Fig. 3

Simulated sampling distribution histogram of average annual income per sow under different PRRSV infection statuses. AÂ PRRSV provisional negative farm. BÂ PRRSV-positive stable farm. CÂ PRRSV-positive unstable farm. The red line represents the probability density cumulative curve, whereas the red rectangles depict the frequency distribution histogram of the sow's average annual income. PRRSV, porcine reproductive and respiratory syndrome virus