Table 4.
Energy requirement of sows during lactation and sow weight loss during lactation (kg over 26 days) associated with three different lactation feed curves (see Appendix 2).
| Energy requirement during lactation | Curve 1 | Curve 2 | Curve 3 | |||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Sow weight (kg) | Maintenance (MJ DE)1 | Milk (MJ DE)2 | Total/day (MJ) | Total/day (kg) | Fed (MJ) | Weight loss3 (kg) | Fed (MJ) | Weight loss3 (kg) | Fed (MJ) | Weight loss3 (kg) |
| 180 | 22.6 | 69.0 | 91.6 | 6.45 | 74.3 | 23.4 | 85.5 | 8.4 | 98.3 | -9.1 |
| 190 | 23.6 | 69.0 | 92.6 | 6.52 | 74.3 | 24.7 | 85.5 | 9.6 | 98.3 | -7.8 |
| 200 | 24.5 | 69.0 | 93.5 | 6.58 | 74.3 | 26.0 | 85.5 | 10.9 | 98.3 | -6.5 |
| 210 | 25.4 | 69.0 | 94.4 | 6.65 | 74.3 | 27.2 | 85.5 | 12.1 | 98.3 | -5.3 |
| 220 | 26.3 | 69.0 | 95.3 | 6.71 | 74.3 | 28.4 | 85.5 | 13.3 | 98.3 | -4.1 |
| 230 | 27.2 | 69.0 | 96.2 | 6.77 | 74.3 | 29.6 | 85.5 | 14.5 | 98.3 | -2.9 |
| 240 | 28.1 | 69.0 | 97.1 | 6.84 | 74.3 | 30.8 | 85.5 | 15.7 | 98.3 | -1.7 |
| 250 | 28.9 | 69.0 | 97.9 | 6.90 | 74.3 | 32.0 | 85.5 | 16.9 | 98.3 | -0.5 |
| 260 | 29.8 | 69.0 | 98.8 | 6.96 | 74.3 | 33.2 | 85.5 | 18.1 | 98.3 | 0.7 |
1 DE for maintenance (MJ DE/day) = ((110 × BW0.75)/1000) × 4.1853 [26] where BW is body weight.
2 DE for milk (MJ DE/day) = ((((6.83 × ADG × pigs) - (125 × pigs)) × 4.1853)/1000)/0.96) [26] where ADG is the daily gain of sucking pigs (assumed here as 250 g/day) and pigs is the number of piglets sucking per sow (assumed here as 10).
3 (Total energy requirement during lactation - Energy fed )/((5 × 4.1853 × 0.88)/0.96) = weight loss [25].