饲粮植酸与锌摩尔比作为评定鸡饲料锌利用方法的研究

STUDIES ON PHYTIC ACID:Zn MOLAR BATIO IN DIETS AS ADETERMINANT OF Zn BIOAVAILABILITY TO CHICKENS

试验观察饲粮植酸与锌摩尔比对肉仔鸡（１１～２５日龄）锌利用的影响。以植酸水溶液取代半纯合饲粮（５０ｐｐｍ锌）中的蔗糖，其植酸与锌摩尔比分别为８：１（对照），１６：１、２５：１、３７：１及５１：１。试验结果表明，植酸与锌磨尔比对肉仔鸡的锌利用有着明显的影响效应。当该比值从１６：１增至５１：１时，中脚趾和胫骨灰分中锌含量分别降低１２．４～１９．６％（Ｐ＜０．０１）和４．４～１０．９％（Ｐ＜０．０５），二组织锌浓度（ｙ）随着植酸与锌摩尔比（ｘ）的增加而呈直线或曲线降低（Ｐ＜０．０１），ｙ中脚趾＝５２９．７９－２．０４６ｘ（ｒ＝０．７２）；ｙ中脚趾＝（ｒ＝０．８１）；ｙ胫骨＝４９５．２１．１．１４５ｘ（ｒ＝－１．７２）。影响肉鸡肝脏、胰脏和全鸡灰分锌含量的最低植酸与锌摩尔比分别为５１：１（Ｐ＜０．０１）、５１：１（Ｐ＜０．０５）及３７：１（Ｐ＜０．０５）。通过讨论认为饲粮植酸与锌摩尔比作为预测和评定鸡饲料锌利用的指标有其理论和实验依据。

The experiment was conducted to measure the effect of phytic acid:Zn molar ra-tio on growth and Zn contents in tissues of broilers. Male broilers (11￣25 days old)were fed on semi-pure diets mainly of isolated soy protein, corn grits, corn starch andsucrose with Zn content of 50mg/kg. Solutions of phytic acid were added to diets toachieve values for Phytic acid:Zn molar ratio of 8:1 (control),16:1, 25:1, 37:1and 51:.1 . It was revealed that Zn contents in tibia ash decreased linearly 4.40%￣10.9%(P<0.05) of Y=475.21-1.145X (r= - 0.72, P<0.01),Zn contents in toe ash de-creased linearly and curvilinearly 12.4￣19.9% (P<0.01) of Y=529.79 - 2.046X (r=-0.72 P<0.01) and Y=424.58e (r=0.81, P<0.01) with the increase of phyticacid.Zn values from 16:1 to 51:1. Zn contents in liver, pancreas and whole body ashdecreased significantly. When dietary phytic acid:Zn molar ratio was more than 51:1,51:1 and 37:1 respectively. It is suggested that phytic acid:Zn molar ratio could beone of the determinants of Zn bioavailability to chickens according to the experimentand ivorks of others.