The purpose of this study was to develop a method for automatically measuring the weight of grazing cattle by incorporating a scale system with Electric Identification (EID) tags. The scale system was installed in front of a water trough in a pasture, and EID tags were placed put on the neck belt of each grazing cattle. When cattle voluntarily visited the weight-measuring system to drink water, the system automatically measured and recorded their individual weight. Weight was recorded an average of 2.1 times per day per cattle. The average difference in weight measurements between those measured manually and those measured using the automated system was 4.5 kg. Weight changes during growth showed similar tendencies between both methods. These results indicate that the automated measuring method is a useful and laborsaving technique for recording the weight of grazing cattle.
