Humphrey Dalton, Becker Spenser, Lee Jason, Haydon Keith, Greiner Laura
Department of Animal Science, Iowa State University, Ames, IA.
CJ America Bio, Fort Dodge, IA.
Transl Anim Sci. 2020 Oct 6;4(4):txaa182. doi: 10.1093/tas/txaa182. eCollection 2020 Oct.
Four hundred and eighty (PIC 337 X 1050, PIC Genus, Hendersonville, TN) pigs were used to evaluate a novel threonine source (ThrPro, CJ America Bio, Fort Dodge, IA) for nursery pigs from approximately 7 to 20 kg body weight (BW). After weaning, pigs were sorted by sex and fed a common diet for 1 wk. Upon completion of the first week, pigs were sorted into randomized complete blocks, equalized by weight, within 16 replications. Pigs were allocated to one of three dietary treatments: positive control (POS)-standard ileal digestible threonine-to-lysine ratio (SID; Thr:Lys) 0.60, negative control (NEG)-SID Thr:Lys ≤0.46, and alternative Thr source (TEST)-SID Thr:Lys 0.60. The alternative Thr source included fermentative biomass and was assumed to contain 75% Thr and a digestibility coefficient of 100% based on the manufacturer's specifications. All other nutrients met or exceeded the NRC recommendations. Growth and intake data were analyzed as repeated measures with a compound symmetry covariance structure using the MIXED procedure in SAS 9.4 (SAS Institute Inc., Cary, NC) with pen as the experimental unit. Treatment, phase, the interaction between treatment and phase, and block were included as fixed effects in the model. Differences in total removals were tested using Fisher's Exact Test of PROC FREQ. Results were considered significant at ≤ 0.05 and considered a trend at > 0.05 and ≤ 0.10. During the first 14 d, pigs fed TEST had decreased gain-to-feed ratio (G:F; 0.77 vs. 0.80, = 0.022) compared to POS and increased G:F (0.77 vs. 0.73, < 0.001) compared to NEG. Over days 14-28, pigs fed TEST had similar G:F (0.71 vs. 0.70, = 0.112) compared to POS and increased G:F (0.71 vs. 0.63, < 0.001) compared to NEG. Overall (days 0-28), pigs fed TEST had similar average daily gain (ADG; 0.47 vs. 0.47 kg/d, = 0.982) and G:F (0.76 vs. 0.74, = 0.395) compared to POS and increased ADG (0.47 vs. 0.43 kg/d, < 0.001) and G:F (0.76 vs. 0.67, < 0.001) compared to NEG. The average daily feed intake was not significantly different across treatments for the entirety of the study. In conclusion, the replacement of crystalline L-Thr with a novel Thr source resulted in similar growth performance in nursery pigs from approximately 7 to 20 kg.
选用480头猪（PIC 337×1050，PIC品种，田纳西州亨德森维尔市）来评估一种新型苏氨酸来源（ThrPro，美国CJ生物公司，爱荷华州福特道奇市）对体重约7至20千克的保育猪的效果。断奶后，按性别对猪进行分类，并饲喂普通日粮1周。第一周结束后，将猪按体重均衡分成随机完全区组，共16个重复。猪被分配到三种日粮处理之一：正对照组（POS）——标准回肠可消化苏氨酸与赖氨酸比例（SID；Thr:Lys）为0.60，负对照组（NEG）——SID Thr:Lys≤0.46，以及替代苏氨酸来源组（TEST）——SID Thr:Lys为0.60。替代苏氨酸来源包括发酵生物质，根据制造商规格，假定其含75%苏氨酸且消化率系数为100%。所有其他营养素均达到或超过NRC建议值。生长和采食量数据采用重复测量分析，协方差结构为复合对称，使用SAS 9.4（SAS软件公司，北卡罗来纳州卡里市）中的MIXED过程，以栏为实验单位。处理、阶段、处理与阶段的交互作用以及区组作为固定效应纳入模型。使用PROC FREQ过程中的Fisher精确检验来检验总淘汰率的差异。结果在P≤0.05时被认为具有显著性，在P>0.05且P≤0.10时被认为有趋势。在最初的14天里，与POS组相比，饲喂TEST组的猪的料重比（G:F）降低（0.77对0.80，P=0.022），与NEG组相比料重比增加（0.77对0.73，P<0.001）。在第14至28天，与POS组相比，饲喂TEST组的猪的料重比相似（0.71对0.70，P=0.112），与NEG组相比料重比增加（0.71对0.63，P<0.001）。总体而言（第0至28天），与POS组相比，饲喂TEST组的猪的平均日增重（ADG）相似（0.47对0.47千克/天，P=0.982）且料重比相似（0.76对0.74，P=0.395），与NEG组相比平均日增重增加（0.47对0.43千克/天，P<0.001）且料重比增加（0.76对0.67，P<0.001）。在整个研究期间，各处理间的平均日采食量无显著差异。总之，用一种新型苏氨酸来源替代结晶L-苏氨酸，使体重约7至20千克的保育猪生长性能相似。
