Table 5

Posterior results for the final multivariable categorical multilevel model for the risk factors (Salmonella negative as reference group)
Variable Typhimurium or 1,4,5,12:i:- Other serotypes
Coefficient SD OR 95% OR CrI Coefficient SD OR 95% OR CrI
HERD
Region of the herd
Alentejo 0 1.0 0 1.0
Centre −1.3 1.5 0.28 0.01-4.30 1.5 0.7 4.57 1.33-17.57
Lisbon and Tagus Valley −0.5 1.1 0.62 0.07-5.05 0.9 0.6 2.56 0.86-8.36
North −0.1 1.7 0.88 0.03-24.31 2.6 0.8 12.9 2.97-64.33
Size of the herd: (number of breeding pigs)
<203 0 1.0 0 1.0
≥203 1.9 0.9 7.04 1.46-60.04 0.5 0.4 1.65 0.83-3.44
Source of semen
Insemination centre – IC 0 1.0 0 1.0
Own boar + IC 0.4 0.8 1.45 0.24-7.77 1.1 0.4 2.91 1.35-6.83
Boar from another herd 3.7 1.6 41.22 2.46-1392.7 1.4 0.8 4.18 0.94-19.30
Control of rodents
No 0 1.0 0 1.0
Yes −2.2 1.8 0.11 0.002- 1.85 −2.0 0.7 0.13 0.03-0.45
PEN
Number of pigs/pen
=10 0 1.0 0 1.0
>10 1.4 0.7 4.06 1.03-19.73 0.6 0.4 1.82 0.88-3.79
Age of the breeding sows
Only gilts or gilts and others 0 1.0 0 1.0
Without gilts −1.8 0.8 0.17 0.03-0.65 0.2 0.3 1.24 0.68-2.24
Breeding sector room
Mating 0 1.0 0 1.0
Gestation 0.1 0.5 1.11 0.44-3.10 −0.2 0.3 0.81 0.45-1.52
Mixture of animals of different sectors 0.2 1.7 1.17 0.03-24.80 0.8 0.7 2.14 0.54-7.78
Farrowing −1.0 0.6 0.36 0.10-1.22 −1.0 0.4 0.38 0.17-0.80
Replacement breeders −0.9 1.1 0.40 0.04-2.72 0.1 0.7 1.15 0.29-3.88
Source of feed
Exclusively own 0 1.0 0 1.0
Not exclusively own 0.5 1.1 1.63 0.18-17.62 2.0 0.7 7.29 2.25-29.46
Herd random effect variance 5.8 0.66 1.4 0.24

Legend: SD – standard deviation, OR – odds ratio, CrI – credible interval, in bold the significant OR for a 95%CrI.

Correia-Gomes et al.

Correia-Gomes et al. BMC Veterinary Research 2012 8:226   doi:10.1186/1746-6148-8-226

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