Backyard Poultry

Beyond the Feeder: How Do Chickens Digest Food?

Flock Management : Flock Health

Flock Management : Layer Nutrition

Flock Management : Egg Production

Patrick Biggs, Ph.D.

Nutritionist, Companion Animal Technical Solutions

Do Chickens Need Grit? Learn How Happy, Healthy Chickens Digest Food


When the dinner bell rings for a backyard flock, the hens come running. There’s nothing like a premium layer feed with the Purina® Oyster Strong® System to help your hens lay strong and stay strong. But what happens after your chickens are finished pecking away at the feeder?
 
Think of a complete chicken feed as a casserole — it’s a mixture of ingredients where each part adds up to a tasty, perfectly balanced dish. Each ingredient is digested by the hen and many of those ingredients work together for bird health and egg production.
 
It’s why all Purina® premium layer feeds are infused with the Oyster Strong® System to ensure your laying hens achieve a balanced supply of calcium through a blend of oyster shell, vitamin D and manganese. These three ingredients work together to help your chickens produce strong-shelled, delicious eggs each day.
 
Few of us consider the digestive events after we bring a bag of chicken feed home; we just know our ladies like us to keep the feeder full! Have you thought about what happens between when a hen eats at the feeder and when she lays an egg 24 – 26 hours later?

Ready to find out how your chickens digest food? Follow the journey beyond the feeder: 
 

Do chickens have teeth?

While chickens need to eat to stay healthy just as people do, a bird’s digestive anatomy is very different than yours.
 
Chickens don’t have teeth and they’re prey animals, so they can’t waste much time chewing. Instead, they swallow food quickly and store it away in their crop, a pouch-like organ meant solely for storage. It’s the first pit stop for her layer feed.
 
Within the crop, very little digestion occurs. Feed will combine with water and some good bacteria to soften food particles before moving through the system. Layer feed in the crop will be released to the rest of the digestive tract throughout the day. 
 

Do chickens need grit to digest their food?

Many new chicken parents wonder if their chickens need grit – a finely ground hard substance that helps your chicken’s body grind up feed. It’s a great question, and the answer depends on what you’re feeding your backyard flock. Purina® complete layer feeds include the necessary nutrients ground up small enough, so your chickens don’t need additional grit.
 
But if you’re not feeding a Purina® complete layer feed, you may need to provide your chickens with grit. And here’s why: after the crop, the next stop in the feed journey is the proventriculus that is equivalent to the human stomach. This is where digestion really begins in the bird. Stomach acid combines with pepsin, a digestive enzyme, to start the breakdown of feed into smaller pieces.
 
For your chickens, feed doesn’t spend much time in the proventriculus. Instead, it quickly moves to the gizzard where the real fun begins. The gizzard is the engine of the digestive system – it’s a muscle meant for grinding food particles.
 
Since chickens lack teeth, they need a different method of mechanically digesting food. Historically, this is where grit would play a big role.
 

What nutrients do chickens need?

Nutrients in the complete layer feed are absorbed through your hen’s small intestine and passed into the bloodstream. These absorbed nutrients are used for building feathers, bones, eggs and more. Many of these essential nutrients must be provided through the diet, like calcium, amino acids, manganese, and vitamins A, D and E.
 
For example, methionine is an essential amino acid only available through the diet. Like all amino acids, methionine comes from protein sources and is needed at the cellular level to build specific proteins used for feathering, growth, reproduction and egg production.
 
This is also where calcium and other minerals are absorbed into the blood stream to be stored for bone strength and shell production. 
 

How are eggs formed?

In addition to absorbing nutrients to stay healthy, hens also channel feed nutrients directly into their eggs.
 
The yolk is formed first. The yolk color comes from fat-soluble pigments, called xanthophylls, which are found in a hen's diet. Hens may direct marigold extract from the feed to create vibrant orange yolks and omega-3 fatty acids to produce more nutritious eggs.
 
Next, the shell is formed around the contents of the egg in the shell gland. This is where shell color is created. Most shells start white and then color is added. Breeds like Orpingtons, Rhode Island Reds, Marans, Ameraucanas or Easter Eggers will apply pigments to transform white eggs to brown, blue or even green.
 
No matter the shell color, calcium is essential at this stage. Calcium travels to the shell gland via the bloodstream. Hens channel calcium first into their eggs and then into their bones. Hens that lack proper calcium levels typically produce soft or brittle eggshells. Sometimes an improper calcium balance can cause hens to pull calcium from their bones to produce eggshells, weakening their overall skeletal structure.
 
The Purina® Oyster Strong® System utilizes larger particles of oyster shell to provide a slow and steady release of calcium during the night when your hens are forming eggshells. Think of vitamin D as the taxi that moves the calcium into your hen’s bloodstream where it’s needed, while manganese helps strengthen and create the structure of the egg. The Oyster Strong® System brings all three nutrients together to help your hens make strong, healthy eggshells.
 
 
 
Choose a layer feed with Oyster Strong® to help your hens lay strong and stay strong. Which layer feed + Oyster Strong® System is right for your flock?
Ready to level up with Oyster Strong®? Sign up for our Feed Greatness® Challenge.