Table 7. Effects of supplementation of ARG sources and PHE levels on apparent ileal digestibility of DM, CP, EE, CF, and GE in cold-stressed broilers fed a CM-based diet at 38 d
Item1) | DM (%) | CP (%) | EE (%) | CF (%) | GE (%) |
Factorial analysis |
ARG sources |
ARG | 77.42a | 77.82 | 87.87b | 23.16 | 74.83 |
GAA | 76.09b | 76.19 | 89.60a | 22.84 | 75.24 |
SEM | 0.346 | 0.634 | 0.510 | 0.263 | 0.667 |
PHE levels |
0 g/kg | 76.76 | 76.95 | 88.05 | 22.87 | 75.01 |
1.5 g/kg | 76.75 | 77.06 | 89.42 | 23.13 | 75.03 |
SEM | 0.346 | 0.634 | 0.510 | 0.263 | 0.667 |
ARG sources × PHE levels |
ARG × 0 g/kg | 77.56 | 77.49 | 87.08 | 22.96 | 74.94 |
ARG × 1.5 g/kg | 77.28 | 78.14 | 88.65 | 23.35 | 74.72 |
GAA × 0 g/kg | 75.96 | 76.40 | 89.02 | 22.79 | 75.08 |
GAA × 1.5 g/kg | 76.22 | 75.99 | 90.18 | 22.91 | 75.40 |
SEM | 0.489 | 0.896 | 0.721 | 0.372 | 0.943 |
p-value |
ARG sources | 0.015 | 0.089 | 0.029 | 0.415 | 0.670 |
PHE levels | 0.980 | 0.899 | 0.076 | 0.496 | 0.960 |
ARG sources × PHE levels | 0.591 | 0.563 | 0.773 | 0.736 | 0.777 |
Orthogonal analysis |
NC2) | 74.59 | 73.11 | 86.07 | 21.93 | 70.53 |
EG3) | 76.76 | 77.01 | 88.73 | 23.00 | 74.04 |
GAA4) | 76.09 | 76.20 | 89.60 | 22.85 | 75.24 |
p-value Ӏ5) | 0.006 | 0.002 | 0.002 | 0.015 | 0.0003 |
p-value Ⅱ6) | 0.064 | 0.018 | 0.0003 | 0.052 | 0.0005 |
Means in the same column with different superscripts differ significantly (p < 0.05).
NC: negative control group (birds fed CM-based diets without supplements), n = 6 replicates; for each replicate, n = 15 birds.
EG: experimental groups (other four treatments fed diets with supplements), n = 24 replicates; for each replicate, n = 15 birds.
GAA: GAA supplemented groups, n = 12 replicates; for each replicate, n = 15 birds.
Ӏ: orthogonal contrast of NC vs. EG
Ⅱ: orthogonal contrast of NC vs. GAA.
ARG, arginine; PHE, phenylalanine; DM, dry matter; CP, crude protein; EE, ether extract; CF, crude fiber; GE, gross energy; GAA, guanidinoactic acid.