Table 5.
Egg quality of Chinese Yellow broiler breeders fed diets with different iron contents.
| Dietary Fe content, mg/kg |
P-value1 |
||||||||
|---|---|---|---|---|---|---|---|---|---|
| Variable | 44 | 58 | 72 | 86 | 100 | SEM1 | Fe level | Linear | Quadratic |
| Egg shape index | 1.31 | 1.33 | 1.34 | 1.35 | 1.30 | 0.010 | 0.037 | 0.873 | 0.027 |
| Shell strength, kgf | 3.45 | 3.53 | 3.10 | 3.11 | 2.78 | 0.174 | 0.037 | 0.004 | 0.013 |
| Shell thickness, mm | 0.322 | 0.311 | 0.306 | 0.308 | 0.302 | 0.006 | 0.154 | ||
| Eggshell proportion, % | 8.65 | 8.37 | 8.23 | 8.42 | 8.37 | 0.143 | 0.409 | ||
| Yolk color score | 8.58 | 9.17 | 8.70 | 8.83 | 8.80 | 0.120 | 0.028 | 0.805 | 0.410 |
| Haugh unit | 68.3 | 72.1 | 69.9 | 69.7 | 67.6 | 1.79 | 0.464 | ||
1
Standard error of the mean (n = 6), linear and quadratic contrasts examined only when Fe level was significant.