Hernandez Gracia M P, Dos Santos Aline C R, Ferreira Matheus F L, Bohnert David, Ranches Juliana
Eastern Oregon Agricultural Research Center, Oregon State University, Burns, OR 97720, USA.
Hill Farm Research Station, Louisiana State University, Homer, LA 71040, USA.
Animals (Basel). 2024 Oct 6;14(19):2875. doi: 10.3390/ani14192875.
In this 2-year study, approximately 84 days prior to weaning, 24 calves/year (Angus × Hereford) were randomly assigned to one of two treatments: trace mineral (Cu, Se, and Zn) supplementation following NASEM (2016) recommendations (Control) or trace mineral supplementation above NASEM (2016) recommendations (Super). Calves were individually fed, and trace minerals were provided in 0.5 kg of dry distiller's grains three times weekly. Body weight (BW), blood, and liver samples were collected on d 0 and at weaning (d 84). Additional BW and blood samples were collected post-weaning on d 85, 87, 88, 91, 95, and 99 during the preconditioning phase. Initial liver concentrations of Se, Cu, and Zn were similar between treatments ( ≥ 0.69). At weaning, a year effect ( < 0.001) and a tendency for treatment × year effect ( = 0.09) were observed for Cu liver concentration. In year 2, but not in year 1, calves assigned to the Super treatment tended to have greater liver Cu concentration than calves assigned to the Control treatment. Except for Cu, a notoriously limited trace mineral in multiple geographical locations, the supplementation of trace minerals above the NASEM (2016) recommendations did not improve the mineral status of calves in this environment.
在这项为期两年的研究中，大约在断奶前84天，每年将24头犊牛（安格斯×赫里福德）随机分配到两种处理方式之一：按照美国国家科学院、工程院和医学院（NASEM，2016）的建议补充微量矿物质（铜、硒和锌）（对照）或高于NASEM（2016）建议水平补充微量矿物质（超量组）。犊牛单独饲养，每周三次在0.5千克干酒糟中提供微量矿物质。在第0天和断奶时（第84天）采集体重（BW）、血液和肝脏样本。在断奶后预处理阶段的第85、87、88、91、95和99天采集额外的体重和血液样本。处理组之间初始肝脏中硒、铜和锌的浓度相似（≥0.69）。断奶时，观察到肝脏铜浓度存在年份效应（P<0.001）以及处理×年份效应的趋势（P = 0.09）。在第2年，但第1年未出现这种情况，分配到超量组的犊牛肝脏铜浓度往往高于分配到对照组的犊牛。除了铜（在多个地理位置是一种众所周知的有限微量矿物质）外，高于NASEM（2016）建议水平补充微量矿物质并未改善该环境下犊牛的矿物质状况。
