6Berg T P.Acute infectious bursal disease in poultry:a review[J].Avian Pathology,2000,29:175-194.
7Boot H J,Hoekman A J W,Gielkens A L J.The enhanced virulence of very virulent infectious bursal disease virus is partly determined by its B-segment[J].Archives of Vrology,2005,150(1):137-144.
8索勋,李国清.鸡球虫学[M].北京:中国农业大学出版社,1998:319-332.
9Rautenschlein S,Yeh H Y,Njenga M K,et al.Role of intrabursal T cells in Infectious bursal disease virus(IBDV) infection:T cells promote viral clearance but delay follicular recovery[J].Archives of Virology,2002,147(2):285-304.