Location, number of samples, surface material, and porosity classification of sampled surfaces in porcine reproductive and respiratory syndrome positive growing pig farms selected for the study.

Location, number of samples, surface material, and porosity classification of sampled surfaces in porcine reproductive and respiratory syndrome positive growing pig farms selected for the study.本研究选取的猪繁殖与呼吸综合征（porcine reproductive and respiratory syndrome）阳性生长猪养殖场内，所采样表面的位置、样本数量、表面材质与孔隙度分级。