ABSTRACT This study was conducted to assess the effect of feeding high-surface ZnO instead of common ZnO on the performance, rumen fermentation, blood minerals, leukocytes and antioxidant capacity of pre- and post-weaning calves. Thirty male suckling Holstein calves were allotted to one of three experimental groups (10 replicates) in a completely randomised design. Calves received: (1) a low Zn diet without Zn supplementation (control diet), (2) a high Zn diet containing 50 mg supplementary Zn/kg dry matter (DM) as common ZnO or (3) a high Zn diet containing 50 mg supplementary Zn/kg DM as high-surface ZnO (nano-ZnO). The control diet contained a native Zn content of 35.5, 34.7 or 33.7 mg/kg DM for the age periods of 7 to 30, 31 to 70 and 71 to 100 d, respectively. Supplementation of the diet with Zn did not change the dry matter intake (DMI) of calves during d 7 to 30 but increased the ADG in this period (p < 0.05). During age periods of 31 to 70 and 71 to 100 d, DMI and ADG of the Zn supplemented calves were higher (p < 0.05) than the control animals. The nutrient digestibility and the concentration of rumen volatile fatty acids were positively affected (p < 0.05) and the rumen ammonia-N concentration decreased (p < 0.05) by dietary Zn supplementation. Furthermore, the incidence of diarrhoea and pneumonia was lower in calves receiving the Zn supplemented diets. Irrespective of ZnO source, the blood total antioxidant capacity, leukocyte and haematocrit levels significantly increased (p < 0.05) with the ZnO supplemented diets. The post-weaning DMI, nutrient digestibility and blood haematocrit levels were higher in calves receiving high-surface ZnO, compared to those supplemented with common ZnO. With inclusion of the Zn sources in pre- and post-weaning diets, the blood Zn concentration increased (p < 0.05), but the blood Cu, Fe, Ca, P and Mg levels remained unchanged. Regardless of source, dietary supplementation of young calves with ZnO improved the performance and decreased rumen ammonia-N and the incidence of diseases. Moreover, high-surface ZnO had advantages over common ZnO in increasing the post-weaning feed intake, digestibility and blood Zn concentration.

中文翻译：

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接受高表面氧化锌代替普通氧化锌的年轻荷斯坦犊牛的性能、瘤胃发酵、血液矿物质、白细胞和抗氧化能力

摘要 本研究旨在评估饲喂高表面氧化锌代替普通氧化锌对断奶前和断奶后犊牛的生产性能、瘤胃发酵、血液矿物质、白细胞和抗氧化能力的影响。30 头雄性荷斯坦乳牛犊被分配到三个实验组中的一个（10 个重复），采用完全随机的设计。犊牛接受：（1）不添加锌的低锌日粮（对照日粮），（2）含有 50 mg 补充锌/公斤干物质（DM）作为普通 ZnO 的高锌日粮或（3）含有 50 毫克锌的高锌日粮mg 补充 Zn/kg DM 作为高表面 ZnO（纳米 ZnO）。对照饮食在 7 至 30、31 至 70 和 71 至 100 天的年龄阶段分别含有 35.5、34.7 或 33.7 mg/kg DM 的天然锌含量。在第 7 天至第 30 天期间，日粮中添加锌并没有改变犊牛的干物质摄入量 (DMI)，但会增加这一时期的 ADG（p < 0.05）。在 31 至 70 天和 71 至 100 天的年龄期间，补充锌的犊牛的 DMI 和 ADG 高于对照动物（p < 0.05）。日粮锌的补充对营养物质的消化率和瘤胃挥发性脂肪酸的浓度有积极影响（p < 0.05），瘤胃氨氮浓度降低（p < 0.05）。此外，接受锌补充日粮的犊牛腹泻和肺炎的发生率较低。不考虑 ZnO 来源，在补充 ZnO 的饮食中，血液总抗氧化能力、白细胞和血细胞比容水平显着增加（p < 0.05）。断奶后 DMI，与补充普通 ZnO 的犊牛相比，接受高表面 ZnO 的犊牛的营养消化率和血细胞比容水平更高。在断奶前和断奶后日粮中加入锌源后，血液锌浓度增加（p < 0.05），但血液中铜、铁、钙、磷和镁的水平保持不变。无论来源如何，在日粮中添加 ZnO 的小牛改善了生产性能并降低了瘤胃氨氮和疾病的发生率。此外，高表面氧化锌在增加断奶后采食量、消化率和血液锌浓度方面优于普通氧化锌。但血液中的铜、铁、钙、磷和镁水平保持不变。无论来源如何，在日粮中添加 ZnO 的小牛改善了生产性能并降低了瘤胃氨氮和疾病的发生率。此外，高表面氧化锌在增加断奶后采食量、消化率和血液锌浓度方面优于普通氧化锌。但血液中的铜、铁、钙、磷和镁水平保持不变。无论来源如何，在幼牛日粮中添加 ZnO 都提高了生产性能并降低了瘤胃氨氮和疾病的发生率。此外，高表面氧化锌在增加断奶后采食量、消化率和血液锌浓度方面优于普通氧化锌。