TABLE 3.
Effects of supplemental zinc source and zinc level on the growth performance of broilers.
| Item | Added Zn (mg/kg) | Day 1–7 | Day 8–14 | Day 1–14 | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| BW on day 7 (g) | AFI (g/bird) | BWG (g/bird) | FCR (g:g) | BW on day 14 (g) | AFI (g/bird) | BWG (g/bird) | FCR (g:g) | AFI (g/bird) | BWG (g/bird) | FCR (g:g) | ||
| Control a | 0 | 132.1 | 132.6 b | 85.5 | 1.55 b | 323.1 | 333.3 | 191.8 | 1.75 | 463.0 | 276.4 | 1.68 |
| ZnSO4 c | 40 | 120.7 | 97.2 | 74.5 | 1.31 c | 304.3 | 292.0 | 183.5 | 1.59 | 389.2 | 258.2 | 1.51 c |
| 80 | 125.8 | 112.9 | 79.2 | 1.46 ab | 310.2 | 280.2 | 182.5 | 1.59 | 421.1 | 278.5 | 1.51 c | |
| 120 | 122.2 | 111.0 | 75.8 | 1.46 ab | 298.2 | 294.0 | 180.5 | 1.67 | 405.0 | 251.8 | 1.61 abc | |
| Zn-Met a | 40 | 126.9 | 110.7 | 80.5 | 1.40 bc | 320.5 | 337.2 | 193.7 | 1.76 | 448.0 | 274.1 | 1.63 abc |
| 80 | 128.6 | 124.1 | 82.1 | 1.51 a | 333.2 | 373.5 | 204.6 | 1.83 | 497.6 | 286.6 | 1.73 a | |
| 120 | 127.7 | 108.8 | 81.1 | 1.36 bc | 325.0 | 314.3 | 197.5 | 1.60 | 424.1 | 278.2 | 1.53 bc | |
| Zn-Gly a | 40 | 129.1 | 108.7 | 82.5 | 1.34 c | 353.7 | 349.6 | 222.4 | 1.72 | 464.3 | 307.0 | 1.51 bc |
| 80 | 136.0 | 114.7 | 89.9 | 1.34 c | 352.9 | 346.3 | 218.4 | 1.68 | 474.1 | 306.9 | 1.58 bc | |
| 120 | 127.0 | 112.8 | 87.2 | 1.31 c | 335.4 | 370.6 | 208.1 | 1.80 | 483.5 | 289.4 | 1.67 ab | |
| SEM | 3.75 | 5.69 | 3.53 | 0.04 | 10.29 | 19.55 | 8.84 | 0.09 | 20.60 | 9.25 | 0.06 | |
| Zn Source c | ZnSO4 | 122.9 | 107.1 | 76.5 b | 1.43 | 304.3 c | 288.7 b | 182.2 c | 1.62 | 405.1 b | 262.9 c | 1.55 |
| Zn-Met | 127.8 | 114.5 | 81.2 a | 1.43 | 326.3 b | 341.6 a | 198.6 b | 1.73 | 456.5 a | 279.7 b | 1.63 | |
| Zn-Gly | 130.7 | 112.1 | 86.5 a | 1.33 | 347.4 a | 355.5 a | 216.3 a | 1.73 | 474.0 a | 301.1 a | 1.59 | |
| SEM | 2.21 | 3.28 | 2.09 | 0.02 | 5.81 | 10.81 | 4.99 | 0.05 | 11.79 | 5.23 | 0.04 | |
| Added Zn c | 40 | 125.6 | 105.5 | 79.2 | 1.35 | 326.3 | 326.3 | 194.9 | 1.69 | 433.8 | 279.8 | 1.55 |
| (mg/kg) | 80 | 130.1 | 117.2 | 83.8 | 1.44 | 332.1 | 333.3 | 201.4 | 1.70 | 464.3 | 290.7 | 1.61 |
| 120 | 125.6 | 110.9 | 81.4 | 1.39 | 319.6 | 326.3 | 195.4 | 1.69 | 437.5 | 273.2 | 1.60 | |
| SEM | 2.16 | 3.28 | 2.11 | 0.02 | 5.69 | 10.30 | 5.88 | 0.04 | 10.86 | 5.11 | 0.03 | |
| p-value | ||||||||||||
| Zn-Source | 0.050 | 0.264 | 0.008 | 0.002 | <0.001 | <0.001 | <0.001 | 0.171 | <0.001 | <0.001 | 0.162 | |
| Added Zn | 0.253 | 0.051 | 0.310 | 0.013 | 0.310 | 0.859 | 0.639 | 0.985 | 0.131 | 0.067 | 0.429 | |
| Interaction | 0.876 | 0.562 | 0.943 | 0.003 | 0.857 | 0.158 | 0.823 | 0.263 | 0.299 | 0.663 | 0.042 | |
BW, body weight; AFI, average feed intake; BWG, body weight gain; FCR, the ratio of feed consumption and body weight gain; Zn-Met, zinc-methionine chelate; Zn-Gly, zinc-glycine chelate; and SEM, standard error of mean.
a
Data are mean values of eight replicate pens per treatment.
b
Different from all Zn supplemental groups (p < 0.05).
c
Data are mean values of 24 replicate pens per treatment.
a-c Means without the same superscript letters in the same column differ (p < 0.05).