|Seong, H. - MINISTRY OF AGRIC/KOREA|
Submitted to: Avian Diseases
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: June 4, 2002
Publication Date: December 31, 2002
Citation: Seong, H.W., Reddy, S.M., Fadly, A.M. 2002. High virus titer in feather pulp of chickens infected with subgroup j avian leukosis virus. Avian Diseases. 46:281-286. Interpretive Summary: Subgroup J avian leukosis is an emerging economically important virus infection that can cause cancer-like disease and other production problems in meat-type chickens. The virus was first reported in 1991 in the United Kingdom and in 1993 in the United States. It is well known that this virus is able to spread from one chicken to another at a high rate. The control of this virus is by testing and eradication of infected flocks. Understanding the distribution of this virus is an important component of any effort to develop specific diagnostics and effective control programs. Our data show that the samples of the feathers can be useful for virus isolation and identification of infected flocks. This new information is significant and should be useful to poultry industry to eradicate this emerging virus from their flocks.
Technical Abstract: Subgroup J avian leukosis viruses (ALVs), which are a recombinant virus between exogenous and endogenous ALVs, can spread by either vertical or horizontal transmission. Exogenous and endogenous ALVs, can be detected in feather pulp. In this study, virus titers in feather pulp of chickens infected with subgroup J ALV were compared with those of plasma and cloacal swab. All of the broiler chickens inoculated with subgroup J ALV at 1 day old were positive for virus from feather pulp during the experimental period of between 2 wk and 8 wk of age. Virus titers in feather pulp of some broiler chickens infected with subgroup J ALV were very high, ranging from 107 to 108 infective units per 0.2 ml. Virus titers in feather pulp were usually the highest among the samples of plasma, cloacal swab, and feather pulp tested. In another experiment in which layer chickens were inoculated with subgroup J ALV at 1 day old, virus was detected in feather pulp from 2 wk until 18 wk of age, and virus persisted longer in feather pulp than in plasma. Almost all of the layer chickens tested were positive for virus by polymerase chain reaction (PCR) with DNA extracted from feather pulp samples at 2, 4, and 10 wk of age, and the PCR from feather pulp was more sensitive than virus isolation from plasma, cloacal swab, and feather pulp. All other results indicate that samples of feather pulp can be useful for virus isolation and PCR to confirm subgroup J ALV infection.