMAMOTO Sadaki Applied Biological Science, HIROSHIMA UNIVERSITY Professor, 生物生産学部, 教授 (20034449)
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| Project Period (FY) |
1995 – 1997
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| Keywords | thermal environment / farm animals / level of body temperature / heat balance / thermosensitivity / rhtym of body temperature / thermoregulation / heat alleviation techniques |
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| Research Abstract |
For the reasonable control of the thermal environment, it is necessary to have knowledge of the character of each thermal factor and a thoroughly understanding of thermoregulation of the farm animals. The method of analysis in heat balance studies has been established by the measurement of heat production, deep body temperature, skin surface temperatures and respiration rate with a fairly high degree of reliability.
The characteristic variation of body temperature in cattle are comprised of both a daily rhythm in which rectal temperature is low in the morning and high in the night, and a change in the level of body temperature which increases with the increase of ambient temperature and plane of nutrition. The increase of body temperature is an essential response for the maintenance of heat balance with increase ambient temperatures. The variation in the level of body temperature may initiate sweating and panting and may adjust the balance between sensible and latent heat loss. The main
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tenance of heat balance may be controlled by the level of mean body temperature. These responses could be explained by use of the concept of thermosensitivity. Thermosensitivity may have a daily rhythm, being high during the day and low at night. Under hot conditions during the night, it is possible to maintain heat balance by enhancing thermosensitivity through increased body temperature. Thermoregulation in chickens is characterized by a clear daily rhythm that is closely associated with day and night. The effects of heat load early in life may promote the ability to cope with the subsequent by altering thermoregulatory responses and behavioral activities.
Reasonable management of thermal factors should be related to the rhythm and the level of body temperature which are related to the thermoregulatory character of farm animals. It is necessary that the effect of thermal factors on variation of the level and distruption of the rhythm of body temperature should be understood, and then heat alleviation techniques applied to cope with heat stress. Less
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