Table 4. Distribution of samples testing positive for detectable levels of 3GC resistant E. coli growth by sample day and dairy farm.
| Dairy Number | ||||
|---|---|---|---|---|
| Growth on MacConkey Agar with Ceftriaxone (4 μg/mL) | Dairy Farm 1 | Dairy Farm 2 | Dairy Farm 3 | Total |
| Sample Day 0 | ||||
| Growth | 4 (4.88%) | 9 (10.71%) | 29 (36.25%) | 42 (9.76%) |
| No Growth | 78 (95.12%) | 75 (89.29%) | 51 (63.75%) | 204 (90.24%) |
| Total | 82 | 84 | 80 | 246 |
| Sample Day 6 | ||||
| Growth | 18 (21.43%) | 8 (10.53%) | 41 (51.90%) | 67 (28.03%) |
| No Growth | 66 (78.57%) | 68 (89.47%) | 38 (48.10%) | 172 (71.97%) |
| Total | 84 | 76 | 79 | 239 |
| Sample Day 16 | ||||
| Growth | 9 (10.84%) | 6 (7.79%) | 35 (44.30%) | 50 (20.92%) |
| No Growth | 74 (89.16%) | 71 (92.21%) | 44 (55.70%) | 189 (79.08%) |
| Total | 83 | 77 | 79 | 239 |
| Sample Day 28 | ||||
| Growth | 11 (13.41%) | 6 (7.89%) | 17 (21.52%) | 34 (14.35%) |
| No Growth | 71 (86.59%) | 70 (92.11%) | 62 (78.48%) | 203 (85.65%) |
| Total | 82 | 76 | 79 | 237 |
| Sample Day 56 | ||||
| Growth | 10 (12.99%) | 1 (1.33%) | 21 (26.92%) | 32 (13.91%) |
| No Growth | 67 (87.01%) | 74 (98.67%) | 57 (73.08%) | 198 (86.09%) |
| Total | 77 | 75 | 78 | 230 |