Table 1.
Herd characteristics for study farms and farms participating in the Alberta Johne’s Disease Initiative (AJDI, n (%))
| Study participants ( n = 18) | Other AJDI farms ( n = 342) | |
|---|---|---|
| Herd size | 0.691 | |
| <50 | 0 (−) | 9 (3) |
| 50 – 99 | 2 (11) | 102 (30) |
| 100 - 149 | 8 (44) | 130 (38) |
| 150 – 199 | 3 (17) | 48 (14) |
| >199 | 4 (22) | 53 (15) |
| History of clinical Johne’s disease | 0.031 | |
| JD has been observed | 10 (56) | 98 (29) |
| Don’t know | 4 (22) | 74 (22) |
| JD has never been observed | 4 (22) | 170 (49) |
| Positive environmental samples | < 0.011 | |
| 0 positives | 2 (11)2 | 188 (55) |
| 1-3 positives | 9 (50) | 84 (25) |
| 4-6 positives | 7 (39) | 70 (20) |
1 P-value based on Chi-square test on contingency table.
2These 2 herds had no MAP culture-positive environmental samples at the last testing event, but had positive environmental samples in 1 of the 2 previous samplings.