of Infectious Bursal Disease and Coccidiosis in Layer Replacement ChickensA

SUMMARY During a floor-pen study on anticoccidial programs for layerreplacement pullets, there was a natural outbreak of infectious bursal disease (IBD). The interaction of coccidiosis and IBD was characterized by: excessive deaths from coccidiosis; and apparent failure of some anticoccidial drug treatments. Immunity to coccidiosis was not blocked by the IBD infection, although immunity was less in some treatments than would be expected with the degree of coccidiosis exposure.