What is the chicken's true stomach called?

The chicken's true stomach is known as the proventriculus, which follows the crop in the digestive system. This glandular stomach plays a critical role in digestion by secreting enzymes and acid that break down food before it moves to the gizzard. The proventriculus is responsible for the initial stages of digestion, allowing the bird to effectively process nutrients from the feed it consumes.

In contrast, the gizzard, which is a muscular organ often confused with the stomach, primarily functions to grind food, especially for chickens that consume whole grains or seeds. The crop serves more as a temporary storage pouch for food before it enters the proventriculus, and the intestines are responsible for nutrient absorption and waste elimination, rather than functioning as the stomach. These distinctions clarify why the proventriculus is specifically recognized as the true stomach in chickens.