Final answer:
Gavage feeding in birds is correctly performed by delivering food to the crop, which is the initial storage site for food before digestion in the bird's two-part stomach system.
Step-by-step explanation:
Gavage feeding in birds is correctly performed when food is delivered to the crop. The avian digestive system is unique in comparison to mammals. Birds have a sac-like structure called the crop where food is stored and moistened before digestion. After the crop, the food passes to the proventriculus, which is the first of the two-part stomach system where digestive juices break down the food. This is followed by the gizzard, or ventriculus, where food is ground, often aided by swallowed stones. It is important not to confuse these different parts when discussing the process of gavage feeding.