The immune potentials of full dose and half dose of bursal derived IBD oil
emulsified vaccine (OEV) and a full dose of check embryo derived IBD oil em
ulsified vaccine were compared. The antibody response was detected by quant
itative agar gel precipitation test (QAGPT). Challenge studies were also pe
rformed. The bursal derived OEV at full and half dose provided higher immun
e response and better protection than chick embryo derived OEV when vaccina
ted at seventh day of age. A half dose of killed bursal derived IBD OEV is
recommended.