Development in the progress of overfeeding machinery for foie gras production.

1. Overfeeding is the main method to obtain foie gras (goose or duck fatty liver). The development of overfeeding machines accompanied with the development of foie gras production. From the simplest manual method to the screw driving overfeeding machine, from the pneumatic overfeeding machine to hydraulic overfeeding machine, this equipment is constantly being improved and innovated.2. This is the first comprehensive review on foie gras overfeeding equipment, offering insights for the industry. Overfeeding is the main method for producing foie gras, with overfeeding machinery evolving alongside the industry. This review summarises global and Chinese foie gras production history, machinery development, three main machine types (screw-driving, pneumatic, hydraulic), performance comparisons and trends.3. Hydraulic machines are the optimal choice: integrating advanced technologies, using mixed feeds, featuring flexible tubes to reduce bird injury, ensuring precise feeding (1 g accuracy), high success rates (>95%), superior product quality and efficient operation. They enhance animal welfare by mitigating stress and oesophageal damage. Equipment trends include multi-function integration, flexible feeding tubes and quantitative technologies.