Graduate School of Agriculture, Kyoto University, Sakyo, Kyoto, Japan.
Anim Sci J. 2009 Feb;80(1):46-51. doi: 10.1111/j.1740-0929.2008.00595.x.
We investigated the effect of dietary phytase on the true absorption and endogenous fecal excretion of zinc (Zn) using (67)Zn in growing pigs given a corn-soybean meal based diet. Ten crossbred barrows were fed the control diet containing 90-mg/kg Zn, 2.3-g/kg phytate-phosphorus and 3.7-g/kg non-phytate-phosphorus or the phytase diet containing similar amounts of Zn and phytate-phosphorus, and 1.4-g/kg non-phytate-phosphorus with 750-PU/kg phytase for 12 h/day. On day 6, the pigs were given 200 g of the corresponding diet labeled by (67)Zn for 2 h. We measured feed intake, fecal Zn concentration and (67)Zn abundance for the determination of apparent absorption, true absorption and endogenous fecal excretion of Zn. Although the apparent absorption of Zn did not significantly differ between the dietary groups, the phytase group had significantly more (P < 0.05) true absorption of Zn than the control group. The endogenous fecal excretion of Zn tended to be more (P = 0.07) in the phytase group than in the control group. These results suggest that dietary phytase improves Zn bioavailability through increasing the true absorption of Zn in growing pigs, which results in stimulating the endogenous fecal excretion of Zn when dietary Zn satisfies its requirement.
我们用（67）Zn 研究了在玉米-豆粕基础饲粮下植酸酶对生长猪锌真吸收率和内源性粪锌排泄量的影响。10 头杂交去势公猪分别饲喂含 90mg/kg 锌、2.3g/kg 植酸磷和 3.7g/kg 非植酸磷的对照饲粮或含等量锌和植酸磷、添加 1.4g/kg 非植酸磷和 750-PU/kg 植酸酶的植酸酶饲粮，每天 12 h。第 6 天，猪饲喂 2 h 相应的（67）Zn 标记饲粮，测定采食量、粪锌浓度和（67）Zn 丰度，以确定锌的表观吸收率、真吸收率和内源性粪锌排泄量。尽管两组饲粮间锌的表观吸收率没有显著差异，但植酸酶组的锌真吸收率显著高于对照组（P<0.05）。植酸酶组的内源性粪锌排泄量有增加的趋势（P=0.07）。这些结果表明，饲粮添加植酸酶可通过提高生长猪锌的真吸收率来提高锌的生物利用率，当饲粮锌满足需要时，会刺激内源性粪锌排泄。
