Phase feeding is employed to optimize lysine levels to meet pigs' requirements. Therefore, our objective was to evaluate the effect of varying lysine levels and phase lengths in nursery pigs. Four-hundred freshly weaned pigs (5.53 ± 0.96 kg BW) were randomly selected and assigned to 1 of 4 dietary treatments (n = 10 pens/treatment, 10 pigs/pen). The treatments for phase (P) 1-3 were: 1) High synthetic amino acids (1.60, 1.45, 1.33% SID Lys, respectively; HighSyn), 2) High soybean meal (1.60, 1.45, 1.33 % SID Lys, respectively; HighSBM), 3) Low Lys (1.30, 1.50, 1.45% SID Lys, respectively; Low), and 4) Continuous 1.42 % SID Lys (Con). Phase 1, 2 and 3 consisted of 7, 14 and 21 d, respectively. Body weights and feed disappearance were recorded on d 0, 7, 21 and 42, and ADG, ADFI and G:F calculated within phase and overall (0-42 d). All data were analyzed using a complete randomized design with pen as the experimental unit. P1 ADG was 42% greater in the HighSBM compared with the other treatments (P = 0.030), while ADFI tended to be 23% higher (P = 0.089). In P2, ADG was 21% higher in the HighSBM compared with the HighSyn pigs, with the other treatments being intermediate (P = 0.012). ADFI tended to be higher in the HighSBM pigs compared with the other treatments in P2 (P = 0.087). No significant performance differences were reported in P3. Overall, HighSMB had higher ADG compared with Con, Low and HighSyn pigs (0.360, 0.338, 0.338 and 0.311 kg/d, respectively; P = 0.007), while overall ADFI and G:F tended to be lower in HighSyn compared with the other treatments (P < 0.10). In conclusion, high synthetic Lys reduced performance, while continuous single-phase feeding offered equal performance to that of higher Lys curves achieved via soybean meal inclusion.

中文翻译：

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146 阶段饲喂和赖氨酸来源和水平对保育猪性能的评价

阶段饲喂用于优化赖氨酸水平以满足猪的需求。因此，我们的目标是评估不同赖氨酸水平和阶段长度对保育猪的影响。随机选择 400 头刚断奶的猪 (5.53 ± 0.96 kg BW) 并分配到 4 种日粮处理中的 1 种（n = 10 栏/处理，10 头猪/栏）。阶段 (P) 1-3 的处理为：1) 高合成氨基酸（分别为 1.60、1.45、1.33% SID Lys；HighSyn），2) 高豆粕（分别为 1.60、1.45、1.33% SID Lys； HighSBM)、3) 低 Lys（分别为 1.30、1.50、1.45% SID Lys；低）和 4) 连续 1.42% SID Lys (Con)。第 1、2 和 3 阶段分别由 7、14 和 21 天组成。在第 0、7、21 和 42 天记录体重和饲料消失，并在阶段和总体（0-42 天）内计算 ADG、ADFI 和 G:F。所有数据均采用完全随机设计，以笔为实验单位。与其他处理相比，HighSBM 的 P1 ADG 高 42%（P = 0.030），而 ADFI 往往高 23%（P = 0.089）。在 P2 中，与 HighSyn 猪相比，HighSBM 猪的 ADG 高 21%，其他处理为中等 (P = 0.012)。与 P2 中的其他处理相比，HighSBM 猪的 ADFI 往往更高（P = 0.087）。P3 中没有报告显着的性能差异。总体而言，与 Con、Low 和 HighSyn 猪相比，HighSMB 具有更高的 ADG（分别为 0.360、0.338、0.338 和 0.311 kg/d；P = 0.007），而与其他猪相比，HighSyn 的总体 ADFI 和 G:F 往往较低处理（P＜0.10）。总之，高合成赖氨酸降低了性能，