The Effects And Mechanism Of Bacillus Coagulans On Production Performance Of Yellow Broilers

Purpose:This experiment was conducted to investigate the effects and mechanism of Bacillus coagulans on production performance of yellow broilers,which will provide the thearetical basis for the application of Bacillus coagulans in yellow broilers feed.Method:A total of 360 one-day-old yellow chicks were randomly allocated to 4 groups with 6 replicates per group and 15 chicks per replicate.The broilers were randomly subjected to one of the following 4 treatments for 70 days:control group(group Ⅰ,fed a basal diet)and three treatments(group Ⅱ,Ⅲ,Ⅳ,fed the basal diet with 100,200 and 300 mg/kg Bacillus coagulans,respectively).Growth and slaughter performance,serum biochemical indices,antioxidant function,immune organ index,duodenal digestive enzyme activity,content of nitrogen in excrement,caecal microflora and intestinal morphology in the four groups were compared and analysed.Results:1 Growth and slaughter performanceOn days 1 to 28,group Ⅲ significantly increased the average daily gain(ADG)and body weight gain(BWG),and decreased the feed/gain ratio(F/G)compared with group Ⅰ(P<0.05).On days 1 to 70,compared with group I,group Ⅲ,Ⅳnotably increased ABG and BWG,and decreased the F/G(P<0.05).The survival rate of group Ⅱ,Ⅲ was higher than group Ⅰ(P<0.05).The breast muscle percentage of group Ⅲ,Ⅳ was notably higher than group Ⅰ on day 70(P<0.05).2 Serum biochemical indexOn 28th day,in terms of alkaline phosphatase(ALP)activity,group Ⅱ,Ⅲ(P<0.01)and group Ⅳ(P<0.05)were remarkable higher than group Ⅰ.On 70th day,ALP,ALB and TP were increased by group Ⅲ compared with that of group I,and the difference was significant(P<0.05).There had been a marked decrease in URE of group Ⅲ(P<0.01)and group Ⅳ(P<0.05)compared with group Ⅰ.3 Antioxidant functionOn 28th day,group Ⅲ markedly increased the total antioxidant capacity(T-AOC)and activity of superoxide dismutase(SOD)compared with group Ⅰ(P<0.05).The content of malonaldehyde(MDA)was decreased obviously by group Ⅱ,Ⅲ,Ⅳ(P<0.01).On 70th day,in terms of T-AOC in the serum,group Ⅲ,Ⅳ were significantly higher than group Ⅰ(P<0.05).The activities of SOD and CAT of group Ⅲ were markedly increased compared with group Ⅰ(P<0.05).In MDA,group Ⅲ,Ⅳ were significantly lower than group Ⅰ(P<0.05).4 Immune organ indexOn 28th day,comparing with group Ⅰ,group Ⅱ,Ⅲ remarkably improved Thymus index and Spleen index(P<0.05).In terms of Bursa index,group Ⅱ,Ⅲ,Ⅳ were higher than group Ⅰ(P<0.05).On 70th day,there were significant increase in Thymus index of group Ⅱ,Ⅲ compared with group I(P<0.05).The Spleen index and Bursa index of group Ⅲ were remarkably higher than group Ⅰ(P<0.05).5 Digestive enzyme activity of duodenumThe best amylase and trypsin activities of duodenum belonged to group Ⅲ,which were remarkably higher than group Ⅰ on days 28 and 70(P<0.05).6 The content of nitrogen in excrement of broilersIn terms of nitrogen in excrement,group Ⅱ,Ⅲ had an obvious decrease from group Ⅰ on day 28(P<0.05).The content of nitrogen of group Ⅲ was remarkably lower than group Ⅰ on day 70(P<0.05).7 Caecal microfloraOn 28th day,group Ⅲ could signif1cantly prove the Lactobacillus in cecum compared with group Ⅰ(P<0.05).On 70th day,in terms of E.coli,group Ⅲ had a lower level than that of group Ⅰ(P<0.05).8 The intestinal morphologyOn 28th day,comparing with group Ⅰ,group Ⅲ could significantly optimize intestinal morphology by promoting the villus height of jejunum and ileum,and shallowing the duodenal crypt depth(P<0.05).Group Ⅲ significantly increased the V/C value in duodenum(P<0.05).The V/C value of ileum in group Ⅲ(P<0.01)and group Ⅱ,Ⅳ(P<0.05)had an obvious improvement.In terms of duodenal wall thickness,group Ⅲ,Ⅳ were remarkably lower than group Ⅰ(P<0.05).On 70th day,the villus height of duodenum were distinctly heightened by group Ⅲ,Ⅳ compared with group Ⅰ(P<0.05),moreover,the villus height of jejunum and ileum also were higher in group Ⅲ(P<0.05).In the duodenal crypt depth,group Ⅱ,Ⅲ,Ⅳ were significantly more shallow than group Ⅰ(P<0.05).In comparision with group Ⅰ,Ⅲ had extremely improvements in the V/C value of duodenum and ileum(P<0.01),and group Ⅱ were markedly enhanced the V/C value of duodenum and ileum(P<0.05),futhermore,group Ⅳ was remarkably higher in the V/C value of duodenum(P<0.05).In duodenal wall thickness,group Ⅱ,Ⅲ were obviously thinner than groupⅠ(P<0.05).Conclusion:1 The Bacillus coagulans added in yellow broilers feed can improve the growth and slaughter performance of broilers.2 Appropriate amount of Bacillus coagulans can improve the digestive absorption on nutrient and disease resistance for yellow broilers to promote the performance,related to the improvement of serum biochemical indices and antioxidant function,the raise of immunologic function and digestive enzyme activity,the decrease of nitrogen in the faeces,the optimization of cecal microbial flora structure and intestinal morphology.3 The suitable dosage of Bacillus coagulans added to the diet of yellow broilers is 2×108 cfu/kg.