Table 3. Effects of supplementation of ARG sources and PHE levels on performance (0 to 38 d) and ascites susceptibility in cold-stressed broilers fed a CM-based diet

Item1) FI (g/bird) BWG (g/bird) FCR NO (μmol/L) Heart (% of BW) RV/TV Ascites mortality (%)
Factorial analysis
 ARG sources
  ARG 2,478.6a 1,310.4a 1.89 45.55a 0.551 23.80b 10.00b
  GAA 2,343.5b 1,238.8b 1.89 38.65b 0.572 27.03a 15.33a
  SEM 27.52 21.74 0.023 0.840 0.009 0.476 1.86
 PHE levels
  0 g/kg 2,511.4a 1,289.0 1.95a 40.49b 0.559 26.12a 13.33
  1.5 g/kg 2,310.7b 1,260.2 1.84b 43.72a 0.565 24.72b 12.00
  SEM 27.52 21.74 0.023 0.840 0.009 0.476 1.86
 ARG sources × PHE levels
  ARG × 0 g/kg 2,626.4a 1,338.7 1.97 43.81 0.540 24.19 10.67
  ARG × 1.5 g/kg 2,330.9b 1,282.0 1.82 47.29 0.562 23.41 9.34
  GAA × 0 g/kg 2,396.5b 1,239.2 1.93 37.16 0.578 28.05 16.00
  GAA × 1.5 g/kg 2,290.5b 1,238.4 1.85 40.14 0.568 26.02 14.67
  SEM 38.91 30.74 0.033 1.19 0.013 0.673 2.62
 p-value
  ARG sources 0.003 0.033 0.939 < .0001 0.108 < .0001 0.046
  PHE levels < .0001 0.364 0.004 0.008 0.641 0.042 0.618
  ARG sources × PHE levels 0.027 0.377 0.317 0.833 0.254 0.355 0.896
Orthogonal analysis
 NC2) 2,394.7 1,149.2 2.09 31.14 0.645 30.06 24.00
 EG3) 2,411.1 1,274.6 1.89 42.10 0.562 25.42 12.67
 GAA4) 2,343.5 1,238.8 1.89 38.65 0.573 27.04 15.34
 p-value Ӏ5) 0.739 0.002 0.0001 < .0001 < .0001 < .0001 0.006
 p-value Ⅱ6) 0.346 0.0270 0.0003 < .0001 < .0001 0.001 0.073
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; CM, canola meal; FI, feed intake; BWG, body weight gain; FCR, feed conversion ratio; NO, nitric oxide; GAA, guanidinoactic acid; BW, body weight; RV/TV, right ventricle weight to total ventricle weight ratio.