Detection And Analysis Of Antibody Against Avian Infuenza Of Chicken Farms In Parts Of Sichuan Province

Avian influenza (AI) is a severely infectious disease, which is fast Spread and wide range of popular. It can threaten human health and the safety of animal products. Chinese chicken and egg production is a large proportion of the world, So the harm of avian influenza is more serious. At present, research on avian influenza has made a lot of progress. There were changing at the breed of chicken, the method of feeding, the epidemic situation, the prevalent strains. Immunization programs need to continue to improve. During AI prevention and control, vaccination is one of the key measures, It is necessary to detect the immune effect. Vaccine manufacturers are important to quality control of vaccines and there were many choises for the manufacturers.This test provide information in immunization program to prevent and control avian flu in Sichuan for chicken farms. This test selected 26 farms from Chengdu, Ya’an, Meishan and other regions of Sichuan. This test detect antibody levels by HI assay, next, investigate avian influenza immunization program, compare different manufacturers vaccines, different numbers of immunization and different first vaccination day-old. Results:The mean antibody titer of avian influenza in layer chicken was 7.2 Iog2, the passing rate was 95.9%. The mean antibody titer of avian influenza in broiler chicken was 4.2 Iog2, the passing rate was 52.2%. Immunity level of layer chicken was better than broiler chicken. The date of initial immunization of layer chicken was 10～15 day-old, and the most chose was 11-13 day-old, but initial immunization at 10-day-old has the best immune effect, average antibody titer was 7.5 Iog2, the passing rate of 100%. The date of initial immunization of broiler chicken was 8～20 day-old, and there are no significant difference in antibody titers. The mean antibodies titers of H5 and H9 were 1.8 log2 and 2.1 Iog2 with no immunization, pass rates of less than 15%; Average antibodies titers with a single dose were 4.1 Iog2 and 5.5 Iog2, pass rates of 61.5% and 86.6%; Average antibodies titers with twice were 5.2 log2 and 7.0 log2, pass rates of 87.9% and 96.3%; Average antibodies titers with three time were 6.7 Iog2 and 7.9 log2, pass rates of 96.6% and 97.6%. The more immune times, the better immune effect. The effect of H5 was less than H9. During the 26 farms, there are 23 farms immune H5,13 farms immune H9 and 3 farms immune nothing. The immune density of H5 was higher than H9. The best date of initial immunization for layer is 10-15 day-old, and for broiler is 10～20 day-old. Layer chicken immunized 3 times; white feather broilers immunized 1 times; yellow feather broilers immunized 2 times; breeding broilers immunized 3 times. There are 10 Vaccine manufacturers and all qualified.