title: Age of cattle as related to resistance to infection with Mycobacterium paratuberculosis.
abstract: Two 1-month-old calves, four 9-month old calves, and 4 adult (5 to 11 years old) cattle were exposed to Mycobacterium paratuberculosis. At 150 days after exposure, all cattle were killed and necropsied, and at that time, tissues of the 1-month-old calves had more bacilli and lesions than did tissues of the 9-month-old calves or the adult cattle. All cattle responded to immunologic tests during the experiment.
mesh_terms: D000284:Administration, Oral; D000367:Age Factors; D000818:Animals; D002417:Cattle / Q000276:immunology*; D002418:Cattle Diseases / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D005243:Feces / Q000382:microbiology; D006968:Hypersensitivity, Delayed / Q000662:veterinary; D008198:Lymph Nodes / Q000382:microbiology; D009161:Mycobacterium / Q000302:isolation & purification; D010283:Paratuberculosis / Q000276:immunology* / Q000382:microbiology / Q000473:pathology; D014374:Tuberculin Test