Computerized and electronic systems for cattle estrus detection and health monitoring, namely, dairy herd computerized management systems comprising a personal computer, control unit comprising electrical controllers and computer software used to gather and analyze data on cattle; computerized and electronic systems for cattle estrus detection and health monitoring comprised of a personal computer, computer software and a control unit comprising of electrical controllers, all for estrus detection, health monitoring, nomination monitoring and for processing and analyzing the collected data; computerized and electronic systems for cattle estrus detection and monitoring, namely, computerized systems comprised of computers and computer software all for controlling, handling and managing dairy herds and for health control through health monitoring, selection of gates to be opened and feed control; computerized and electronic systems for cattle estrus detection and monitoring, namely, electronic devices comprising computer hardware and software for cattle identification and health monitoring, and parts and accessories therefore, namely, body activity sensors, temperature sensors, behavior sensors, transponders and data receivers, data terminal with display comprising computer monitors, antennas and optical readers