Haematological Profiles of Pigs on Different Farms Reflect Their Health Status

Abstract

BackgroundHaematological examination is an important diagnostic tool in the assessment of pig health status. The present study aimed to assess haematological parameters in pigs of different age categories from six farrow-to-finish farms differing in herd health status. The following pig categories were included: 5 age groups of growers (5, 7, 9–10, 11 and 12–13 weeks-old), fatteners and breeding pregnant sows. Individual blood samples for determining complete blood count and white blood cell differential count were taken and group samples of oral fluid and faeces were collected from each animal category in each of the six farms and tested for the detection of Porcine Circovirus Type 2 (PCV2), Porcine Reproductive and Respiratory Virus (PRRSV), and Hepatitis E Virus (HEV) using PCR, RT-PCR, and qRT-PCR protocols. Individual blood samples were analysed using an automated laser-based haematology analyser. The following haematological parameters were reported: white blood cell count (WBC), red blood cell count (RBC), haemoglobin concentration (Hb), haematocrit (Hct), mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), mean corpuscular haemoglobin concentration (MCHC), platelet count (PLT), and percentage and number of neutrophils, lymphocytes, monocytes, eosinophils, basophils, and "large unstained cells" - LUCs. ResultsOn farms free of PRRSV, PCV2 and HEV, age had significant effect on the following parameters: WBC, Hb, MCH, MCHC, PLT, percentage of neutrophils, lymphocytes and eosinophils and absolute numbers of neutrophils, lymphocytes, monocytes, basophils and LUCs. On farms with PRRS, PCV2 and/or HEV, age significantly affected all observed blood parameters except the percentage of LUCs. The percentages of lymphocytes, MCV and Hct were significantly lower by PRRSV while WBC, PLT, percentage and absolute number of neutrophils, basophils and LUCs increased. Significantly lower percentages of lymphocytes and increased percentages and absolute numbers of neutrophils, eosinophils and basophils were caused by PCV2 presence. Significantly lower percentage of lymphocytes and MCV and increased RBC, Hb, percentage and number of basophils and percentage of neutrophils were caused by HEV. Conclusions Alterations of haematological parameters reflected the health status of pigs of different categories on infected and on non-infected farms. Age-related changes in haematological parameters occurred in clinically healthy and in infected pigs.