Questionnaire-based study to assess the association between management practices and mastitis within tie-stall and free-stall dairy housing systems in Switzerland

Table 5 Final multivariable negative binomial regression model between management practices and high somatic cell counts (incidence rate ratios (IRR) and 95% confidence intervals (CI)) from 219 Swiss dairy farms with a free-stall and >10 cows in 2010

Factor	Category	IRR (95% CI)	P-value
Hands and arms are cleaned if intervention during calving is required	Yes	0.81 (0.70-0.93)	0.003
	No	1.0	-
Important characteristic when selecting a bull for artificial insemination	Beef production	0.66 (0.47-0.93)	0.02
	Other†	1.0	-

^†Milk yield, fat and protein content of milk, somatic cell count in milk, exterior, ease of calving, length of productive life, milking speed/persistence of lactation, fertility of the dam, total merit.

ISSN: 1746-6148