Both of them has no affection on the spleen growth and can maintain the serum antibody against IBDV at higher level and longer time than that of the control.

• （2）合成BS组、表达BS高剂量组、表达BS低剂量组各组间的脾脏指数差异不明显，IBD疫苗对脾脏也无明显不良影响3）合成BS组、表达BS高剂量组、表达BS低剂量组的IBDV抗体上升较对照组有上升趋势，但它们之间的差异不显著。