Table 3 Logistic GEE model for the probability of a herd with an SCC > 400,000 cells/mL
From: Insights into udder health and intramammary antibiotic usage on Irish dairy farms during 2003-2010
Variable | Â | b | S. E. | p-value | OR | 95% CI | |
|---|---|---|---|---|---|---|---|
Intercept | Â | -0.79 | 0.04 | < 0.001 | 0.45 | 0.42 | 0.49 |
Month | 1 | 0.00 | 0.00 | . | 1.00 | 1.00 | 1.00 |
2 | -0.15 | 0.03 | < 0.001 | 0.86 | 0.82 | 0.91 | |
3 | -0.32 | 0.03 | < 0.001 | 0.73 | 0.69 | 0.76 | |
4 | -0.73 | 0.03 | < 0.001 | 0.48 | 0.46 | 0.51 | |
5 | -0.83 | 0.03 | < 0.001 | 0.44 | 0.41 | 0.46 | |
6 | -0.67 | 0.03 | < 0.001 | 0.51 | 0.48 | 0.54 | |
7 | -0.32 | 0.03 | < 0.001 | 0.73 | 0.69 | 0.77 | |
8 | -0.39 | 0.03 | < 0.001 | 0.67 | 0.64 | 0.71 | |
9 | -0.46 | 0.03 | < 0.001 | 0.63 | 0.60 | 0.67 | |
10 | -0.33 | 0.03 | < 0.001 | 0.72 | 0.68 | 0.76 | |
11 | 0.01 | 0.03 | 0.735 | 1.01 | 0.96 | 1.06 | |
12 | 0.16 | 0.03 | < 0.001 | 1.17 | 1.11 | 1.23 | |
Year | 2004 | 0.00 | 0.00 | . | 1.00 | 1.00 | 1.00 |
2005 | 0.09 | 0.02 | < 0.001 | 1.09 | 1.04 | 1.15 | |
2006 | 0.08 | 0.03 | 0.007 | 1.08 | 1.02 | 1.14 | |
2007 | -0.11 | 0.03 | < 0.001 | 0.90 | 0.84 | 0.95 | |
2008 | -0.04 | 0.03 | 0.167 | 0.96 | 0.90 | 1.02 | |
2009 | 0.34 | 0.03 | < 0.001 | 1.40 | 1.32 | 1.49 | |
2010 | 0.38 | 0.03 | < 0.001 | 1.46 | 1.37 | 1.56 | |
Herd sizea | Q1 | 0.00 | 0.00 | . | 1.00 | 1.00 | 1.00 |
Q2 | -0.15 | 0.03 | < 0.001 | 0.86 | 0.81 | 0.91 | |
Q3 | -0.24 | 0.03 | < 0.001 | 0.79 | 0.74 | 0.84 | |
Q4 | -0.31 | 0.04 | < 0.001 | 0.73 | 0.68 | 0.79 | |
Spring Calving | Non-Spring | 0.00 | 0.00 | . | 1.00 | 1.00 | 1.00 |
Spring | 0.15 | 0.07 | 0.049 | 1.16 | 1.00 | 1.34 | |
Spring × Monthb | Spring: 1 | 1 | 0.00 | . | 1.00 | 1.00 | 1.00 |
Spring: 2 | 1 | -0.27 | < 0.001 | 0.76 | 0.66 | 0.88 | |
Spring: 3 | 1 | -0.43 | < 0.001 | 0.65 | 0.56 | 0.75 | |
Spring: 4 | 1 | -0.44 | < 0.001 | 0.64 | 0.56 | 0.74 | |
Spring: 5 | 1 | -0.48 | < 0.001 | 0.62 | 0.53 | 0.71 | |
Spring: 6 | 1 | -0.60 | < 0.001 | 0.55 | 0.48 | 0.63 | |
Spring: 7 | 1 | -0.65 | < 0.001 | 0.52 | 0.45 | 0.60 | |
Spring: 8 | 1 | -0.61 | < 0.001 | 0.54 | 0.47 | 0.62 | |
Spring: 9 | 1 | -0.50 | < 0.001 | 0.61 | 0.53 | 0.70 | |
Spring: 10 | 1 | -0.28 | < 0.001 | 0.76 | 0.66 | 0.87 | |
Spring: 11 | 1 | 0.05 | 0.478 | 1.05 | 0.91 | 1.21 | |
Spring: 12 | 1 | 0.36 | < 0.001 | 1.43 | 1.23 | 1.68 | |
Spring × Yearb | Spring: 2004 | 0.00 | 0.00 | . | 1.00 | 1.00 | 1.00 |
Spring: 2005 | -0.05 | 0.05 | 0.310 | 0.95 | 0.86 | 1.05 | |
Spring: 2006 | -0.11 | 0.05 | 0.037 | 0.90 | 0.81 | 0.99 | |
Spring: 2007 | -0.16 | 0.06 | 0.004 | 0.85 | 0.76 | 0.95 | |
Spring: 2008 | -0.14 | 0.06 | 0.015 | 0.87 | 0.78 | 0.97 | |
Spring: 2009 | -0.14 | 0.06 | 0.010 | 0.87 | 0.78 | 0.97 | |
Spring: 2010 | -0.31 | 0.06 | < 0.001 | 0.73 | 0.66 | 0.82 | |