Bailey J D, Ansotegui R P, Paterson J A, Swenson C K, Johnson A B
Department of Animal and Range Sciences, Montana State University, Bozeman 59717-2900, USA.
J Anim Sci. 2001 Nov;79(11):2926-34. doi: 10.2527/2001.79112926x.
Performance, immune response, and liver trace mineral status were measured in growing heifers supplemented with different copper (Cu) concentrations and sources when diets contained the Cu antagonists Mo, S, and Fe. Sixty Angus x Hereford heifers were managed in two groups for 112 d and were either individually fed diets and mineral treatments using individual feeding stalls (Stall) or pen-fed grass hay and individually supplemented mineral treatments (Pen). The basal diet of grass hay, rolled barley, and soybean meal was analyzed to contain 6 mg Cu/kg DM. The treatments consisted of 1) no supplemental Cu (Control); 2) 49 mg Cu/kg DM from Cu sulfate (i.e. approximately five times NRC recommendation for Cu from CuSO4) (5X-SO4); 3). 22 mg Cu/kg DM from CuSO4 (2X-SO4); 4). 22 mg Cu/kg DM from a combination of 50% CuSO4 and 50% Cu-amino acid complex (50-50); and 5). 22 mg Cu/kg DM from a combination of 25% CuSO4, 50% Cu-amino acid complex, and 25% Cu oxide (CuG) (25-50-25). All heifers were supplemented with the Cu antagonists Mo (10 mg/kg DM), S (2,900 mg/kg DM), and Fe (500 mg/kg DM). These diets resulted in dietary Cu:Mo ratios that averaged 0.5:1 for Control, 4.5:1 for the 5X-SO4, and 2.4:1 for 2X-SO4, 50-50, and 25-50-25. Rate and efficiencies of gain and cell-mediated immune function were not different (P > 0.10) among treatments. Data suggest supplements containing combinations of inorganic and complexed Cu interacted differently in the presence of Mo, S, and Fe. Heifers consuming the 25-50-25 supplement in the Stall group initially lost hepatic Cu rapidly but this loss slowed from d 50 to d 100 compared to the Control (P = 0.07), 50-50 (P < 0.05), and 2X-SO4 (P < 0.05) heifers and was similar (P > 0.10) to that in the 5X-SO4 heifers. In the Pen group, total hepatic Cu loss tended to be greater for 25-50-25 and 2X-SO4 compared to 5X-SO4 heifers (P = 0.09 and P = 0.06, respectively); Cu loss in the 50-50 heifers was similar (P > 0.10) to that in the 5X-SO4 heifers. This suggests that supplementing combinations of inorganic and amino acid-complexed Cu was as effective in limiting hepatic Cu loss during antagonism as was increasing dietary Cu levels to five times the NRC recommendation. A combination of 25% CuSO4 , 50% Cu-amino acid complex, and 25% CuO limited liver accumulation of Mo compared to supplements without CuO and could provide a strategic supplementation tool in limiting the systemic effects of Cu antagonism in beef cattle.
在日粮含有铜拮抗剂钼（Mo）、硫（S）和铁（Fe）的情况下，对补充不同铜（Cu）浓度和来源的生长小母牛的生产性能、免疫反应和肝脏微量矿物质状况进行了测定。60头安格斯×赫里福德小母牛分为两组，饲养112天，一组使用个体饲养栏单独饲喂日粮和矿物质处理（栏饲组），另一组饲喂青贮干草并单独补充矿物质处理（圈饲组）。分析基础日粮（青贮干草、压碎大麦和豆粕）的铜含量为6毫克/千克干物质。处理包括：1）不补充铜（对照组）；2）硫酸铜提供49毫克铜/千克干物质（即约为美国国家研究委员会（NRC）对硫酸铜铜推荐量的5倍）（5倍硫酸铜组）；3）硫酸铜提供22毫克铜/千克干物质（2倍硫酸铜组）；4）50%硫酸铜和50%氨基酸铜络合物组合提供22毫克铜/千克干物质（50-50组）；5）25%硫酸铜、50%氨基酸铜络合物和25%氧化铜组合提供22毫克铜/千克干物质（25-50-25组）。所有小母牛均补充了铜拮抗剂钼（10毫克/千克干物质）、硫（2900毫克/千克干物质）和铁（500毫克/千克干物质）。这些日粮导致对照组的日粮铜:钼平均比例为0.5:1，5倍硫酸铜组为4.5:1，2倍硫酸铜组、50-50组和25-50-25组为2.4:1。各处理间的增重速度、增重效率和细胞介导免疫功能无差异（P>0.10）。数据表明，在存在钼、硫和铁的情况下，含有无机铜和复合铜组合的补充剂相互作用方式不同。栏饲组中采食25-50-25组补充剂的小母牛最初肝脏铜快速流失，但与对照组（P=0.07）、50-50组（P<0.05）和2倍硫酸铜组（P<0.05）相比，从第50天到第100天流失速度减缓，且与5倍硫酸铜组小母牛相似（P>0.10）。在圈饲组中，25-50-25组和2倍硫酸铜组的肝脏总铜流失量与5倍硫酸铜组小母牛相比有增加趋势（分别为P=0.09和P=0.06）；50-50组小母牛的铜流失量与5倍硫酸铜组小母牛相似（P>0.10）。这表明，补充无机铜和氨基酸络合铜的组合在拮抗过程中限制肝脏铜流失的效果与将日粮铜水平提高到NRC推荐量的5倍相同。与不含氧化铜的补充剂相比，25%硫酸铜、50%氨基酸铜络合物和25%氧化铜的组合限制了钼在肝脏中的蓄积，并且可以作为一种策略性补充工具来限制肉牛体内铜拮抗的全身效应。
