Table 3.
Weekly growth performance of pigs fed with low-protein diets supplemented with a corn-expressed phytase.
| Item | Diets 1 | SEM 2 | p-Value | |||||
|---|---|---|---|---|---|---|---|---|
| PC | NC | LD | HD | LDR | HDR | |||
| BWG 3, g | ||||||||
| Wk 1 | 3242 ± 1515 a | 851 ± 511 b | 2157 ± 1157 ab | 1192 ± 872 b | 1475 ± 1022 b | 1232 ± 934 b | 185 | <0.001 |
| Wk 2 | 4994 ± 741 a | 1021 ± 630 b | 1589 ± 594 bc | 1702 ± 321 bc | 1702 ± 1131 bc | 2334 ± 1241 c | 220 | <0.001 |
| Wk 3 | 4994 ± 945 a | 1646 ± 415 a | 2724 ± 1372 b | 1816 ± 908 b | 1645 ± 1110 b | 1816 ± 1112 b | 224 | <0.001 |
| Wk 4 | 5513 ± 714 a | 1135 ± 1864 b | 2100 ± 1349 b | 2497 ± 1329 b | 2894 ± 1371 b | 2983 ± 1591 b | 278 | <0.001 |
| CFI 3, g | ||||||||
| Wk1 | 5714 ± 80 a | 3746 ± 1063b# | 4665 ± 158 b#$ | 3950 ± 799 b | 3768 ± 688 b$ | 4190 ± 375 b | 135 | <0.001 |
| Wk 2 | 6557 ± 458 a | 3995 ± 1183 b | 4937 ± 169 b | 4461 ± 928 b | 4256 ± 785 b | 4404 ± 376 b | 161 | <0.001 |
| Wk 3 | 6726 ± 550 a | 4222 ± 1317 b | 4880 ± 105 b | 4574 ± 1014 b | 4381 ± 956 b | 4248 ± 324 b | 171 | <0.001 |
| Wk 4 | 7686 ± 897 a | 4903 ± 1363 b | 5522 ± 417 b | 5335 ± 1481 b | 4881 ± 942 b | 4884 ± 631 b | 203 | <0.001 |
| CPI 3, g | ||||||||
| Wk 1 | 1378 ± 18 a | 509 ± 144 b | 630 ± 21 b | 541 ± 109 b | 516 ± 94 b | 587 ± 52 b | 44 | <0.001 |
| Wk 2 | 1491 ± 93 a | 479 ± 142 b | 588 ± 20 b | 544 ± 113 b | 562 ± 103 b | 511 ± 43 b | 51 | <0.001 |
| Wk 3 | 1526 ± 113 a | 507 ± 158 b | 581 ± 12 b | 558 ± 123 b | 578 ± 126 b | 493 ± 37 b | 53 | <0.001 |
| Wk 4 | 1716 ± 149 a | 588 ± 163 b | 657 ± 49 b | 651 ± 180 b | 644 ± 124 b | 567 ± 73 b | 59 | <0.001 |
| G:F 3, g/g | ||||||||
| Wk 1 | 0.56 ± 0.26 * | 0.23 ± 0.16 * | 0.46 ± 0.25 | 0.30 ± 0.24 | 0.39 ± 0.23 | 0.29 ± 0.21 | 0.36 | 0.10 |
| Wk 2 | 0.76 ± 0.15 a | 0.26 ± 0.15 b | 0.32 ± 0.12 b | 0.38 ± 0.14 b | 0.40 ± 0.23 b | 0.53 ± 0.25 ab | 0.35 | <0.001 |
| Wk 3 | 0.74 ± 0.14 a | 0.40 ± 0.09 b | 0.56 ± 0.27 ab | 0.40 ± 0.27 ab | 0.38 ± 0.21 b | 0.43 ± 0.26 ab | 0.36 | 0.02 |
| Wk 4 | 0.72 ± 0.13 a | 0.23 ± 0.25 bc | 0.38 ± 0.23 acd | 0.47 ± 0.23 ac | 0.59 ± 0.35 ad | 0.62 ± 0.24 ad | 0.42 | <0.001 |
| G:P 3, g/g | ||||||||
| Wk 1 | 2.36 ± 1.08 | 1.67 ± 1.23 | 3.42 ± 1.90 | 2.20 ± 1.76 | 2.86 ± 1.97 | 2.10 ± 1.52 | 0.24 | 0.36 |
| Wk 2 | 3.35 ± 0.67 ab | 2.13 ± 1.25 a | 2.70 ± 1.03 ab | 3.13 ± 1.19 ab | 3.03 ± 1.96 ab | 4.58 ± 2.21 b | 0.23 | 0.11 |
| Wk 3 | 3.27 ± 0.64 | 3.25 ± 0.82 | 4.69 ± 0.2.27 | 3.25 ± 2.27 | 2.85 ± 1.65 | 3.68 ± 2.26 | 0.26 | 0.43 |
| Wk 4 | 3.21 ± 0.58 ab | 1.93 ± 3.13 a | 3.20 ± 1.95 ab | 3.84 ± 1.89 ab | 4.49 ± 2.69 b | 5.26 ± 2.14 b | 0.36 | 0.03 |
1 PC (positive control): normal protein, adequate Ca and available phosphorous (aP), no corn-expressed phytase (CEP) added; NC (negative control): low protein, adequate Ca and aP, no CEP added; LD: NC + CEP added at low dose, i.e., 2000 FTU/kg of diet; HD: NC + CEP added at high dose, i.e., 4000 FTU/kg of diet; LDR: LD with reduced calcium (Ca) and phosphorus (P); HDR: HD with reduced Ca and P. The p values for the overall model effects for diet, week and diet × week for BWG were < 0.01, < 0.01 and 0.03, respectively, for CFI were < 0.01, < 0.01 and < 0.01, respectively, for CPI were < 0.01, < 0.01 and < 0.01, respectively, for G:F were < 0.01, 0.01 and 0.11, respectively, and for G:P were < 0.01, 0.05 and 0.22, respectively. Values are means ± standard deviations. n = 8 for each dietary group. 2 SEM standard error of the mean 3 BWG: body weight gain; CFI: cumulative feed intake; CPI: cumulative protein intake; G:F: gain:feed ratio; G:P: gain: protein ratio. a–c Within a row, values without a common superscript letter differ (p ≤ 0.05). *#$ Within a row, values with a common superscript symbol tend to be different (0.05 < p ≤ 0.1).