Department of Animal Science, Iowa State University, Ames, IA 50011, USA.
CJ America - Bio, Fort Dodge, IA 50501, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae226.
A total of 480 newly weaned pigs (PIC 337 × 1050; Genus, Hendersonville, TN) with an initial body weight (BW) of 6.20 ± 0.61 kg were used in a dose-response study to investigate the impact of increasing standardized ileal digestible (SID) Arg:Lys on nursery pig growth performance. At weaning, pigs were placed into 48 pens with 5 barrows and 5 gilts per pen. Pens were randomly assigned to 1 of 6 dietary treatments. The experimental diets were formulated with increasing SID Arg:Lys, achieved by substituting corn starch, glycine, and l-alanine with l-arginine, resulting in SID Arg:Lys ranging from 45% to 145%. Diets were sublimiting in SID Lys and exceeded all other essential amino acid requirements. The experimental diets were fed across two feeding phases from days 0 to 10 and 10 to 27, with adjustments made to account for the Lys requirement of the pigs. All pens were placed on a common diet for the remaining 14 d of the study to evaluate carryover effects. Pigs and feeders were weighed at the start and end of each phase to calculate average daily gain (ADG), average daily feed intake (ADFI), and feed efficiency (G:F). Data were analyzed according to a linear regression model, which included the linear and quadratic effects of SID Arg:Lys and initial BW. Pen was the experimental unit, and results were considered significant at P ≤ 0.05 and a tendency at 0.50 < P ≤ 0.10. From days 0 to 27, Arg:Lys tended to have a quadratic effect on ADFI (P = 0.058), where 97.00 ± 7.631% SID Arg:Lys maximized feed intake. Similarly, Arg:Lys had a quadratic impact on ADG (P = 0.046), where ADG was maximized at a SID Arg:Lys of 95.65 ± 7.165. Correspondingly, Arg:Lys had a quadratic effect on pig BW on day 27 (P = 0.014). These effects were carried through the end of the study, where Arg:Lys quadratically impacted days 0 to 41 ADFI (P = 0.006), ADG (P = 0.077), and day 41 BW (P = 0.028). There was no evidence of an effect of SID Arg:Lys on G:F throughout the study (P ≥ 0.315). In conclusion, SID Arg:Lys quadratically impacted ADFI and ADG in 6- to 13-kg nursery pigs, where ADFI was maximized at a SID Arg:Lys of 97.00% (95% CI [81.6%, 112.4%]), and ADG was maximized at a SID Arg:Lys of 95.65% (95% CI [81.2%, 110.1%]). Together, these data suggest that the SID Arg:Lys requirement of nursery pigs is at least 81%, based on the lower bounds of the 95% CI for maximum ADG and ADFI, and excessive Arg supplementation may negatively affect growth performance.
共有 480 头刚断奶的仔猪（PIC 337×1050；Genus，Hendersonville，TN），初始体重（BW）为 6.20±0.61kg，用于一项剂量反应研究，以调查增加标准化回肠可消化（SID）Arg：Lys 对仔猪生长性能的影响。在断奶时，将仔猪放入 48 个栏中，每个栏中有 5 头公猪和 5 头母猪。栏被随机分配到 6 种饮食处理之一。实验日粮通过用 L-精氨酸替代玉米淀粉、甘氨酸和 L-丙氨酸来配制，以实现 SID Arg：Lys 的增加，从而使 SID Arg：Lys 从 45%到 145%不等。日粮在 SID Lys 中达到了亚精氨酸的最低要求，超过了所有其他必需氨基酸的需求。实验日粮在 0 至 10 天和 10 至 27 天的两个喂养阶段中进行饲喂，根据猪的赖氨酸需求进行调整。在研究的剩余 14 天内，所有栏都被放在相同的日粮上，以评估残留效应。在每个阶段开始和结束时对猪和饲养器进行称重，以计算平均日增重（ADG）、平均日采食量（ADFI）和饲料效率（G：F）。数据根据线性回归模型进行分析，该模型包括 SID Arg：Lys 和初始 BW 的线性和二次效应。栏是实验单位，结果在 P≤0.05 时被认为具有显著意义，在 0.50<P≤0.10 时具有趋势。从 0 至 27 天，Arg：Lys 对 ADFI 有二次效应（P=0.058），其中 97.00±7.631%的 SID Arg：Lys 最大限度地提高了饲料摄入量。同样，Arg：Lys 对 ADG 有二次影响（P=0.046），其中 ADG 在 SID Arg：Lys 为 95.65±7.165 时达到最大值。相应地，Arg：Lys 对第 27 天的猪 BW 有二次影响（P=0.014）。这些影响一直持续到研究结束，在 0 至 41 天期间，Arg：Lys 对 ADFI（P=0.006）、ADG（P=0.077）和第 41 天 BW（P=0.028）有二次影响。在整个研究过程中，SID Arg：Lys 对 G：F 没有影响（P≥0.315）。总之，SID Arg：Lys 对 6 至 13kg 仔猪的 ADFI 和 ADG 有二次影响，其中 ADFI 在 SID Arg：Lys 为 97.00%（95%CI[81.6%，112.4%]）时达到最大值，ADG 在 SID Arg：Lys 为 95.65%（95%CI[81.2%，110.1%]）时达到最大值。这些数据表明，基于最大 ADG 和 ADFI 的 95%CI 的下限，仔猪的 SID Arg：Lys 需求至少为 81%，过量的 Arg 补充可能会对生长性能产生负面影响。
