Effects Of Two Probiotics On The Growth And Immune Indexes Of Litopenaeus Vannamei

The current shrimp farming industries often face problems of disease outbreading caused by pathogens brought from shrimp larva.Litopenaeid vannamei juveniles with multiple pathogen positives,which may usually be only available for common farms,were used as cultivated animals of this study,to investigate effects of on growth and survival of shrimp fed with probiotics added diets under the circumstance of practical production.The experimental population of juveniles was fed for 60 d with Pseudoalteromonas sp.strain KL-3 2010 added diets and Exiguobacterium sp.strain KLC2 2014 added diets,respectively.The main research contents include the following aspects: 1 Characteristics of two stains ProbioticsAntagonistic analysis and protease characterization of a highly virulent pathogenic Vibrio parahaemolyticus(VPAHPND)were performed on a strain of Pseudomonas sp.And a microbacterium.The results showed that Pseudoalteromonas sp.KL-3 2010 had bacteriostatic effect on this strain of Vibrio parahaemolyticus,Pseudoalteromonas sp.KL-3 2010 and Exiguobacterium sp.KL-C2 2014 have protease activity.2 Analysis on the Results of Simply Fermented pellet feed added ProbioticsWith commercially available No.0 and No.1 shrimp pellet feed(Chia Tai Group Co.,Ltd.)as the basis for fermentation feed.The results showed that there was no sensory change in odor and color after 24h-36 h fermentation,and the granules became larger and softened.The results showed that there was no significant difference in odor and color.(P <0.05).The number of viable cells in the P.aeruginosa(P.KL-3 2010)was reduced to 0,The amount of reduction of 2 to 3 orders of magnitude.SDS-PAGE analysis showed that there was no change in protein bands before and after fermentation.3 Effects of Fermented Feed on Growth,Immune Index and Intestinal Dominant Bacteria ofLitopenaeus vannameiLitopenaeus vannamei juveniles with multiple pathogen positives,which may usually be only available for common farms,were used as cultivated animals of this study,to investigate effects of on growth and survival of shrimp fed with probiotics added diets under the circumstance of practical production.The experimental population of juveniles,which was detected positive of White spot syndrome(WSSV),Vibrio parahaemolyticus causing acute hepatopancreatic necrosis disease(VPAHPND),and Enterocytozoon hepatopenaei(EHP)was fed for 60 d with Pseudoalteromonas sp.strain KL-3 2010 added diets(P group),Exiguobacterium sp.strain KL-C2 2014 added diets(E group),two diets equal alternation(PE group)and normal diets control(C group),respectively.The results showed that P.KL-3 2010 diets could significantly improve the survival rate of shrimp by(213±43)%(P<0.01),while E.KL-C2 2014 diets significantly increased the specific growth rate of shrimp by(105.5±28.1)%(P<0.05),and the two diet alternation could simultaneously improve shrimp survival by(184±52)%(P<0.05)and specific growth rate by(70.6±32.8)%.The specific growth rates of all probiotics added diet groups began to surpass significantly the control group during 31–45 d cultivation(P<0.05).Feeding with P.KL-3 2010 diets and E.KL-C2 2014 diets significantly affected the species and quantity of dominant flora colonized in midgut.The study indicated that diets added with above probiotics may provide an practical approach for cultivation of shrimp even with multiple pathogens positive.