Table 1 Characteristics of sow herds participating in the studya
From: Longitudinal piglet sampling in commercial sow farms highlights the challenge of PRRSV detection
| Farm A | Farm B | Farm C | Farm D | Farm E | Farm F | |
|---|---|---|---|---|---|---|
| Sow inventory | 3000 | 3000 | 3000 | 3000 | 6000 | 3300 |
| Distance to the nearest farm | 800 m | 8 km | 800 m | 3.2 km | > 32 km | 2.4 km |
| Farrowing rooms (crates/room) | 18 (28) | 15 (24) | 14 (28) | 20 (32) | 20 (56) | 13 (56) |
| Most recent PRRSV outbreak | 18 months | 6 months | 6 months | 6 months | 3 months | 5 months |
| PRRSV RFLP patternb | 1–7-4 | 1–10-4 | 1–7-4 | 1–7-4 | 1–8-4 | 1–7-4 |
| PRRSV control | ||||||
| - PRRSV MLV | Quarterly | Quarterly | Quarterly | Quarterly | Yes | No |
| - Live virus inoculation | No | No | No | No | Yes | Yes |
| - Shower in/shower out | Yes | Yes | Yes | Yes | Yes | Yes |
| - Supplies disinfected at entry | Yes | Yes | Yes | Yes | Yes | Yes |
| - Gilt quarantine | Yes | No | Yes | No | Yes | Yes |
| Surveillance specimens | ||||||
| - Processing fluids (PF) | ||||||
| Weeks sampled | 1–19 | 1–19 | 1–19 | 1–19 | 1–38 | 1–18 |
| Total PF samples | 87 | 83 | 74 | 94 | 167 | 56 |
| - Family oral fluids (FOF) | ||||||
| Weeks sampled | 9–11, 13 | 11–14, 16–19 | 13–19 | 12–18 | 3–5, 7–8, 10–12, 14–16, 18, 20–22, 25–31, 33 | 1–9, 11, 12, 14–17 |
| Total FOF samples | 109 | 480 | 439 | 573 | 498 | 301 |
| - Serum | ||||||
| Sampling period (weeks) | Not done | Not done | Not done | Not done | 14, 18, 22, 24–31, 33 | 8, 12 |
| Total pooledc serum samples | 108 | 12 | ||||