Table 4. Effects of supplementation of exogenous carbohydrase on the reducing sugar release rate and the improved dry matter digestibility of diets for broilers aged 1 to 3 wk.
Item | Content | Quadratic regression equation | P value | Optimal supplement level, U/g | Maximun RS, mg/g or improved DMD, % | ||||||
---|---|---|---|---|---|---|---|---|---|---|---|
Glucoamylase | Supplement level, U/g | 10.00 | 20.00 | 40.00 | 80.00 | 160.00 | 320.00 | y = -0.001x2 + 0.539x + 2.786 | <0.01 | 269.65 | 75.50 |
RSA, mg/g | 6.87 | 15.71 | 22.47 | 37.91 | 65.91 | 77.85 | |||||
Pullulanase | Supplement level, U/g | 10.00 | 20.00 | 40.00 | 80.00 | 160.00 | 320.00 | y = -0.000001x2 + 0.106x - 0.998 | <0.01 | 532.50 | 27.36 |
RSA, mg/g | 0.12 | 1.22 | 3.16 | 6.29 | 13.70 | 22.27 | |||||
Maltase | Supplement level, U/g | 0.16 | 0.31 | 0.63 | 1.25 | 2.50 | 5.00 | y = -2.092x2 + 8.382x + 1.187 | <0.01 | 2.00 | 9.58 |
RSA, mg/g | 1.90 | 3.50 | 6.21 | 8.88 | 8.53 | -9.10 | |||||
Thermostable α-amylase | Supplement level, U/g | 80.00 | 160.00 | 320.00 | 640.00 | 1,280.00 | 2,560.00 | y = -0.000007x2 + 0.019x - 0.945 | <0.01 | 1,385.71 | 12.50 |
RSA, mg/g | 0.99 | 1.95 | 4.16 | 8.57 | 13.30 | 5.10 | |||||
Medium temperature α-amylase | Supplement level, U/g | 10.63 | 21.25 | 42.50 | 85.00 | 170.00 | 340.00 | y = -0.0002x2 + 0.108x + 1.431 | <0.01 | 269.50 | 15.96 |
RSA, mg/g | 2.71 | 3.93 | 5.80 | 8.33 | 15.91 | 19.69 | |||||
Cold-active α-amylase | Supplement level, U/g | 64.00 | 128.00 | 256.00 | 512.00 | 1,024.00 | 2,048.00 | y = -0.00001x2 + 0.039x + 3.597 | <0.01 | 1,965.00 | 42.21 |
RSA, mg/g | 5.15 | 7.96 | 14.68 | 20.08 | 29.33 | 28.18 | |||||
Glucoamylase | Supplement level, U/g | 12.50 | 25.00 | 50.00 | 100.00 | 200.00 | 400.00 | y = -0.000004x2 + 0.002x + 0.217 | <0.01 | 300.00 | 0.58 |
Improved DMD, % | 0.23 | 0.28 | 0.32 | 0.43 | 0.53 | 0.57 | |||||
Pullulanase | Supplement level, U/g | 25.00 | 50.00 | 100.00 | 200.00 | 400.00 | 800.00 | y = -0.000003x2 + 0.003x + 0.408 | <0.01 | 550.00 | 1.32 |
Improved DMD, % | 0.51 | 0.59 | 0.67 | 0.91 | 1.29 | 1.16 | |||||
Maltase | Supplement level, U/g | 0.16 | 0.31 | 0.63 | 1.25 | 2.50 | 5.00 | y = -0.024x2 + 0.152x + 0.213 | <0.01 | 3.20 | 0.46 |
Improved DMD, % | 0.23 | 0.27 | 0.30 | 0.35 | 0.45 | 0.38 | |||||
Thermostable α-amylase | Supplement level, U/g | 68.75 | 137.50 | 275.00 | 550.00 | 1,100.00 | 2,200.00 | y = -0.0000002x2 + 0.0006x + 0.16 | <0.01 | 1,500.00 | 0.61 |
Improved DMD, % | 0.19 | 0.23 | 0.32 | 0.43 | 0.54 | 0.40 | |||||
Medium temperature α-amylase | Supplement level, U/g | 10.00 | 20.00 | 40.00 | 80.00 | 160.00 | 320.00 | y = -0.00002x2 + 0.011x + 0.131 | <0.01 | 285.00 | 1.76 |
Improved DMD, % | 0.28 | 0.32 | 0.48 | 1.03 | 1.39 | 1.71 | |||||
Cold-active α-amylase | Supplement level, U/g | 68.75 | 137.50 | 275.00 | 550.00 | 1,100.00 | 2,200.00 | y = -0.0000001x2 + 0.0004x + 0.128 | <0.01 | 2,000.00 | 0.53 |
Improved DMD, % | 0.15 | 0.18 | 0.27 | 0.35 | 0.50 | 0.64 |
RSA: Reducing sugar release rate; DMD: Dry matter digestibility.