Initial Observations on the Effect of Corticosterone and Inbred Antibody Competency in Chickens on Population Development of the Northern Fowl Mite

Roosters from a line artificially selected for high initial antibody response to sheep red blood cells were more resistant to development of populations of Ornitbonyssus sylviarum (Canestrini and Fanzago) than were birds selected for low antibody response. Oral administration of corticosterone to test chickens at doses ranging from 10 to 40 ppm did not affect mite development. The steroid regimen was shown to reduce lymphocyte and testes mass as well as total weight gain. Postmortem measurements were not different for the 2 inbred lines. Analysis of data indicated that antibody competency alone probably was not responsbile for the observed differences in mite populations.