The invention regards an animal monitoring system and method for determining feed consumption of one or more animals feeding at a feeding area. The system comprises an imaging unit for range imaging the feeding area, identification means configured to uniquely identify each feeding animal, and processing means configured for acquiring a series of subsequent range images of the feeding area in front of each identified animal over a period of time while said animal(s) are feeding, identifying the reduction of feed between subsequent range images in said series of range images and assessing the amount of feed consumed by each identified animal by correlating the reduction of feed between subsequent range images with the feed consumption of each identified animal.