1991 Fiscal Year Final Research Report Summary
Study on absorbed amount and absorption rate of Ca, P and Mg from the digestive tract of ruminants
| Project/Area Number |
63480084
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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 |
畜産化学
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| Research Institution | Kyoto University |
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Principal Investigator |
KAWASHIMA Ryoji Kyoto Univ. Agric. Professor, 農学部, 教授 (50026382)
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| Co-Investigator(Kenkyū-buntansha) |
YANO Fumiko Kyoto Univ. Agric. Instructor, 農学部, 助手 (30101249)
ISHIDA Naohiko Kyoto Univ. Agric. Instructor, 農学部, 助手 (00026593)
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| Project Period (FY) |
1988 – 1990
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| Keywords | sheep / Ca / P / Mg / digestive tract / absorption |
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| Research Abstract |
An absorbed amount of Ca, P and M- and absorption rate of these minerals from the digestive tract were studied in ruminants.
P was shown to be secreted before the duodenum. The absorbed amount of P, however, was chanced by concentrate-foughage ratio, the amount of feed intake and physical characteristics of feed. The above results indicated that P secretion before the duodenum was thought to be through saliva. Passing amount of P in the duodenum was 2 to 6 times larger than the amount of dietary P and was largely changed by the amount of feed intake, physical form of diet and P status in the animal body. Therefore, the actual P absorption after the duodenum was obviously different from apparent P absorption. The absorbed amount of P after the duodenum was almost equal to the secreted amount of P via saliva. The absorption efficiency of P ranging from 60 to 87% seemed to be affected by P status of livestock. The main absorption site of P was the Lipper part of small intestine and P absor
… More
ption appeared to be small in the large intestine. P absorption in the small intestine was observed to be affected by flow rate of digesta, and P concentration and pH in digests.
It was observed that net Ca absorption occurred before the duodenum when high concentrate diets were fed. Ca secretion was 1 to 2 times of dietary Ca in sheep given high roughage diets, indicating that Ca was secreted via saliva. Ca balance became negative in sheep which secreted a large amount of Ca viasaliva, even though the amount of Ca absorption and Ca absorption efficiency were high.
Net Mg absorption Yeas observed before the duodenum in sheep given high concentrate diets. In sheep fed high roughage diets, there was net Mg. absorption before the duodenum although salivary Mg secretion was increased. Unabsorbed Mg before the duodenum was absorbed in the small intestine.
Although we are investigating factors affecting Ca and Ma absorption from the digestive tract, adequate answer has not been obtained yet. A formula in which factors affecting Ca, P and Mg metabolism are shown will be made after taking. al all data. Less
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