Table 7.
Effects of feeding strategies based on number of dietary phases (one, two, three, and four dietary phases) and lysine specifications (96%, 98%, and 100% of estimated requirements for growth rate) on carcass characteristics of grow-finish pigs1,2
| Item | Experiment 1 | |||||
|---|---|---|---|---|---|---|
| Two-phase 100% | Four-phase 100% | Four-phase 96% | Four-phase 96%/100% | SEM | P | |
| HCW, kg | 94.6 | 94.2 | 92.7 | 94.0 | 0.81 | <0.219 |
| Yield, % | 72.8 | 72.6 | 72.9 | 72.6 | 0.15 | <0.338 |
| Back fat3, mm | 17.0 | 16.6 | 17.1 | 17.0 | 0.31 | <0.450 |
| Loin depth3, mm | 68.7 | 68.4 | 68.3 | 67.6 | 0.57 | <0.459 |
| Lean3, % | 56.7 | 57.0 | 56.6 | 56.6 | 0.22 | <0.430 |
| Experiment 2 | ||||||
| One-phase 100% | Two-phase 100% | Three-phase 100% | Four-phase 100% | SEM | P | |
| HCW, kg | 95.1b | 97.6a | 96.4ab | 97.8a | 1.05 | <0.014 |
| Yield, % | 76.8 | 77.4 | 76.8 | 77.2 | 0.22 | <0.120 |
| Back fat3, mm | 16.8 | 16.3 | 16.5 | 16.3 | 0.24 | <0.365 |
| Loin depth3, mm | 68.1 | 68.3 | 66.8 | 67.1 | 0.59 | <0.111 |
| Lean3, % | 56.8 | 57.1 | 56.8 | 57.0 | 0.19 | <0.519 |
| Experiment 3 | ||||||
| One-phase 98% | Two-phase 98% | Three-phase 98% | Four-phase 98% | SEM | P | |
| HCW, kg | 95.4b | 97.0ab | 97.6ab | 98.6a | 0.73 | <0.005 |
| Yield, % | 74.0 | 73.7 | 74.1 | 74.0 | 0.37 | <0.932 |
| Back fat3, mm | 17.0 | 16.7 | 16.8 | 16.4 | 0.27 | <0.429 |
| Loin depth3, mm | 67.5 | 68.8 | 67.6 | 68.0 | 0.61 | <0.400 |
| Lean3, % | 56.6 | 56.9 | 56.7 | 57.0 | 0.21 | <0.411 |
| Experiment 4 | ||||||
| Two-phase 98% | Two-phase 98%/100% | Three-phase 98% | Four-phase 98% | SEM | P | |
| HCW, kg | 95.3 | 96.0 | 96.9 | 96.2 | 0.66 | <0.231 |
| Yield, % | 74.1 | 73.7 | 74.1 | 74.2 | 0.32 | <0.652 |
| Back fat3, mm | 16.5 | 17.1 | 16.8 | 16.6 | 0.28 | <0.582 |
| Loin depth3, mm | 68.9 | 68.6 | 68.8 | 69.9 | 0.52 | <0.327 |
| Lean3, % | 57.0 | 56.7 | 56.8 | 57.1 | 0.20 | <0.487 |
1A total of four experiments were conducted at a commercial research facility with 1,100 to 1,188 pigs (PIC 359 × 1,050) per experiment in pens of 25 to 27 mixed-gender pigs per pen and 11 replicates per treatment. Experiments were conducted from ~27 to 127 kg BW for ~120 d.
2Lysine specifications at 96%, 98%, and 100% of estimated requirements for growth rate were derived from the genetic supplier’s lysine requirement prediction equation based on commercial experiments (Genus PIC; Gonçalves et al., 2017). For 96%/100%, lysine specifications at 96% of estimated requirements were applied in growing (27 to 72 kg BW) and lysine specifications at 100% of estimated requirements were applied in finishing (72 to 127 kg BW). For 98%/100%, lysine specifications at 98% of estimated requirements were applied in growing-finishing (27 to 100 kg BW) and lysine specifications at 100% of estimated requirements were applied in late finishing (100 to 127 kg BW).
3Adjusted using HCW as covariate.
abcMeans with different superscripts are significantly different (P ≤ 0.05) in the row.