Two studies were conducted to estimate the SID Lys requirement for growth and feed efficiency of 35-80-kg DNA finishing pigs. In Exp. 1, 608 pigs (600 × 241, DNA; initially 36.3±0.91kg) were used to estimate the SID Lys requirement from 35-55-kg. In Exp. 2, 700 pigs (DNA 600×241; initial BW of 53.2±0.86kg) were used to estimate the SID Lys requirement form 50-80-kg. Pens of pigs were blocked by BW and randomly allotted to 1 of 6 dietary treatments with 7-10 pigs/pen in a randomized complete block design with 12 replications per treatment. Diets were corn-soybean meal-based and SID Lys increased by increasing soybean meal and feed-grade amino acids while maintaining minimum ratios for other amino acids. Increasing SID Lys increased (linear, P < 0.05) ADG in both studies. From 50-80-kg, ADFI decreased, then increased (quadratic, P = 0.004) with increasing SID Lys. Feed efficiency improved, while Lys intake/d, and Lys intake/kg of gain increased (linear, P < 0.05, 35-55-kg; quadratic, P < 0.05, 50-80-kg) with increasing SID Lys. At current ingredient and pig prices, there were no statistical differences in income over feed cost (IOFC) from 35-55 kg. From 50-80-kg, increasing SID Lys increased (linear, P < 0.001) IOFC. Linear models resulted in the best fit for ADG, G:F and IOFC from 35-55-kg, with optimum performance at 1.20% SID Lys or greater. A quadratic polynomial model predicted a requirement of 0.97% SID Lys for optimum G:F from 50-80-kg. Meanwhile, a broken-line linear model predicted optimal IOFC at 0.76% SID Lys from 50-80-kg. In summary, these results suggest that the optimal SID Lys level for 35-55-kg DNA finishing pigs is at least 1.20%. The optimal SID Lys level for 50-80-kg DNA finishing pigs depends on the response criteria, with growth performance optimized at or above 0.97% SID Lys and IOFC maximized at 0.76% SID Lys.

中文翻译：

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156 标准化回肠可消化赖氨酸水平对 35 至 80 公斤 DNA 育肥猪生长性能的影响

进行了两项研究来估计 35-80 公斤 DNA 育肥猪的生长和饲料效率对 SID 赖氨酸的需求。在 Exp。1, 608 头猪 (600 × 241, DNA; 最初 36.3±0.91kg) 用于估计 35-55-kg 的 SID Lys 需求。在 Exp。2、700头猪（DNA 600×241；初始体重53.2±0.86kg）用于估计50-80-kg的SID赖氨酸需求量。猪栏被 BW 封闭并随机分配到 6 种饮食治疗中的 1 种，每栏 7-10 头猪，采用随机完整区组设计，每个治疗重复 12 次。日粮以玉米-豆粕为主，SID Lys 通过增加豆粕和饲料级氨基酸而增加，同时保持其他氨基酸的最低比例。在两项研究中，增加 SID Lys 都会增加（线性，P < 0.05）ADG。从 50-80 公斤，ADFI 下降，然后上升（二次方，P = 0。004) 随着 SID Lys 的增加。随着 SID Lys 的增加，饲料效率提高，而 Lys 摄入量/d 和 Lys 摄入量/kg 增重增加（线性，P < 0.05，35-55-kg；二次，P < 0.05，50-80-kg）。在目前的原料和猪价下，35-55 公斤的饲料成本收入（IOFC）没有统计学差异。从 50-80-kg，增加 SID Lys 增加（线性，P < 0.001）IOFC。线性模型最适合 35-55 公斤的 ADG、G:F 和 IOFC，在 1.20% SID Lys 或更高时具有最佳性能。二次多项式模型预测 50-80-kg 的最佳 G:F 需要 0.97% SID Lys。同时，折线线性模型预测 50-80-kg 的最佳 IOFC 为 0.76% SID Lys。总之，这些结果表明，35-55-kg DNA 肥育猪的最佳 SID Lys 水平至少为 1.20%。