Table 7.
Causes of death of chickens in the last culled flock on organic/free-range farms.
| Initial Number of Hens and Causes of Death and Disappearance | Mean Number of Hens (Minimum–Maximum) | Percentage (%) of Hens, Relative to Initial Number (Minimum–Maximum) |
|---|---|---|
| Initial number of hens | 17,868 (200–46,000) | 100 |
| Killed by disease | 1543 (3–10,371) | 8.1 (1.5–41.9 2) |
| Found dead on free-range, death caused by predator | 172 (0–1400) | 1.2 (0.0–5.4) |
| Found dead on free-range, cause of death other than by predator | 29 (0–300) | 0.3 (0.0–6.0) |
| Birds missing after comparing arrivals at slaughterhouse with farm records | 406 (0–1817) | 2.5 (0.0–10.0) |
| Mortality caused by predation 1 | 579 (5–2600) | 3.7 (0.2–12.0) |
| Total mortality | 2150 (9–12,588) | 12.2 (3.3–50.8) |
1 Mortality caused by predation is the total number of animals found dead in the free-range area after having been killed by a predator, plus those that are missing, after comparing the numbers arriving at the slaughterhouse with farm mortality records. 2 In one flock, mortality was extremely high due to an infection with Pasteurella multocida.