Table 4 Digestibility of gross energy (GE) and minerals in diets containing 0, 250, 500, 1,000, 2,000, or 4,000 units of microbial phytase (FTU)/kg of complete dieta
Item, % | Phytase, FTU/kg | SEM | P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
0 | 250 | 500 | 1,000 | 2,000 | 4,000 | Linear | Quadratic | ||
Apparent ileal digestibility | |||||||||
 Ca | 61.6 | 74.2 | 76.7 | 77.1 | 80.7 | 76.8 | 1.99 | 0.001 |  < 0.001 |
 P | 27.1 | 45.1 | 56.7 | 63.0 | 75.5 | 80.0 | 1.43 |  < 0.001 |  < 0.001 |
 K | 81.1 | 83.6 | 85.1 | 83.8 | 87.0 | 86.7 | 1.18 | 0.003 | 0.072 |
Apparent total tract digestibility | |||||||||
 GE | 82.7 | 83.2 | 84.3 | 82.2 | 83.9 | 81.8 | 1.27 | 0.415 | 0.439 |
 Ca | 57.9 | 66.3 | 73.4 | 72.8 | 79.9 | 75.7 | 3.09 |  < 0.001 |  < 0.001 |
 P | 29.9 | 45.5 | 54.4 | 63.8 | 74.3 | 78.3 | 3.07 |  < 0.001 |  < 0.001 |
 K | 79.4 | 83.3 | 85.2 | 87.0 | 89.5 | 88.2 | 1.46 |  < 0.001 |  < 0.001 |
 Mg | 21.4 | 18.1 | 21.5 | 24.7 | 27.9 | 26.6 | 4.56 | 0.135 | 0.333 |
 Na | 83.3 | 82.5 | 83.5 | 84.3 | 85.7 | 89.7 | 2.54 | 0.035 | 0.840 |