Table 2 Relative risk (odds ratio) for trichostrongyle infections and the quantitative egg output in relation to different variables. Single regression model on ± trichostrongyle faecal egg positive animals. Differences between related figures are statistically significant (p < 0.05).
From: The Dynamics, Prevalence and Impact of Nematode Infections in Organically Raised Sheep in Sweden
Categories, examined animals and variables | Relative risk of infection | EPG | |
|---|---|---|---|
Odds ratio | 95% Cl | Geometric mean | |
Lambing time | |||
Ewes soon after lambing | |||
Winter | 1 | - | 13 |
Spring | 8.3 | 3.4 – 20.1 | 123 |
High EPG – values | |||
Ewes soon after lambing | |||
Haemonchus negative flocks | 1 | - | 118 |
Haemonchus positive flocks | 26 | 10 – 71 | 776 |
Different sampling times in the same flocks | |||
Lambs in Sept. – Oct. | 1 | - | 37 |
Lambs in Nov. | 5.0 | 2.8 – 8.7 | 213 |
Slaughtering time | |||
Lambs in Sept. – Oct. | |||
All lambs slaughtered before Dec. 1 | 1 | - | 10 |
≥ 1% of the lambs slaughtered after Dec 1. | 3.9 | 2.5 – 6.1 | 83 |
Accommodation from birth to turn out in spring | |||
Lambs after appr. 4 weeks grazing | |||
Stable – new grazing area | 1 | - | 3 |
Stable – old grazing area | 3.8 | 2.4 – 5.9 | 22 |
Winter area – new grazing area | 2.3 | 1.6 – 3.3 | 10 |
Winter area – old grazing area | 9.1 | 5.6 – 14.6 | 63 |
Permanent outdoors | 3.9 | 2.4 – 6.3 | 25 |
Pasture managament | |||
Ewes not dewormed | |||
Lambs after appr. 4 weeks grazing | |||
New grazing area | 1 | - | 4 |
Old grazing area | 5.9 | 4.3 – 7.9 | 53 |
Ewes dewormed before turn out | |||
Lambs after appr. 4 weeks grazing | |||
New grazing area | 1 | - | 4 |
Old grazing area | 4.9 | 2.4 – 10.0 | 45 |
Lambs in Sept. – Oct. | |||
New spring grazing area + New autumn grazing area | 1 | - | 8 |
New spring grazing area + Old autumn grazing area | 7.4 | 2.9 – 19.3 | 156 |