What Is A Chicken Gizzard? How Exactly Do Chickens Chew?

Is a chicken’s digestive system any similar to ours? How do they chew if their beaks have no teeth? And…

what is a chicken gizzard?

Take a quick journey through the chicken’s eating pipeline and uncover the workings of one of the most efficient digestive systems of the animal kingdom.


What are Chicken Gizzards? A Peek into the Chicken Digestive System

Animals’ digestive systems can be classified into 4 main types:

  • Monogastric
  • Ruminant
  • Pseudo-ruminant
  • Avian

Not surprisingly, chickens have an avian digestive system.

The avian digestive system has both a glandular stomach, called the proventriculus, and a muscular stomach, called the gizzard.

 The gizzard is therefore one of the two stomachs a chicken has. It grinds, or “chews” food with small stones or grit before passing it back to the other stomach. 

Animals with this digestive system are able to eat a wide variety of food, from seeds and fruits, to small insects and meats from larger animals.

You can compare the avian digestive system with the other 3 by reading this PDF on the topic. 

Note: Learn how to feed your flock appropriately by reading our comprehensive guide on What to Feed (…and Not to Feed) Your Chickens.

How does a chicken’s digestive system work? Chicken digestive system functions

A chicken’s alimentary canal features a long, tubed conduit that stretches from beak to vent and oversees the ingestion and breakdown of food, the absorption of nutrients, and the elimination of waste.

In short, food will follow the trajectory described below:

Food enters the chicken’s beak and is promptly pushed into the esophagus.

The esophagus connects the mouth with the crop (a small sac that will hold food for up to 12 hours), and then drive it to the proventriculus.

The proventriculus will produce juices or enzymes to break food down into nutrients, and then move it into the gizzard.

Food will finally be “chewed” in the gizzard, and driven to the small intestine where the breakdown will continue and the absorption of nutrients will take place.

Leftovers then go to the cloaca, where they mix with waste coming from the urinary system to subsequently be expelled.

To find out more about the chicken digestive system parts and functions, check out Poultry Hub’s explanation of the digestive system of a chicken. If you prefer a visual tutorial, simply watch Nutrena’s 1 minute video on the topic.

Function of the gizzard in chickens

A chicken gizzard is flat, round, and somewhat lopsided in shape. It has a thick, strong muscular wall and keeps a stock of gastroliths or grit – both necessary to grind and pulverize food.

This organ, in other words, is your chickens’ version of teeth.

According to the World’s Poultry Science Journal, the gizzard’s fundamental functions are:

  • To aid with digestion by crushing foodstuff into smaller pieces,
  • Carry out a chemical breakdown of nutrients,
  • Control feed flow,
  • And to react to changes in the bird’s diet.

Note: If your chickens are struggling with their diet, it may not be a problem with their gizzard, you may be feeding them the wrong foods. Didn't think chocolate was bad? Think again - find out answers to your questions, here. 

The full length of the chicken digestive system

Research on the Gross and Histological Studies of Digestive Tract of Broilers during Postnatal Growth and Development shared average measurements for different organs. At day 28 the length of a chicken’s esophagus is 13.75 cm long; the proventriculus is 3.7 cm long, the gizzard 5.32 cm, the small intestine 188.63 cm, and the large intestine 26.95 cm.

To get an idea about the chicken digestive system capacity, take a look at Adelaide University’s study on the Variation in the Digestive System Capacity of the Broiler Chicken.


Encapsulating the Chickens’ Munching Mechanism

Chickens certainly have an interesting digestive system. Their tract ingests, stores, breaks down, chews, absorbs, and ejects… all in that bizarre order. 

The gizzard is a crucial organ that makes this exceptional machine work, by crushing and grinding the feed-stuff.

We hope this article helped answer your questions! Let us know about your thoughts and opinions in the comments section below, and please remember to share!

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