Table 1 Frequencies of farm characteristics in farms re-infected with respiratory diseases and control farms as assessed during a case-control study conducted in Switzerland (only variables with p < 0.2).
Variable description | Cases (%), n = 107 | Controls (%), n = 107 | P | OR |
|---|---|---|---|---|
Production system | ||||
Membership of Swiss Pig Health Service | 71.0 | 82.2 | 0.052a) | 0.5 |
Breeding farms | 19.6 | 45.8 | <0.001a) | 0.3 |
Finishing-only farms | 67.3 | 37.4 | <0.001a) | 3.4 |
Mixed breeding-finishing farm with at maximum 99 fattening pigs | 4.7 | 15.0 | 0.011a) | 0.3 |
Mixed breeding-finishing farm with at least 100 fattening pigs | 8.4 | 1.9 | 0.030a) | 4.8 |
Environment | ||||
Farms with exercise area or pasture | 2.8 | 9.3 | 0.045a) | 0.3 |
One additional re-infected neighbour | n.a.b) | n.a.b) | <0.001a) | 3.7 |
Transport route close to farm | 66.4 | 47.7 | 0.006a) | 2.2 |
Parking site for transport vehicles close to farm | 21.5 | 4.7 | <0.001a) | 5.6 |
Distance to parking site ≤ 300 m | 9.3 | 1.9 | 0.017a) | 5.4 |
Veterinarian may enter the pig stable | 63 | 81 | 0.009a) | 0.5 |
Moderate smell of ammonia in the stable | 30.6c) | 9.9c) | 0.053 | 1.9 |
Dust film on window sills in the stable | 12.2c) | 5.0c) | 0.066 | 2.7 |
An increased altitude of the farm location by 50 meters | n.a.d) | n.a.d) | <0.001a) | 0.7 |
Animal purchase practices | ||||
Pigs typically loaded before 0700 a.m. | 73.8 | 44.9 | <0.001a) | 3.5 |
Pigs typically loaded between 0700 a.m. and noon. | 22.4 | 54.2 | <0.001a) | 0.2 |
Pigs typically loaded between noon and 0800 p.m. | 2.8 | 0.0 | 0.081 | Not calculable |
Drivers of transport vehicles may enter the stable | 32.7 | 24.3 | 0.173 | 1.5 |
Pig owner has complained about cleanliness of transport vehicles | 11.2 | 0.9 | 0.002a) | 13.4 |
Farmers delivers pigs to the butcher himself | 66.4 | 77.6 | 0.068 | 0.6 |
Farmer cleans his transport vehicle after being at the butchery | 43.9 | 55.1 | 0.101 | 0.6 |
Farmer disinfects his transport vehicle after being at the slaughterhouse | 5.6 | 1.9 | 0.149 | 3.1 |
Always the same animal suppliers | 22.4 | 42.1 | 0.002a) | 0.4 |
No supplier (closed farm) | 21.2 | 18.2 | 0.529 | 1.2 |
Only 1 animal supplier | 21.5 | 56.1 | <0.001a) | 0.2 |
2 or 3 animal suppliers | 18.7 | 12.1 | 0.185 | 1.7 |
more than 3 animal suppliers | 32.7 | 8.4 | <0.001a) | 5.3 |