Table 2

Summary of logistic modelling of risk factors for clinical mastitis in heifers on the day of calving in eleven Estonian dairy herds.
Risk factor
 Number of cases(n = 68)
 Number of controls(n = 995)
 OR1
 95% CI OR2
 P-value
Model 1




Tiestall, short stall-length (≤ 175 cm), vs. tiestall, long stall-length (> 175 cm)
 27/14
 214/168
 2.12
 0.32–14.2
 0.43
Freestall vs.tiestall, long stall-length
 27/14
 613/168
 0.60
 0.09–3.75
 0.58
Model 2




Freestall
 27
 613
 0.39
 0.85–1.83
 0.237
Tiestall
 41
 382
 1

>14 day between movement to calving facility and day of calving
 32
 419
 3.39
 1.42–8.07
 0.006
>14 days between movement to calving facility and day of calving
 36
 576
 1

Tiestall and >14 days
 16
 260
 1

Tiestall and ≤14 days
 25
 122
 5.91
 1.98–17.66
 0.001
Freestall and >14 days
 20
 284
 0.78
 0.13–4.57
 0.79
Freestall and ≤14 day
 7
 329
 1.08
 0.16–7.05
 0.94

1 Odds ratio

2 95% confidence interval odds ratio

Kalmus et al. Acta Veterinaria Scandinavica 2006 48:21   doi:10.1186/1751-0147-48-21