Table 1. Definition of the moderators used in the meta-regression.
| Moderator | Classes | Definition |
|---|---|---|
| FPTDIAG1 | 1 | Threshold1: IgG = 3.5–5 g/L or TP = 40 g/L |
| 2 | Threshold: IgG = 8 g/L or TP = 45–50 g/L | |
| 3 | Threshold: IgG = 10–12 g/L or TP = 54–55 g/L | |
| 4 | Threshold: IgG = 15–24 g/L | |
| FPTDIAG2 | 1 | Threshold: IgG = 3.5–5 g/L or TP = 40 g/L |
| 2 | Threshold: IgG = 8–10 g/L or TP = 45–50 g/L | |
| 3 | Threshold: IgG = 12 g/L or TP = 54–55 g/L | |
| 4 | Threshold: IgG = 15 g/L or TP = 15–24 g/L | |
| FPTGAP | 0 | No gap in IgG or TP to define FPT2 |
| 1 | A gap in IgG or TP to define FPT3 | |
| FPTTHRES | 0 | FPT is defined relative to all values above or below the threshold4 |
| 1 | FPT is defined relative to ranges of values above or below the threshold5 | |
| OUTTIME_MORT6 | 1 | Duration of observation of the outcomes7 = 0 to 60 days of life |
| 2 | Duration of observation of the outcomes = 0 to 90–110 days of life | |
| 3 | Duration of observation of the outcomes = 0 to 160–200 days of life | |
| OUTTIME_RESPI8 | 1 | Duration of observation of the outcomes7 = 0 to 1, 3 or 4 months of life |
| 2 | Duration of observation of the outcomes = 0 to 5 or 6 months of life | |
| 3 | Duration of observation of the outcomes = 0 to 15 months of life | |
| OUTMORBIDITY9 | 1 | Models with outcome = “at least one disease or treatment” |
| 2 | Models with outcome = “diarrhoea” | |
| 3 | Models with outcome = “BRD” |
1: The threshold is used to distinguish between calves with and without FPT. IgG is blood immunoglobulin G, and TP is blood total proteins
2: Calves with FPT have a TP < 50 g/L and calves without FPT have a TP > 50 g/L
3: Calves with FPT have a TP < 45 g/L and calves without FPT have a TP > 55 g/L
4: Calves with FPT have a TP < 45 g/L
5: Calves with FPT have a TP between 40 and 45 g/L
6: For the meta-regression related to mortality only
7: The duration of observation of the outcomes always started at birth and different studies used different endpoints
8: For the 2 meta-regressions related to bovine respiratory disease and at least one other disorder or treatment
9: For the meta-regression related to BRD, diarrhoea and at least one other disorder or treatment.