Other methods to determine feed intake have been developed. Radiography has been applied to determine individual feed intake using feed labeled with dense particulatemarkers detectable by radiography. This eliminated drawbacks ofthe weighing and count method, but was primarily used to charac-terize feeding hierarchies and to determineindividual feed intake. Radiographyhas several disadvantages. The addition of the marker is time-consuming and requires expertise for adequate distribution. Theadded particulate marker affects digestibility,which reduces ingestion rate. Radiographywas determined to be inadequate for the determination of biolog-ical FCR values by Talbot and Higgins.