Effects of Bacillus licheniformis on Intestinal Structure and Cecum Microflora in Mayu Broiler Chickens

The experiment was conducted to study the effects of Bacillus licheniformis on intestinal structure and cecal gut microflora in Mayu broiler chickens. Three hundred one-day-old broiler chickens were randomly divided into 5 groups with 4 replicates each and 15 broilers in each replicate. Group Ⅰwas fed with the basal diet as the control group without any antibiotics; the experimental groups (groups Ⅱ,Ⅲ,Ⅳ) were fed with the basal diet supplemented with 50,100 and 200 mg/kg of Bacillus licheniformis,respectively; the group Ⅴ was fed with the basal diet supplemented with 30 mg/kg Bacitracin zinc and 6 mg/kg Kangdisu sulfas. The experiment lasted for 70 days. The results indicated that: at 28 days of age,the villous height (VH) of group Ⅱ was 11.35% higher than that of group Ⅰ,5.81% higher than that of group Ⅴ,the quantity of Escherichia coli in cecum of group Ⅱ was lower than that of group Ⅰ (P0.05),the quantity of Lactobacillus and Bacillus bifidus of group Ⅱ were higher than that of group Ⅴ (P0.05); at 70 days of age,the cryptae depth (CD) of groups Ⅲ and Ⅳ were 25.67%,24.72% lower than that of groupⅠ,the differences were significantly (P0.05),the quantity of Escherichia coli in cecum of experimental groups was lower than that of group Ⅰ (P0.05),the quantity of Lactobacillus and Bacillus bifidus of group Ⅳ was higher than that of group Ⅴ (P0.05). In conclusion,dietary Bacillus licheniformis supplementation was beneficial to the development of intestinal and the balance of cecum microflora,dietary Bacillus licheniformis level (50 mg/kg in early time and 200 mg/kg in latter time) could optimize intestinal structure and inhibit the growth of harmful bacteria in the cecum significantly.