Present results get support from works reported by earlier workers that addition of supernormal levels (125–250 mg/kg) of copper (Cu) in the form of sulphate improve growth rate and feed efficiency in broilers chickens [19]. Similarly, Ruiz et al. [20] stated that higher dietary Cu level promoted growth and increased performance of broiler chickens, while Nys [21] stated that the Cu promoted the growth of chicken when it was administered at higher doses. The feed intake during different growth phases did not differ significantly due to either main effect or interaction between different copper sources and levels. Present results are in agreement with work reported by Iqbal et al. [22] who also reported that feed intake of broilers chicks did not influenced significantly due to feeding different sources and concentrations of copper. The feed conversion ratio was significantly (P < 0.05) better in CuP supplemented diet than other sources of copper during 4–6 and 0–6 wk of age. During (0-3wk) of age, feed conversion ratio did not differ significantly due to different dietary copper sources. The feed conversion efficiency was better (P < 0.05) at 200 mg Cu/kg diet than those recorded at other dietary copper levels different growth phases. There was no significant difference in feed conversion ratio due to interaction between copper sources and levels. Improvement of feed conversion ratio has been reported when broilers were fed diets supplemented with 125–250 ppm of copper in the form of sulphate [23]. Similarly, Paik [24] reported that supplementation of Met-Cu chelate at the level of 100–125 ppm Cu improved growth performance of broilers and pigs. It was also reported that supplementation of 100 ppm of Cu as Met-Cu or Met-Cu-Zn improved performance in broilers [25] and egg production was increased by supplementation of 100 ppm of Cu as Met-Cu chelates in layers [26]. Mortality was not affected by the treatments.
Present results get strength from the previous finding reported by Kulkarni [27] who reported that Cu sources (copper propionate and copper sulphate) and levels (8, 12 and 16 mg/kg) could not bring any significant change in length and width (proximal, mid shaft, distal) of tibia bone of broiler chicks. Similarly, Zheng et al. [28] reported that measurement evaluating in terms of length, proximal width, mid shaft width and distal width of femurs and tibiae did not reveal substantial benefit to skeletal integrity from above 40 mg Zn/kg supplementation. Iqbal et al. [9] also reported that bone length, proximal width and mid shaft width of bone did not alter statistically due to Cu sources and levels.
Present results get support from earlier observation reported by Hashish et al. [29] who also observed a non-significant effect on tibia bone weight, calcium and phosphorus content of tibia bone by feeding 0 to 200 mg copper/kg diet. In the present finding lower tibia Zn content was recorded at higher levels of Cu (150 and 200mg/kg diet) than those recorded at lower levels of Cu (8 and 100mg/kg diet). The reason may be due to the interaction between Cu and Zn contents in the diet, because excess concentration of dietary copper will decrease the availability of zinc due to antagonistic effect. Thus deposition of zinc in the bone will decrease at higher levels of copper. In the present finding tibia bone Cu content was changed significantly due to copper sources [30].
These results received support from the earlier work reported by Leeson [31] who also reported that when bioavailability of reagent grade Cu sulphate was set as 100% the relative bioavailability of Cu was 111.63% in 14 days and 110.7% in 35 days of broiler chicks. Similarly, organic Cu sources, such as proteinate and amino acid chelate, have been shown to have higher relative bio-availability than that of inorganic mineral sources, such as oxide and sulphate [13]. In contrary to present finding Iqbal et al [9] who reported that tibia bone copper content was varied due to different levels of copper in the diet. These results partially support by earlier finding reported by Ao et al [32] who observed that organic form of mineral sources such as proteinate and amino acid chelate have been shown to have relative bioavailability than that of inorganic mineral sources, such as oxide and sulphate which may influenced the higher iron content in tibia bone in copper propionate supplemented diet. Reeves et al. [33] who observed that copper facilitates the absorption of iron in the body.
