Dynamics of Viremia and Antibody Responses in Chickens Inoculated with ALV-J

【Objective】 To understand the dynamics of viremia,virus shedding and antibody responses in chickens inoculated with avian leukosis vrius subgroup J(ALV-J) and provide essential epidemiological data for prevention and eradicationo of ALV-J infection.【Method】 Viremia,virus shedding and antibody response were successively measured after inoculation with ALV-J strain HN0001 intraperitoneally,orally or in contact in SPF chickens at 1 day and 49 days.【Result】 The dynamics of viremia and antiboty responses were very different in chickens inoculated with ALV-J at different ages.Viremia and p27 in cloaca swabs started to be detected from the 2nd week after inoculation with ALV-J at 1-day-old.In the group inoculated intraperitoneally with ALV-J,71%(5/7) continuously demonstrated viremia and p27-shedding.Viremia and virus shedding lasted for at least 45 weeks in 3 chickens.Among them,only 1 chicken showed transient antibody reaction at 16-week-old,another 2 were in tolerant viremia without any antibody reactions.In the group inoculated orally with ALV-J,11%(1/9) demonstrated persistant viremia and p27-shedding but no antibody response,44%(4/9) showed transient viremia or p27-shedding,and then antibody responses from 8-week-old.No control bird kept in contact with inoculated birds in the same isolators demonstrated viremia or p27-shedding,and also no antibody responses.It indicated there was no horizontal infection.In chickens intraperitoneally inoculated with ALV-J at 49-day-old,neither viremia nor p27-shedding were detected in 5 separate testing during the 19th week after inoculation,but antibody reaction started to be detected 1 week after inoculation.In the orally inoculated chickens or the contacted control chicken,all samples were negative in vriremia,p27-shedding and antibody reactions.【Conclusion】 Inoculation with ALV-J at 1-day-old easily induced immune tolerence,chickens inoculated demonstrated persistant viremia or p27-shedding,but no antibody reactions.Chickens inoculated with ALV-J at 49-day-old,antibody could detected 1 week after inoculation,but no viremia and p27-shedding were detected.Inoculation routes significantly influenced the dynamic variety of ALV-J inoculation,intraperitoneally injection induced higher viremia levels and increased percentages with tolerant viremia when compared to oral inoculation.