| This experiment aimed to construct an investigation of the effects of recombinant Bacillus subtilis SE1 spores(Our previous studies,we displayed Salmonella pullorum OmpC protein on the B.subtilis spore coat using the spore coat protein CotB as a fusion partner.)on growth performance,immunity function and antioxidant capacity in broilers.A total of 120 one-day-old broilers were randomly divided into 3 groups(4 replicates per treatment)as follow:The control group was fed the basal diet;168 group was fed the basal diet supplemented with spores of wild-type Bacillus subtilis 168(1.0×106 cfu spores/g);Group SE1 was fed with a basal diet supplemented with spores of recombinant B.subtilis(1.0×106 cfu spores/g).The feeding trial conducted for 42 days.Daily diet and body weight of each pen were weighted on the morning of 28d and 42 d.Growth performance,immune organ index,immune organ structure,T lymphocyte proliferation,liver and serum antioxidant,digestive enzyme,intestinal microflora,PCR-DGGE fingerprint of cecum microflora,OmpC-specific serum IgG titers and intestinal mucosal IgA titers was calculated.The results showed as follow:1.SE1 group had significantly lower F/G(P<0.01)than the control group in the 7-28 d.Jejunum lipase activity in SE1 group was significantly higher than that in control group on 28d(P<0.05)and 42d(P<0.01).Jejunum protease activity in SE1 group was significantly higher than that in control group on 42d(P<0.05).Ileum protease activity in SE1 group was significantly higher than that in control group on 28d and 42d(P<0.01).There were no significant differences on the weight gain and amylase activity of broilers.2.In SE1 group,area of the fabricius lobules and cortex was enlarged and the lymphocytes arrangement was closer;the thymus cortex was thicker,the lymphocytes was denser;the spleen cellular arrangement was closer,white pulp was enlarged on 28d.T lymphocyte proliferation of SE1 group was significantly higher than the control group(P<0.05)on 28d.There were no significant effects of immune organ index of broilers.3.SE1 group had higher CAT activities in the liver and SOD activities of serum(P<0.05)on 42d and lower MDA content in liver(P<0.01)or serum(P<0.05)than the control group on 28d.There were no significant effects of GSH-PX activities in liver or serum.4.Compared with the control group,the ratio of E.coli in ileum and cecum of broilers in SE1 group was significantly decreased,on 28d(P<0.05)and 42d(P<0.01).In SE1 group,the number of Lactobacillus in ileum of broilers was significantly increased(P<0.01)on 42d,the number of Lactobacillus in cecum was higher than the control group(P<0.05)on 28d and 42d.PCR-DGGE fingerprint of cecum microflora showed that the abundance,evenness and Shannon-Wiener of cecum microflora in SE1 group was higher(P<0.01)than the control group,while the similar degree of cecum diversity in SE1 group was 26.78%and 15.61%higher on 28d and on 42d respectively than the control group.In PCR-DGGE fingerprint of cecum microflora,SE1 group had a significant larger number of bands compared with the control group.5.OmpC-specific serum IgG levels of SE1 group had significantly higher than 168 group and the control group(P<0.01)on 28d,that higher than 168 group(P<0.05)and the control group(P<0.01)on 42d.P/N(168/Control)<1.5,P/N(SE1)>2.1,on 28d and 42d.OmpC-specific intestinal mucoss IgA titers in SE1 group was no significant effects with that in the control group(P>0.05),but P/N(168/Control)<1.5,P/N(SE1)>2.1,on 28d and 42d. |
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