Johnin test


  • Johnin is a purified protein derivative of Mycobacterium paratuberculosis (Johne’s bacterium) prepared on the same lines as tuberculin and used as a diagnostic test for Johne’s disease in cattle and buffaloes.
  • Johnin test is also done like single intradermal test done for tuberculosis. A painful indurated skin with an increase in skin thickness more than 4 mm is taken as positive.
  • All positive animals are culled and destroyed.
Last modified: Thursday, 5 April 2012, 10:06 AM