Estimation of plant and cattle growth using the energy-flow model in grazed pasture.
| Project/Area Number |
60560279
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
畜産学(含草地学)
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| Research Institution | The University of Tokyo, Faculty of Agricultural Science. (1986, 1988)
Nagoya University (1985) |
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Principal Investigator |
OKUBO Tadakatsu Professor of The University of Tokyo, 農学部(附属牧場), 教授 (90115535)
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| Co-Investigator(Kenkyū-buntansha) |
MATSUI Kanji Assistant Professor of The University of Tokyo, 農学部(附属牧場), 助手 (50126166)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1988)
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| Budget Amount *help |
¥1,800,000 (Direct Cost: ¥1,800,000)
Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Grazing of Holstein calf / Tallfescue pasture / Energy efficiency / 放牧 / 牛のエネルギー代謝 / トールフェスク / 生態システムのモデル / 草地のエナジーフロー / 牛の生長モデル |
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| Research Abstract |
A systems analytical approach was carried on the flow of solar energy in grazed pasture of Tallfescue. To determine the initial values and parameters for the OKUBO-JACQUARD model (1985), the dry matter production of Tallfescue under grazing was measured in every three or four week intervals. The plant materials were divided into each plant organ and measured in digestibility in-vitro. Herbage available, herbage intake, residual herbage available, di-gestible herbage and body weight change (daily gain) were also measured and converted into the energy values. Solar energy conversion efficiency in the each step of energy flow was calculated and it's seasonal difference was analyzed.
Daily gain of Holstein-Friesian calves varied remarkably by season from 1.1 kg of live weight per head in spring and early autumn to 0.0 kg in summer and late autumn and the gain was mainly releted to their herbage intake. They grazed about 0.03 kg per kg of live weight per day in spring and early autumn but about 0.02 kg in summer. Digestibility of the grasses was not so largely different and the efficiency of energy conversion from digestible energy to metabolisable energy was varied seasonally and very low in summer. From the measurement of heat production under grazing, it was infered that the calves might control themselves in lower heat production by lower intake in summer season. Conversion ratio ME/DE was lower in our grazing calves than the values of SRC (1965) in all the season.
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Report
(2 results)
Research Products
(8 results)
