Abstract

This study has been administered to broilers which were given vaccine prepared form sporulated oocyst of E. tenella that attenuated by X-ray (10, 15, 20) K rad, in its 1st day with dose 1×104 oocyt /bird orally. Levamisole was used as an immunostimualant with 15mg/kg- body weight during 4 days after the vaccination. The broilers were divided into 8 groups they were watched during the 1st–2nd weeks after vaccination, as well as clinical signs, mortality rate 5 – 8 days post vaccination and oocyst detection was performed too, blood picture was also performed , Packed cell volum (PCV ) and Diffrential count ( DLC). Challenging of immunized group and 7th group in 22 days was done using the 6×104 oocyst/bird The results neither showed any clinical signs and mortality rate for the 1st, 2nd, 3rd and 4th, groups in spite of noticing oocyst in their excrement, mean while the 5th and 6th groups showed milde clinical signs, and blood picture variations between immunized and the sontrol group were noticed.