Efficacy of phytases on egg production and nutrient digestibility in layers fed reduced phosphorus diets
Efficacy of phytases on egg production and nutrient digestibility in layers fed reduced phosphorus diets
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DOI：
10.3382/ps.2007-00079
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发表时间：
2007-11-01
期刊：
影响因子：
4.4
通讯作者：
Ru, Y. J.
中科院分区：
文献类型：
--
作者：
Liu, N.;Liu, G. H.;Ru, Y. J.
选用320只23 ~ 28周龄海兰褐蛋鸡，研究了植酸酶对产蛋鸡生产性能和玉米、豆粕及副产品日粮养分回肠消化率的影响。将蛋鸡随机分为5个处理，每个处理8个重复，每个重复8只蛋鸡。这5种饮食由含有足够钙的阳性对照饮食组成（3.30%），总P（0.50%）和非植酸磷（NPP;对照组饲料中钙、总磷、净初级生产力分别降低0.12%、0.14%、0.13%，（来源于尼日尔曲霉的植酸酶A，和来源于大肠杆菌的植酸酶B和C）分别补充300植酸酶单位/kg饲料。每天记录产蛋量和采食量，并在6周饲养期结束时测定蛋壳质量和回肠营养物质消化率。结果表明，降低阳性对照日粮中Ca、P的水平显著降低了蛋鸡的采食量、蛋重、蛋壳硬度以及N、Ca、P和氨基酸的消化率（P < 0.05）。在阴性对照日粮中添加植酸酶可使磷和钙的消化率分别提高11.08%和9.81%（P < 0.05），氨基酸的消化率提高2 ~ 8%（P < 0.05）。然而，大多数氨基酸的消化率没有恢复到阳性对照饮食的水平，通过应用植酸酶。在阴性对照饮食中补充植酸酶将产蛋率、蛋质量和蛋壳质量提高到饲喂阳性对照饮食的禽类的水平。这些结果表明，添加植酸酶不仅可以提高钙和磷的消化率，而且还可以提高氨基酸的消化率，饲喂玉米，大豆和副产品为基础的饮食。
The effects of phytases on the performance of layers and the ileal nutrient digestibility of corn-, soybean-, and by-product meal-based diets were assessed with 320 Hy-Line brown layers from 23 to 28 wk of age. Layers were grouped randomly into 5 treatments, with 8 replicates per treatment and 8 layers per replicate. The 5 diets consisted of a positive control diet with adequate Ca (3.30%), total P (0.50%), and nonphytate P (NPP; 0.28%), and a negative control diet with Ca reduced by 0.12%, total P reduced by 0.14%, NPP reduced by 0.13%, and 3 phytases (phytase A derived from Aspergillus niger, and phytases B and C derived from Escherichia coli) supplemented at 300 phytase units/kg of feed, respectively. Egg production and feed intake were recorded daily, and eggshell quality and ileal nutrient digestibility were measured at the end of a 6-wk feeding period. The results revealed that the reduction of Ca and P from the positive control diet significantly depressed feed intake, egg mass, eggshell hardness, and the digestibility of N, Ca, P, and amino acids (P < 0.05). Phytase supplementation in the negative control diet improved the digestibility of P and Ca by 11.08 and 9.81% (P < 0.05), respectively, whereas it improved the digestibility of amino acids by 2 to 8% (P < 0.05). However, the digestibility of most amino acids was not restored to the levels of the positive control diet by the application of phytases. Supplementing phytases in the negative control diet improved the rate of lay, egg mass, and egshell quality to the levels of birds fed the positive control diet. These results suggest that supplementing phytases can improve the digestibility not only of Ca and P, but also of amino acids in layers fed a corn-, soybean-, and by-product-based diet.