為研究高致病性豬繁殖與呼吸綜合征病毒（highly pathogenic porcine reproductive and respiratory syndrome virus，HP-PRRSV）感染后豬血液指標的變化及與病毒載量的關系，以大白豬×通城豬高代橫交群體為對象，選用72頭平均11周齡的健康仔豬進行HP-PRRSV人工感染，在感染前和感染后第4、7、11、14、21、28天和第35天進行白細胞計數、淋巴細胞百分比、單核細胞計數、粒細胞百分比4種血常規指標的測定，并與病毒載量進行相關分析。結果顯示：（1）感染與感染前相比，感染第4、7天的白細胞計數、淋巴細胞百分比、單核細胞計數均極顯著降低，粒細胞百分比極顯著升高；感染第11、14天的淋巴細胞百分比顯著降低，粒細胞百分比顯著升高，其他時間點均無顯著變化。（2）抗病組和易感組的淋巴細胞百分比和粒細胞百分比在感染第7天存在顯著差異，其中抗病組的淋巴細胞百分比顯著高于易感組（P<0.05），粒細胞百分比顯著低于易感組（P<0.05）。（3） 4種血液指標與病毒載量之間均存在中度相關（P<0.01）。以上結果表明，血液指標可以考慮作為PRRS早期抗病性的指示性狀。
The highly pathogenic porcine reproductive and respiratory syndrome (PRRS) is the most important infectious disease of pigs. The host would respond to PRRSV by regulating different immune responses at different days post infection (DPI). The routine blood testing is the most intuitive way to detect changes of blood cell in the body. Therefore,it is necessary to detect and analyze hematological parameters for predicting the process of the disease. To investigate the changes of hematological parameters after infection with HR-PRRSV,72 Large White×Tongcheng advanced generation inter-cross piglets with an average age of 11 weeks,were used for the artificial HP-PRRSV infection experiment. The white blood cell (WBC) count,the lymphocyte percentage,the monocyte count and the granulocyte percentage were determined at 0,4,7,11,14,21,28,35 DPI,then association analysis of them with viremia were carried on. The results showed that when compared to 0 DPI,the WBC count,lymphocyte percentage and monocyte count were significantly reduced,and the granulocyte percentage was significantly increased at both 4 DPI and 7 DPI. The lymphocyte percentage was significantly reduced and the granulocyte percentage was significantly increased at both 11 DPI and 14 DPI,but there were no significant differences at the other DPI. Groups of piglets with PRRS-resistant and PRRS-susceptible were set on the basis of viremia and survive rate. It was showed that the lymphocyte and the granulocyte percentage were significantly different at 7 DPI between groups. The lymphocyte percentage of the PRRS-resistant group was significantly higher (P<0.05),and the granulocyte percentage was significantly lower (P<0.05) than the PRRS-susceptible group. For other DPI,as well as other hematological parameters,there were no significant differences. Furthermore,correlation analysis showed that the hematological parameters and viremia at all DPI in piglets were moderately correlated (P<0.01). The results demonstrated that the lymphocyte percentage and granulocyte percentage could be used as indicators of resistance to PRRS. Our current study provides basic data for further research on the changes of hematological parameters after PRRSV infection and relationship with viremia.