In a fodder mixing wagon (1), comprising a mixing container (3) containing amixing device (M),which is adapted to be driven in a mixing process of at least two foddercomponents, and atleast one electronically operable sensor system (S) having a head (H) and usedfor determiningfodder values of at least one fodder component, the head (H) is arranged suchthat it isoperable in the interior of the fodder mixture (F) during the mixing processfor determining foddervalues of all loaded fodder components and/or the mixing accuracy of thefodder mixture (F).