Richeson J T, Beck P A, Gadberry M S, Gunter S A, Hess T W, Hubbell D S, Jones C
University of Arkansas, Division of Agriculture, Department of Animal Science, Fayetteville 72701, USA.
J Anim Sci. 2008 Apr;86(4):999-1005. doi: 10.2527/jas.2007-0593. Epub 2008 Jan 11.
Stress commonly associated with weaning, marketing, and shipment of feeder cattle can temporarily compromise immune function, thereby reducing the effective response to vaccination intended to control bovine respiratory disease (BRD). Two vaccination timing treatments were used to evaluate the effect of timing of a multivalent modified live virus (MLV) BRD vaccine on health, performance, and infectious bovine rhinotracheitis (IBR) antibody titers of newly received stocker cattle. Crossbred bull and steer calves (n = 528) were weighed (197 +/- 2.4 kg) and randomly assigned to MLV vaccination treatment: 1) MLV vaccination upon arrival (AMLV), or 2) delayed (14 d) MLV vaccination (DMLV). All cattle were processed similarly according to routine procedures, with the exception of the initial MLV vaccination timing. Subsequently, BW were recorded on d 14, 28, and 42. Blood samples were collected on d 0, 14, 28, and 42 to determine serum IBR titers, and comparisons were made between treatments on a receiving-day basis and an equivalent postvaccination day basis. Daily BW gains were greater (P < or = 0.05) for DMLV calves from d 0 to 14 (1.16 vs. 0.88 +/- 0.22 kg/d) and from d 0 to 42 (0.75 vs. 0.65 +/- 0.09 kg/d). Days to first treatment, total treatment cost, percentage death loss, and pasture ADG after the 42-d receiving period did not differ (P > or = 0.15). Morbidity rates for BRD were high for both AMLV and DMLV (71.5 and 63.5%, respectively) and did not differ (P = 0.12). Positive IBR titer seroconversion was greater (P < or = 0.03) for DMLV calves on d 42 of the study, and for the 28- and 42-d equivalent postvaccination basis. Delaying vaccination by 14 d may increase ADG during the receiving period compared with AMLV, and seroconversion to IBR was greater in DMLV calves, indicating a possible improvement in acquired immune response when MLV vaccination is delayed.
与断奶、销售和运输架子牛通常相关的应激会暂时损害免疫功能，从而降低对旨在控制牛呼吸道疾病（BRD）的疫苗接种的有效反应。采用两种疫苗接种时间处理方式来评估多价改良活病毒（MLV）BRD疫苗的接种时间对新购入的架子牛的健康、性能和传染性牛鼻气管炎（IBR）抗体滴度的影响。对杂交公牛和阉牛犊牛（n = 528）进行称重（197±2.4千克），并随机分配至MLV疫苗接种处理组：1）到达时接种MLV（AMLV），或2）延迟（14天）接种MLV（DMLV）。除初始MLV疫苗接种时间外，所有牛均按照常规程序进行类似处理。随后，在第14、28和42天记录体重。在第0、14、28和42天采集血样以测定血清IBR滴度，并在接收日和等效的接种后日基础上对处理组之间进行比较。DMLV犊牛从第0天至第14天（1.16对0.88±0.22千克/天）以及从第0天至第42天（0.75对0.65±0.09千克/天）的日增重更大（P≤0.05）。首次治疗天数、总治疗成本、死亡损失百分比以及42天接收期后的牧场平均日增重没有差异（P≥0.15）。AMLV和DMLV的BRD发病率均较高（分别为71.5%和63.5%），且没有差异（P = 0.12）。在研究的第42天以及接种后第28天和第42天的等效基础上，DMLV犊牛的IBR滴度阳性血清转化率更高（P≤0.03）。与AMLV相比，延迟14天接种疫苗可能会增加接收期内的平均日增重，并且DMLV犊牛对IBR的血清转化率更高，这表明延迟MLV疫苗接种时获得性免疫反应可能会有所改善。
