Ma Y L, Zanton G I, Zhao J, Wedekind K, Escobar J, Vazquez-Añón M
J Anim Sci. 2015 Feb;93(2):606-14. doi: 10.2527/jas.2014-7796.
A multitrial analysis was conducted to evaluate the effect of different levels of Cu from either Cu(2-hydroxy-4-(methylthio)butanoic acid [HMTBa])2 or CuSO4 on growth performance in nursery pigs. Six nursery trials were conducted from 2007 to 2012 under the same commercial conditions with initial BW of 5.75 ± 0.41 kg at 21 ± 3 d of age; the trials lasted for 42 d with a 3-phase feeding program (7 d in Phase I, 14 d in Phase II, and 21 d in Phase III). Diets were medicated with antibiotics and supplemented with 3,000 mg/kg Zn as ZnO during phases I and/or II. Treatments included a basal diet without added Cu or according to the NRC (1998) and supplemental levels of Cu (50 to 250 mg Cu/kg diet) from either Cu(HMTBa)2 or CuSO4; HMTBa was supplemented to make diets isomethionine. Treatments from each trial included 6 or 9 replicate pens/treatment with 22 to 25 piglets/pen. Mixed model analysis was conducted in which trial was considered a random effect, Cu level was considered a continuous fixed effect, and Cu source was a fixed effect. The basal diet within trial and statistical tests of the intercept between sources were not different, resulting in fitting a common intercept mixed model to the overall responses across phases. Cumulative ADG and ADFI quadratically responded (P < 0.05) with increasing Cu supplementation; predicted optimal ADG and ADFI occurred at 174 and 119 mg/kg, respectively. Increasing Cu supplementation linearly improved G:F (P = 0.054). No differences between sources were observed in ADG or ADFI. Numerically, pigs fed Cu(HMTBa)2 had higher ADG and lower ADFI compared to pigs fed CuSO4, resulting in better G:F for pigs supplemented with Cu(HMTBa)2 compared to pigs supplemented with CuSO4 (P < 0.01). The linear slope for increasing Cu supplementation on G:F was 2.1-fold higher for Cu(HMTBa)2 than that of CuSO4, with larger differences occurring in Phase II. In conclusion, Cu supplementation in nursery diets resulted in improved performance and Cu(HMTBa)2 is more effective than CuSO4 in improving feed efficiency.
进行了一项多试验分析，以评估来自Cu(2-羟基-4-(甲硫基)丁酸[HMTBa])₂或硫酸铜的不同水平铜对保育猪生长性能的影响。2007年至2012年期间，在相同商业条件下进行了6次保育试验，仔猪初始体重为5.75±0.41千克，年龄为21±3日龄；试验持续42天，采用三阶段饲喂方案（第一阶段7天，第二阶段14天，第三阶段21天）。日粮在第一阶段和/或第二阶段添加抗生素，并添加3000毫克/千克氧化锌形式的锌。处理包括不添加铜的基础日粮或根据NRC(1998)标准的日粮，以及来自Cu(HMTBa)₂或硫酸铜的铜补充水平（50至250毫克铜/千克日粮）；添加HMTBa以使日粮等蛋氨酸。每次试验的处理包括每个处理6或9个重复栏，每栏22至25头仔猪。进行混合模型分析，其中试验被视为随机效应，铜水平被视为连续固定效应，铜来源为固定效应。试验内的基础日粮以及来源间截距的统计检验无差异，从而拟合一个通用截距混合模型来分析各阶段的总体反应。随着铜添加量增加，累积平均日增重(ADG)和平均日采食量(ADFI)呈二次反应(P<0.05)；预测的最佳ADG和ADFI分别出现在174和119毫克/千克。增加铜添加量使料重比(G:F)呈线性改善(P=0.054)。在ADG或ADFI方面未观察到来源间的差异。在数值上，与饲喂硫酸铜的猪相比，饲喂Cu(HMTBa)₂的猪ADG更高，ADFI更低，导致饲喂Cu(HMTBa)₂的猪比饲喂硫酸铜的猪G:F更好(P<0.01)。Cu(HMTBa)₂使铜添加量增加对G:F的线性斜率比硫酸铜高2.1倍，在第二阶段差异更大。总之，保育日粮中添加铜可提高生产性能，且Cu(HMTBa)₂在提高饲料效率方面比硫酸铜更有效。
