Ward J D, Spears J W
Department of Animal Science and Interdepartmental Nutrition Program, North Carolina State University, Raleigh 27695-7621, USA.
J Anim Sci. 1999 Jan;77(1):230-7. doi: 10.2527/1999.771230x.
Angus bull calves (n = 42; 7 mo of age; 254 kg initial BW) were used to investigate the effects of dietary Cu and Mo on immune function of stressed cattle. Randomly selected calves (n = 22) were injected with 90 mg of Cu as Cu glycinate 28 d before weaning and castrated at weaning. These calves received 7.5 and 5 mg of supplemental Cu/kg of DM during a 41-d receiving phase and a 196-d growing phase, respectively. The remainder of the steers received no supplemental Cu during the experiment. Copper-supplemented steers had adequate Cu status at weaning, whereas unsupplemented calves were marginally Cu-deficient. Cell-mediated response to intradermal injection of phytohemagglutinin was not affected by dietary treatment during the receiving phase. During the growing phase, half of the steers in each Cu treatment were given 5 mg of supplemental Mo/kg of DM. Copper supplementation increased (P<.05) humoral response to ovalbumin injected on d 133 of the growing phase. On d 168 of the growing phase, calves receiving only supplemental Mo were severely Cu-deficient based on plasma and liver Cu concentrations. The other treatment groups had adequate Cu status. Before feeding on d 168 of the growing phase, half of the steers were loaded onto trailers and transported 2.5 h, and they remained on the trailers an additional 9.5 h. Humoral response to porcine erythrocytes (PRBC) and delayed-type hypersensitivity (DTH) to dinitrochlorobenzene was tested at the end of the stress period. There was a Cu x stress interaction for humoral response to PRBC, with Cu decreasing antibody titers in unstressed calves and increasing titers in stressed steers. Stressed steers had lower (P = .03) ADG during the 28 d following stress. The results of this study indicate that Cu deficiency and 5 mg of supplemental Mo/kg of DM do not dramatically alter the specific immunity of stressed cattle.
选用安格斯公牛犊（n = 42；7月龄；初始体重254千克）来研究日粮中铜（Cu）和钼（Mo）对处于应激状态牛的免疫功能的影响。随机挑选的犊牛（n = 22）在断奶前28天注射90毫克甘氨酸铜形式的铜，并在断奶时去势。在41天的适应期和196天的生长阶段，这些犊牛分别摄入7.5毫克和5毫克额外添加的铜/千克干物质。实验期间，其余的公牛未补充额外的铜。补充铜的公牛在断奶时铜状态良好，而未补充铜的犊牛处于边缘性铜缺乏状态。适应期内，皮内注射植物血凝素后的细胞介导反应不受日粮处理的影响。在生长阶段，每个铜处理组中的一半公牛额外摄入5毫克钼/千克干物质。补充铜提高了（P<0.05）生长阶段第133天注射卵清蛋白后的体液反应。在生长阶段第168天，仅摄入额外钼的犊牛根据血浆和肝脏铜浓度判断处于严重铜缺乏状态。其他处理组铜状态良好。在生长阶段第168天喂食前，一半公牛被装上拖车运输2.5小时，并在拖车上再停留9.5小时。在应激期结束时，检测了对猪红细胞（PRBC）的体液反应和对二硝基氯苯的迟发型超敏反应（DTH）。对PRBC的体液反应存在铜×应激交互作用，铜降低了未应激犊牛的抗体滴度，而提高了应激公牛的滴度。应激公牛在应激后的28天内平均日增重较低（P = 0.03）。本研究结果表明，铜缺乏和5毫克额外添加的钼/千克干物质不会显著改变处于应激状态牛的特异性免疫。
