Comparison Immunization Effect of the Two Kinds Emulsion Inactivated Vaccine of E. Coli in Chicken

In order to explore the differences between two vaccines used in the study, The two kinds of oil emulsion inactivated vaccine were made, in one of which, the E·coli standard strains and local strains were propagated on solid media, and in another, the same strains were propagated in embryonated eggs. 10 days chickens were vaccinated with two kinds vaccine respectively. The antibodies titer reached peaks at 21 d postimmunization and retained over 3log2 35 d. The challenge mixture bacteria acted at 42 d postimmunization. The embryonated eggs vaccine vaccinated group chickens showed 93.3% protectivity, but solid culture medium vaccine only 83.3%.