Table 8 Variables considered for inclusion in two regression models in the cohort study of post-weaning diarrhea
Variables | Scale of measurement | Model 1 (Cox PH) | Model 2 (Mixed linear) |
|---|---|---|---|
Producer | Dichotomous (A, B) | Covariate | Fixed effect |
Pen in nursery | Nominal (n = 8) | Covariate | Fixed effect |
Sow/pen before weaning | Nominal (n = 45) |  | Random effect |
Dam | Nominal (n = 30) | Shared frailty | Random effect |
Dam parity | Discrete (1–7) | Covariate | Fixed effect |
Total (still + live born) litter size, dam | Discrete (total n pigs 14–28) | Covariate | Fixed effect |
Proportion of litter stillborn | Proportion (0–1) | Covariate | Fixed effect |
Sex at insertion to nursery | Nominal (castrated male, intact male, female) | Covariate | Fixed effect |
Weight at birth | Continuous (grams) | Covariate | Fixed effect |
Weight at birth, dichotomized | Dichotomous (low birth weight, normal or high birth weight) | Covariate | Â |
Moved in the farrowing unit | Dichotomous (stayed with dam, moved) | Covariate | Fixed effect |
Time of weaning | Dichotomous (weaned in the farrowing unit, weaned at insertion to nursery) A Time varying effect was added | Covariate | Fixed effect |
Weight at insertion | Continuous (grams) | Covariate | Fixed effect |
Body condition score at insertion to nursery | Dichotomous (normal, below normal) | Covariate | Fixed effect |
Days with hollow flanks | Discrete (n days with hollow flanks 0–14) |  | Fixed effect |
Days suffering from diarrhea | Nominal: (0 days, 1 day, 2 days, 3 days, 4–6 days) |  | Fixed effect |