This experiment evaluated the impacts of supplementing organic complexed Cu, Co, Mn, and Zn on productive and health responses of high-risk beef cattle during a 60-d backgrounding phase. Crossbred steers (n = 120) were purchased at auction and transported to the experimental facility. Steer BW was recorded at arrival (d -1; initial shrunk BW = 227.7 ± 1.3 kg). On d 0, steers were ranked by BW and allocated to 1 of 8 groups (8 steers/group) and housed in drylot pens (6 m x 12 m) equipped with GrowSafe automated feeding systems (Model 8000; 2 bunks/pen; d 0 to 60). Groups were randomly assigned to receive a total mixed ration (TMR; 47% corn) containing: 1) sulfate sources of Cu, Co, Mn, and Zn (INR; n = 40); 2) organic complexed sources of Cu, Mn, Co, and Zn (AAC; Zinpro Availa 4; Zinpro Corp., Eden Prairie, MN; n = 40); or 3) AAC and an organic complexed trace mineral drench (APF; 30 mL/hd; Zinpro ProFusion, Zinpro Corp.) on d 0 and ancillary to morbidity treatment (n = 40). Diets provided the same daily amount of energy, protein, macro minerals and trace minerals based on 7 g/steer daily of Zinpro Availa 4. Steers were assessed for bovine respiratory disease (BRD) signs daily. Liver biopsies were performed on day 0, 28 and 60. Final BW was recorded on d 60 and 61. Blood samples were collected on d 0, 2, 6, 10, 13, 21, 28 and 45. No treatment differences were detected (P ≥ 0.23) for TMR intake, final BW, ADG, feed efficiency, or BRD incidence. Mean liver Co concentrations were greater (P = 0.02) in AAC and APF compared with INR steers. Mean liver Cu was greater (P = 0.02) in APF compared with AAC steers. Liver Zn tended to be greater (P = 0.10) on d 28 but less (P = 0.05) on d 60 for INR compared with AAC and APF steers. Plasma cortisol was least (P = 0.05) for steers supplemented with AAC on d 6, whereas AAC steers tended to have greater (P = 0.09) plasma cortisol on d 13 compared with APF. Plasma haptoglobin tended to be greater (P ≤ 0.10) for INR steers on d 28 and 45 compared with AAC and APF. While supplementing cattle with AAC or INR results in similar animal performance and clinical disease, AAC and APF reduces stress and acute phase protein responses.

中文翻译：

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88 在 60 天的背景阶段中微量矿物质来源和辅助浇水对转向性能的影响

该实验评估了在 60 天的背景阶段补充有机复合铜、钴、锰和锌对高风险肉牛生产和健康反应的影响。杂交公牛 (n = 120) 在拍卖会上购买并运输到实验设施。到达时记录转向体重（d -1；初始收缩体重 = 227.7 ± 1.3 kg）。第 0 天，按体重对公牛进行排名，并分配到 8 组中的一组（8 头公牛/组），饲养在配备 GrowSafe 自动饲喂系统（型号 8000；2 个铺位/栏；d 0）的干燥围栏（6 mx 12 m）中至 60）。各组被随机分配接受总混合日粮（TMR；47% 玉米），其中包含： 1) 铜、钴、锰和锌的硫酸盐来源（INR；n = 40）；2) Cu、Mn、Co 和 Zn 的有机络合源（AAC；Zinpro Availa 4；Zinpro Corp.，Eden Prairie，MN；n = 40）；或 3) 第 0 天 AAC 和有机复合微量矿物质浸泡液（APF；30 mL/hd；Zinpro ProFusion，Zinpro Corp.）并辅助发病治疗（n = 40）。基于每天 7 克/牛的 Zinpro Availa 4，日粮提供相同的每日能量、蛋白质、常量矿物质和微量矿物质。每天对牛进行牛呼吸道疾病 (BRD) 症状评估。在第 0、28 和 60 天进行肝活检。在第 60 和 61 天记录最终体重。在第 0、2、6、10、13、21、28 和 45 天收集血样。未检测到治疗差异（ P ≥ 0.23) 对于 TMR 采食量、最终体重、日增重、饲料效率或 BRD 发生率。与 INR 阉牛相比，AAC 和 APF 的平均肝脏 Co 浓度更高 (P = 0.02)。与 AAC 阉牛相比，APF 阉牛的平均肝脏铜含量更高 (P = 0.02)。与 AAC 和 APF 阉牛相比，INR 的肝脏 Zn 在第 28 天时往往较高（P = 0.10），但在第 60 天时较低（P = 0.05）。第 6 天补充 AAC 的阉牛的血浆皮质醇含量最低（P = 0.05），而与 APF 相比，第 13 天补充 AAC 的阉牛的血浆皮质醇往往更高（P = 0.09）。与 AAC 和 APF 相比，第 28 和 45 天 INR 转向的血浆触珠蛋白往往更高 (P ≤ 0.10)。虽然给牛补充 AAC 或 INR 会导致类似的动物性能和临床疾病，但 AAC 和 APF 可以减少应激和急性期蛋白反应。