Table 3.
Effect of a higher eggshell temperature (EST) of 38.9°C during week 2 of incubation (Higher) and/or a lower EST of 36.7°C during week 3 of incubation (Lower) compared with a control EST of 37.8°C (Control) and sex on Newcastle disease (NCD) titer of broilers at hatch, at day 22 (7 d after NCD vaccination), and slaughter age (day 41 or 42).
| NCD titer | |||
|---|---|---|---|
| Treatment | Hatch1 (log10titer) | Day 222 (log10titer) | Slaughter2 (log10titer) |
| EST week 2 | |||
| Control | 3.2 | 1.5 | 2.6b |
| Higher | 3.1 | 1.7 | 2.8a |
| SEM | 0.1 | 0.1 | 0.1 |
| EST week 3 | |||
| Lower | 3.0 | 1.5 | 2.8 |
| Control | 3.2 | 1.7 | 2.7 |
| SEM | 0.1 | 0.1 | 0.1 |
| EST week 2 × week 3 | |||
| Control × Lower | 3.0 | 1.4 | 2.7 |
| Control × Control | 3.3 | 1.6 | 2.6 |
| Higher × Lower | 3.0 | 1.6 | 2.8 |
| Higher × Control | 3.1 | 1.7 | 2.8 |
| SEM | 0.1 | 0.2 | 0.1 |
| P-value | |||
| Week 2 | 0.38 | 0.41 | 0.02 |
| Week 3 | 0.15 | 0.50 | 0.08 |
| Week 2 × week 3 | 0.58 | 0.79 | 0.82 |
| Sex | 0.28 | 0.60 | 0.02 |
1
n = 13, 12, 12, 12 for treatments Control x Lower, Control× Control, Higher × Lower, Higher × Control, respectively.
2
n = 16/treatment.