Table 4.
Effect of HYD and EO on eggshell ultrastructure of laying hens after 12 wk of treatment during 48 to 60 wk of age.
| Item1 | Control | HVD+EO | SEM | P-value |
|---|---|---|---|---|
| Mammillary knob width, μm | 87.6 | 74.3 | 2.51 | <0.01 |
| Mammillary thickness, μm | 91.3 | 72.4 | 3.45 | 0.03 |
| Effective thickness, μm | 266 | 283 | 4.60 | 0.01 |
| Total thickness, μm | 356 | 369 | 4.30 | <0.01 |
| Mammillary layer, % | 25.65 | 19.62 | 0.79 | <0.01 |
| Effective layer, % | 74.35 | 80.38 | 0.84 | 0.04 |
1
Each mean represents 10 replicates per treatment, with 3 eggs per replicate.
Abbreviations: EO, 200 mg/kg thymol + 50 mg/kg carvacrol; HVD, 25-hydroxyvitamin D.