The concentrations of calcium (Ca), phosphorus (P), Cu, manganese (Mn), Zn and iron (Fe) in excreta did not differed significantly due to interaction between different Cu sources and concentrations (Table 4). However, as increasing dietary Cu concentration, increased excreta Cu concentration with dose response. Present result is in close agreement with earlier observation reported by Bao et al. [34] who reported that the excretion of Cu increased linearly with increasing intake of the element through the diet. In the present finding excreta Cu content was not change significantly due to copper sources, but numerically less excreta copper content was observed in organic source of copper than inorganic sources of copper, which indicate higher retention of copper in organic source than inorganic source of copper. These result received support from the earlier observation of Lee et al. [35] also reported that excreta Cu content was greatly reduced when organic source of mineral supplemented in broiler diet. Similarly, Shamsudeen et al. [36] reported that a higher retention of Cu in Cu chelate group than its counterpart Cu-inorganic group in broiler chickens. Iqbal et al. [9] also found non-significant effect on excreta calcium and phosphorus content when diet fed variable levels of Cu, Zn and their sources in broiler diets. These results also support present finding. Higher excreta Mn content was recorded in Cu chloride supplemented diet than Cu sulphate supplemented diet and significantly lowest excreta Mn content was recorded in Cu propionate supplemented diet. The lower excreta Mn content found in Cu propionate supplemented diet which suggesting that organic source of Cu had higher retention of minerals than inorganic source copper chloride and copper sulphate. Lee et al. [35] also reported that excreta Cu content was greatly reduced when organic source of mineral supplemented in broiler diet Shamsudeen et al. [36] reported that a higher retention of Cu in Cu chelate group than its counterpart Cu-inorganic group in broiler chickens. Excreta Mn content was recorded higher at 200mg/kg than 150mg/kg diet and lower at 8 and 100mgCu/kg diet. Contrary to the present finding El-Damrawy et al. [37] who reported that manganese retention was unaffected by source and dose of copper in the diet. Excreta Zn content was higher in Cu sulphate supplemented diet than Cu chloride supplemented diet and lowest excreta Zn content was recorded in Cu propionate supplemented diet than those observed in Cu sulphate and Cu chloride supplemented diet. Higher excreta Fe content was observed in Cu sulphate and Cu chloride supplemented diet than that recorded in Cu propionate supplemented diet. The lower excreta Zn and Fe content found in Cu propionate supplemented diet which suggesting that organic source copper propionate had higher retention of Zn and Fe than inorganic sources copper sulphate and copper chloride. El-Damrawy et al. [37] also observed that supplementation of copper propionate had higher Zn and Fe retention than its counterpart copper sulphate supplemented diet.
Table 4
Tibia bone mineralization of broiler chickens as influenced by feeding different sources and concentrations of copper
Treatments | Bone wt. (g) | Ash (%) | Ca (%) | P (%) | Zn (mg/kg) | Cu (mg/kg) | Mn (mg/kg) | Fe (mg/kg) |
Sources | Levels |
Interaction effect |
Cu S | 8 | 5.81 | 40.31 | 15.39 | 7.81 | 154.00cd | 3.46d | 30.00 | 193.50 |
| 100 | 5.71 | 41.48 | 15.53 | 7.88 | 149.00bc | 2.66ab | 27.50 | 232.17 |
| 150 | 6.07 | 38.72 | 15.64 | 7.82 | 121.33ab | 2.41a | 25.17 | 187.50 |
| 200 | 5.93 | 18.42 | 15.63 | 7.93 | 109.33a | 2.38a | 30.67 | 205.00 |
Cu cl | 8 | 5.85 | 39.52 | 15.41 | 7.74 | 179.50d | 2.74ab | 29.50 | 238.50 |
