Table 7 Generalised linear models (GLM) relating the proportion of animals with evidence of fluke infection at post-mortem within-herds for the years 2011, 2012 and 2013 respectively. The GLM was fitted with a logit link function to ensure predictions from the model would be constrained between 0 and 1 (i.e. 0 to 100 % infected within herd)
GLM | 2011 | N = 4,680 | 2012 | N = 4,794 | 2013 | N = 4,874 | |
|---|---|---|---|---|---|---|---|
Predictor | OR | Sig. | OR | Sig. | OR | Sig. | |
Abattoir | 0 | 1 | 1 | 1 | |||
1 | 1.953 | *** | 2.158 | *** | 2.014 | *** | |
2 | 1.652 | *** | 1.798 | *** | 1.307 | *** | |
3 | 1.817 | *** | 1.777 | *** | 1.911 | *** | |
4 | 0.613 | *** | 0.636 | *** | 0.586 | *** | |
5 | 0.791 | ** | 0.979 | 0.758 | ** | ||
6 | 1.110 | 1.086 | 0.926 | ||||
7 | 1.442 | *** | 2.005 | *** | 1.936 | *** | |
Herd size | herdsize | 0.971^ | *** | ||||
Min. temp. | mintemp | 0.885 | *** | ||||
SD min. temp. | SD mintemp | 0.777 | * | ||||
SD humidity | SD humidity | 1.074 | ** | 1.088 | ** | ||
Humidity | humidity | 0.931 | * | ||||
Herd type | Beef breeding | 1 | 1 | 1 | |||
Beef fattening | 0.919 | * | 0.938 | 0.917 | * | ||
Beef rearing | 0.978 | 0.921 | 0.960 | ||||
Dairy | 1.098 | ** | 1.188 | *** | 1.059 | ||
Other | 1.011 | 1.028 | 0.940 | ||||
Region | Armagh | 1 | 1 | 1 | |||
Ballymena | 1.229 | *** | 1.585 | *** | 1.374 | *** | |
Coleraine | 1.139 | ** | 1.379 | *** | 1.359 | *** | |
Derry | 1.025 | 1.273 | * | 1.148 | |||
Dungannon | 1.093 | 1.195 | *** | 1.032 | |||
Enniskillen | 1.318 | *** | 1.438 | *** | 1.156 | * | |
Larne | 1.001 | 1.390 | *** | 1.373 | *** | ||
Newry | 1.034 | 1.086 | 0.982 | ||||
Newtownards | 1.074 | 1.120 | * | 1.296 | *** | ||
Omagh | 1.041 | 1.317 | *** | 1.064 |