A survey of visitors on Swedish livestock farms with reference to the spread of animal diseases

BMC Veterinary Research

Table 4 Regression results, number of professional visitors

Variable	Coef.	95% confidence interval		P
category
Negative binomial part of the model
Constant	1.87	1.02	2.72	<0.001
Animal species
cattle
swine	−0.48	−0.75	−0.22	<0.001
sheep or goat	−2.15	−2.78	−1.52	<0.001
mixed	−0.33	−0.61	−0.05	0.023
Herd size
hobby
medium	0.01	−0.86	0.89	0.974
large	0.59	−0.28	1.47	0.185
Logistic part of model (probability of no visitors)
Constant	1.08	0.30	1.85	0.007
Animal species
cattle
swine	−2.36	−4.73	0.01	0.051
sheep or goat	−1.33	−5.00	2.33	0.476
mixed	0.05	−0.54	0.64	0.867
Contact log period
summer
autumn	−0.89	−1.60	−0.18	0.014
winter	−0.39	−0.92	0.14	0.149
spring	−0.52	−1.00	−0.05	0.031
Herd size
hobby
medium	−1.80	−2.88	−0.72	0.001
large	−3.49	−5.14	−1.84	<0.001

Estimates from a negative binomial regression model used to analyse the number of professional visitors in Swedish livestock herds, based on replies to a contact log sent out in 2006–2007.

ISSN: 1746-6148