ANATOMY

Detailed explanation-1: -The rumen (on the left side of the animal) is the largest stomach compartment and consists of several sacs. It can hold 25 gallons or more of material depending on the size of the cow. Because of its size, the rumen acts as a storage or holding vat for feed. Aside from storage, the rumen is also a fermentation vat.

Detailed explanation-2: -The rumen is the largest stomach compartment, holding up to 40 gallons in a mature cow. The reticulum holds approximately 5 gallons in the mature cow. Typically, the rumen and reticulum are considered one organ because they have similar functions and are only separated by a small muscular fold of tissue.

Detailed explanation-3: -Cows are known as “ruminants” because the largest pouch of the stomach is called the rumen. Imagine a large 55-gallon trashcan. In a mature cow, the rumen is about the same size! Its large size allows cows to consume large amounts of grass.

Detailed explanation-4: -The ruminant stomach has 4 compartments: 1) rumen, 2) reticulum, 3) omasum, and 4) abomasum (Van Soest, 1994). Pregastric fermentation and breakdown of feeds occurs in the rumen, reticulum, and omasum, whereas the abomasum is the true stomach and is similar in structure and function to the non-ruminant stomach.