Twelve of the the15investigated chicken farms showed positive to serium antibody of CRD with direct agglutination test. The average positive rate of the300tested serum was33%.

• 共检测了300份鸡血清 ,平均阳性率33%25。 被调查的15个鸡场中的12个鸡场显示有CRD血清抗体阳性鸡 ,表明沈阳地区一些鸡场鸡群已被鸡败血霉形体(MG )感染 ,有的鸡场还相当严重。