Table 3.
Total tract N retention, gross energy (GE) and abdominal fat of broilers fed different levels of crude protein and protease enzyme over 15–28 days.
| Item | Total Tract N Retention (%) | GE (Kcal/kg) | Abdominal Fat (%) |
|---|---|---|---|
| CP 1 | |||
| CP-17 | 66.00 b | 2889.0 b | 0.87 a |
| CP-19 | 68.00 a | 2928.0 a | 0.59 b |
| CP-21 | 68.25 a | 2930.0 a | 0.55 c |
| Pooled SEM | 1.74 | 103.55 | 0.01 |
| Enzyme 2 | |||
| Without enzyme | 66.08 b | 2904.0 | 0.72 a |
| CP + enzyme | 68.29 a | 2927.1 | 0.62 b |
| Pooled SEM | 2.42 | 203.45 | 0.01 |
| CP × Enzyme | |||
| CP-170 | 62.71 d | 2876.0 b | 0.96 a |
| CP-17E | 64.00 c | 2902.0 ab | 0.77 b |
| CP-190 | 67.00 b | 2919.0 ab | 0.63 c |
| CP-19E | 68.19 ab | 2936.5 a | 0.55 d |
| CP-210 | 68.18 ab | 2917.0 ab | 0.57 d |
| CP-21E | 68.36 a | 2943.2 a | 0.53 d |
| Pooled SEM | 3.33 | 107.00 | 0.01 |
| p-value | |||
| CP | <0.001 | <0.001 | 0.0348 |
| Enzyme | 0.0007 | <0.001 | 0.0919 |
| CP × Enzyme | 0.0339 | 0.0009 | 0.0052 |
Means in the same column with different superscripts differ significantly (p < 0.05). 1 Diets contained different levels of CP: CP-1 = 17% CP; CP-2 = 19% CP; CP-3 = 21% CP (all these diets were with or without protease enzyme). 2 Protease enzyme at 30,000 UI/kg.