枯草芽孢杆菌B7对肉鸡生长性能及免疫性能的影响

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42 d。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。

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

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, 2×10⁵,5×10⁵,8×10⁵ and 1×10⁶ 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 Ⅱ 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 5×10⁵ CFU/g Bacillus subtilis B7 in diet could improve the growth performance and enhance the immune function of broilers. These results indicated that the 5×10⁵ CFU/g was the best supplementation.