Foot-and-mouth disease (FMD) is a highly contagious disease of livestock and has severely affected livestock industries during the past two decades in previously FMD-free countries. The disease was eliminated in North America in 1953 but remains a threat for re-introduction. Approximately 44% of the on-feed beef cattle in the U.S. are concentrated in feedlots <32,000 heads, but little information is available on dynamics of FMD in large feedlots. Therefore, there is a need to explore possible management and intervention strategies that might be implemented during potential FMD outbreaks on feedlots. We used a within home-pen stochastic susceptible-latent-infectious-recovered (SLIR) FMD dynamics model nested in a meta-population model of home-pens in a feedlot. The combinatory model was previously developed to simulate foot-and-mouth disease virus (FMDv) transmission within U.S. beef feedlots. We evaluated three intervention strategies initiated on the day of FMD detection: stopping movements of cattle between home-pens and hospital-pen(s) (NH), barrier depopulation combined with NH (NH-BD), and targeted depopulation of at-risk home-pens combined with NH (NH-TD). Depopulation rates investigated ranged from 500 to 4,000 cattle per day. We evaluated the projected effectiveness of interventions by comparing them with the no-intervention FMD dynamics in the feedlot. We modeled a small-size (4,000 cattle), medium-size (12,000 cattle), and large-size (24,000 cattle) feedlots. Implementation of NH delayed the outbreak progression, but it did not prevent infection of the entire feedlot. Implementation of NH-BD resulted in depopulation of 50% of cattle in small- and medium-size feedlots, and 25% in large-size feedlots, but the intervention prevented infection of the entire feedlot in 40% of simulated outbreaks in medium-size feedlots, and in 8% in large-size feedlots. Implementation of NH-TD resulted in depopulation of up to 50% of cattle in small-size feedlots, 75% in medium-size feedlots, and 25% in large-size feedlots, but rarely prevented infection of the entire feedlot. Number of hospital-pens in the feedlot was shown to weakly impact the success of NH-TD. Overall, the results suggest that stopping cattle movements between the home-pens and hospital-pens, without or with barrier or targeted cattle depopulation, would not be highly effective to interrupt FMDv transmission within a feedlot.

口蹄疫是一种高度传染性的牲畜疾病，在过去的二十年中，在以前没有口蹄疫的国家中，口蹄疫已严重影响了畜牧业。该病于1953年在北美被消灭，但仍然存在重新引入的威胁。在美国，约有44％的饲喂肉牛集中在小于32,000头的饲养场中，但是关于大型饲养场中口蹄疫动态的信息很少。因此，有必要探索可能在饲养场潜在口蹄疫暴发期间实施的可能的管理和干预策略。我们使用嵌套在饲养场中家庭围栏的元人口模型中的内部围栏随机易感潜伏感染恢复（SLIR）FMD动力学模型。先前已开发出组合模型来模拟口蹄疫病毒（FMDv）在美国牛肉饲养场中的传播。我们评估了FMD检测当天启动的三种干预策略：停止牛在家庭围栏和医院围栏之间的移动（NH），与NH结合的屏障种群减少（NH-BD）和高危人群的定向消除与NH（NH-TD）结合的家用笔。每天调查的人口减少范围为500至4,000头牛。我们通过将其与育肥场中的无干预口蹄疫动态进行比较，评估了干预措施的预计效果。我们对小型（4,000头），中型（12,000头）和大型（24,000头）饲养场进行了建模。NH的实施延迟了疫情的进展，但并不能防止整个饲养场的感染。实施NH-BD导致中小型饲养场的牛减少了50％，大型饲养场的牛减少了25％，但是该干预措施阻止了40％的中等规模模拟暴发中整个饲养场的感染饲养场，大型饲养场中占8％。实施NH-TD导致小型饲养场中多达50％的牛减少，中型饲养场中有75％的牛减少，大型饲养场中有25％的牛减少，但很少能预防整个饲养场的感染。饲养场的医院围栏数量显示出对NH-TD成功的影响很小。总体而言，结果表明，在没有或没有障碍物或有针对性的牛群减少的情况下，阻止家畜栏和医院围栏之间的牛移动，对中断饲养场内的FMDv传播不是非常有效。