小麦替代玉米饲粮添加木聚糖酶对生长猪生长性能、结肠菌群和氮排放的影响

Effects of Xylanase Supplementation in Diets with Corn Replaced by Wheat on Growth Performance,Intestinal Microbiota and Nitrogen Emissions of Growing Pigs

本试验旨在研究小麦替代玉米饲粮添加木聚糖酶对生长猪生长性能、结肠菌群和氮排放的影响。试验选用126头体重约为45 kg的"杜×长×大"三元杂交生长猪,分为7组,每组3个重复,每个重复6头猪。具体分组是:对照组(CON组)饲喂玉米-豆粕型基础饲粮,W20组饲喂20%小麦基础饲粮,W20X组饲喂20%小麦基础饲粮+200 U/kg木聚糖酶,W40组饲喂40%小麦基础饲粮,W40X组饲喂40%小麦基础饲粮+200 U/kg木聚糖酶,W60组饲喂60%小麦基础饲粮,W60X组饲喂60%小麦基础饲粮+200 U/kg木聚糖酶。试验期50 d。结果表明:与对照组相比,W60组平均日增重显著降低(P<0.05),料重比显著提高(P<0.05),结肠梭菌、大肠杆菌数量显著增加(P<0.05),粪氮排放量显著增加(P<0.05);W20X和W40X组间平均日增重、料重比差异不显著(P>0.05);W40X组结肠乳酸杆菌数量显著增加(P<0.05),大肠杆菌、梭菌数量显著降低(P<0.05),粪样pH、脲酶活性显著降低(P<0.05)。综上所述,木聚糖酶有明显的益生作用,能刺激肠道有益菌增殖并抑制有害菌增殖,减少氮排放。本试验条件下,添加200 U/kg木聚糖酶的小麦饲粮中,小麦最适替代量为40%。

This experiment was conducted to investigate the effects of xylanase supplementation in diets with corn replaced by wheat on growth performance, intestinal microbiota and nitrogen emissions of growing pigs. A total of 126 growing pigs （DurocxLandracexYorkshire） with an average body weight of 45 kg were allotted to 7 groups with 3 replicates in each group and 6 pigs in each replicate. The groups were control group （ CON group, corn-soybean meal-based diet）, W20 group （20% wheat-based diet）, W20X group （20% wheat- based diet＋200 U/kg xylanase） , W40 group （40% wheat-based diet）, W40X group （40% wheat-based diet＋200 U/kg xylanase）, W60 group （60% wheat-based diet）, and W60X group （60% wheat-based diet＋ 200 U/kg xylanase）, respectively. The experiment lasted for 50 d. The results showed as follows： compared with the control group, the average daily gain was significantly reduced （P〈0.05）, and feed to gain ratio was significantly increased （P〈0.05）, and the number of Clostridium and Escherichia coli in colonic and fecal ni- trogen emission were significantly increased in W60 group （P〈0.05） ; the average daily gain and feed to gain ratio were not significantly different between W20X group and W40X group （P〉0.05） ; the number of Lacto- bacillus was significantly increased （P〈0.05）, the number of Clostridium and Escherichia coli was significantly decreased （P〈0.05）, and fecal pH and urease activity were significantly decreased in W40X group （P〈 0.05 ）. In conclusion, the supplementation of xylanase in wheat-based diet can stimulate the proliferation of intestinal beneficial bacterium, and decrease nitrogen excretion. Results also indicate that the optimal replacement level of wheat is 40% in 200 U/kg xylanase diets for growing pigs.