Table 1.
Summary of studies evaluating the effect of dietary lactose concentration on growth performance of weanling pigs used in the meta-analysis
| Study | Weaning age, d | Initial BW, kg | Growth promotersa | Duration of feeding, d of age | Dietary CP, % | Lactose level, % | ADFI, g/d | ADG, g/d | G:F |
|---|---|---|---|---|---|---|---|---|---|
| Nessmith et al. [43] | 19 | 5.3 | + (AGP) | 19–26 | – | 0, 20, 40 | 196, 215, 220 | 234, 252, 246 | 1.19, 1.18, 1.15 |
| Nessmith et al. [43] | 19 | 5.3 | + (AGP) | 26–33 | – | 0, 20, 40 | 310, 301, 300 | 328, 322, 322 | 1.06, 1.08, 1.08 |
| Nessmith et al. [60] | 10 | 3.7 | + (AGP) | 10–15 | – | 0, 20, 40 | 87, 104, 107 | 109, 119, 125 | 1.21, 1.16, 1.15 |
| Nessmith et al. [60] | 10 | 3.7 | + (AGP) | 15–20 | – | 0, 20, 40 | 152, 180, 180 | 156, 181, 184 | 1.02, 1.00, 1.03 |
| Tran et al. [54] | 20 | 6.07 | + (AGP) | 20–27 | 22% | 0, 20 | 113, 117 | 50, 71 | 0.44, 0.61 |
| Tran et al. [54] | 20 | 6.07 | + (AGP) | 27–34 | 22% | 0, 20 | 340, 390 | 286, 310 | 0.84, 0.82 |
| Tran et al. [54] | 20 | 6.07 | + (AGP) | 34–48 | 22% | 0, 15 | 765, 828 | 545, 567 | 0.71, 0.68 |
| Tran et al. [54] | 20 | 6.07 | + (AGP) | 48–55 | 22% | 0, 5 | 1044, 1072 | 717, 719 | 0.69, 0.67 |
| O′ Doherty et al. [47] | 24 | 7.6 | – | 24–31 | 20% | 15, 25 | 242, 239 | 100, 146 | 0.41, 0.59 |
| O′ Doherty et al. [47] | 24 | 7.6 | – | 31–38 | 20% | 15, 25 | 415, 450 | 302, 325 | 0.75, 0.73 |
| O′ Doherty et al. [47] | 24 | 7.6 | – | 38–49 | 20% | 15, 25 | 682, 683 | 438, 388 | 063, 0.57 |
| O′ Doherty et al. [46] | 22, 28 | 7, 7.7 | + (AGP) | 25–32 | 22% | 0, 17.5, 35 | 209, 223, 224 | 72, 122, 163 | 0.34, 0.55, 073 |
| O′ Doherty et al. [46] | 22, 28 | 7, 7.7 | + (AGP) | 32–42 | 22% | 0, 17.5, 35 | 363, 403, 404 | 180, 281, 265 | 0.46, 0.66, 0.61 |
| O′ Doherty et al. [46] | 22, 28 | 7, 7.7 | + (AGP) | 42–50 | 22% | 0, 17.5, 35 | 558, 660, 704 | 267, 424, 478 | 0.47, 0.64, 0.65 |
| Kim et al. [48] | 21 | 6.94 | + (AGP) | 21–28 | 21% | 15, 25 | 298, 335 | 247, 289 | 0.83, 0.86 |
| Kim et al. [48] | 28 | 9.57 | + (AGP) | 28–35 | 21% | 15, 25 | 542, 579 | 423, 461 | 0.78, 0.79 |
| Pierce et al. [49] | 24 | 7.1 | – | 24–31 | 20% | 6.5, 17, 27.5 | 189, 192, 196 | 73, 80, 80 | 0.39, 0.42, 0.41 |
| Pierce et al. [49] | 24 | 7.1 | – | 31–38 | 20% | 6.5, 17, 27.5 | 335, 329, 341 | 175, 224, 212 | 0.52, 0.68, 0.63 |
| Pierce et al. [49] | 24 | 7.1 | – | 38–45 | 20% | 6.5, 17, 27.5 | 512, 511, 567 | 292, 322, 358 | 0.61, 0.68, 0.66 |
| Pierce et al. [49] | 24 | 7.1 | – | 45–52 | 20% | 6.5, 17, 27.5 | 652, 677, 737 | 399, 461, 487 | 0.56, 0.65, 0.63 |
| Pierce et al. [33] | 24 | 6 | – | 24–31 | 22% | 17, 29.5 | 254, 323 | 99, 179 | 0.39, 0.56 |
| Pierce et al. [33] | 24 | 6 | – | 31–38 | 22% | 17, 29.5 | 441, 507 | 290, 331 | 0.66, 0.65 |
| Pierce et al. [33] | 24 | 6 | – | 38–45 | 22% | 17, 29.5 | 757, 876 | 452, 527 | 0.6, 0.61 |
