Hundred and twenty chicks of 42 day old were divided into 8 groups, 3 of them were infected and treated with dilutions 1/10, 1/100  And 1/1000 of yolk from immune dams as compared to 3 other parallel groups treated with  yolk from non-immune dams. Infected nontreated group and non-infected nontreated group were kept as controls for the experiment. Clinical signs, mortaity seroconversion and bursal body weight ratio were measured . The different parameters were presented and effect of yolk inoculation from immune dams on the course of ‘the bursal body weight ratio, mortality rate and Gumboro infection was discussed.