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