Table 1.
The effect of flock age, preincubation heat treatment, and turning during storage on the stage of blastoderm development on day 5 after egg collection.
| Item | n1 | Average stage (EGK) | |
|---|---|---|---|
| Flock age2 | |||
| Young | 60 | 10.27b | |
| Old | 60 | 11.10a | |
| Preincubation heat treatment3 | |||
| Control | 60 | 10.24b | |
| SPIDES | 60 | 11.13a | |
| Turning treatment4 | |||
| 0 times/day | 60 | 10.47b | |
| 4 times/day | 60 | 10.90a | |
| SEM | 0.131 | ||
| Flock age × turning treatment | |||
| Young | 0 times/day | 30 | 10.25a |
| 4 times/day | 30 | 10.29a | |
| Old | 0 times/day | 30 | 10.68a |
| 4 times/day | 30 | 11.52b | |
| SEM | 0.185 | ||
| P value | |||
| FA | <0.001 | ||
| PHT | <0.001 | ||
| TT | 0.020 | ||
| FA × PHT | 0.179 | ||
| FA × TT | 0.035 | ||
| PHT × TT | 0.532 | ||
| FA × PHT × TT | 0.778 | ||
a,bMeans with different superscripts differ significantly (P ≤ 0.05).
EGK = developmental stage of the embryo according to Eyal-Giladi and Kochav (1976).
There were 60 eggs opened for flock age, heat treatment, and turning treatment; 30 eggs for a flock age × turning treatment group.
Flock age (FA): young = 29 wk, old = 58 wk.
Preincubation heat treatment (PHT): control = not heated during storage, and short period of incubation during egg storage (SPIDES) = heated over 32°C EST for 3.5 h and remained at 35°C for 2.5 h on day 5 after egg collection.
Turning treatment (TT): 0 or 4 times/day during the storage period.