Table III.
Risk factors for Shiga toxin-encoding bacteria fecal shedding in cattle in multivariable logistic regression models
| Model | Variable | Level | Number of cattle | % positive | OR | 95% CI | P-value |
|---|---|---|---|---|---|---|---|
| All cattle | Cattle group | Preweaned calf | 385 | 5.5 | 2.6 | 1.2–5.7 | 0.02 |
| Other adults | 1823 | 2.7 | 1.0 | ||||
| Farm type/size | Small organic | 458 | 6.6 | 4.5 | 2.2–9.5 | < 0.01 | |
| Small conventional | 579 | 4.0 | 2.6 | 1.0–6.6 | 0.05 | ||
| Large conventional | 1171 | 1.5 | 1.0 | ||||
| All calves | Calf age | 29–56 d old | 217 | 6.9 | 2.0 | 1.0–4.4 | 0.06 |
| < 29 d old | 168 | 3.6 | 1.0 | ||||
| Farm type/size | Small organic | 48 | 8.3 | 2.0 | 0.4–10.5 | 0.40 | |
| Small conventional | 84 | 7.1 | 1.6 | 0.4–7.5 | 0.53 | ||
| Large conventional | 253 | 4.4 | 1.0 | ||||
| All cows | Number of Parity | ≥ 4 | 379 | 4.2 | 1.7 | 0.9–3.1 | 0.11 |
| < 4 | 1413 | 0.9 | 1.0 | ||||
| Farm type/size | Small organic | 410 | 6.3 | 7.7 | 2.6–22.3 | < 0.01 | |
| Small conventional | 495 | 3.4 | 4.4 | 1.2–16.4 | 0.03 | ||
| Large conventional | 918 | 0.8 | 1.0 |
OR — odds ratio.
95% CI — 95% confidence interval.
Farm type/size and season were forced to be included as covariates in all 3 models.