有机锌在肉仔鸡小肠不同部位中的吸收特点

STUDIES ON CHARACTERIZATIONS OF ORGANIC ZINC ABSORPTION IN DIFFERENT INTESTINAL SEGMENTS IN BROILERS

目的研究肉仔鸡小肠各段对无机锌和有机锌吸收特点的差异。方法采用原位结扎灌注肠段法,包括2个试验:试验1:以硫酸锌为锌源,根据锌的吸收率与肠段灌注时间(5个时间点)的曲线关系确定最佳灌注时间,试验2:在此灌注时间下比较不同形态锌(8种锌源)在肉仔鸡小肠中的吸收差异。结果(1)锌的吸收率在30min时即可达最大吸收的85%～90%;(2)不同锌源锌在回肠中的吸收均显著高于十二指肠和空肠;(3)十二指肠和空肠中锌的吸收率受到添加锌源的显著影响,其中,弱、中和强络合强度有机锌组及蛋氨酸锌组、赖氨酸锌组锌的吸收率明显高于硫酸锌、硫酸锌和蛋氨酸混合物组、硫酸锌和甘氨酸锌混合物组。结论30min为肠段的最适灌注时间;回肠是肉仔鸡小肠吸收锌的主要部位;有机锌吸收要好于无机锌。

Objective To study the absorption characterizations of Zn as different sources in duodenum, jejunum and ileum of broilers. Method Two experiments were included in this research by in situ ligated loops. Experiment 1 was performed to obtain an optimal perfusion time of ligated loops according to the change of Zn absorption with time （five time points ）. Experiment 2 was carried out to evaluate the effect of different Zn sources （eight sources） on the intestinal absorption of Zn in broilers at above optimal perfusion time. Results （1） The absorption amount of Zn in 30 min was above 85%--90% of what it would be at the time point of maximum absorption in each segment; （2） The absorption percentage of Zn as different sources in the ileum was significantly higher than those in duodenum and jejunum; （3） The effect of Zn sources on Zn absorption in duodenum and jejunum was obvious, the absorption of organic Zn, given as Zn-Gly chelate, Zn-Met chelate, Zn-AAC （weak complex strength）, Zn-ProB （moderate complex strength） and Zn-ProA （strong complex strength）, was significantly higher than Zn＋Gly mixture, Zn＋Met mixture and ZnSO4. Conclusion The optimal perfusion time of ligated loops was 30 min and ileum was the main absorption site of Zn in intestines of broilers. The absorption of organic Zn was better than inorganic Zn.