高剂量植酸酶对肉鸡生长性能和消化率的影响

Effects of high dose phytase on growth performance and digestibility of broilers

文章旨在研究植酸酶对1~42日龄肉鸡生长发育的影响。采用完全随机试验设计,试验共分为5组,每组6个重复,每个重复24只鸡,各组分别为阳性对照组、负对照、负对照日粮+1000、2000和3000IU/kg植酸酶,试验结束后测定各组对骨功能、骨质量和血液矿物质的影响。随着日粮植酸酶添加水平的升高,显著改善了1~21d肉鸡日增重、采食量和料比(P<0.05),而1~42d肉鸡生长性能表现为显著二次曲线效应(P<0.05),其中负对照组肉鸡日增重和采食量最低(P<0.05),料比最高(P<0.05)。对照组较负对照组显著提高了42d肉鸡胫骨干物质含量(P<0.05)。随着植酸酶添加水平的升高,21d肉鸡血钙浓度表现为显著线性降低(P<0.05),而血磷浓度先升高后降低,负对照日粮+1000IU/kg植酸酶组最高(P<0.05)。42d肉鸡血磷浓度随日粮植酸酶水平的升高表现为二次曲线效应。对照组和负对照组较处理组显著提高了42d肉鸡血钙浓度(P<0.05)。与对照和负对照组相比,负对照添加植酸酶组显著降低了矿物质回肠表观消化系数(P<0.05),而负对照组+3000IU/kg植酸酶较对照组显著降低了能量回肠表观消化系数(P<0.05)。植酸酶在回归分析的基础上提高了肉鸡生长性能,添加高剂量植酸酶3000IU/kg显著提高21d肉鸡日增重。试验为期42d,日粮添加2000IU/kg植酸酶对肉鸡的增重和饲料转化率效果较好。

The objective of this trial was to evaluate the effects of dietary phytase on broilers from 1 to 42 d.Five treatments were distributed in a completely randomized design,with 6 replicates of 24 birds per replicate.The treatments consisted of a positive control diet,a negative control diet,the negative control diet+1000,2000 and 3000 IU/kg phytase.The effects of dietary treatments on performance,bone quality and blood minerals were determined.Results showed that from 1~21 d,weight gain,feed intake and feed conversion ratio showed an improvement with increasing levels of phytase(P<0.05),while performance was increased by phytase addition in a quadratic manner(P<0.05)from 1~42 d.From 1~42 d,dry matter in tibia were significantly different(P<0.05)compared to the positive control treatment.At 21 d,blood Ca decreased in a linear manner,P increased and then decreased,with the maximum achieved in negative control group+1000 IU/kg phatase(P<0.05).Compared with the positive and negative group,the treatment groups increased the ilea apparent digestibility of minerals(P<0.05),and the negative control group+3000 IU/kg phytase had lower ilea apparent digestibility of energy than the positive control(P<0.05).In conclusion,phytase improves broiler performance based on regression analysis.At 21 d,the high dose of 3000 IU/kg phytase improved weight gain.Considering the total period of 42 d,2000 IU/kg phytase had better weight gain and feed conversion ratio,respectively.