Submitted to: International Symposium On Alv J
Publication Type: Proceedings
Publication Acceptance Date: June 17, 2000
Publication Date: N/A
Technical Abstract: Observations on progeny of a commercial broiler breeder flock known to be infected with ALV-J revealed rapid horizontal spread in the first 4 weeks of life. A high proportion of horizontally infected chickens became persistently viremic, developed tumors and transmitted virus to progeny. Chicks where viremias were detected at 2 weeks were at highest risk to develop persistent infection. The period between exposure and first detection of viremia in two strains of chickens exposed to graded doses of ALV-J virus by intranasal/cloacal inoculation or by contact with viremic hatchmates varied between 7 and 28 days depending on dose. Using a 28-day bioassay, transmission within the hatcher and during various manipulations in the hatchery room immediately post-hatch was demonstrated. Successful transmission required substantial levels of exposure. Housing in adjacent pens with solid walls, separate feed and water, but common air supply, greatly reduced transmission between infected and noninfected groups through 4 weeks. Based on these results, it appears that segregation of chickens in small groups during and immediately following hatching may reduce horizontal spread of virus.