Effects Of Lactobacillus Plantarum Cultures On Broilers

In order to comparative study the effect of sterilized fermentation cultures of L. plantarum and fermentation cultures with viable L. plantarum on growth performance, blood parameters, immune function and intestinal physiology of broilers, and to provide a theoretical basis for the using of Lactobacillus plantarum cultures as the additive in broilers production. The study was conducted as a 2(whether infected with E.coli O78 or not)×4(four diet managements) multifactor experimental design, to investigate the possible of using Lactobacillus plantarum cultures as a suitable antimicrobial growth promoter. A total of 240 one-day-old AA broiler chickens were randomly allotted to 8 groups with 3 replicates. The normal and infected broilers were fed with basal diet(groupⅠ, infected groupⅠ), the basal diet supplemented with 1.6 ‰ sterilized fermentation cultures of L. plantarum(groupⅡ, infected groupⅡ), 1.6 ‰ fermentation cultures with viable L. plantarum(groupⅢ, infected groupⅢ), and 0.1 ‰ aureomycin(groupⅣ, infected groupⅣ), respectively. The period of experiment was 42 d and was divided as starter(d 0-21) and finisher(d 21-42) two parts. The results showed that:1、Sterilized fermentation cultures of L. plantarum could improve grow performance in challenge and unchallenged trials at varied degrees, and increase significantly average daily gain in finisher period(P < 0.05), and feed conversion ratio were decreased. Moreover, the improvement effect with grow performence of fermentation cultures of L. plantarum was equal with fermentation cultures with viable L. plantarum, and better than antibiotic.2、Sterilized fermentation cultures of L. plantarum could improve blood biochemical index of broilers, repair the organic damage of infected broilers. Serum BUN was decrease in challenge and unchallenged trials, the level of serum AST and ALT were increase in unchallenged trial and decrease in challenge trial, indicated that it can improve metabolism and absorption of protein, enhance the growth rate accordingly. Meanwhile, Sterilized fermentation cultures of L. plantarum could enhance ALB significantly(P<0.05).3、In immunologic function aspect, Sterilized fermentation cultures of L. plantarum could enhance the immunity function thymus index and IgA were significant increase when compared with groupⅠ(P<0.05), fermentation cultures with viable L. plantarum could increase mRNA relative transcript level of IL-2, although the mRNA relative transcript level of IFN-γ in this two group was increased, there is no significant difference when compared with groupⅠ(P>0.05). After challenged, thymus index, IgA and the mRNA relative transcript level of IL-2 and IFN-γ were significant decreased by Sterilized fermentation cultures of L. plantarum and fermentation cultures with viable L. plantarum. The interaction effect between addition and infected factors have significant impact on thymus index and IgA(P<0.05).4、The height of intestinal villus of duodenum, jejunum and ileum were increased by sterilized fermentation cultures of L. plantarum and fermentation cultures with viable L. plantarum significantly. Group of Sterilized fermentation cultures of L. plantarum have more DGGE finger print, 35 strips, was higher than groupⅠ, indicate that the species of bacterium were increase, after infected, the strips were decrease, infected groupⅠ has only 27 strips, the number of strips were obviously increase in infected group Ⅱand Ⅳ. The similarity factor of group Ⅱ, Ⅲ and Ⅳwere 48.1%、66.3%、54.4% compared with groupⅠ, the similarity factor of infected group Ⅱ, Ⅲ and Ⅳwere 57.5%、59.2%、53.5% compared with infected groupⅠ, The similarity factor of group Ⅱwas lower when compared with groupⅠ, indicated that there is larger difference in microflora.In conclusion, under the normal and infected conditions, sterilized L. plantarum cultures could made the contribution to the growth performance, blood parameters and immune function of broilers, alter the secretion of antibody and expression of cytokines, reflect some anti inflammatory. Meanwhile, sterilized L. plantarum cultures could increase the height of intestinal villi significantly, have some effect on cecum bacterial diversity. Compared as a whole, sterilized fermentation cultures of L. plantarum and fermentation cultures with viable L. plantarum have equal feeding effect, all better than antibiotic.