Buchanan J W, MacNeil M D, Raymond R C, McClain A R, Van Eenennaam A L
J Anim Sci. 2016 Dec;94(12):5456-5460. doi: 10.2527/jas.2016-1001.
Variance components were estimated and relative economic importance of bovine respiratory disease (BRD) was derived from 3 yr of performance, morbidity, and mortality data collected from a single beef cattle finishing operation. One thousand one hundred eighty nine of 12,812 Charolais-sired calves were treated for BRD during the finishing period. Weaning weight (WW), DMI, days to harvest (D2H), HCW, yield grade (YG), and marbling score determined by image analysis (MARB) were collected to quantify the economic impact associated with treatment for BRD. Observed means and (co)variances for carcass and production traits were used to simulate populations of 10,000 healthy and 10,000 BRD treated calves. A bio-economic model was developed to derive the economic value associated with the incidence and number of treatments for BRD during the finishing period. Carcasses from healthy calves were worth $58.28 more on average compared to calves treated at least once for BRD. Heritability estimates for BRD were 0.15 when the trait was measured as number of treatments (0 to 4), and 0.14 when measured as incidence (0 or 1). The model indicated that D2H had the lowest relative economic importance in this system, with a cost of $1.91 per head for each additional day on feed. Furthermore, the relative economic value of BRD morbidity was approximately 10.65 greater than D2H when recording the BRD phenotype as the number of BRD treatments. The economic values of HCW, WW, and DMI were 11.47, 5.15, and 3.61 times more important than D2H, respectively. This indicates BRD morbidity has the second greatest relative economic value in this system, with a one percent increase in morbidity associated with an average loss of $2.08 per head. These results indicate that BRD morbidity can have an equal or greater economic importance when compared to carcass and production traits during the finishing period. Further, this indicates the opportunity exists to increase the genetic merit for profitability during the finishing period by incorporating BRD incidence into terminal-sire selection indexes.
通过从一个肉牛育肥场收集的3年性能、发病率和死亡率数据，估计了方差分量，并得出了牛呼吸道疾病（BRD）的相对经济重要性。在12812头夏洛莱种公牛犊中，有1189头在育肥期接受了BRD治疗。收集断奶体重（WW）、干物质采食量（DMI）、出栏天数（D2H）、热胴体重（HCW）、产量等级（YG）和通过图像分析确定的大理石花纹评分（MARB），以量化与BRD治疗相关的经济影响。利用观察到的胴体和生产性状的均值和（协）方差，模拟了10000头健康犊牛和10000头接受BRD治疗的犊牛群体。开发了一个生物经济模型，以得出育肥期BRD发病率和治疗次数的经济价值。与至少接受过一次BRD治疗的犊牛相比，健康犊牛的胴体平均价值高出58.28美元。当将BRD性状测量为治疗次数（0至4次）时，BRD的遗传力估计值为0.15；当测量为发病率（0或1）时，遗传力估计值为0.14。该模型表明，在这个系统中，D2H的相对经济重要性最低，每多喂一天，每头牛的成本为1.91美元。此外，当将BRD表型记录为BRD治疗次数时，BRD发病率的相对经济价值比D2H大约高10.65倍。HCW、WW和DMI的经济价值分别比D2H重要11.47、5.15和3.61倍。这表明BRD发病率在这个系统中具有第二大的相对经济价值，发病率每增加1%，每头牛平均损失2.08美元。这些结果表明，在育肥期，与胴体和生产性状相比，BRD发病率可能具有同等或更大的经济重要性。此外，这表明通过将BRD发病率纳入终端父本选择指数，有机会在育肥期提高盈利的遗传价值。
