Whole blood gas and biochemical reference intervals for Lohmann Silver layers

The blood gas and biochemical reference range established with i-STAT clinical analyzer in avian has become common, however, the reference value for various laying hen lines is limited. Therefore, blood gas and biochemical reference intervals will be established for Lohmann Silver layers in the pre- and post-laying periods. The blood sample was collected at a 4-wk interval. A total of 230 Lohmann Silver layers including 80 pullets (5-17 wk) and 150 laying hens (21-37 wk) were collected for whole blood measurement with the i-STAT clinical analyzer. The CG8+ cartridge provides values of the following 13 parameters: sodium (Na mmol/L), potassium (K mmol/L), ionized calcium (iCa mmol/L), glucose (Glu mg/dL), hematocrit (Hct% Packed Cell Volume [PCV]), pH, partial pressure carbon dioxide (PCO₂ mm Hg), partial pressure oxygen (PO₂ mm Hg), total concentration carbon dioxide (TCO₂ mmol/L), bicarbonate (HCO₃ mmol/L), base excess (BE mmol/L), oxygen saturation (sO₂%), and hemoglobin (Hb g/dL). The correlation of these parameters and the effect of physiological status were investigated. The reference value interval was established with a reference value advisor for pre-laying and post-laying birds. Correlations were found to be statistically significant, especially between BE and HCO₃ and TCO₂. Besides, values in Na, iCa, K, Hct, Hb, sO₂ differed significantly between the pre- and post-laying periods. Data in this study might serve as important information for facilitating the genetic selection and assessing the health of Lohmann Silver laying hens.