EN
Thirteen sheep were infected orally with M. johnei. Seven of them died before the end of two-year observation period. Decreased body weight, depression and accelerated respiration were the main clinical symptoms. Sensitivity to johnin and avian tuberculin appeaired about 8 weeks after inoculation, persisted 6-8 months and gradually disappared. The Johne's bacilli were found in the feaces 12-14 months after infection. In the dead animals or slaughtered when the experiment was finished, post-mortem lesions were found in varying degree.