A highly automated method and system for providing individual animal electronic identification, measurement and value based management of cattle in a large cattle feedlot. Through the use of (1) a computer system integrated with (2) automatic individual animal identification (3) multiple measurement and remeasurement systems with automatic data input and (4) a cattle handling and sorting system, animals are individually (a) identified and (b) measured by weight, external dimensions and characteristics of internal body tissue. With this information together with animal physiological characteristics and historical data, the computer system calculates the optimum (c) slaughter weight, (d) economic end point and (e) marketing date for shipment to a packing plant. After measurement, individual animals are (f) sorted by direction of the computer in response to calculations from the measurements. The computer system also calculates from individual animal data and other data (g) each animal's pro rata share of total feed intake for the animal's feed group. The computer system (h) stores individual animal measurement, performance and location data, which is used by management to (i) select animals for shipment from the feedlot for slaughter at the optimum time. Following an animal's shipment to a slaughter facility, its identification in the computer system is used to (j) correlate the live animal physical characteristics and performance data to the measured and evaluated carcass characteristics data obtained during the slaughter process and (k) build a data base to more accurately identify and measure value-based characteristics in subsequent animals produced and fed for more effective value-based selection and management of those animals.