Table 1 Characteristics of farms included in this study
| Herd | Operation | N. of sows | N. of batches |
|---|---|---|---|
| 1 | Farrow-to-finish | 550 | 20 |
| 2 | Farrow-to-wean | 1000 | 20 |
| 3 | Farrow-to-finish | 350 | 4 |
| 4 | Farrow-to-finish | 450 | 10 |
| 5 | Farrow-to-finish | 175 | 4 |
| 6 | Farrow-to-finish | 250 | 7 |
| 7 | Farrow-to-wean | 900 | 20 |
| 8 | Farrow-to-finish | 320 | 7 |
| 9 | Farrow-to-finish | 80 | 4 |
| 10 | Farrow-to-finish | 280 | 4 |