Table 2.
Example calculation of energy digestibility by the difference method1
| Basal diet (BD) | Test diet (TD) | Test ingredient (TI) | ||||
|---|---|---|---|---|---|---|
| Energy yielding component in diets (g/kg) | 967.5 | 967.5 | 1,000 | |||
| TI (g/kg) | 0 | 300 | 1,000 | |||
| Gross energy (as-is basis, kcal/g) | 3.927 | 4.103 | 4.985 | |||
| Dry matter (DM, %) | 88.41 | 88.76 | 92.74 | |||
| Gross energy (DM basis, kcal/g) | 3.927÷88.41×100 | 4.4418 | 4.103÷88.76×100 | 4.6226 | 4.985÷92.74×100 | 5.375 |
| Energy from BD (DM basis, kcal/kg) | 4.4418×1,000 | 4,441.8 | 3.927×(967.5–300) ÷967.5×1,000÷88.41×100 | 3,064.5 | ||
| Energy from TI (DM basis, kcal/kg) | 4.985×300÷92.74×100 | 1,612.6 | ||||
| Energy from BD+TI (DM basis, kcal/kg) | 3,064.5+1,612.6 | 4,677.1 | ||||
| Proportional contribution of energy by TI to TD (Pti) | 1,612.6÷4,677.1 | 0.3448 | ||||
| Digestibility of energy in BD (Dbd, %)2 | 86.22 | |||||
| Digestibility of energy in TD (Dtd, %)2 | 80.40 | |||||
| Digestibility of energy in TI (Dti, %) | 86.22+(80.40–86.22) ÷0.3448 | 69.34 | ||||
1
Data were taken from Adeola and Kong (2014).
2
Determined by either the total collection or index method.