Montgomery S P, Sindt J J, Greenquist M A, Miller W F, Pike J N, Loe E R, Sulpizio M J, Drouillard J S
Department of Animal Sciences and Industry, Kansas State University, Manhattan 66506-1600, USA.
J Anim Sci. 2009 Jan;87(1):328-33. doi: 10.2527/jas.2008-0969. Epub 2008 Sep 26.
Six hundred sixty-five crossbred beef heifers initially weighing 225 kg were used in a completely randomized design to measure plasma glucose, lactate, and urea N concentrations at time of initial processing, determine the incidence of apparent bovine respiratory disease (BRD) in receiving cattle, and evaluate the effect of apparent BRD on subsequent cattle growth and carcass characteristics. Heifers were processed within 24 h of arrival, and processing included vaccination against common viral and clostridial diseases, recording rectal temperature, and sampling whole blood for subsequent measurement of plasma glucose, lactate, and urea concentrations. Heifers were monitored for clinical signs of apparent BRD, including depression, lethargy, anorexia, coughing, rapid breathing, and nasal or ocular discharge. Heifers exhibiting signs of apparent BRD received antibiotic therapy, and the number of times a heifer was treated for apparent BRD was recorded. Following the 36-d receiving period, heifers were transported to native grass pastures and allowed to graze for 136 d. At the end of the grazing season, heifers were transported to a commercial feedlot where they were adapted to a common finishing diet offered for ad libitum consumption. Following the 124-d finishing period, heifers were slaughtered and carcass data were collected. Heifers treated for apparent BRD had decreased plasma glucose (linear, P < 0.01), lactate (linear, P < 0.01), and urea N concentrations (linear, P < 0.06) measured at time of initial processing. Rectal temperature measured at time of initial processing tended to be greater (linear, P < 0.11) for heifers treated for apparent BRD. Heifers treated for apparent BRD during the receiving period had decreased overall ADG (linear, P < 0.10), final BW (linear, P < 0.01), HCW (linear, P < 0.01), fat thickness (linear, P < 0.01), and marbling score (linear, P < 0.03). These data suggest that initial plasma glucose and lactate concentrations might be affected by the health status of receiving cattle and that increased incidence of apparent BRD in cattle decreases ADG and carcass quality.
665头初始体重为225千克的杂交肉牛小母牛被用于一项完全随机设计的实验，以测量初次处理时血浆葡萄糖、乳酸和尿素氮的浓度，确定待宰牛群中明显牛呼吸道疾病（BRD）的发病率，并评估明显BRD对后续牛生长和胴体特征的影响。小母牛在到达后的24小时内进行处理，处理内容包括接种预防常见病毒和梭菌疾病的疫苗、记录直肠温度以及采集全血用于后续测量血浆葡萄糖、乳酸和尿素浓度。对小母牛监测明显BRD的临床症状，包括抑郁、嗜睡、厌食、咳嗽、呼吸急促以及鼻或眼分泌物。出现明显BRD症状的小母牛接受抗生素治疗，并记录每头小母牛因明显BRD接受治疗的次数。在36天的待宰期过后，小母牛被运至天然草地牧场并放牧136天。在放牧季节结束时，小母牛被运至商业饲养场，在那里它们适应一种可自由采食的常见育肥牛日粮。在124天的育肥期过后，小母牛被屠宰并收集胴体数据。因明显BRD接受治疗的小母牛在初次处理时测量的血浆葡萄糖（线性关系，P < 0.01）、乳酸（线性关系，P < 0.01）和尿素氮浓度（线性关系，P < 0.06）均降低。初次处理时测量的直肠温度对于因明显BRD接受治疗的小母牛往往更高（线性关系，P < 0.11）。在待宰期因明显BRD接受治疗的小母牛总体平均日增重（线性关系，P < 0.10）、最终体重（线性关系，P < 0.01）、热胴体重（线性关系，P < 0.01）、脂肪厚度（线性关系，P < 0.01）和大理石花纹评分（线性关系，P < 0.03）均降低。这些数据表明，初次血浆葡萄糖和乳酸浓度可能受待宰牛健康状况的影响，且牛群中明显BRD发病率的增加会降低平均日增重和胴体品质。
