Table 3.
Results from multivariate logistic models investigating the influence of predictor variables on O. ostertagi BTM ELISA results (North: Df = 172; East: Df = 183; South: Df = 190). Significant ORs and CIs are printed in bold.
| North | East | South | ||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Variable | OR | 95% CI | -2LL | nDF | F | p | OR | 95% CI | -2LL | nDF | F | p | OR | 95% CI | -2LL | nDF | F | p |
| Access to fresh grass | - | - | 185.90 | 1 | 18.47 | <0.001 | - | - | 207.85 | 1 | 11.86 | <0.001 | - | - | 179.54 | 1 | 23.11 | <0.001 |
| Yes vs. no | 5.53 | 2.52–12.12 | - | - | - | - | 3.73 | 1.75–7.94 | - | - | - | - | 6.96 | 3.14–15.42 | - | - | - | - |
| Silage quality | - | - | 185.90 | 2 | 5.47 | 0.005 | - | - | - | - | - | - | - | - | - | - | - | - |
| Lower vs. normal | 0.43 | 0.07–2.54 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Spoiled vs. normal | 3.03 | 1.42–6.48 | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - | - |
| Anthelmintic treatment Calves & young cattle | - | - | 185.90 | 2 | 2.33 | 0.100 | - | - | 207.85 | 2 | 1.42 | 0.245 | - | - | 179.54 | 2 | 2.98 | 0.053 |
| Both vs. no treatment | 1.45 | 0.41–5.16 | - | - | - | - | 3.16 | 0.34–29.16 | - | - | - | - | 4.65 | 1.01–21.40 | - | - | - | - |
| Yc vs. no treatment | 2.59 | 1.00–6.71 | - | - | - | - | 1.84 | 0.84–4.02 | - | - | - | - | 2.89 | 1.08–7.78 | - | - | - | - |
|
Anthelmintic treatment
Lactating & dry cows |
- | - | 185.90 | 3 | 1.28 | 0.281 | - | - | 207.85 | 3 | 1.56 | 0.200 | - | - | 179.54 | 2 | 0.26 | 0.771 |
| Both vs. no treatment | 1.00 | 0.44–2.24 | - | - | - | - | 0.26 | 0.06–1.07 | - | - | - | - | 1.12 | 0.33–3.74 | - | - | - | - |
| Lc vs. no treatment | 4.34 | 0.92–20.45 | - | - | - | - | 1.52 | 0.31–7.59 | - | - | - | - | - | - | - | - | - | - |
| Dc vs. no treatment | 0.80 | 0.10–6.16 | - | - | - | - | 1.50 | 0.37–6.01 | - | - | - | - | 2.08 | 0.28–15.27 | - | - | - | - |
| Lameness | - | - | - | - | - | - | - | - | - | - | - | - | - | - | 179.54 | 1 | 1.92 | 0.167 |
| 10% increase from mean | - | - | - | - | - | - | - | - | - | - | - | - | 0.82 | 0.62–1.09 | - | - | - | - |
| Milk yield | - | - | 185.90 | 1 | 6.08 | 0.015 | - | - | 207.85 | 1 | 10.88 | 0.001 | - | - | 179.54 | 1 | 13.08 | <0.001 |
| 500 kg increase from mean | 0.83 | 0.72–0.96 | - | - | - | - | 0.82 | 0.73–0.92 | - | - | - | - | 0.75 | 0.64–0.88 | - | - | - | - |
Abbreviations: -2LL, -2 Log-Likelihood; nDf, numeric degrees of freedom; F, F-Value; OR, odds ratio; CI, confidence interval; yc, young cattle; lc, lactating cows; dc, dry cows.