Which rumen compartment breaks down cellulose?

Which rumen compartment breaks down cellulose?

• A. Rumen
• B. Reticulum
• C. Abomasum
• D. Omasum

Answer: (A)

Cellulose digestion in ruminants happens where the microbial fermentation in the first stomach chamber occurs. The rumen hosts cellulolytic bacteria and protozoa that produce cellulase enzymes to break down cellulose into simple sugars, which are then fermented by those microbes into volatile fatty acids. These VFAs—mostly acetate, propionate, and butyrate—are absorbed through the rumen wall and provide a major energy source for the animal. The other compartments serve different roles: the reticulum helps with cud formation and particle sorting, the omasum assists in reducing particle size and absorbing water, and the abomasum is the true gastric stomach where acids and enzymes digest proteins. Thus, the rumen is the primary site for breaking down cellulose.

Cellulose digestion in ruminants happens where the microbial fermentation in the first stomach chamber occurs. The rumen hosts cellulolytic bacteria and protozoa that produce cellulase enzymes to break down cellulose into simple sugars, which are then fermented by those microbes into volatile fatty acids. These VFAs—mostly acetate, propionate, and butyrate—are absorbed through the rumen wall and provide a major energy source for the animal. The other compartments serve different roles: the reticulum helps with cud formation and particle sorting, the omasum assists in reducing particle size and absorbing water, and the abomasum is the true gastric stomach where acids and enzymes digest proteins. Thus, the rumen is the primary site for breaking down cellulose.