This study aimed to determine the changes of cytokines,specific serum IgG and several parameters in chickens vaccinated ......

运用Ｊｅｆｆｅｒｓ（１９７５）选育法进行了Ｅ．ｂｒｕｎｅｔｔｉ早熟弱毒虫的选育，经过连续七代的选育，获得了Ｅｉｍｅｒｉａｂｒｕｎｅｔｔｉ早熟弱毒虫株，该虫株的潜隐期为１０８ｈ，比Ｅ．ｂｒｕｎｅｔｔｉ亲本毒株提前了１２ｈ以上。......