中文摘要：

研究植酸酶对蛋鸭锌、铜、镁生物学利用率的影响。选取200日龄产蛋期金定鸭1 000只,随机分为5个处理,每个处理4个重复,每个重复50只。处理A为对照组,有效磷水平为0.45%;处理B、C、D、E有效磷水平依次为0.38%、0.32%、0.25%、0.18%,同时添加植酸酶500 FTU/kg。结果表明：日粮有效磷水平从0.45%降低到0.25%,同时添加500 FTU/kg植酸酶,不会影响蛋鸭对Ca、P、Cu、Zn的表观利用率及其在蛋鸭血清和胫骨中的含量（P〉0.05）。当日粮中有效磷水平为0.18%时,即使添加了植酸酶,Ca、P、Cu、Zn的表观利用率及其在蛋鸭血清和胫骨中的含量都会显著降低（P〈0.05）。降低有效磷水平和添加植酸酶与否不会影响Mg的生物学利用率。添加植酸酶可以降低蛋鸭日粮中的有效磷水平,对Zn、Mg、Cu的生物学利用率无影响,日粮中有效磷水平的适宜范围为0.25%~0.45%。

英文摘要：

Aim To determine the effects of phytase on biological availability of Zn,Cu and Mg in laying ducks.Methods A total of 1000 laying ducks（200d-old） were allotted randomly to 5 treatments with 4 replicates.Group A was control group,diet AP（available P） 0.45% with no phytase addition.Groups B,C,D,E were fed diet supplemented with phytase 500 FTU/kg and diet AP concentration was 0.38%,0.32%,0.25%,0.18% respectively.Results Decreasing diet AP from 0.45% to 0.25% and meanwhile supplementing with 500 phytase do not affect the apparent absorption of Ca,P,Cu,Zn and the contents of Ca,P,Cu,Zn in plasma and tibia（P〉0.05）,but when AP is 0.18% even with phytase addition,the apparent absorption of Ca,P,Cu,Zn and the contents of Ca,P,Cu,Zn in plasma and tibia decrease significantly（P〈0.05）.Diet AP decrease and phytase addition do not influence the biological availability of Mg.Conclusion With phytase addition,diet AP concentration can be decreased without affecting the biological availability of Zn,Cu and Mg in laying ducks.The proper diet AP concentration is 0.25%～0.45%.