Development Of Solid Complex Probiotics For Broilers

Probiotics, in micro-ecology theory, is defined as beneficial bacteria that can be good or growth-promoting substances for humans or animal bodies and their metabolites. Probiotics could enhance host immunity, prevent from diarrhea, relieve symptoms of lactose intolerance, be the allergy relief role, prevent human beings from cancer,inhibit the growth of tumors and do good for the host in other aspects.They have been widely used in human daily life,or replaced of antibiotics in animal husbandry as one of the main alternative.The experiment is for developing a product in the complex solid-state form to apply to the breeding of broilers.So surrounding this purpose, the test selected bacillus and yeast strains as candidates for probiotics, optimized the culture conditions of candidates Bacillus in the form of solid-state fermentation, and did some preliminary research on broilers intestinal contents.The results include four parts are followings:1.Screening Strains of probiotics.From the laboratory database,27 strains of Bacillus and 13 strains of yeast were tested, and we found that 3 strains of Bacillus subtilis(B395. B605 and BM1) and 1 strain of yeast, who were suitable to apply to poultry breeding and regarded as candidates strains of complex probiotics.All of B395,B605 and BM1 were able to grow normally at 42℃,could inhibit E. coli, Staphylococcus aureus, and could withstand 0.3% bile salts,could produce amylase,protease, cellulase.Tropical Candida Y13 could withstand in 42℃.2.Optimization solid fermentation. As an index of the viable cells number, we chose B395 and BM1 as experimental strains to optimize their solid fermentation culture conditions, with orthogonal and the single factor experiments,we got the cheap solid fermentation medium and proper culture conditions.Solid fermentation culture conditions of BM1 were:bran ratio rice husk 1:1.glucose 0.5%,urea 3%,KH2PO4 0.5%.humidity 50%,inoculum concentration 5% and cultivation 3d; B395 were:bran ratio rice husk 3:2, glucose0.5%,urea 2%, KH2PO4 0.5%,humidity 40%, inoculum concentration 5% and cultivation 3d. In order to make manufactory, culturing the B395,BM1,B605 and Y13 using solid fermentation in platter-form properly, we counted that the viable cells were 1.79×1011 cfu/g,1.4×1010 cfu/g,5.2×109cfu/g and 5.7×107cfu/g respectively. We tested that when the fermentation products were placing in the room the bacillus could transform to spores, while the ratio of transforming is high. And after 30 days, the numbers of the spores in fermentation product could be stable, so we could set this placed process as the "post-harvest" process.3.Feeding experiment. Through the enema test, we further ensured the security of the candidate strains.In first feeding experiment, we observed that agents group could promote the growth of broilers by 9.6% and enhance the feed conversion rate by 2.4%. Then in the second feeding experiment, after using the self-made complex probiotics of solid state fermentation, in 28 days feeding, we observed the growth of broilers in microbe with oligo fructose groups,microbe group and oligo fructose group could be significantly promoted by 2.9%,9.8% and 18.1% respectively; and the feed conversion rates could be enhanced by 1.9%,0.6% and 1.2% respectively.4.Preliminary studying on intestinal contents.In this study, microbiological cultivation techniques of counting and PCR-DGGE were used to analysis the intestinal content. Lactic acid bacteria and E. coll were cultivated in aerobic conditions.The results showed that the feeding of microbe and oligo fructose could reduce the number of E.coli and the number of lactic acid bacteria could be increased by adding oligo fructose in the agents group, which could improve the structure of broilers intestinal flora.Analyzing the results of PCR-DGGE and the second feeding experiment, we confered that there might be close links between the body metabolism and the diversity of healthy animal intestinal flora. We got the structure and the diversity of ileal and cecal flora from PCR-DGGE with software, and the results indicated that the flora of duodenum and cecam changed largely during the feeding period, while ileal flora were similar. We detected that in the whole feeding experiment the trends of the broilers ileal flora diversity index (Shannon-index) was in accord with Intermediate Disturbance Hypothesis in ecology, and surmised that the trends between broilers ileal flora diversity index and average body weight maybe were positive.