The influence of age, farm, and physiological status on pig hematological profiles

Abstract

Objectives: To evaluate influence of age, farm, and physiological status on pig hematological profiles. Materials and methods: This study was carried out on five 1-site, farrow-to-finish pig farms in Slovenia, where a total of 382 clinically normal pigs were sampled. All farms were free of Aujeszky’s disease (pseudorabies), classical swine fever, and porcine reproductive and respiratory syndrome. Blood samples were taken from the anterior vena cava. Hematological analyses were performed with an automated hematological analyser. The following hematological variables were measured: red blood cell count (RBC), white blood cell count (WBC), hematocrit (Hct), hemoglobin concentration (Hb), erythrocyte indices, and platelet count (PLT). Differential WBC counts were determined manually using stained smears. Results: The farms themselves influenced all of the investigated variables except RBC and WBC differential (ie, lymphocytes, monocytes, and band neutrophils). A trend of lower values of RBC, Hb, and Hct, higher WBC numbers, and a higher percentage of segmented granulocytes were observed in lactating sows when compared to pregnant sows. Age significantly influenced hematological values and differential WBC counts except basophils, monocytes, and band neutrophils. Values of mean corpuscular volume (MCV) increased with age, the highest values being found in sows. Numbers of WBC and PLT decreased with age, the lowest number being observed in sows. Implications: Hematological examination may be an important diagnostic tool in the assessment of pig health status, but to interpret the results properly, it is important to consider pig age, health history, and clinical data.