Cheek Robin A, Kegley Elizabeth B, Russell Jason R, Reynolds Jana L, Midkiff Kirsten A, Galloway Doug, Powell Jeremy G
Department of Animal Science, University of Arkansas System Division of Agriculture, Fayetteville, AR 72701, USA.
Zinpro Corp., Eden Prairie, MN 55344, USA.
J Anim Sci. 2024 Jan 3;102. doi: 10.1093/jas/skae056.
To investigate effects of inorganic or complexed trace mineral source (zinc, copper, manganese, and cobalt) on receiving period performance and morbidity, crossbred beef heifer calves (n = 287) arriving on three delivery dates were used in a 42-d receiving trial. Heifers were processed after arrival, stratified by day -1 body weights (BW) and allocated randomly to eight pens (11 to 13 heifers/pen, 24 pens total). Within truckload, pens were assigned randomly to dietary treatment (n = 12 pens/treatment). Heifers were housed on 0.42-ha grass paddocks, provided ad libitum bermudagrass hay and provided dietary treatments in grain supplements fed daily. Treatments consisted of supplemental zinc (360 mg/d), copper (125 mg/d), manganese (200 mg/d), and cobalt (12 mg/d) from complexed (Zinpro Availa 4, Zinpro Corp. Eden Prairie, MN) or inorganic sources (sulfates). Heifers were observed daily for clinical bovine respiratory disease (BRD). If presenting BRD symptoms and rectal temperature ≥ 40 °C, heifers were deemed morbid and treated with antibiotics. Six heifers/pen were bled to determine serum haptoglobin concentrations on days 0, 14, and 28. Liver biopsies were taken on day 5 ± 2 and 43 ± 1 from three calves selected randomly from each pen for mineral status comparisons. Statistical analyses were performed using the MIXED, GLIMMIX, and repeated measures procedures of SAS 9.4 with truckload as a random effect and pen within truckload specified as subject. There tended to be a treatment by day interaction for BW (P = 0.07). Heifer BW did not differ on day 0 (P = 0.82) and day 14 (P = 0.36), but heifers fed complexed trace minerals had greater BW on day 28 (P = 0.04) and day 42 (P = 0.05). Overall average daily gains were greater for heifers fed complexed trace minerals (P = 0.05; 0.78 vs. 0.70 kg, SE = 0.03). Heifers supplemented with inorganic trace minerals had greater BRD incidence (P = 0.03; 58 vs. 46%, SE = 3.6). Haptoglobin concentrations decreased throughout the trial (P < 0.001), and heifers fed complexed trace minerals tended to have a decrease in haptoglobin concentrations (P = 0.07). The source of trace mineral supplementation had no effect (P ≥ 0.20) on liver mineral concentrations and there were no treatment × day interactions (P ≥ 0.35). In conclusion, supplementing diets for the first 42 d after arrival with complexed trace mineral sources improved heifer performance as compared to heifers supplemented with inorganic trace minerals.
为研究无机或复合微量矿物质来源（锌、铜、锰和钴）对育肥牛犊接收期性能和发病率的影响，对三个交货日期到达的杂交肉牛小母牛犊（n = 287）进行了为期42天的接收试验。小母牛到达后进行处理，按-1日体重（BW）分层，并随机分配到八个围栏（每围栏11至13头小母牛，共24个围栏）。在卡车内，围栏被随机分配到日粮处理组（每个处理12个围栏）。小母牛饲养在0.42公顷的草地围场上，自由采食百慕大草干草，并在每日饲喂的谷物补充料中提供日粮处理。处理包括来自复合来源（Zinpro Availa 4，Zinpro公司，伊甸草原，明尼苏达州）或无机来源（硫酸盐）的补充锌（360毫克/天）、铜（125毫克/天）、锰（200毫克/天）和钴（12毫克/天）。每天观察小母牛是否患有临床牛呼吸道疾病（BRD）。如果出现BRD症状且直肠温度≥40°C，则小母牛被视为患病并使用抗生素治疗。在第0、14和28天，从每个围栏中随机选择三头小母牛采血以测定血清触珠蛋白浓度。在第5±2天和第43±1天，从每个围栏中随机选择三头小母牛进行肝脏活检，以比较矿物质状态。使用SAS 9.4的MIXED、GLIMMIX和重复测量程序进行统计分析，以卡车运输作为随机效应，并将卡车内的围栏指定为研究对象。体重（BW）存在处理×日的交互作用趋势（P = 0.07）。小母牛在第0天（P = 0.82）和第14天（P = 0.36）体重无差异，但饲喂复合微量矿物质的小母牛在第28天（P = 0.04）和第42天（P = 0.05）体重更大。饲喂复合微量矿物质的小母牛总体平均日增重更高（P = 0.05；0.78对0.70千克，标准误 = 0.03）。补充无机微量矿物质的小母牛BRD发病率更高（P = 0.03；58%对46%，标准误 = 3.6）。在整个试验过程中，触珠蛋白浓度下降（P < 0.001），饲喂复合微量矿物质的小母牛触珠蛋白浓度有下降趋势（P = 0.07）。微量矿物质补充来源对肝脏矿物质浓度无影响（P≥0.20），也没有处理×日的交互作用（P≥0.35）。总之，与补充无机微量矿物质的小母牛相比，在到达后的前42天补充复合微量矿物质来源的日粮可提高小母牛的性能。
