Henderson Jacob A, Hansen Stephanie L
Department of Animal Science, Iowa State University, Ames, IA 50011.
J Anim Sci. 2025 Jan 4;103. doi: 10.1093/jas/skaf219.
Two experiments were conducted to determine the bioavailability of Cu carbonate (CuCO3) and tribasic Cu chloride (TBCC) relative to Cu sulfate (CuSO4). Experiment 1 utilized 84 steers (282 ± 19 kg) in a 96-d study stratified by weight into pens (six steers per pen) equipped with GrowSafe feed bunks (GrowSafe Systems Ltd, Airdire, AB, Canada). Two pens (n = 12 steers per treatment) were randomly assigned to one of seven treatments: no supplemental Cu (CON), 5 or 10 mg Cu/kg diet dry matter (DM) from CuCO3 (CO5 and CO10, respectively), 5 or 10 mg Cu/kg diet DM from CuSO4 (SUL5 and SUL10, respectively), and 5 or 10 mg Cu/kg diet DM from TBCC (TBCC5 and TBCC10, respectively). All animals were supplemented with 2 mg Mo/kg diet DM and 0.1% S. Blood and liver samples were collected on days 5 and 4 and on days 95 and 96 with treatments stratified across sampling days. Weight was measured on days -1, 0, 26, 56, 93, and 94. Liver samples were used to determine liver Cu concentration and expression of genes relating to Cu trafficking. Blood samples were used to determine plasma Cu and ceruloplasmin concentrations. Markers of Cu status were used to determine the relative bioavailability (RBV) of each test source against CuSO4. Based on liver Cu, CuCO3, and TBCC were not as bioavailable as CuSO4 (89% and 88%, respectively, P < 0.01). There were no differences in RBV between sources based on plasma Cu; however, based on ceruloplasmin, CuCO3 tended to be more bioavailable than CuSO4 (186%; P = 0.08). Experiment 2 compared rates of repletion of Cu-depleted steers fed each source at 5 mg Cu/kg DM (plus 5 mg Mo/kg DM) for 21 d. Controls had the lowest liver Cu following depletion (P ≤ 0.01), while Cu-supplemented treatments were not different (P ≥ 0.40). Plasma Cu was affected by day (P < 0.01), where days 7 and 14 of repletion were similar (P = 0.23) and greater than day 21 (P ≤ 0.01). There was a tendency for a treatment × day interaction where ceruloplasmin tended to be greater on day 14 than on day 7 (P ≤ 0.09), while CON remained consistent on days 7 and 14 (P = 0.51), and decreased from day 14 to day 21 (P = 0.03). Environmental factors and initial Cu status may have impacted the outcome of Exp. 2. In conclusion, Cu from CuCO3 tended to result in more Cu in circulation as ceruloplasmin than CuSO4 and TBCC.
进行了两项试验以测定碳酸铜（CuCO₃）和碱式氯化铜（TBCC）相对于硫酸铜（CuSO₄）的生物利用率。试验1在一项为期96天的研究中使用了84头阉牛（体重282±19千克），按体重分层分栏（每栏6头阉牛），栏舍配备GrowSafe自动采食槽（GrowSafe Systems Ltd，加拿大阿尔伯塔省艾尔德里）。将两栏（每种处理12头阉牛）随机分配到7种处理之一：不添加铜（CON），日粮干物质（DM）中添加5或10毫克/千克铜的碳酸铜（分别为CO5和CO10），日粮DM中添加5或10毫克/千克铜的硫酸铜（分别为SUL5和SUL10），以及日粮DM中添加5或10毫克/千克铜的碱式氯化铜（分别为TBCC5和TBCC10）。所有动物日粮DM中均添加2毫克钼/千克和0.1%的硫。在第5天和第4天以及第95天和第96天采集血液和肝脏样本，处理在采样日分层。在第 -1、0、26、56、93和94天测量体重。肝脏样本用于测定肝脏铜浓度以及与铜转运相关基因的表达。血液样本用于测定血浆铜和铜蓝蛋白浓度。用铜状态指标来测定每种试验来源相对于硫酸铜的相对生物利用率（RBV）。基于肝脏铜，碳酸铜和碱式氯化铜的生物利用率不如硫酸铜（分别为89%和88%，P<0.01）。基于血浆铜，各来源的RBV没有差异；然而，基于铜蓝蛋白，碳酸铜的生物利用率倾向于高于硫酸铜（186%；P = 0.08）。试验2比较了给缺铜阉牛饲喂每种来源5毫克铜/千克DM（加5毫克钼/千克DM）21天的补充速率。对照组在缺铜后肝脏铜含量最低（P≤0.01），而补充铜的处理组之间没有差异（P≥0.40）。血浆铜受天数影响（P<0.01），补充的第7天和第14天相似（P = 0.23）且高于第21天（P≤0.01）。存在处理×天数的交互作用趋势，即铜蓝蛋白在第14天倾向于高于第7天（P≤0.09），而对照组在第7天和第14天保持一致（P = 0.51），并从第14天到第21天下降（P = 0.03）。环境因素和初始铜状态可能影响了试验2的结果。总之，与硫酸铜和碱式氯化铜相比，碳酸铜中的铜作为铜蓝蛋白在循环中产生的铜倾向于更多。
