| Budget Amount *help |
¥3,950,000 (Direct Cost: ¥3,800,000、Indirect Cost: ¥150,000)
Fiscal Year 2007: ¥650,000 (Direct Cost: ¥500,000、Indirect Cost: ¥150,000)
Fiscal Year 2006: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 2005: ¥2,800,000 (Direct Cost: ¥2,800,000)
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| Research Abstract |
Zinc metabolism was studied by using a stable isotopic zinc, ^<67>Zn natural enrichment, 4.1%) as a tracer in pigs and goats. First, we validated the analysis of isotopic ratio of zinc (^<67>Zn /^<67>Zn by ICP-MS in ^<67>Zn-enriched goat feces. When the Sc concentration was no less than 10 μg/L, the repeatability, reproducibility, linearity, recovery of the ratio assay were high enough.
Second, ^<67>Zn was orally administered as a tracer to investigate the effict of dietary phytase on zinc metabolism in pigs. Fecal ^<67>Zn enrichment rapidly decreased from day 3 and the reduction was remarkable on day 4 and day 5. The addition of phytase did not affect the apparent absorption of zinc. However, the true absorption of zinc was increased by the addition of phytase (P<0.05, 18.25±1.37 vs. 26.00±1.97 mg/d (Mean ± SE)). The endogenous fecal excretion of zinc was increased by the addition of phytase (P=0.07, 3.63±1.46 vs. 9.62± 2.15 mg/d). These results suggested that phytase stimulated zinc absorption through degrading phytase and the in cream in zinc absorption stimulated endogenous fecal excretion of zinc.
Third,^<67>Zn was orally administered as a tracer to evaluate zinc metabolism in goats. Fecal ^<67>Zn enrichment was peaked on day 3 and decreased rapidly thereafter. On day 7, the enrichment became slight (no less than 10%) and stable. The apparent absorption of zinc was -0.6± 1.2 mg/d, the true absorption of zinc was 9.6 ± 1.2 mg/d, and the endogenous fecal excretion of zinc was 10.2 ±0.6 mg/d. The amount of the endogenously excreted zinc was as much as that of the absorbed zinc in the goats given sufficient amount of zinc.
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