1. At present Mycobacterium paratuberculosis is the favoured candidate.

2. Mycobacterium paratuberculosis is the causative agent of Johne's disease, a chronic enteritis in ruminants and in other animals.

3. Comprehending dynamic of Bovine Paratuberculosis and health status of the whole herd in time will actively contributes to control and prevent extension of Bovine Paratuberculosis.

4. Six Crohn's disease cultures and a single non-inflammatory bowel disease control were positive for M paratuberculosis.

5. The authors believed that their serological results supported the view that infection with M paratuberculosis might cause Crohn's disease.

6. The result of PPD test: The herd has been intracutaneous inoculated paratuberculine of bovine to carry out allergy to make a survey of Bovine Paratuberculosis.

7. ELISA has merits of fast, sensitiveness and specificity to detected antibody of Mycobacterium paratuberculosis in serum of the cattle, the result was in accordance with that of clinical test.

8. This finding does not support a significant role for Mycobacterium avium subspecies paratuberculosis in the pathogenesis of Crohn's disease in the majority of patients.

9. We need research to see if the antibiotic that can kill mycobacterium paratuberculosis that may be the cause of Crohn's disease, will also help control ankylosing spondylitis.