Table 2.
Qualitative and quantitative evaluation of ESCr E. coli for a cattle herd residing at a feedlot
| Period | No. sampled | Fecal samples |
Hide samples |
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|---|---|---|---|---|---|---|---|---|---|---|---|---|
| % ESCr E. coli prevalence (frequency)a | No. of samples in each class of log CFU/swab values |
% ESCr E. coli prevalence (frequency)a | No. of samples in each class of log CFU/100 cm2 values |
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| 1.70 to 1.99 | 2.00 to 2.99 | 3.00 to 3.99 | 4.00 to 4.99 | >4.99 | 1.30 to 1.99 | 2.00 to 2.99 | 3.00 to 3.99 | >3.99 | ||||
| Feedlot arrival | 153 | 3.9 (6) AB | 2 | 2 | 1 | 0 | 1 | 15.0 (23) A | 16 | 6 | 1 | 0 |
| Increased disease susceptibility | 128 | 5.5 (7) AB | 2 | 4 | 0 | 1 | 0 | 11.7 (15) A | 14 | 1 | 0 | 0 |
| December 2009 | 173 | 2.9 (5) B | 3 | 1 | 1 | 0 | 0 | 7.5 (13) AB | 3 | 8 | 2 | 0 |
| March 2010 | 178 | 1.7 (3) B | 1 | 1 | 1 | 0 | 0 | 1.7 (3) B | 3 | 0 | 0 | 0 |
| May 2010 | 178 | 2.2 (4) B | 3 | 1 | 0 | 0 | 0 | 17.4 (31) A | 28 | 2 | 1 | 0 |
| July 2010 | 178 | 11.2 (20) A | 12 | 8 | 0 | 0 | 0 | 8.4 (15) A | 15 | 0 | 0 | 0 |
| Total | 988 | 4.6 (45) | 23 | 17 | 3 | 1 | 1 | 10.1 (100) | 79 | 17 | 4 | 0 |
a
Prevalence values in the same column that do not have a common letter are statistically significantly different (P < 0.05).