Chronic pneumonia in calves after experimental infection with Mycoplasma bovis strain 1067: characterization of lung pathology, persistence of variable surface protein antigens and local immune response

牛支原体 1067 菌株实验性感染后患上慢性肺炎：肺病理学特征、可变表面蛋白抗原的持久性和局部免疫反应