| Project/Area Number |
63480077
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
農業気象・生物環境制御学
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| Research Institution | Kitasato University |
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Principal Investigator |
ICHIKAWA Tadao Fac. of Eng. for Animal Hus, Prof., 獣医畜産学部, 教授 (70091882)
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| Co-Investigator(Kenkyū-buntansha) |
MINAGAWA Hideo Fac. of Eng. for Animal Hus., Lect., 獣医畜産学部, 講師 (70146520)
KAMATA Toshihiko Dept. of Agr., Tokyo Univ. of Agr. & Tech., Assoc. Prof., 農学部, 助教授 (70015121)
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| Project Period (FY) |
1988 – 1990
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| Project Status |
Completed (Fiscal Year 1990)
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| Budget Amount *help |
¥7,000,000 (Direct Cost: ¥7,000,000)
Fiscal Year 1990: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1989: ¥1,600,000 (Direct Cost: ¥1,600,000)
Fiscal Year 1988: ¥4,600,000 (Direct Cost: ¥4,600,000)
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| Keywords | natural ventilation / confinement barn / cattle / open ridge / open wall / cold region / 寒冷地 / アンモニアガス濃度 / 空中浮遊細菌 / 牛舎 / 牛 / 産熱量 / 換気 |
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| Research Abstract |
In indirect calorimetric measurement of 6 beef cattle with a mask in a barn, heat production rates were not increased in the air temperature range of about -5^ﾟC to +5^ﾟC. The range may belong to a thermal neutral zone for the cattle. Heat production data were used for developing an natural ventilation barn.
Using of a continuous open ridge barn with 0.15m in wide opening, of 8.4m width, 10.8m depth, 4.8m high and 350m^3 volume, the effect of an upstand of 0.3m in high at the opening on natural ventilation was measured in winter in comparison with no upstand and with an upstand narrowing half in the wide opening. The barn has open eaves of 0.1m width in both side walls. As a factor of buoyancy, electric heaters of which the amount of heat were equivalent to those produced by about 12 cattle was set in the barn. The upstand and no upstand types maintained 8/hr and 6/hr in air exchange rates respectively when wind speed of outside was 0m/s. However the narrowing upstand type was below 4/hr, which is recommended in minimum air exchange rate in winter. Both upstand types were found to be effective to keep out snow.
In summer, natural ventilation was measured in the open ridge barn with a continuous upstand of 0.3m in high and with open eaves and hinged walls. When the hinged walls were opened, the air exchange rate increased 2 to 3 times when the average outside wind speed ranged 0.5m/s to 5m/s. Air exchange by the wall openings shared about 50% of total air exchange.
An open ridge barn with a continuous upstand may be suitable for cattle in a cold region. In summer, however, the walls are necessary to be opened to increase ventilation effect.
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