Research Note: Effect of age on hematological parameter and reference intervals for commercial Lohmann silver layer

Hematological parameters play a key role in assessing the disease states and physiological status of birds, however the reliable information of hematological reference values for Lohmann silver in the pre- and post-laying periods is limited. Thus, the aim of this study was to research the effect of age on hematological parameters and provide reliable reference intervals for commercial Lohmann silver layer. Blood samples were obtained from 231 laying hens at different ages (5-37 wk) with 4-wk sampling intervals. A total of 12 hematological parameters including leucocytes (WBC, 109/L), red blood cell (RBC,1012/L), hemoglobin (HGB, g/L), hematocrit (HCT,%), mean corpuscular volume (MCV, fL), mean corpuscular hemoglobin (MCH, pg), mean corpuscular hemoglobin concentration (MCHC, g/L), red cell distribution width (RDW,%), platelet count (PLT,109/L), mean platelet volume (MPV, fL), platelet volume distribution width (PDW), plateletcrit (PCT, fL) were determined with a reference value advisor. One-ANOVA and Tukey test were utilized to test for significant differences of each parameter between ages. Our findings showed that these parameters were significantly affected by age, except for HCT in the pre-laying period. And reference intervals for all parameters except MCH, MCHC, MCV, MPV, and PDW in the pre-laying period were higher than that in the post-laying period. The results of this study may serve as indispensable information when diagnosing the health of Lohmann silver layer.