Researching And Producing On Piglet Compound Probiotics With Lactobacillus Bifidobacterium And Bacillus Natto

With the development of industrial pig farming, the number and size of herd growing Increasingly, contacts become more frequently between the individual, opportunities for the spread of disease are increasing, the losses caused by diarrhea has become increasingly prominent. At present, Piglet Diarrhea Prevention mainly to the use of antibiotics, Antibiotics have the advantages of fast cure, but long-term and a great quantity use of antibiotics will cause residual contamination and break the balance of the host bacteria, Probiotics is natural, non-toxic, no side effects, non-polluting, non-residue, secure, reliable, and not resistance, and is regarded as a substitute for antibiotics, is a hot research at home and abroad. For the prevention and treatment of piglets diarrhea and Reducing the incidence of piglets diarrhea, this study is to develop a compound probiotics with Lactobacillus, Bifidobacterium, Bacillus natto, whice promote the growth of pigs ,improve feed efficiency and provide a theoretical basis and technical support for industrial production of compound probiotics .In this study, 64 faecal samples were obtained in piglets of 12～60 age from different pig farms in Province. The strains isolated from the faecal samples were analyzed by morphology,biochemical identification and PCR assay; The bionomics of Lactobacillus, Bifidobacterium, Bacillus natto was studied and researched by antimicrobial activity,pH tolerance,bile-salt resistance,digestive enzyme resistance and heat resistance,et al, thereby Strong resistance strains were screened; The ingredients for fermentative medium and Cryoprotectants were optimized by using the Quadratic Orthogonal Rotation Combination Design; and Response Surface Methodology was applied to analyze test data. The effect on application of compound probiotics was researched by Feeding trial of piglets.48 strains are identified as Gram-Positive,anaerobic and nonspore-bearing bacillus through the observation of colonial morphology and cultural character. Then, 18 strains are defined eventually as Lactobacillus through the physiological and biochemical identification and PCR assay. 7 strains were defined as L.reuteri,4 strains as L.acidophilus,2 strains as L.johnsonnii,1 strain as L. brevis, 1 strain as L.casei subsp.pseudoplantarum,1 strain as L. plantarum and 1 strain as L. jensenii.It is can be sure that Bifidobacterium, Bacillus natto and 6 strains as Lactobacillus can inhibit E.coli and Salmonella of swine and Bifidobacterium, Bacillus natto, strains DYF5,DYF1 and DYF8 have better tolerance on On the temperature, pH, bile-salt and digestive enzymes by tolerance screening test. By the single factor experiment, it is sured that The optimal growth condition of Lactobacillus is as follows: 37℃, pH6.5, inoculum amount 3%, medium volume 3/5, stationary culture 16h, then by using the Quadratic Orthogonal Rotation Combination Design and Response Surface Methodology, the optimum conditions of Lactobacillus fermentative medium are as follows: 5% soy peptone, 1% glucose, 1% yeast powder and 0.3% oligosaccharide, the average 16h OD620 reached a higher level of 1.073 and the optimum conditions of Cryoprotectant are as follows: 15% Sucrose, 3% glycerine, 15% Sorbitol and 15% skimmed milk. the Average survival rate reached a higher level of 71.6%, The ratio is 1:1(bacteria suspension (v):Cryoprotectant (v) ).The results of feeding trial of piglets showed that compound probiotics can remarkably raise piglets daily weight gain and feed efficiency, reduce the rate of piglets diarrhea, enhance economic efficiencyIn short, Lactobacillus has more types in Healthy piglets intestine,and L.acidophilus,L. reuteri,L.casei,Bifidobacterium and Bacillus Natto has strong tolerance with environmental factors of the gastrointestinal tract. Then the probiotics that can be use to prevention and cure piglet diarrhea was completed base on the results.