In order to detect levels of blood Se and serum antibody against Salmonella dublin, blood specimens of the young yaks inoculated respectively with two batches of the bovine paratyphoid live vaccine with Se were sampled on day 7,30,60 and 90 post-immunization. 用2批含硒型牛副伤寒活疫苗(200101200201)分别免疫牦牛,在免疫后第7、30、60和90d采血,进行了血硒含量及血清抗体的检测。