Analysis Application Of Lytical Bacteriophage And Antimicrobial Peptides In Broiler Chicken Breeding Industry

With the rapid development of broiler chicken feeding industry, bacteriosis,especially the colibacillosis became more and more fiercely. This disease brought huge economic losses.Colibacillosis permeates in broiler chickens farms and E.coli has many different serotypes,therefore, the effect of immune prevention is not well used in broiler chicken feeding industry.So many antibiotics and drugs were used to control this disease. It did not only reinforce the drug resistance, but also produced drug residues in the products. It brought more and more healthy threats to the consumers. In order to let the chicken consumers eat the green and healthy products, the research used the lytic bacteriophage and antimicrobial peptides through water to prevent colibacillosis. At the first, the lytic bacteriophages were isolated from the feces samples in one chicken farm around Shihezi. After the purification and identification, 6strains lytic bacteriophages were screened. Then 1900 Sanhuang broiler chickens were chosen,randomly divided them into 10 groups. The groups included 6 bacteriophage sets(100 broiler chickens per set),and the bacteriophage sets were divided into single strain bacteriophage set(300 broiler chickens) and mixed strains bacteriophage set(300 broiler chickens), then the single strain bacteriophage set and the mixed strains bacteriophage set were added the bacteriophage through the water as the dose of 0.25 ml,0.50 ml and 1.00 ml per broiler,respectively. The blank control group(100 broiler),ofloxacinand,florfenicol as antibiotics sets divided into 2 different sets(400 broiler chickens per set), antimicrobial peptides set(400broiler chickens). In order to count the survival rate, feed conversion ratio and the other production-index, number of death, daily increase weight and daily feed consumption were record from 25 days of old. The mainly results are as follows:(1) 7 strains of lytic bacteriophages were isolated by using double-deck agar method, and name Ecp1, Ecp2, Ecp3, Ecp4, Ecp5, Ecp6 and Ecp7, respectively. The titer of all isolated strains were over 108 pfu/ml. The lytic rate of the bacteriophages was detected. The lytic rate of Ecp1 was higher than the others, which is 44.44%. Ecp1 could be used as the single strain bacteriophage set to prevent colibacillosis.(2) The bacteriophage sets to prevent colibacillosis were divided into single strain bacteriophage set and mixed strains bacteriophage set, the bacteriophag.e was added through the water as the dose of 0.25 ml per broiler, 0.50 ml per broiler and 1.00 ml per broiler,respectively. Through the statistics, it was found that there was no significant difference between the single strain bacteriophage set and mixed strains bacteriophage set on the survival rate and feed conversion ratio(p>0.05). Compare with the feed conversion ratio of the sets, it was found that the mixed strain bacteriophage set of added 0.50 ml per broiler is better,which was 2.56,there was significant difference between it and the florfenicol set(3.00)(p<0.05). Compare with the survival rate of two sets, the single strains bacteriophage set of added 0.50 ml per broiler was better, which was 98.95%, and there was very significant difference among the single strains bacteriophage set of added 0.50 ml per broiler, the ofloxacin set(96.04%)and the florfenicol set(96.98%)(p<0.01).(3)The survival rate of antimicrobial peptides set was highest in the sets of adding antimicrobial peptides, ofloxacin and florfenicol, which was 98.14%,there was very significant difference(P<0.01) among them.The feed conservation ratio of antimicrobial peptides was highest, which was 2.30,there was significant difference between it and ofloxacin(P<0.05).There was no significant difference between it and florfenicol(P>0.05).The antimicrobial peptides played significant role on resist bacteriosis during the process of feeding. At the same time, it significantly increased the production performance on broilers chicken breeding.(4) After adding lytic bacteriophages and antimicrobial peptides 3 times,14 different drugs and antibiotics, including florfenicol,quinolonetes,tracyclines and sulfonamides were analyzed by chromatographic method. The result showed that there was no antibiotic residues in the products.