Table 6 Multilevel regression of pig’s age at 100 kg if they are infected with influenza A(H1N1)pdm09 virus

Breed

Landrace

Reference

Duroc

7.3

0.83

<0.001

5.7

9.0

Birthdate

−0.006

0.0005

<0.001

−0.007

−0.005

Average daily feed intake

−28.5

0.94

<0.001

−30.3

−26.6

Infection status group

SERONEG

Reference

SEROPOS

−0.4

0.34

0.292

−1.0

0.3

VIR1

1.6

0.67

0.017

0.3

2.9

VIR2

1.8

1.20

0.129

−0.5

4.2

VIR3

2.4

1.15

0.038

0.1

4.6

Constant (β ₀ )

316.8

9.4

<0.001

298.3

335.3