不同非淀粉多糖复合酶在肉鸡小麦型饲粮中的应用效果

Application Effects of Different Non-Starch Polysaccharide Complex Enzymes on Wheat-Based Diets for Broilers

本试验旨在研究低能量水平的小麦型饲粮中添加不同非淀粉多糖（NSP）复合酶对肉鸡生长性能、消化道生理、屠宰性能、肠道微生物数量及经济效益的影响,以确定适宜的NSP复合酶.试验采用单因子完全随机设计,选取900只1日龄的科宝肉公鸡,按体重无差异原则随机分为5个组,正对照组（PC组）饲喂正常能量水平的基础饲粮;负对照组（NC组）饲喂在PC组饲粮的基础上降低350kJ/kg能量水平的饲粮;NSP复合酶组饲喂在NC组饲粮中分别添加NSP复合酶1（300g/t）、NSP复合酶2（300 g/t）、NSP复合酶3（500 g/t）的饲粮,每个组10个重复,每个重复18只鸡.试验分为前期（1～21 d）、后期（22 ～42 d）2阶段进行.结果表明：1）各组在试验各阶段的平均体重、平均体增重、平均采食量、料重比差异均不显著（P＞0.05）;与PC组相比,NC组平均体重、平均体增重略低（P＞0.05）,料重比均增加（P＞0.05）,而添加NSP复合酶后有所改善.2）各组第21和42天的肌胃、腺胃、十二指肠、空肠、回肠、盲肠相对重量差异均不显著（P＞0.05）;与NC组相比,NSP复合酶1组、NSP复合酶2组第21和42天的空肠、回肠相对重量降低（P＞0.05）,盲肠相对重量提高（P＞0.05）.各组第21和42天的十二指肠、空肠、回肠、盲肠相对长度差异均不显著（P＞0.05）;与PC组相比,NC组各肠段相对长度（第21天十二指肠相对长度除外）均提高（P＞0.05）,与NC组相比,NSP复合酶1组、NSP复合酶2组第21和42天的空肠、回肠相对长度均降低（P＞0.05）.3）试验第21天,与PC组相比,NSP复合酶组十二指肠隐窝深度显著提高（P＜0.05）,NC组空肠隐窝深度显著提高（P＜0.05）;各组间各肠段肌层厚度差异均不显著（P＞0.05）.试验第42天,与PC组相比,其余组十二指肠绒毛高度均降低（P＞0.05）;与NC组相比,添加NSP复合酶后空肠绒毛高度显著降低（P＜0.05）.4）各组屠宰性能差异均不显著（P＞0.05）;与PC组相比,NC组的腹脂率有所下降（P＞0.05）,与NC组相比,NSP复合酶3组屠宰率、半净膛率、全净膛率、胸肌率均有所提高（P＞0.05）.5）各组第7、21、42天的大肠杆菌、乳酸杆菌、双歧杆菌数量差异均不显著（P＞0.05）.与PC组相比,NC组第7、42天大肠杆菌、乳酸杆菌数量和第7、21、42天双歧杆菌数量有所降低（P＞0.05）.与NC组相比,NSP复合酶1组、NSP复合酶2组第42天乳酸杆菌、双歧杆菌数量有所提高（P＞0.05）.6）以PC组利润为100％,与之相比,NSP复合酶1组提高的利润幅度最大.从结果中可以看出,在小麦型饲粮中降低一定能量水平后添加NSP复合酶可在一定程度上改善肉鸡生长性能、肠道形态和肠道微生态环境,并可不同程度地提高养殖经济效益.综合考虑,本试验中NSP复合酶1的应用效果最优.

This experiment was conducted to investigate the effects of dietary different non-starch polysaccharide （NSP） complex enzymes on growth performance,digestive tract physiology,carcass performance,the number of intestinal microorganism and economic efficiency of broilers fed wheat-based diets.A total of 900 Cobb male broilers aged 1 day were randomly assigned to 5 groups.A positive control group （PC group） was fed a basal diet with normal energy level,and a negative control group （NC group） was fed a diet with a lower energy level （350 kJ/kg metabolizable energy reduction from PC group diet）.Other three complex enzyme groups were fed the NC group diets added with NSP complex enzyme 1 （300 g/t）,NSP complex enzyme 2 （300 g/t） and NSP complex enzyme 3 （500 g/t）,respectively.This experiment included 2 periods,early period （1 to 21 d） and later period （22 to 42 d）.The results showed as follows：1） there were no significant differences in the average body weight,average body weight gain,average feed intake and feed/gain among all groups in every period of the experiment （P 〉 0.05）.Compared with PC group,the average body weight and average body weight gain in NC group were slightly decreased （P 〉 0.05）,and the feed/gain was increased （P 〉 0.05）,but adding NSP complex enzymes could improve those indices.2） There was no significant difference in the relative weight of muscular stomach,glandular stomach,duodenum,jejunum,ileum and cecum on 21 d and 42 d among all groups （P 〉 0.05）.Compared with NC group,the relative weight of jejunum and ileum on 21 d and 42 d in NSP complex enzyme 1 group and NSP complex enzyme 2 group was decreased （P 〉 0.05）,and the relative weight of cecum was increased （P 〉 0.05）.There was no significant difference in the relative length of duodenum,jejunum,ileum and cecum on 21 d and 42 d among all groups （P 〉 0.05）.Compared with PC group,the relative length of intestine （expect for duodenum on 21 d） in NC group were increased （P 〉0.05）.Compared with NC group,the relative length of jejunum and ileum on 21 d and 42 d in NSP complex enzyme 1 group and NSP complex enzyme 2 group was decreased （P 〉 0.05）.3） On 21 d,compared with PC group,the crypt depth of duodenum in NSP complex enzyme groups was significantly increased （P 〈 0.05）,and the crypt depth of jejunum in NC group was significantly increased （P 〈0.05）.There was no significant difference in the intestine muscular thickness among all groups （P 〉 0.05）.On 42 d,compared with PC group,the villus height of duodenum in other groups was decreased （P 〉 0.05）.Adding NSP complex enzymes significantly decreased the villus height of jejunum compared with NC group （P 〈 0.05）.4） There was no significant difference in carcass performance among all groups （P 〉 0.05）.Compared with PC group,the percentage of abdominal fat in NC group was decreased （P 〉 0.05）.The dressing percentage and the percentages of half-eviscerated yield,eviscerated yield and breast muscle in NSP complex enzyme 3 group were slightly improved compared with NC group （P 〉 0.05）.5） There was no significant difference in the number of Escherichia coli,Bifidobacteria and Lactobacillus on 7,21 and 42 d among all groups （P 〉 0.05）.Compared with PC group,the number of Escherichia coli and Lactobacillus on 7 and 42 d and the number of Bifidobacteria on 7,21 and 42 d in NC group were slightly decreased （P 〉 0.05）.Compared with NC group,the number of Bifidobacteria and Lactobacillus in NSP complex enzyme 1 group and NSP complex enzyme 2 group on 42 d was increased （P 〉0.05）.6） As the profit in PC group of 100%,adding NSP complex enzyme 1 could get the largest profit.In conclusion,dietary NSP complex enzymes in wheat-based diets with lower energy level can improve the growth performance,intestinal morphology and intestinal microorganism quantity; the economic efficiency is also improved in different degrees.In this experiment,the NSP complex enzyme 1 can obtain the best application effect.