| Mahan and Newton [50] | 23 | 6.5 | + (AGP) | 23–37 | – | 0, 22.5, 35.0 | 301, 338, 312 | 243, 278, 258 | 0.81, 0.82, 0.82 |
| Bertol et al. [51] | 21 | + (AGP) | 21–35 | 20% | 0, 7, 14, 21 | 240, 280, 300, 334 | 142, 186, 191, 219 | 0.55, 0.65, 0.63, 0.65 | |
| Bertol et al. [51] | 19 | 6.3 | + (AGP) | 19–26 | – | 10, 15, 20, 25, 30, 35 | 190, 207, 202, 214, 225, 194 | 84, 99, 103, 114, 130, 103 | 0.42, 0.48, 0.51, 0.53, 0.58, 0.53 |
| Bertol et al. [51] | 19 | 6.3 | + (AGP) | 26–33 | – | 10, 15, 20, 25, 30, 35 | 401, 412, 423, 428, 421, 409 | 346, 349, 370, 360, 359,330 | 0.86, 0.85, 0.88, 0.84, 0.86, 0.83 |
| Bertol et al. [51] | 19 | 6.3 | + (AGP) | 26–33 | – | 7, 12, 17, 22, 27, 32 | 421, 397, 426, 448, 427, 449 | 278, 285, 315, 335, 317, 331 | 0.66, 0.72, 0.74, 0.75, 0.74, 0.74 |
| Bertol et al. [51] | 19 | 6.3 | + (AGP) | 33–40 | – | 7, 12, 17, 22, 27, 32 | 700, 690, 736, 718, 705, 718 | 507, 509, 525, 514, 529, 540 | 0.72, 0.74, 0.71, 0.70, 0.75, 0.75 |
| Bertol et al. [51] | 19 | 6.3 | + (AGP) | 40–54 | – | 0, 5, 10, 15, 20 | 1095, 1104, 1106, 1124, 1135 | 657, 685, 678, 695, 686 | 0.6, 0.62, 0.61, 0.62. 0.60 |
| Molino et al. [58] | 21 | 6.1 | + (AGP) | 21–35 | 21% | 0, 4, 8, 12 | 250, 308, 280, 306 | 195, 244, 220, 248 | 0.78, 0.78, 0.78, 0.8 |
| Cromwell et al. [59] | 20 | 6.2 | + (AGP) | 30–37 | 22% | 0, 2.5, 5, 7.5, 10 | 613, 618, 643, 646, 648 | 467, 467, 503, 505, 506 | 0.76, 0.76, 0.78, 0.78, 0.78 |
| Cromwell et al. [59] | 20 | 6.2 | + (AGP) | 37–44 | 22% | 0, 2.5, 5, 7.5, 10 | 833, 830, 826, 860, 856 | 597, 600, 592, 610, 610 | 0.72, 0.73, 0.73, 0.72, 0.72 |
| Pierce et al. [61] | 21 | 7.6 | – | 33–45 | 16% | 12.5, 21.5 | 600, 600 | 270, 300 | 0.45, 0.5 |
| Pierce et al. [61] | 21 | 7.6 | – | 45–54 | 16% | 12.5, 21.5 | 920, 870 | 520, 490 | 0.55, 0.51 |
| Pierce et al. [61] | 21 | 7.6 | – | 33–45 | 18.5% | 12.5, 21.5 | 650, 640 | 400, 380 | 0.61, 0.59 |
| Pierce et al. [61] | 21 | 7.6 | – | 45–54 | 18.5% | 12.5, 21.5 | 1070, 890 | 620, 590 | 0.56, 0.66 |
| Pierce et al. [61] | 21 | 7.6 | – | 33–45 | 21% | 12.5, 21.5 | 600, 700 | 400, 400 | 0.67, 0.59 |
| Pierce et al. [61] | 21 | 7.6 | – | 45–54 | 21% | 12.5, 21.5 | 970, 1100 | 570, 700 | 0.6, 0.63 |
| O′ Connell et al. [62] | 24 | 6 | – | 24–31 | 20% | 17, 27.5 | 190, 212 | 104, 121 | 0.55, 0.57 |
| O′ Connell et al. [62] | 24 | 6 | – | 31–38 | 20% | 17, 27.5 | 434, 462 | 364, 394 | 0.84, 0.85 |
| O′ Connell et al. [62] | 24 | 6 | – | 38–49 | 20% | 17, 27.5 | 615, 691 | 422, 475 | 0.69, 0.69 |
| O′ Connell et al. [62] | 24 | 6 | – | 49–57 | 20% | 17, 27.5 | 870, 883 | 561, 538 | 0.65, 0.61 |
a+ indicates the use of in feed antibiotic growth promotors (AGP) and/or pharmacological dose of ZnO (> 1500 ppm) and/or pharmacological dose of CuSO4 (> 150 ppm). ADFI Average daily feed intake, ADG Average daily gain, BW Body weight, CP Crude protein, G:F The ratio of weight gain to feed intake