In the digestive system of poultry, where does the actual grinding of food occur?

The gizzard is the part of the poultry digestive system where the actual grinding of food occurs. Unlike mammals, poultry do not have teeth to break down food mechanically. Instead, the gizzard functions as a muscular organ that uses strong contractions to grind food into smaller, more digestible pieces. The presence of grit—small stones or sand—assists in this grinding process, enhancing the effectiveness of the gizzard by providing additional surface area for the mechanical breakdown of food.

The crop serves primarily as a storage area for food before it moves into the gizzard, while the proventriculus is the glandular stomach responsible for secreting digestive enzymes but does not carry out grinding. The intestine is crucial for nutrient absorption rather than for the physical breakdown of food. Therefore, the gizzard distinctly fulfills the function of grinding within the poultry digestive system.