ARS | Publication request: Study of Naturally Occurring Avian Leukosis Virus Infection in a Commercial White Leghorn Breeder Flock

Submitted to: American Veterinary Medical Association Abstract
Publication Acceptance Date: July 28, 2004
Publication Date: July 28, 2004
Citation: Mays, J.K., Pandiri, A.R., Silva, R.F., Fadly, A.M. 2004. Study Of Naturally Occurring Avian Leukosis Virus Infection In A Commercial White Leghorn Breeder Flock [abstract]. American Veterinary Medical Association. P. 56.

Technical Abstract: Progeny chicks from a commercial egg-type breeder flock that had previously experienced myeloid leukosis as a result of infection with a naturally occurring recombinant avian leukosis virus (ALV) containing the envelope of subgroup B and the long terminal repeat (LTR) of subgroup J ALV were hatched and reared at USDA-ARS Avian Disease and Oncology Laboratory (ADOL). At hatch, 4, 8, and 16 weeks of age, chickens were tested for ALV viremia and shedding and for neutralizing antibodies against subgroup A (RAV-1), B (RAV-2) and J (ADOL-Hc1) of ALV. At Hatch, 19% of chicks tested positive for exogenous ALV; by 4 and 8 weeks of age, the incidence of ALV-induced viremia increased rapidly and reached 42% and 48%, respectively. At 8 and 16 weeks of age, 1/100 (1%) and 16/88 (18%) of chickens tested positive for neutralizing antibodies to subgroup A ALV; none of the chickens exhibited antibodies to subgroup B or J ALV. This exogenous ALV failed to propagate in chicken embryo fibroblasts that are resistant to subgroup A ALV, confirming that the virus is a subgroup A ALV. The data show this commercial white leghorn breeder flock is currently infected with an ALV-A-variant virus and not the recombinant ALV previously isolated from another flock of the same line.