| Project/Area Number |
60560301
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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 |
畜産化学
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| Research Institution | Nagoya University |
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Principal Investigator |
TASAKI Iwao School of Agriculture, Nagoya University, 農学部, 教授 (70023364)
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| Co-Investigator(Kenkyū-buntansha) |
MURAMATSU Tatsuo School of Agriculture, Nagoya University, 農学部, 助手 (60166303)
OKUMURA Jun-ichi School of Agriculture, Nagoya University, 農学部, 助教授 (10023425)
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| Project Period (FY) |
1985 – 1986
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| Project Status |
Completed (Fiscal Year 1986)
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| Budget Amount *help |
¥2,000,000 (Direct Cost: ¥2,000,000)
Fiscal Year 1986: ¥800,000 (Direct Cost: ¥800,000)
Fiscal Year 1985: ¥1,200,000 (Direct Cost: ¥1,200,000)
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| Keywords | Chicken / Energetic efficiency / Protein turnover / 熱発生量 |
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| Research Abstract |
1. Fasting heat production and protein turnover were measured in chicks in vivo by a carcass analysis method and a large dose injection method of a [ H]labelled amino acid, respectively. The results showed that the energy cost of protein synthesis accounted for about 14 to 17% of basal metabolic rate.
2. Protein turnover rates of chicks in a fed state were lower in meat-type than in egg-type birds, whereas in a fasted state these values were almost the same. There was no difference in the contribution of protein syntheis to basal metabolic rates between meat-type and egg-type chicks.
3. By varying dietary protein contents, it was found that body protein synthesis was enhanced by increasing dietary protein levels up to 20%, and above this level no further increase or even decrease was observed.
4. When dietary energy level was changed, there was no effect on protein turnover rates under an ad libitum feeding condition due to the adjustment of energy intake by chicks voluntarily. By decreasing energy intake per se, protein turnover rates in chicks were lowered almost linearly below 90% of voluntary energy intake.
5. In laying hens, protein turnover rates were reduced by 7-day protein depletion while the reduction was completely offset by 7-day protein repletion.
6. Whole body protein synthesis in laying hens was lowered by protein starvation already on day 1, and on day 7 of protein depletion almost half the reduction in protein synthesis in the whole body was accounted for by that in the liver and oviduct.
7. Although the relationship between protein turnover and the efficiency of energy utilization in chickens has been clarified to a certain extent, there is a large portion of uncertainty on the energy cost of protein synthesis. Further studies are necessary for applying the results obtained here to the practical poultry industry.
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