Digestion in ruminants, such as cows and sheep, is mainly microbial and enzymatic.
Ruminants have a four-chambered stomach that allows them to digest tough plant materials like cellulose. The first chamber, the rumen, is where microbial fermentation occurs. Bacteria, protozoa, and fungi in the rumen break down the cellulose and other complex carbohydrates in the food into simpler compounds that can be absorbed by the animal.
Enzymes produced by the animal and microbes in the rumen also break down proteins and fats into simpler compounds that can be absorbed. The rumen also acts as a storage chamber, allowing the animal to regurgitate and re-chew their food (mastication) before swallowing it again for further digestion.
The other three chambers of the ruminant stomach (reticulum, omasum, and abomasum) continue the enzymatic and microbial breakdown of the food before it moves into the small intestine for absorption of nutrients.
In summary, digestion in ruminants is mainly microbial and enzymatic. The rumen, with its complex microbial community, plays a crucial role in breaking down complex carbohydrates in the diet, while enzymatic digestion of proteins and fats occurs throughout the digestive tract.