Digestion in the rumen is mainly microbial. The rumen is the first stomach chamber of ruminants, such as cows, sheep, and goats, where food is broken down by microorganisms, such as bacteria, protozoa, and fungi, that live in the rumen. These microorganisms break down complex carbohydrates and fibrous material in the feed into simpler compounds that can be absorbed and utilized by the animal. This process is known as fermentation, and it produces short-chain fatty acids, which are a major source of energy for the animal. The microbial digestion in the rumen is an essential part of the digestive process of ruminants, and it allows them to extract maximum nutrition from their food.