Which of the following is the main stomach or true stomach of poultry? Proventriculus Gizzard Rumen Crop

The main stomach or true stomach of poultry is the proventriculus. The proventriculus is the glandular stomach where the digestion of food begins. The gizzard is a muscular part of the stomach that grinds up food, but it is not considered the true stomach. The rumen is a part of the stomach in ruminant animals, not poultry. The crop is a pouch-like structure in the esophagus where food is temporarily stored before moving to the stomach.