Effect of Bacillus coagulans on Growth Performance,Antioxidant Capacity and Immune Function of Laying Chicks Infected with Salmonella Pullorum
[Objective]The experiment was conducted to investigate the effects of feed supplementation with avian autochthonous Bacillus coagulans BC-362 on the growth performance,antioxidant capacity and immune function of laying chicks infected with Salmonella Pullorum(SP).[Method]150 one-day-old healthy Jinghong-1 SPF laying chicks with similar body weights were randomly divided into control group(group A),probiotic group(group B),SP+probiotic group(group C),SP+antibiotic group(group D),and SP model group(group E).Each group was comprised of 6 replicates,with five chicks per replicate.The basal diet was given to groups A,D,and E,while groups B and C were supplemented with 1.0×108 CFU/g of Bacillus coagulans in the basal diet.At 7 days,groups C,D,and E were gavaged with 1.0×109 CFU of SP(0.5 mL),and groups A and B were gavaged with the same dose of sterile water.Additionally,group D was supplemented with 0.375 g/kg of neomycin sulphate in the basal diet starting from the second day of gavage.The experimental period lasted for 14 days.At 14 days,the growth performance of the chicks was measured;Blood,immune organs,and jejunum tissues were collected to determine levels of serum antioxidant and immunity,immune organ index,jejunum morphology,CD3 immunohistochemistry expression,and transcript levels of inflammatory and antioxidant-related genes.[Result]①Compared with group A,the average daily gain(ADG)of laying chicks in group B was significantly increased,and the feed to gain ratio(F/G)was significantly decreased(P＜0.05).In group E,both the average daily feed intake(ADFI)and ADG of laying chicks were significantly decreased(P＜0.05).Compared with group E,the ADFI and ADG of laying chicks in groups C and D were significantly increased(P＜0.05).There were no significant differences in ADFI,ADG,and F/G of laying chicks between groups C and D(P＞0.05).②Compared with group A,the activities of serum superoxide dismutase(SOD)and catalase(CAT)of laying chicks were significantly higher(P＜0.05)in group B,and the activities of serum SOD,CAT and glutathione peroxidase(GSH-Px)and total antioxidant capacity(T-AOC)of laying chicks were significantly decreased(P＜0.05),while the malondialdehyde(MDA)content were significantly increased(P＜0.05)in group E.Compared with group E,serum SOD activity and T-AOC of laying chicks were increased significantly(P＜0.05),and the MDA content of laying chicks were decreased significantly(P＜0.05)in both groups C and D.The activities of serum CAT and GSH-Px of laying chicks in group C were significantly higher than those in group D(P＜0.05).③Compared with group A,the serum IgA and IgM contents of laying chicks were significantly higher in group B(P＜0.05),while the serum IgA,IgM and IgG contents of laying chicks were significantly lower in group E(P＜0.05).Compared with group E,the serum IgA,IgM,and IgG contents of laying chicks were significantly increased in groups C and D(P＜0.05),with the IgM content of laying chicks in group C was significantly higher than that in group D(P＜0.05).④Compared with group A,the thymus index of laying chicks were significantly higher in group B(P＜0.05),and the immune organ index of laying chicks were significantly lower in group E(P＜0.05).The thymus and bursa indices of laying chicks were significantly higher in groups C and D compared to group E(P＜0.05).The spleen index of laying chicks were significantly higher in group C than that in group D(P＜0.05).⑤Compared with group A,there was no significant difference in the number of goblet cells and CD3 expression in jejunal tissues of laying chicks in group B(P＞0.05),while the numbers of goblet cells and CD3 expression were significantly reduced in group E(P＜0.05).The expression of CD3 in jejunal tissues of laying chicks were significantly higher in groups C and D compared to group E(P＜0.05),and the number of goblet cells in jejunal tissues of laying chicks in group C was significantly higher than that in group D(P＜0.05).⑥Compared with group A,the relative expression of inflammation-related genes Toll-like receptor 4(TLR4),myeloid differentiation factor 88(MYD88),nuclear factor kappa-B(NF-κB)and interleukin-6(IL-6)in jejunal tissues of laying chicks were significantly downregulate in group B(P＜0.05),while the relative expression of antioxidant-related genes Kelch-like ECH associated protein 1(Keap1),glutathione peroxidase 1(GPX1),and glutamate-cysteine ligase catalytic subunit(GCLC)were significantly upregulate(P＜0.05).The relative expression of inflammation-related genes TLR4,MYD88,IL-1β,NF-κB and IL-6 in jejunal tissues of laying chicks in group E was significantly upregulated(P＜0.05),while the relative expression of antioxidant-related genes NADH quinone dehydrogenase 1(NQO1),heme oxygenase 1(HO-1),GCLC,and nuclear factor E2-associated factor(Nrf2)were significantly downregulated(P＜0.05).In groups C and D,the relative expression of inflammation-related genes TLR4,MYD88,IL-1β,NF-κB and IL-6 of laying chicks were significantly lower than those in group E(P＜0.05),whereas the relative expression of antioxidant-related gene NQO1 and GCLC was significantly higher than in group E(P＜0.05).Compared with group D,the relative expression of TLR4,MYD88,and IL-1β was significantly downregulate(P＜0.05),and the relative expression of Keap1 and GCLC was significantly upregulate in group C(P＜0.05).[Conclusion]The supplementation of avian autochthonous Bacillus coagulans BC-362 to diets improved the growth performance of SP-infected laying chicks and enhanced the body's antioxidant and immune capabilities,thereby reducing the intestinal inflammatory response infected with SP in laying chicks.
万方数据
维普
