2007 Fiscal Year Final Research Report Summary
Nutritional and Endocrine Regulation of Pynthesis and Degradation in Sheep Exposed to Cold
| Project/Area Number |
17580244
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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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 | Iwate University |
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Principal Investigator |
SANO Hiroaki Iwate University, Faculty of Agriculture, Professor (20196306)
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| Project Period (FY) |
2005 – 2007
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| Keywords | Ruminant / Sheep / Protein Synthesis / Amino Acid Metabolism / Isotope Dilution Method / Cold Exposure / Energy Intake / Insulin |
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| Research Abstract |
(Objectives) The present experiment was conducted to demonstrate the effect of dietary energy intake on whole body protein synthesis (WBPS) and degradation (WBPD) in sheep exposed to cold.
(Experiment 1) The [^2H_5] phenylalanine model was compared with the [1^<-13>C] leucine method in order to determine WBPS and WBPD fed at two levels of dietary intake. Although the absolute values of protein metabolism were slightly different, the response to dietary intake was similar between the techniques. Therefore, it is suggested that both techniques can be applied for determination of protein metabolism in sheep.
(Experiment 2) The [^2H_5] Phe model was used to determine the effects of dietary metabolizable enenrgy (ME) intake (Hi-ME and Me-ME diet) and cold exposure on WBPS and WBPD in sheep. Whole body protein synthesis and WBPD were greater for the Hi-ME diet than for the Me-ME diet and increased during cold exposure. No significant diet x environment interaction was detected in WBPS and WBPD. It is concluded that kinetics of plasma Phe, Tyr, WBPS and WBPD were influenced by dietary ME intake and increased during cold exposure, but the responses to cold exposure were not modified by ME intake in sheep under conditions of the present experiment.
(Experiment 3) The [^2H_5] Phe model was used to determine the effects of cold exposure and infusion of energy substrate (glucose, VFA or saline) and insulin on WBPS in sheep. Whole body protein synthesis was influenced by neither cold exposure and energy substrates. It may suggest that kinetics of plasma Phe, Tyr and WBPS were not influenced by a short term infusion of energy substrate and insulin influenced selectively amino acid metabolism.
(Conclusion) It should be emphasized that feeding management such as energy intake was important in ruminants exposed to cold.
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