Lesions and tuberculin sensitivity in calves inoculated with group III mycobacterial isolates from swine, pen soil, and cattle feed.

FIFTEEN calves, 7 to 11 months of age, were inoculated intradermally with group III mycobacteria ---6 isolates from swine, 1 isolate from cattle feed, and 2 isolates from soil of swine farrowing pens. Calves were tuberculin tested at 50 days and killed approximately 60 days after inoculation. Only 1 of the cultures, that of porcine origin (93c-0), produced any lesions. There were a caseo-calcareous granuloma 3mm in diameter in the regional lymph node (left prescapular) and a granuloma at the skin inoculation site. None of the 5 calves inoculated with soil- or feed-origin mycobacteria had any lesions. Three of the calves inoculated with porcine origin group III mycobacteria had suspicious or positive caudal fold reactions. Two of these had granulomas at the skin-inoculation sites and one had no lesions. The calf having lymph node and skin-inoculation site granulomas was negative. The 5 calves inoculated with feed- or soil-origin mycobacteria had negative caudal fold tuberculin tests.