Table 4.
Effect of royal jelly (RJ) administration on egg-laying performance and internal egg quality of laying hens at the late stage of production.
| Traits | Experimental Groups | ||||
|---|---|---|---|---|---|
| 1 CON | 2 R1 | 3 R2 | 4 RSD | p-Value | |
| 5 HDEP (%) | 76.05 b | 80.36 a | 82.14 a | 1.59 | 0.025 |
| Egg weight (g) | 62.16 b | 63.34 ab | 66.57 a | 5.43 | 0.032 |
| Albumen weight (g) | 38.49 | 39.55 | 41.39 | 3.25 | 0.212 |
| Albumen ratio | 61.83 | 62.51 | 61.84 | 2.49 | 0.532 |
| Yolk weight (g) | 17.27 b | 17.94 b | 20.09 a | 1.99 | 0.008 |
| Yolk ratio | 28.20 a,b | 27.92 b | 29.80 a | 2.27 | 0.040 |
| Albumen height (mm) | 5.96 c | 7.66 b | 8.39 a | 0.61 | 0.001 |
| Yolk height (mm) | 15.96 b | 17.01 a | 17.56 a | 1.34 | 0.012 |
| Yolk diameter (mm) | 41.67 | 40.53 | 41.32 | 2.79 | 0.409 |
| Haugh unit | 78.31 b | 83.94 a | 85.14 a | 3.24 | 0.016 |
| Yolk index (%) | 38.47 b | 42.04 a | 42.51 a | 0.81 | 0.002 |
1 CON: control group; 2 R1; 100 mg RJ kg−1; 3 R2: 200 mg RJ kg−1; 4 RSD: residual standard deviation; 5 HDEP: hen–day egg production. a,b,c Values within a row with different superscripts differ significantly.