Preparation Of A Compound Microecological Agent And Its Preliminary Application In The Production Of Piglets

In order to obtain high resistance, high biological activity of probiotic strains to study their physiological characteristics, so thar we can apply them to production. In this study, strains ZZS16 and strains LYP06-2 were isolated from healthy pigs’ feces and intestinal contents, traditional foods and other sources, they both showed strong resistance and potential probiotic properties, both of which can survive in artificial gastric juice, artificial intestinal fluid and different concentrations of bile environment, and maintain a high survival rate.According to bacterial colony morphology, strain staining, biochemical tests and 16S rDNA sequence analysis and homology comparison, strains ZZS16 was comprehensively identified as Bacillus subtilis, strains LYP06-2 as Lactobacillus plantarum. Bacillus subtilis ZZS16-3 can produce a variety of enzymes, such as protease, lipase, amylase, cellulase and xylanase enzymes, and it can inhibit Staphylococcus aureus, Lactobacillus plantarum LYP06-2 can produce acid, it can inhibit E. coli, showed potential prebiotic properties.From the perspective of toxicology to evaluate the safety of Bacillus subtilis ZZS16-3 and Lactobacillus plantarum LYP06-2, the acute toxicity test result found that Kunming mouse still alive and had no symptom of poisoning, necropsy showed no abnormalities. Both strains’ MTD> 15000mg/Kg, according to the acute toxicity (LD50) dose classification table of GB15193.3-2003, they were non-toxic. The 30 days’ feeding test showed that compared with control group, the mixture had no harm to the SD rats growth and metabolism, no abnormalities had found in blood, blood biochemistry and pathological examination.By univariate analysis, yeast extract powder was determine to be the best carbon source, gelatin as best nitrogen source, CaCl2 as the best inorganic salts.The best medium formula was obtained by orthogonal experimental analysis:0.5% yeast extract powder,1.5% gelatin,1.5% CaCl2.Optimization of fermentation conditions found that the best condition should be controlled to be initial pH 7.2, culture temperature 37℃, rotation speed 150 r/min, tank pressure 0.05 Mpa, ventilation ratio:1:0.8, culture 18 h. Then we can get the culture with 90% above of bacillus generation rate and viable count of 3.1×109 CFU/mL.Compound microecological agent containing Bacillus subtilis ZZS16-3 and Lactobacillus plantarum LYP06-2 was added to the dietary of weaned piglets, to some extent, it can improve the growth performance of piglets and reduce the diarrhea of piglets, lower feed conversion ratio.