The abomasum is the fourth stomach compartment in ruminant animals, such as cows, sheep, and goats. It is often referred to as the "true stomach" because it functions similarly to the stomach in non-ruminant animals. The abomasum is responsible for the digestion of proteins and the absorption of nutrients. In the digestive process, food first passes through the rumen, reticulum, and omasum before reaching the abomasum. Here, gastric juices break down food further, allowing for nutrient absorption in the intestines. The abomasum plays a crucial role in the overall digestive efficiency of ruminants.