Table 3.
Ultrastructural variables in eggshell and mammillary layer in young (36 wk of age) and aged (70 wk of age) ducks.
| Variables1 | Young duck | Aged duck | P-value |
|---|---|---|---|
| Eggshell ultrastructure | |||
| Mammillary knob width (μm) | 96.6 ± 5.30b | 109 ± 7.88a | 0.008 |
| Mammillary thickness (μm) | 109 ± 8.43 | 109 ± 8.21 | 0.916 |
| Effective thickness (μm) | 234 ± 5.64a | 205 ± 14.2b | 0.001 |
| Total thickness (μm) | 344 ± 6.60a | 313 ± 19.5b | 0.011 |
| Mammillary layer (%) | 31.8 ± 2.05b | 34.7 ± 1.73a | 0.024 |
| Effective layer (%) | 68.2 ± 2.05a | 65.3 ± 1.73b | 0.024 |
| Ultrastructure of mammillary layer | |||
| Mammillae density | 224.18 ± 5.98 | 221.47 ± 2.31 | 0.679 |
| Confluence | 3.68 ± 0.10 | 3.74 ± 0.07 | 0.617 |
| Type B | 1.25 ± 0.19 | 1.28 ± 0.28 | 0.782 |
| Type A | 1.25 ± 0.07 | 1.23 ± 0.08 | 0.854 |
| Aragonite | 1.07 ± 0.05 | 1.21 ± 0.09 | 0.150 |
| Early fusion | 1.44 ± 0.66b | 2.38 ± 0.14a | < 0.001 |
| Late fusion | 2.83 ± 0.16 | 2.59 ± 0.16 | 0.296 |
| Cuffing | 3.19 ± 0.17b | 3.92 ± 0.27a | 0.038 |
| Pitted | 1.28 ± 0.41 | 1.54 ± 0.45 | 0.242 |
| Caps | 1.86 ± 0.12b | 2.36 ± 0.44a | 0.022 |
| Total score | 17.86 ± 0.29b | 20.27 ± 0.28a | < 0.001 |
a-b
Values within a row with no common superscripts differ significantly (P < 0.05)
1
Mean of 6 replicates (10 eggs per replicate) per treatment.