Monitoring of the Maternal Antibody and Immune Antibody against Avian Influenza of Chicken in Hanzhong Area and the Establishment of Its Immune Procedure

[Objective] The research aimed to provide basis for the establishment of the immune procedure for avian influenza.[Method] Serum samples of Roman hens were collected from certain large-scale chicken farm in Hanzhong city to detect the antibody level in different stages.After inoculating the inactivated oil-emulsion vaccine against avain influenza,the antibody level in the chickling serum were detected after the chicklings were immunized with different dose of the vaccine.[Result] The average titer of the maternal antibody in one-day-old chickling was 8.9 and it deceased to 4.3 in nineteen-day-old.After immunizing 36 d,the average antibody level reached 6.37 and the protective rate was 100%.After immunizing 85 d,the antibody reached the maxium.After immunizing 9 weeks,the average antibody level reduced to 4.17 and the protective period was about two months.The primary immunity time should be the 19th to 22nd d after birth.After the primary immunity 85 d,the HI antibody gradually reduced to the critical value.It was suggested that the 2nd immunity should be about the 3rd month after birth and the dose could be increased to 0.5 ml per chicken.[Conclusion] The monitoring means of the antibody titer should be established in chicken farm and the re-inoculation should be made on the chicken flock with partially lower or blank antibody level.