Blood samples were immediately collected from each chicken and
transferred to the laboratory in the ice box for hematological analysis and immunoglobulin assay. Heterophils,
lymphocyte, monocyte, eosinophil, and basophil were counted manually under the microscope. Plasma was
separated by centrifugation (4,000 rpm × 10 min), and immunoglobulin (IgA and IgM) were measured by Abnova
Chicken Elisa Kit (version 3) in plasma.