Relative risk of exposure, by integrator group.

*Reference population is a farm that is not affiliated with the integrator group of the index farm at the same model parameters (viral survival and duration of infectiousness). Confidence intervals obtained using nonparametric bootstrapping resampling in Crystal Ball.

* 参照群体（reference population）指与指标农场不属于同一整合商集团，且模型参数（病毒存活能力与传染持续时长）一致的农场。置信区间通过Crystal Ball软件中的非参数自助重采样方法计算得到。