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Effects of copper source and level on growth performance and bone mineralization in pigs fed phytase-supplemented diets
It is well documented that high levels of trace minerals can inhibit phytase activity and that chelated trace minerals are highly stable, hence, less prone to interact with other dietary components. The objective of this trial was to study the effect of 2 Cu sources and levels in pig diets supplemented with phytase on growth performance and bone characteristics. A total of 144 pigs (initial BW: 42.9 ± 4.95 kg) were allocated (2 pigs/pen) to 6 treatments: 2 control diets with no supplemented Cu, without (NC) or with 500 FTU/kg of phytase (NC+Phy; CIBENZA® PHYTAVERSE®, Novus International, Inc., St Charles, MO), and 4 diets with 500 FTU/kg of phytase with Cu sulfate (CuSO4) or Cu- Cu methionine hydroxyl analog chelate (Cu-MMHAC, MINTREX®, Novus International, Inc., St Charles, MO) at 2 different levels (80 or 250 mg/kg). Diets were corn-soybean meal-based, P deficient (STTD P = 0.31%) and were fed for 21 d. A contrast statement was used to determine the main effect of phytase (NC vs. NC+Phy). Data was also analyzed as a 2 × 2 factorial with 2 Cu sources and 2 Cu levels supplemented to phytase containing diets (Table). Phytase inclusion increased (NC+Phy vs. NC; P < 0.01) final BW and ADG 0-21 d (62.3 vs. 60.2 kg, and 0.943 vs. 0.844 kg, respectively), and bone content of ash (P < 0.01; 2.94 vs. 2.38 g/bone), P (P < 0.01; 0.507 vs. 0.383 g/bone), and Ca (P < 0.01; 0.937 vs. 0.726 g/bone). Growth performance parameters were not different among Cu supplemented pigs. Copper source (P = 0.033) and Cu level (P = 0.028) impacted bone P content, without an interaction between Cu source and level (P = 0.174). Highest bone P content was obtained with Cu-MHAC-80 (0.55 g/bone) and lowest with CuSO4-250 (0.42 g/bone). Bone Ca was affected by Cu source (P = 0.039) and Cu level (P = 0.023), but there was no interaction (P = 0.180). Bone Ca was highest for Cu-MHAC-80 (1.02 g/bone) and lowest for CuSO4-250 (0.77 g/bone). In conclusion, growth performance was not affected by Cu source. As expected, exogenous phytase improved growth and bone parameters. Likewise, Cu-MHAC supplemented at 80 ppm increased bone P and Ca.
Effects of Cu source and level on bone measurements (g/bone) |
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Bone ash |
Bone P |
Bone Ca |
Cu-MHAC80 |
3.00 |
0.55a |
1.02a |
Cu-MHAC250 |
2.83 |
0.51ab |
0.93ab |
CuSO4 80 |
3.00 |
0.52ab |
0.96ab |
CuSO4 250 |
2.70 |
0.42b |
0.77b |
SEM |
0.13 |
0.03 |
0.05 |
P-values |
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Cu source |
0.618 |
0.033 |
0.039 |
Cu level |
0.150 |
0.028 |
0.023 |
Interaction |
0.573 |
0.174 |
0.180 |
Keywords: copper, phytase, growing pigs