Table 1.

Description of variables included in the count models (Poisson, quasi-Poisson, and negative binomial model) and in the count-part of the zero-inflated Poisson and the hurdle model.

	Farms with fattening pigs (%)
N	48
Moving single pigs,a n (%)	39 (81.25)
Seperate pen for diseased pigs,a n (%)	32 (66.67)
Use of purchased feed only,a n (%)	11 (22.92)
Water birds in 1 km radius of farm,a n (%)	17 (35.42)
Disinfection of livestock trail
Never,b n (%)	8 (16.67)
After housing out, n (%)	33 (68.75)
Less frequent than after housing out, n (%)	7 (14.58)
Disinfection with chlorine,a n (%)	8 (16.67)
Number of fattening pigs
0 to ≤1,000,b n (%)	20 (41.67)
>1,000 to ≤1,500, n (%)	14 (29.17)
>1,500, n (%)	14 (29.17)

^a“No” as reference category.

^bReference category.