Table 2.
Overall growth performance and bone minerals 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 | |||
| Initial BW, kg | 9.85 ± 2.02 | 10.21 ± 1.39 | 10.15 ± 1.66 | 10.32 ± 0.99 | 10.10 ± 0.58 | 10.44 ± 2.23 | 0.21 | 0.56 |
| Final BW, kg | 28.60 ± 2.40 a | 14.87 ± 2.68 b*# | 18.73 ± 3.82 b* | 17.53 ± 1.13 b | 17.82 ± 2.02 b | 18.80 ± 3.76 b# | 0.73 | <0.01 |
| ADG 3, g/d | 669 ± 81 a | 166 ± 80 c* | 306 ± 101 b | 257 ± 53 bc | 276 ± 78 bc* | 299 ± 80 b | 26 | <0.01 |
| ADFI 3, g/d | 953 ± 64 a | 602 ± 174 b | 714 ± 20 b | 654 ± 141 b | 617 ± 118 b | 633 ± 48 b | 23 | <0.01 |
| G:F 3, g/g | 0.70 ± 0.13 a | 0.28 ± 0.11 b*#$ | 0.43 ± 0.14 b* | 0.39 ± 0.09 b | 0.45 ± 0.12 b# | 0.47 ± 0.08 b$ | 0.02 | <0.01 |
| G:P 3, g/g | 3.05 ± 0.42 ab | 2.25 ± 0.67 a* | 3.50 ± 1.12 ab* | 3.31 ± 1.09 ab | 3.31 ± 1.21 ab | 3.91 ± 0.79 b | 0.15 | 0.03 |
| BMD 4, g/cm 2 | 0.64 ± 0.06 ac# | 0.53 ± 0.03 b* | 0.61 ± 0.04 bc* | 0.62 ± 0.04 cd | 0.56 ± 0.04 bcd# | 0.63 ± 0.09 cd | 0.01 | 0.01 |
| BMC 5, g | 378.92 ± 64 ac | 287.33 ± 36 b | 371.67 ± 63 cd | 344.14 ± 57 bc | 292.02 ± 19 b | 326.84 ± 22 bc | 9.21 | <0.01 |
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 a 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. Values are means ± standard deviations. n = 8 for each dietary group. 2 SEM: standard errors of means. 3 ADG: average daily gain; ADFI: average daily feed intake; G:F: gain:feed ratio; G:P: gain:protein ratio. 4 BMD: bone mineral density. 5 BMC: bone mineral content. a–d 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).