COW STOMACHS:
a tour through the landscape
The inside of a cow’s stomach has a rich texture and structure. It can remind you of a rough landscape or the skin of a fantastic animal.
Let us start with an introduction to the four different stomachs of the cow, taking a tour through the digestion system as if we were the cow’s food.
1
RUMEN
The rumen is the first stomach we would slide into. It is the biggest of the four. This first stomach serves as temporary storage in the process of ruminating. Dairy cow rumen can contain 120 kg of food mush (you and I would fit in together!).
The rumen is not round like a ball but is composed of several muscular sacs. The lining of this stomach has scale-like structures that almost look like fur in some places. These textures increase the surface, allowing for better absorption of substances. Other parts of this stomach are wrinkled like the skin of an elephant.
2
RETICULUM
The second stomach is the reticulum. The rumen and reticulum are remarkably similar in structure and function. They are separated only by a muscular fold of tissue. In both stomachs, digestion happens through fermentation by microbes. They can be considered as one organ but differ in the texture of their lining. The reticulum is much smaller than the rumen. It has a netlike structure, creating little chambers in the stomach lining. This structure reminds you of honeycombs and feels almost reptilian.
3
OMASUM
The omasum is the third stomach. The lining of this stomach is highly folded. The folds and creases are covered with little globules and soft prickles. The numerous folds trap digestive particles so the maximum amount of nutrients can be absorbed. In the slaughterhouse, the folds are called leaves, and the Dutch name of the omasum refers to them as pages: this is also called the ‘book stomach’ (boekmaag). This leather reminds of a winding landscape.
4
ABOMASUM
The last stomach is the abomasum. This smooth, slimy pink stomach vastly differs from the dark and textured previous three. It consists of two distinct parts, a chamber with a soft lining and the second part lined with smooth parallel creases and folds, like a skirt. The abomasum resembles the stomach of mammals with a single stomach, such as humans. This last stomach is not suitable for tanning.
