In Japan, the number of dairy farms is declining, while the number of animals per dairy farm is significantly increasing. The aging population of the dairy farmers has led to a serious labour shortage. Due to the necessity for daily milking, many dairy farmers are forced to work long hours and cannot take time off. Additionally, feed production adds to their workload. To address these challenges, the development of smart dairy farming technology is becoming increasingly important. This chapter introduces the following new technologies used in silage production: (1) aerial image analysis for measuring weed growth and planting density in forage corn fields, (2) chemical spraying using UAV, (3) estimation of corn yield and determination of harvest timing by image analysis, (4) an automatic recording and real-time monitoring system of forage harvesting and silage preparing operation, and (5) an IoT-based total mixed ration (TMR) producing system.