Table 4. Effects of dietary Cu concentrations and sources on nutrients digestibility in broiler chickens

Dry matter Gross energy Crude protein
7 to 14 d 28 to 35 d 7 to 14 d 28 to 35 d 7 to 14 d 28 to 35 d
Cu source × Concentration
 INO (ppm) 16 69.49 68.59 70.04 69.42 61.22 60.93
40 71.82 69.32 72.00 70.03 62.18 61.42
80 72.07 73.51 73.19 71.39 62.46 61.87
120 71.27 70.63 71.60 71.26 61.51 61.25
 HME (ppm) 16 71.30 70.58 71.55 69.30 61.38 61.03
40 71.02 70.14 71.18 70.01 60.92 60.73
80 71.92 71.19 70.82 69.49 61.10 60.92
120 71.81 70.77 72.35 71.52 62.25 61.76
 Pooled SEM 0.29 0.70 0.28 0.36 0.28 0.33
Contrast
 INO vs HME 0.559 0.662 0.507 0.921 0.583 0.743
 Effect of INO level
  SEM 0.45 1.36 0.46 0.63 0.30 0.48
  Linear 0.149 0.449 0.109 0.290 0.686 0.777
  Quadratic 0.080 0.552 0.040 0.791 0.155 0.627
 Effect of HME level
  SEM 0.36 0.48 0.34 0.38 0.48 0.47
  Linear 0.527 0.748 0.527 0.066 0.575 0.631
  Quadratic 0.921 0.994 0.201 0.334 0.469 0.610
INO, copper sulfate; HME, hot melt extrusion copper sulfate.