枯草芽孢杆菌B7对肉鸡生长性能及免疫性能的影响

Effects of Bacillus Subtilis on Growth Performance and Immune Function of Broilers

试验旨在研究肉鸡日粮中添加枯草芽孢杆菌B7对其生长性能及免疫功能的影响。将200只1日龄健康爱拔益加肉雏鸡随机分成5组,每组4个重复,每个重复10只。对照组饲喂基础日粮,试验Ⅰ、Ⅱ、Ⅲ、Ⅳ组分别在基础日粮中添加2×105、5×105、8×105和1×106 CFU/g枯草芽孢杆菌B7。试验期42d。结果表明:①在整个试验阶段,除29～35日龄外,试验Ⅱ组肉鸡的日增重均高于对照组,料重比均低于对照组;36～42日龄时,与对照组相比,试验Ⅱ组肉鸡的日增重显著提高了10.25%(P<0.05),料重比显著降低了14.83%(P<0.05)。②28日龄时,试验Ⅱ组脾脏指数高于对照组31.96%,差异显著(P<0.05);除14和28日龄外,试验Ⅱ组法氏囊指数均显著高于对照组(P<0.05);试验Ⅱ组新城疫抗体效价处于较高水平,28和35日龄时,试验Ⅱ组新城疫抗体效价分别高于对照组16.04%和18.09%,差异显著(P<0.05);21、35和42日龄时,试验Ⅱ组血清中IgG含量分别高于对照组81.94%、46.67%和15.63%,差异显著(P<0.05)。由此可知,添加5×105 CFU/g枯草芽孢杆菌B7能够提高肉鸡的生长性能,增强肉鸡的免疫功能,综合比较,试验Ⅱ组的5×105 CFU/g为枯草芽孢杆菌B7的最佳添加量。

This experiment was conducted to study the effect of Bacillus subtilis on growth performance and immunity in broilers. 200 one-day AA bilers with similar body weight were randomly divided into 5 groups with 4 replicates in each group, and with 10 broilers in each replicate. The groups received the same basal diet supplemented with 0, 2×10^5 , 5×10^5, 8×10^5 and 1×10^6 CFU/g of Bacillus subtilis, respectively. The feeding trial lasted 42 days. The results showed as follows., in every test period, compared with the control group, the average daily gain in the group Ⅱ was higher, the F/G in group Ⅱ was lower, except at the age of 29 to 35 days. At the age of 36 to 42 days, the average daily gain in group Ⅱ increased significantly by 10.25% （P〈0.05）, the F/G in group Ⅱ decreased significantly by 14.83% （P〈0.05）, at the age of 28 days, the spleen index was significant higher than those in the control group, higher above 31.96 % （P〈0.05） ,the bursa of fabricius index in group Ⅱ was significant higher than those in the control group, except at the age of 14 and 28 days, the antibody titer in group U was higher than those in the control group, at the age of 28 and 35 days, higher above 16.04% and 18.09%, respectively（P〈0.05） ;at the age of 21,35 and 42 days, the serum immunoglobulin G concentrations in group Ⅱ was higher those in control group, higher above 81.94%, 46.67% and 15.63% ,respectively（P〈0.05）. In conclusion, adding 5×10^5 CFU/g Bacillus subtilis B7 in diet could improve the growth performance and enhance the immune function of broilers. These results indicated that the 5×10^5 CFU/g was the best supplementation.