Effect Of Bacillus Subtilis And Bursin On The Growth Performance, Serum Biochemical, Immunity Function And Intestinal Microflora In Broilers

The arm of this present paper is to study the effects of Bacillus subtilis, Bursin (BS) and their interaction on the growth performance, metabolism, antioxidant, immune function and intestinal microflora in broilers.200 one-day-old Coob-500 broilers were randomly divdied into four groups with 5 replicates each and 10 broilers in each replicate. The control group (group I) was only fed basal diet. The BS group (group Ⅱ) was fed basal diet and injected with BS (0.01 mg/kg), at 4 and 7 day. Group Ⅲ was fed basal diet with 1×106cfu/g Bacillus subtilis. GroupⅣ was fed basal diet with 1×106cfu/g Bacillus subtilis and injested with BS (0.01 mg/kg), at 4 and 7 day. Meanwhile, group I and III were injected with normal saline. The trial lasted for 42 days and divided into the starter period (1-21 day) and the finisher period (22-42 day).Result:(1) Dietry supplementation with 1×106cfu/g B. subtilis singnificantly increased the body weight gain and decreased the feed conversion raitio in the starter period (P <0.05), but no significant effect on the feed intake. BS had no significant effect on the body weight gain, feed intake and feed conversion ratio, but had a tended to increase the body weight gain and decrase the feed conversion ratio during the starter period, finisher period and entire period. The interaction of B. subtilis and BS significant effect on body weight gain during the starter period and feed intake during the finisher and entire period (P<0.05), but have no significant effect on feed conversion ratio of broiler.(2) Dietry supplementation with B. subtilis, increased the concentrations of total TP, ALB and total TC in serum at 21 day (P<0.05), however B. subtilis had no significant effect on the concentrations of TP, ALB and TG in serum at 42 day (P> 0.05). Injection of BS increased the concentrations of TP and TC in serum at 21 day (P<0.05), but BS had no singnificant effect on TP, TC and TG at 42 day (P>0.05). The interaction of B. subtilis and BS had no significant effect on TP and ALB at 21 and 42 day (P>0.05), but had significant effect on TC and TG at 21 day (P<0.05). B. subtilis, BS and the interaction of B. subtilis and BS had no significant effect on the concentrations of BUN, IgG, IL-2, IL-6, FT3 and FT4 in serum at 21 and 42 day (P> 0.05).(3)5. subtilis increased the activity of CAT in serum at 21 day (P<0.05), and decreased the concentration of MDA in serum at 21 and 42 day (P<0.05). BS significantly increased the activity of CAT in serum at 21 and 42 day (P<0.05). But B. subtilis and BS had no significant effect on the activities of SOD and GSH-Px in serum at 21 and 42 day (P>0.05). The interaction of B. subtilis and BS had significant effect on the activity of CAT in serum at 21 day and on the concentration of MDA in serum at 42 day (P<0.05). B. subtilis had no significant effect on the activities of SOD, CAT and GSH-Px and the concentration of MDA in liver at 21 and 42 day (P>0.05), while BS significantly increased the activity of GSH-Px in liver at 42 day (P<0.05). The interaction of B. subtilis and BS had significant effect on the concentration of MDA in liver at 21 day and on the activity of GSH-Px in liver at 42 day (P<0.05).(4)At 21 and 42 day, adding B. subtilis had no significant effect on broiler immune organ index (P>0.05), but injection BS significantly increased broiler thymus index at 21 day (P<0.05). B. subtilis and BS significantly increased the ConA-stimulated lymphocyte proliferation conversion ratio (P<0.05), but no significant effect on the level of HI antibody against ND (P>0.05). The interaction of B. subtilis and BS had no significant effect on broiler immune organ index, ConA-stimulated lymphocyte proliferation conversion ratio and level of HI antibody against ND(P>0.05).(5) At 42 day, B. subtilis significantly increased the activity of duodenal amylase and BS significantly improved the jejunum villus height of broiler (P<0.05). However, B. subtilis and BS had no significant effect on jejunum crypt depth, VH/CD and on the activities of duodenal lipase and trypsin (P>0.05), at 21 and 42 day. The interaction of B. subtilis and BS had no significant effect on the structure of jejunum mucosa and on the activity of digestive enzyme in duodenal of broiler (P>0.05).(6) At 21 day, adding B. subtilis increased the number of Bacillus in cecal of broiler (P<0.05). At 42 day, B. subtilis decreased the number of E. coli, increased the number of Lactobacillus spp. and Bacillus in cecal of broiler (P<0.05). Injection BS significsntly increased the number of Bifidobacterium spp. in cecal of broiler at 42 day (P<0.05), but no significant effect on the number of cecal flora at 21 day (P> 0.05). The interaction of B. subtilis and BS had significant effect on the number of Bifidobacterium spp. in cecal of broiler at 42 day (P<0.05).DGGE analysis showed that B. subtilis, BS and their combination had affects on the structure of cecal flora of broiler, and combined effect is more obvious than alone. However, B. subtilis, BS and their combination had no significant effect on the number of advantage flora in cecal flora of broiler (P>0.05).Conclusion:All the above indicators showed that adding B. subtilis could promote growth performance, antioxidant capacity, immune function and gut microflora of broiler. Injection BS could promote antioxidant capacity, immunity and improved intestinal morphology of broiler. Combination B. subtilis and BS also improve growth performance, antioxidant capacity and gut microflora of broiler, but the effect is not better than alone B. subtilis.