|
Variable name
|
Value
|
Number of PRRSV positive (%)
|
Number of PRRSV negative (%)
|
OR
|
95% CI
|
P-value
|
|---|
|
Herd size
|
<250
|
14 (31.1)
|
38 (48.1)
|
1.0
| | |
|
(Number of sows)
|
≥250
|
31(68.9)
|
41(51.9)
|
2.0
|
0.9-4.4
|
0.06
|
|
Farm type
|
outdoor
|
8 (17.8)
|
29 (34.5)
|
1.0
| | |
| |
indoor
|
37 (82.2)
|
55 (65.5)
|
2.4
|
1.0-5.9
|
0.05
|
|
PRRS vaccine
|
none
|
16 (34.8)
|
68 (80.0)
|
1.0
| | |
| |
killed
|
2 (4.3)
|
6 (7.1)
|
1.4
|
0.2-7.6
| |
| |
live
|
28 (60.9)
|
11 (12.9)
|
10.8
|
4.4-26.2
|
<0.01
|
|
APP ELISA
|
negative
|
7 (15.2)
|
29 (34.1)
|
1.0
| | |
| |
positive
|
39 (84.8)
|
56 (65.9)
|
2.9
|
1.1-7.2
|
0.02
|
|
Avian-like H1N1
|
negative
|
31 (68.9)
|
74 (87.1)
|
1.0
| | |
| |
positive
|
14 (31.1)
|
11 (12.9)
|
3.0
|
1.2-7.4
|
0.01
|
|
Age at weaning in days
|
21-27
|
30 (65.2)
|
33 (40.7)
|
1.0
| | |
| |
≥28
|
16 (34.8)
|
48 (59.3)
|
0.3
|
0.1-0.7
|
<0.01
|
|
Disposal of dead pigs
|
incineration
|
6 (13.0)
|
33 (42.9)
|
1.0
| | |
| |
collection
|
40 (87.0)
|
44 (57.1)
|
5.0
|
1.8-13.1
|
<0.01
|
|
Frequency of live
|
never
|
14 (31.1)
|
22 (28.2)
|
1.0
| | |
|
animals
|
1-6/year
|
11 (24.4)
|
45 (57.7)
|
0.3
|
0.1-0.9
| |
| |
>6/year
|
20 (44.5)
|
11 (14.1)
|
2.8
|
1.0-7.7
|
<0.01
|
|
Pig density*
|
<15000
|
20 (43.5)
|
68 (81.0)
|
1.0
| | |
| |
≥15000
|
26 (56.5)
|
16 (19.0)
|
5.5
|
2.4-12.2
|
<0.01
|
|
Other production species
|
no
|
34 (73.9)
|
44 (53.0)
|
1.0
| | |
| |
yes
|
12 (26.1)
|
39 (47.0)
|
0.4
|
0.1-0.8
|
0.02
|
|
Number of farm
|
1-2
|
5 (10.8)
|
28 (35.0)
|
1.0
| | |
|
workers
|
3
|
16 (34.8)
|
20 (25.0)
|
4.4
|
1.4-14.2
| |
| |
4
|
14 (30.4)
|
12 (15.0)
|
6.5
|
1.9-22.2
| |
| |
>4
|
11 (23.9)
|
20 (25.0)
|
3.1
|
0.9-10.2
|
0.01
|
|
Use of straw yards
|
no
|
16 (38.1)
|
43 (53.1)
|
1.0
| | |
| |
yes
|
26 (61.9)
|
38 (46.9)
|
1.8
|
0.8-3.9
|
0.11
|
|
Ventilation weaners
|
natural
|
22 (47.8)
|
54 (64.3)
|
1.0
| | |
| |
artificial
|
14 (30.4)
|
20 (23.8)
|
1.7
|
0.7-3.9
| |
| |
both
|
10 (21.7)
|
10 (11.9)
|
2.4
|
0.9-6.7
|
0.15
|
|
Ventilation growers
|
natural
|
26 (56.5)
|
61 (73.5)
|
1.0
| | |
| |
artificial
|
7 (15.2)
|
9 (10.8)
|
1.8
|
0.6-5.4
| |
| |
both
|
13 (28.3)
|
13 (15.7)
|
2.3
|
0.9-5.7
|
0.13
|
|
Ventilation finishers
|
natural
|
22 (51.1)
|
60 (72.3)
|
1.0
| | |
| |
artificial
|
14 (32.6)
|
12 (14.5)
|
3.1
|
1.2-7.9
| |
| |
both
|
7 (16.3)
|
11 (13.2)
|
1.7
|
0.6-5.0
|
0.04
|
|
Ventilation lactating
|
natural
|
16 (34.8)
|
43 (51.8)
|
1.0
| | |
|
sows
|
artificial
|
21 (45.6)
|
28 (33.7)
|
2.0
|
0.9-4.5
| |
| |
both
|
9 (19.6)
|
12 (14.5)
|
2.0
|
0.7-5.6
|
0.17
|
|
Lighting weaners
|
natural
|
15 (32.6)
|
41 (48.8)
|
1.0
| | |
| |
artificial
|
13 (28.3)
|
17 (20.2)
|
2.1
|
0.8-5.3
| |
| |
both
|
18 (39.1)
|
26 (31.0)
|
1.9
|
0.8-4.4
|
0.19
|
|
Lighting lactating
|
natural
|
9 (19.6)
|
30 (36.1)
|
1.0
| | |
|
sows
|
artificial
|
21 (45.6)
|
22 (26.5)
|
3.2
|
1.2-8.3
| |
| |
both
|
16 (34.8)
|
31 (37.4)
|
1.7
|
0.6-4.5
|
0.04
|
|
Presence of cattle
|
no
|
40 (87.0)
|
64 (77.1)
|
1.0
| | |
| |
yes
|
6 (13.0)
|
19 (22.9)
|
0.5
|
0.2-1.3
|
0.18
|
|
Presence of poultry
|
no
|
41 (89.1)
|
64 (77.1)
|
1.0
| | |
| |
yes
|
5 (10.9)
|
19 (22.9)
|
0.4
|
0.1-1.1
|
0.10
|
|
Large white in breed
|
0
|
2 (4.4)
|
13 (16.3)
|
1.0
| | |
|
composition in %
|
1-25
|
36 (80.0)
|
55 (68.7)
|
4.2
|
0.9-19.9
| |
| |
>25
|
7 (15.6)
|
12 (15.0)
|
3.8
|
0.6-21.9
|
0.11
|
- *total number of pigs within 10km radius from the farm, OR: odds ratio, CI: confidence interval.