| 100 | 6.01 | 41.48 | 15.77 | 7.78 | 143.67bc | 2.64ab | 26.50 | 274.67 |
| 150 | 5.58 | 41.06 | 15.84 | 7.89 | 113.00b | 2.67ab | 25.33 | 324.14 |
| 200 | 6.14 | 40.65 | 15.78 | 7.95 | 111.33a | 2.79ab | 27.00 | 164.50 |
Cu P | 8 | 5.99 | 39.91 | 15.54 | 7.78 | 153.67cd | 2.36ab | 27.33 | 280.17 |
| 100 | 6.10 | 41.52 | 16.03 | 7.88 | 154.67cd | 2.95bc | 29.17 | 311.33 |
| 150 | 6.06 | 40.11 | 16.09 | 7.98 | 146.00bc | 3.06bcd | 28.50 | 320.83 |
| 200 | 6.12 | 40.57 | 15.87 | 7.84 | 142.33bc | 3.33ab | 27.83 | 327.17 |
Pooled SEM | 0.109 | 0.290 | 0.257 | 0.045 | 3.52 | 0.057 | 0.569 | 11.536 |
Main effect |
Copper sources |
CuS | 5.89 | 39.73 | 15.55 | 7.86 | 133.42a | 2.73a | 28.33 | 204.54a |
Cucl | 5.90 | 40.68 | 15.69 | 7.84 | 136.84ab | 2.71a | 27.08 | 250.46a |
Cu P | 6.07 | 40.53 | 15.88 | 7.87 | 147.17b | 2.99b | 28.21 | 309.88b |
Copper levels |
8 | 5.89 | 39.91 | 15.45 | 7.78 | 162.39b | 2.94 | 28.94 | 237.39 |
100 | 5.96 | 41.49 | 15.78 | 7.85 | 149.11b | 2.75 | 27.72 | 272.73 |
150 | 5.90 | 39.96 | 15.86 | 7.90 | 126.78a | 2.72 | 26.33 | 277.50 |
200 | 6.06 | 39.88 | 15.76 | 7.91 | 121.00a | 2.84 | 28.50 | 232.22 |
Probabilities |
Interaction | NS | NS | NS | NS | P ≤ 0.0) | P ≤ 0.01 | NS | NS |
Cu sources | NS | NS | NS | NS | P ≤ 0.05 | P ≤ 0.05 | NS | P ≤ 0.01 |
Cu levels | NS | NS | NS | NS | P ≤ 0.01 | NS | NS | NS |
Values bearing different superscripts within a column differ significantly, (P ≤ 0.05), (P ≤ 0.01) |
NS –Non significant |
Table 5
Excreta mineral contents of broiler chickens as influenced by feeding different sources and concentrations of copper
Treatments | Calcium (%) | Phosphorus (%) | Copper (mg/kg) | Manganese (mg/kg) | Zinc (mg/kg) | Iron (mg/kg) |
Sources | Levels |
Interaction effect |
Cu S | 8 | 2.35 | 1.49 | 12.52 | 622.67 | 511.00 | 424.33 |
| 100 | 2.40 | 1.41 | 117.45 | 684.67 | 608.00 | 608.33 |
| 150 | 2.39 | 1.62 | 149.99 | 760.33 | 645.00 | 460.33 |
| 200 | 2.37 | 1.38 | 204.03 | 799.00 | 675.67 | 678.00 |
Cu cl | 8 | 2.51 | 1.35 | 19.07 | 922.00 | 374.33 | 624.67 |
| 100 | 2.36 | 1.45 | 97.48 | 964.67 | 412.00 | 381.00 |
| 150 | 2.50 | 1.46 | 154.97 | 1025.33 | 526.33 | 435.67 |
| 200 | 2.38 | 1.39 | 219.54 | 1133.33 | 531.33 | 510.33 |
Cu P | 8 | 2.48 | 1.36 | 11.79 | 398.67 | 271.67 | 203.33 |
| 100 | 2.42 | 1.33 | 117.98 | 445.00 | 302.66 | 302.00 |
| 150 | 2.21 | 1.42 | 148.28 | 546.67 | 330.67 | 443.33 |
| 200 | 2.32 | 1.34 | 197.70 | 596.36 | 436.33 | 337.33 |
Pooled SEM | 0.032 | 0.023 | 12.09 | 38.61 | 31.33 | 34.81 |
Main effect |
Copper sources |
CuS | 2.38 | 1.48 | 120.99 | 716.67b | 609.92c | 542.75b |
Cucl | 2.44 | 1.41 | 122.76 | 1011.33c | 461.00b | 487.92b |
Cu P | 2.36 | 1.36 | 118.94 | 496.67a | 335.33a | 321.50a |
Copper levels |
8 | 2.45 | 1.40 | 14.46a | 647.78a | 385.67 | 417.44 |
100 | 2.39 | 1.39 | 110.97b | 698.11a | 440.89 | 430.44 |
150 | 2.37 | 1.50 | 151.08c | 777.44b | 500.67 | 446.44 |
200 | 2.36 | 1.37 | 207.09d | 842.89c | 547.78 | 508.56 |
Probabilities |
Interaction | NS | NS | NS | NS | NS | NS |
Cu sources | NS | NS | NS | P ≤ 0.01 | P ≤ 0.01 | P ≤ 0.05 |
Cu levels | NS | NS | P ≤ 0.01 | P ≤ 0.01 | NS | NS |
Values bearing different superscripts within a column differ significantly, (P ≤ 0.05), (P ≤ 0.01) NS –Non significant |
Therefore, it can be concluded that feeding dietary Cu concentrations up to 200 mg Cu/kg diet, effective in promoting growth, feed conversion efficiency regardless of different sources, and had no negative effects on bone morphometry and mineralization features, with the exception of a decrease in tibia zinc content., However, compared to Cu sulphate and Cu chloride supplemented diets; Cu propionate considerably increased the retention of trace minerals.