The Rumen takes up most of the left side of the abdominal cavity. It is also the first chamber of a goat's four chambered stomach, and it plays a crucial role in their digestive system. The rumen is a fermentation tank that breaks down cellulose in plant material, allowing the goat to extract nutrients from its diet. 🐐🐐🐐. It’s important to feed the rumen of a goat which involves providing it with fiber rich foods that are high in cellulose, such as..🐐🐐🐐… hay, grass, legume, or cereal hay �