枯草芽孢杆菌对肉鸡生长性能、肠道组织形态和盲肠微生物组成的影响

Effects of Bacillus subtilis on Growth Performance,Intestinal Morphology and Cecal Microbial Composition of Broilers

本试验旨在研究枯草芽孢杆菌对肉鸡生长性能、肠道组织形态及盲肠微生物组成的影响。试验选用270只1日龄平均体重为(42.11±0.10) g的雄性肉鸡,随机分为3组,每组6个重复,每个重复15只鸡。阴性对照组(NC组)饲喂基础饲粮,阳性对照组(PC组)在基础饲粮中添加250 g/t杆菌肽锌,试验组(BS组)在基础饲粮中添加750 g/t枯草芽孢杆菌。试验期为42 d。结果表明:1)与NC组相比,BS组42日龄的平均体重极显著提高(P<0.01);22~42日龄平均日增重极显著提高(P<0.01),平均日采食量显著提高(P<0.05),料重比显著降低(P <0.05);1~42平均日增重极显著提高(P<0.01),料重比显著降低(P<0.05),欧洲效益指数显著提高(P<0.05)。与NC组相比,PC组42日龄的平均体重显著提高(P<0.05);1~42日龄料重比显著降低(P<0.05),欧洲效益指数极显著提高(P<0.01)。2)与NC组相比,BS组的回肠绒毛高度/隐窝深度显著提高(P<0.05)。各组之间十二指肠和空肠的绒毛高度、隐窝深度和绒毛高度/隐窝深度无显著差异(P>0.05)。3)与NC组相比,饲粮添加枯草芽孢杆菌和杆菌肽锌均未改变肉鸡盲肠微生物多样性,但提高了盲肠中与碳水化合物代谢和丁酸、丁酸盐产生有关的微生物黄杆菌属(Flavonifractor)、劳特氏菌属(Blautia)、粪杆菌属(Faecalibacterium)的相对丰度。综上所述,饲粮添加枯草芽孢杆菌可以提高肉鸡的生长性能和回肠绒毛高度/隐窝深度,其良好的促生长性能可能与Flavonifractor、Blautia、Faecalibacterium的相对丰度增加有关,可作为肉鸡抗生素潜在替代品。

The purpose of this experiment was to study the effects of Bacillus subtilis on growth performance,intestinal morphology and cecal microbial composition of broilers.A total of 270 one⁃day⁃old male broilers with average body weight of(42.11±0.10)g were randomly divided into 3 groups with 6 replicates in each group and 15 chickens in each replicate.Broilers in the negative control group(NC group)were fed a basal diet,broilers in the positive control group(PC group)were fed the basal diet added 250 g/t bacitracin zinc,and broilers in the test group(BS group)were fed the basal diet added 750 g/t Bacillus subtilis.The experimental period was 42 days.The results showed as follows:1)compared with the NC group,the average body weight at 42 days of age of BS group was significantly increased(P<0.01);the average daily gain during 22 to 42 days of age was significantly increased(P<0.01),the average daily feed intake was significantly increased(P<0.05),and the feed to gain ratio was significantly decreased(P<0.05);the average daily gain during 1 to 42 days of age was significantly increased(P<0.01),the feed to gain ratio was significantly decreased(P<0.05),and the European benefit index was significantly increased(P<0.05).Compared with the NC group,the average body weight at 42 days of age of PC group was significantly increased(P<0.05);the feed to gain ratio during 1 to 42 days of age was significantly decreased(P<0.05),and the European benefit index was significantly increased(P<0.01).2)Compared with the NC group,the villi height/crypt depth in ileum of BS group was significantly increased(P<0.05).There were no significant differences on villi height,crypt depth and villi height/crypt depth in duodenum and jejunum among all groups(P>0.05).3)Compared with the NC group,dietary Bacillus subtilis and bacitracin zinc did not change the cecal microbial diversity of broil⁃ers,but increased the relative abundance of Flavifractor,Blautia and Faecalibacterium in cecum,which were related to carbohydrate metabolism and production of butyrate and butyric acid.In conclusion,dietary Bacillus subtilis can significantly improve the growth performance and ileal villi height/crypt depth of broilers.The good growth promoting performance may be related to the increase of the relative abundance of Flavifractor,Blautia and Faecalibacterium,which can be used as a potential substitute of antibiotics in broilers.