Effect Of Pediococcus Pentosaceus PP-23 On The Growth And Immunological Ability Of AA Broilers And Oreochromis Niloticus

Pediococcus pentosaceus,as a kind of lactic acid bacteria,has the characteristics of green,pollution-free,and residue-free,which can inhibit the proliferation of pathogenic bacteria,improve the intestinal micro-ecological environment,and enhance the immunity of breeding animals,to reduce the body fat deposition of farmed animals.However,in the current research,the same strain of probiotics is applied to different cultured animals,and there are few reports on the influence of the same strain of probiotics on the growth and immune performance of different cultured animals.In this study,in order to further promote the application of Pediococcus pentosaceus PP-23 in the production of different cultured animals,expand is application scope,and promote the development of animal husbandry and aquaculture through healthy production mode,Pediococcus pentosaceus PP-23 was added to the diet of cultured animals to study its effects on growth performance,intestinal morphology and immune related gene expression of AA Broilers and Oreochromis niloticus.The results are as follows:(1)Morphological identification and growth curve determination of Pentosaceus pentosaceus PP-23.The colony of Pentosaceus pentosaceus PP-23 colonies appear round,milky white,smooth,convex,neatly edged,opaque,and grow slowly.After anaerobic culture for 24 hours,itcould grow to 2-5 mm in diameter.The slide of Pentosaceus pentosaceus PP-23was made,after Gram staining,it was observed under microscope.It was found that the cells were spherical,not elongated,and many cells were connected in one piece,showing a short chain spherical shape.Gram staining was positive.Through the determination of the growth curve found that the anaerobic culture more than 16 hours strain concentration to reach a stable state.(2)Effect of Pentosaceus pentosaceus PP-23 on the growth and immunity effect of AA broilers.After three weeks of breeding experiment of AA broiler,it was found that Pentosaceus pentosaceus PP-23 could significantly improve the growth and immune effect of AA broilers,and when the feed concentration was 1×10~7 CFU/g,the growth promoting effect was the best.Compared with the control group,addition the optimal concentration of Pentosaceus pentosaceus PP-23 could increase the daily gain of broilers by 7.71%;increase the full evisceration rate by 4%and the half evisceration rate by 2.8%;increase the thymus index by51.21%,spleen index by 11.39%,and the bursa index by 59.51%;increase the amylase(α-AMS)in small intestine by more than 50%;and decrease the expression of IL-1βand IFN-γin jejunum and spleen.The villus height,crypt depth,ratio of villus to crypt and muscle thickness of duodenum were increased by 40.5%,28.28%,8.35%and 20.62%,respectively;the villus height,crypt depth and ratio of villus to crypt of jejunum were increased by 50.54%,13.97%and36.18%,respectively;the villus height,thickness of muscle layer and ratio of villus to crypt of ileum were increased by 41.54%,3.61%and 48.72%,respectively.(3)Effects of Pediococcus pentosaceus PP-23 on growth and immunity of Oreochromis niloticus.After two months of tilapia culture experiment,it was found that the best growth index was obtained when the concentration of Pediococcus pentosaceus PP-23 was 1×10~7CFU/g.Compared with the control group,adding the optimal concentration of Pediococcus pentosaceus PP-23 could increase the specific growth rate of Oreochromis niloticus by 10%;significantly increase the activity of amylase and alkaline phosphatase in serum of Oreochromis niloticus;decrease the gene expression levels of IL-1βand IFN-γin head kidney and spleen of Oreochromis niloticus;increase the midgut villus length,the depth of fossa,the ratio of cashmere to saphenous and the thickness of muscular layerby 23.89%,52.93%,20.09%and16.98%respectively.In conclusion,adding Pediococcus pentosaceus PP-23 in the feed can significantly improve the growth rate and immune ability of AA Broilers and Oreochromis niloticus,and the best growth promotion effect is obtained when the addition amount is 1×10~7 CFU/g.This experiment shows that Pediococcus pentosaceus PP-23 has good application potential as a microbial feed additive.