Table 7.
Effects of dietary manganese (Mn) supplementation on the tibial characteristics and ash, Ca, and P content in the tibia of duck breeders at the end of the trial (34 wk).
| Variables | Mn supplemental level (mg/kg)1 |
SEM |
P-value |
|||||||
|---|---|---|---|---|---|---|---|---|---|---|
| 0 | 20 | 40 | 80 | 120 | 160 | ANOVA | Linear | Quadratic | ||
| Bone fresh weight (g) | 5.67 | 5.77 | 5.92 | 5.85 | 5.98 | 5.68 | 0.057 | 0.558 | 0.796 | 0.219 |
| Fat-free dry weight (g) | 3.43 | 3.57 | 3.60 | 3.64 | 3.60 | 3.40 | 0.038 | 0.304 | 0.848 | 0.050 |
| Length (mm) | 94.9 | 94.9 | 95.1 | 95.5 | 97.1 | 95.4 | 0.353 | 0.428 | 0.181 | 0.267 |
| Midpoint circumference (mm) | 16.4 | 16.9 | 17.5 | 17.3 | 17.3 | 17.1 | 0.146 | 0.280 | 0.246 | 0.086 |
| Bone mineral density (g/cm2) | 0.258 | 0.280 | 0.306 | 0.305 | 0.284 | 0.286 | 0.004 | 0.008 | 0.231 | 0.006 |
| Bone mineral content (g) | 1.46 | 1.48 | 1.62 | 1.58 | 1.53 | 1.53 | 0.025 | 0.216 | 0.329 | 0.088 |
| Breaking strength (N) | 97.1 | 98.5 | 101 | 101 | 102 | 90.2 | 1.21 | 0.038 | 0.389 | 0.014 |
| Ash content (%) | 65.7 | 65.2 | 65.6 | 64.6 | 64.9 | 64.9 | 0.169 | 0.336 | 0.109 | 0.167 |
| Ca content (%)2 | 23.7 | 23.7 | 23.8 | 23.1 | 23.2 | 23.1 | 0.080 | 0.005 | <0.001 | 0.001 |
| P content (%)2 | 10.5 | 10.5 | 10.5 | 10.5 | 10.4 | 10.5 | 0.034 | 0.918 | 0.338 | 0.607 |
| Mn content (%) | 15.4 | 15.0 | 17.3 | 18.2 | 18.5 | 18.5 | 0.353 | 0.001 | <0.001 | <0.001 |
1
Mean of 6 replicates (2 ducks per replicate) per treatment.
2
Ca: calcium; P: phosphorus.