Table 4.
Parameter estimates and standard error for the models quantifying the effect of the different rearing system characteristics on the mortality of broiler chickens.
| Mortality | ||||
|---|---|---|---|---|
| Variable1 | (%; n = 334) | P-value | ||
| Intercept | 3.73 | 2.74 | 0.1828 | |
| ED | −0.288 | 0.108 | 0.0082 | |
| ED × ED | 0.004 | 0.002 | 0.0190 | |
| EIA | −0.332 | 0.069 | <0.0001 | |
| EIA × EIA | 0.010 | 0.001 | <0.0001 | |
| Breed | Aviagen | −0.368 | 1.322 | 0.4346 |
| Aviagen × Cobb Vantress | 0.396 | 2.949 | ||
| Cobb Vantress | −0.927 | 1.361 | ||
| Group Grimaud | 4.08 | 4.04 | ||
| Others | 0 | - | ||
| Sex | Females | −1.33 | 1.01 | 0.0017 |
| Males | 0.602 | 0.898 | ||
| Mixed | 0 | - | ||
| FP | 1 | −0.712 | 3.432 | 0.8071 |
| 2 | −0.135 | 1.201 | ||
| 3 | −0.719 | 1.141 | ||
| >3 | 0 | - | ||
| SD | 0.114 | 0.090 | 0.2066 | |
| SD × SD | −0.001 | 0.002 | 0.1563 | |
| GS | −0.0010 | 0.0007 | 0.1571 | |
| BM | No | −0.043 | 1.402 | 0.9754 |
| Yes | 0 | - | ||
| Enrichment | No | −0.074 | 0.472 | 0.8755 |
| Yes | 0 | - | ||
| DP | −0.026 | 0.065 | 0.6868 | |
| DS | No | 0.539 | 1.770 | 0.7611 |
| Yes | 0 | - | ||
| EC | No | 0.882 | 1.187 | 0.4584 |
| Yes | 0 | - | ||
| MU | No | 0.784 | 1.305 | 0.5485 |
| Yes | 0 | - | ||
| EIA × ED | 0.008 | 0.003 | 0.0010 | |
| EIA × SD | −0.007 | 0.001 | <0.0001 | |
| SD × GS | 0.00004 | 0.00002 | 0.0528 | |
| SD × DP | 0.005 | 0.003 | 0.0660 | |
| RMSE | 0.06 | |||
1ED: duration of the experimental period (d); EIA: experimental initial age (d); FP: feeding phases; SD: stocking density (kg/m2); GS: group size (n); BM: bedding material; DP: duration of the photoperiod (h); DS: divided scotoperiod (h); EC: environmental control; MU: use of vaccines and other medications.