Factor

Level

Crude disease prevalence per 100 animal years at risk

Cumulative disease incidence rate (%)

Production environment

Low-stress (n = 386)

21.87 ± 5.95

5.59 ± 1.46

High-stress (n = 408)

33.43 ± 6.62

8.46 ± 1.63

Mean difference

11.56

2.88

p-value

0.1945

0.1899

Farm (environment)

Low-stress

Positive deviants (n = 15)

10.13 ± 11.67

2.74 ± 2.87

Typical (n = 371)

33.61 ± 2.35

8.44 ± 0.58

Mean difference

23.48

5.70

p-value

0.0489

0.0522

High-stress

Positive deviants (n = 12)

9.56 ± 13.05

2.58 ± 3.21

Typical (n = 396)

57.30 ± 2.27

14.34 ± 0.56

Mean difference

47.74

11.76

p-value

0.0003

0.0003

Farm

Positive deviants (n = 27)

9.85 ± 8.75

2.66 ± 2.15

Typical (n = 767)

45.46 ± 1.63

11.39 ± 0.40

Mean difference

35.61

8.73

p-value

<0.0001

<0.0001