Arthington John D, Silveira Maria L, Caramalac Luana S, Fernandes Henrique J, Heldt Jeff S, Ranches Juliana
Department of Animal Sciences, University of Florida, Gainesville, FL 32611, USA.
Range Cattle Research and Education Center, University of Florida, Ona, FL 33865, USA.
Transl Anim Sci. 2021 Mar 7;5(2):txab046. doi: 10.1093/tas/txab046. eCollection 2021 Apr.
Three studies were completed to evaluate the effects of Cu, Zn, and Mn source on preferential intake, trace mineral status, and rainfall-induced metal loss of salt-based mineral supplements. Mineral supplements were formulated to contain 2,500, 5,500, and 4,000 mg/kg of Cu, Zn, and Mn, respectively. Supplements differed only by source of Cu, Zn, and Mn, which were hydroxychloride, organic, or sulfate sources. In Exp. 1, the three formulations were offered simultaneously for 18 wk to preweaned beef calves (four pastures; 17 calves per pasture) within separate containers inside covered cow-exclusion areas. Consumption averaged 21 ± 2.4 g/calf daily (sum of all three sources), with a greater ( < 0.001) percentage of the total intake coming from the hydroxychloride vs. organic or sulfate sources of Cu, Zn, and Mn. In Exp. 2, the same sulfate and hydroxychloride formulations were randomly assigned to pastures ( = 4 pastures per treatment) containing 18 to 20 cow-calf pairs/pasture. Treatments were offered for 20 wk within covered areas designed to assess cow and calf intake separately. At weaning, liver biopsies were collected from four cow-calf pairs/pasture ( = 16 cows and calves per treatment). Source of Cu, Zn, and Mn had no effect on voluntary mineral intake among calves ( 0.44) and cows ( 0.14). Calves consuming mineral containing hydroxychloride sources of Cu, Zn, and Mn tended ( 0.06) to have greater average daily gain over the 20-wk period compared with calves consuming sulfate sources of the same elements (1.09 vs. 1.06 kg/d; SEM = 0.013). Mineral status of cows and calves was not affected ( ≥ 0.17) by source of Cu, Zn, and Mn. In Exp. 3, each of the mineral formulations from Exp. 1 was exposed to a 10.2-cm precipitation event delivered in three equal 3.4-cm applications within a week. To accomplish this, 750 g of mineral was placed into Buchner funnels (177 cm) on 20- to 25-µm pore filter paper. Deionized water (pH adjusted to 5.6) was poured over the mineral. Total leaching losses of Cu, Zn, and Mn were less ( < 0.001) for formulations containing hydroxychloride vs. organic and sulfate sources. These results imply that, when offered a choice, calves preferentially consume mineral supplements formulated with hydroxychloride vs. sulfate or organic sources of Cu, Zn, and Mn. In addition, hydroxychloride sources of Cu, Zn, and Mn are less susceptible to rainfall-induced leaching losses compared with sulfate and organic sources.
开展了三项研究，以评估铜、锌和锰的来源对盐基矿物质补充剂的优先摄入量、微量矿物质状况以及降雨引起的金属损失的影响。矿物质补充剂的配方分别含有2500、5500和4000mg/kg的铜、锌和锰。补充剂之间的差异仅在于铜、锌和锰的来源，分别为氢氯化物、有机或硫酸盐来源。在试验1中，将三种配方同时提供给断奶前的肉牛犊（四个牧场；每个牧场17头犊牛），置于有遮盖的母牛禁入区域内的单独容器中，为期18周。平均消耗量为每头犊牛每天21±2.4g（所有三种来源的总和），来自氢氯化物形式的铜、锌和锰的总摄入量百分比高于有机或硫酸盐形式（P<0.001）。在试验2中，将相同的硫酸盐和氢氯化物配方随机分配到牧场（每个处理4个牧场），每个牧场有18至20对母牛-犊牛。在设计用于分别评估母牛和犊牛摄入量的有遮盖区域内提供处理，为期20周。断奶时，从每个牧场的4对母牛-犊牛中采集肝脏活检样本（每个处理16头母牛和犊牛）。铜、锌和锰的来源对犊牛（P = 0.44）和母牛（P = 0.14）的自愿矿物质摄入量没有影响。与摄入相同元素硫酸盐形式的犊牛相比，摄入含有氢氯化物形式铜、锌和锰矿物质的犊牛在20周期间的平均日增重有增加趋势（P = 0.06）（分别为1.09和1.06kg/d；标准误 = 0.013）。母牛和犊牛的矿物质状况不受铜、锌和锰来源的影响（P≥0.17）。在试验3中，将试验1中的每种矿物质配方暴露于一周内分三次等量施加的10.2cm降水事件中。为此，将750g矿物质置于布氏漏斗（177cm）中，漏斗底部铺有20至25μm孔径的滤纸。将去离子水（pH值调至5.6）倒在矿物质上。与有机和硫酸盐来源的配方相比，含有氢氯化物的配方中铜、锌和锰的总浸出损失较少（P<0.001）。这些结果表明，当有选择时，犊牛优先选择含有氢氯化物形式而非硫酸盐或有机形式的铜、锌和锰的矿物质补充剂。此外，与硫酸盐和有机来源相比，氢氯化物形式的铜、锌和锰更不易受降雨引起的浸出损失影响。
