Effects Of Different Bacillus Subtilis Used In Diets Without Antibiotics On Growth Performance, Antioxidant Capacity And Intestinal Morphology In Broiler

This study was conducted to determine the effects of different sources of Bacillus subtilis on growth performance, serum antioxidant indices and microorganism in yellow-feathered broilers aged from 43 to 63 days. A total of 1800 43-day-old yellow-feather broilers were randomly divided into five groups, Broilers in control group were fed a basal diet,and the others were fed the basal diet supplemented with 500 g/t marine sources Bacillus subtilis and 500 g/t land sources Bacillus subtilis and 50 g/t Maxus. Each group included six replicates(75 broilers per replicate). The experiment lasted for 21 days. Test chickens were feed intake and drinking water ad libitum. On 63 d at the end of feeding trial, 2 birds with the BW close to the average weight each repeat were randomly selected to collect the serums, and slaughtered to collect the small intestine and the intestinal mucosa samples. Besides, chymes in ileum were taken too. The samples of small intestine were used to observe the morphology,serum and mucosa samples were used to determined antioxidant capacity, and chymes was used to test the bacterial population.The results as following:(1) The loss of two kinds of bacillus subtilis under feed processing process was not obvious(P>0.05).(2) Compared with group 1, group 2 significantly decreased the feed conversion ratio of Chicken by 3.60% in the stage from 42 to 63 d(P<0.05).(3) Compared with the control group, group 4 significantly improved serum T-AOC content of yellow broilers(P <0.05). But, there were no significant difference in GSH, T-AOC and T-SOD of small intestine(P>0.05).(4) Compared with control group the groups with Bacillus subtilis and Maxus supplemented in diets didn't affect the villus height, crypt depth and villus height / crypt depth of duodenum and ileum in the yellow-feather broilers(P>0.05).(5) Compared with control group, group 2 significantly reduced the total bacterial content chymes in ileum(P <0.05).In conclusion: the two Bacillus subtilis all showed good stability. On the basis of adding500 g/t, there were no significant effect on the growth performance, antioxidant indices,intestinal morphology and the number of ileal bacterial flora in Yellow-feather Broiler.