Table 4. The parameters of eggshell ultrastructure according to hen age.
| Hen age (wk) | Eggshell thickness (µm) | Palisade layer thickness (µm) | Mammillary layer thickness (µm) | Palisade layer rate (%) | Mammillary layer rate (%) | Mammillary knob density (1 mm2) |
|---|---|---|---|---|---|---|
| 30 | 353.46±10.80 | 259.49±15.94 | 93.97±9.22b | 73.37a | 26.63b | 235.10±19.86a |
| 60 | 368.80±20.16 | 254.19±26.51 | 114.61±20.89a | 68.88ab | 31.12ab | 178.25±11.09b |
| 78 | 353.67±25.16 | 238.85±18.09 | 114.81±17.62a | 67.61b | 32.39a | 143.63±12.01c |
a,b Values (n=10) with different superscripts in the column are significantly different (p<0.05).
Palisade layer rate (%)=Palisade layer thickness/Eggshell thickness×100.
Mammillary layer rate (%)=Mammillary layer thickness/Eggshell thickness×100.
Mammillary knob density; Number of normal mammillary bodies in eggshell inner surface (1 mm2).