Poultry's digestive tracts are different from that of ruminants and non-ruminants. Examples of poultry include chickens, turkeys, ducks, and geese. Unlike the mouth of ruminants and non-ruminants, the beak of poultry animals does not have lips or teeth, so it doesn't partake in chewing. It does have a esophagus, and on the esophagus is what is called the crop. The crop is much like saliva in ruminants and non-ruminants because it moistens and softens the food. However, little digestion actually occurs here. Next, poultry have what is called a proventriculus, which is considered the true stomach. This is the place where large amounts of digestive enzymes are added to food. The gizzard is what is used to grind up the food and should contain small tones to help with the grinding process. The small stones are a key part in the digestion, and not having those stones can prove to be fatal. The feed of poultry should be very high in nutrients because of how quickly food works through their digestive system. The liver, small intestine, and large intestine all have similar functions to that of ruminant and non-ruminant digestive tracts. Poultry also have two ceca, while others only have one. The ceca contain undigested feed, but the real purpose of it is unknown. The final part of the poultry's digestive tract is the vent. The vent is the place where digestive, urinary, and reproductive tracts open. As you can see, poultry vary quite a bit from ruminant and non-ruminant animals, but there are some similarities.