Table 2.
Summary of the logistic regression model evaluating the effect of the clinical presentation groups (MET, PUS, or CTL) and the days in milk (DIM) on the odds ratio of isolation of E. coli from intrauterine swabs collected from cows at 25 commercial dairy farms.
| Variable | Odds ratio | OR (95% Confidence interval) | P value | |
|---|---|---|---|---|
| Lower | Upper | |||
| Clinical groupa | 0.005 | |||
| MET vs PUS | 1.67 | 0.87 | 3.2 | 0.11 |
| MET vs CTL | 2.00 | 1.07 | 3.7 | 0.03 |
| PUS vs CTL | 1.19 | 0.68 | 2.1 | 0.53 |
| DIM2 | 0.0008 | |||
| Clinical groupa * DIMb | 0.02 | |||
| MET | 0.85 | 0.71 | 0.98 | 0.01 |
| PUS | 0.88 | 0.80 | 0.96 | 0.004 |
| CTL | 0.99 | 0.93 | 1.06 | 0.92 |
aClinical presentation group (MET, PUS, or CTL) of cows when intrauterine samples were collected. (MET) metritis discharge defined as a watery, red or brown colored, and fetid vaginal discharge; (PUS) purulent discharge defined as a non-fetid purulent or mucopurulent vaginal discharge; and (CTL) control, healthy discharge defined as cows with either no vaginal discharge, clear mucus, or clear lochia.
bDays in Milk at sampling time.