Assessing risk profiles for Salmonella serotypes in breeding pig operations in Portugal using a Bayesian hierarchical model

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.

ISSN: 1746-6148