Evaluation of Blood Cell Effects and Estimation of Retinol Concentration in Whole Blood of Fattening Cattle in the Excitation Emission Matrix

Abstract

　Japanese farmers control feed during the fattening period to lower blood retinol levels in cattle for marbled beef production, but routine monitoring is difficult, costly, and time-consuming. To address this, we developed a rapid method using Excitation Emission Matrix (EEM) in surface fluorescence of whole blood. PLS analysis showed a strong correlation between EEM and retinol levels (R²＝0.87, RMSEP＝11.2 IU/dL). Further analysis using PLS-DA could identify cows with retinol levels below 30 IU/dL with 91 % accuracy. This method allows frequent and accurate monitoring of blood retinol in about 10 minutes, enabling more precise and cost-effective husbandry.