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Chicken and Eggs

Gallus domesticus

Importance to Oregon

While Oregon may not be the number one chicken and egg producer in the nation, both still play a large role in Oregon’s state economy. According to the 2012 Census of Agriculture, there are roughly 6,352 chicken producers, with 91% of those producers involved in table egg production. In 2015, eggs were ranked as the number 12 commodity, valued over $116 million! As for chickens, the largest proportion of chickens found are layers and pullets, with 2.8 million birds accounted for, and valued at $8.14 million.

History of Chickens and Eggs

Which came first: the chicken or the egg? While this age old question may not ever be answered, the history of chickens is pretty well documented. The ancestors to the chickens we know today are traced back to ancient Egypt some 3,200 years ago. The birds were originally domesticated for sport; the male chickens, would be forced to fight each other. However, it was soon realized that the meat and eggs were good sources of food, and chickens became livestock. As people moved throughout the world, chickens moved with them, cementing their place as valuable in the human diet. It is believed that chickens came to the New World with Christopher Columbus on his second voyage.

Chickens are a dual purpose animal, meaning they give two commodities: meat and eggs. What is neat about egg production is hens do not need a rooster to be able to lay eggs that are destined for human consumption. Since chickens were first domesticated, most people raised their own chickens in their backyards, and were able to sustain themselves with the eggs produced by their flock and the occasional chicken was used for meat.

The egg industry began with farmers selling their eggs at the local farmers market. As more people moved to the cities and fewer had their own flocks, it became profitable for farmers to have large numbers of hens and sell the eggs. By the 1930’s, laying hens were moved into large houses to keep them safer from predators, and to keep diseases and parasites away from the hens. Over the next few decades, more and more research was done to ensure that the hens were healthy, and the eggs that were being produced were as safe as possible. The layers were also specially bred to give more eggs during the year. Today a hen can lay between 250-300 eggs per year. This is thanks to research done at Oregon State University and Dr. Dryden.

Around the same time the egg industry was taking off, so was the chicken meat industry. The development of the broiler was the main beginnings of this commercial industry; the broiler was bred to give more meat, particularly in the breast muscles. The fifty years between the 1920’s and 1970’s saw a large expansion in the chicken meat industry. The rapid expansion can be credited to vertical integration. In the early days, one person owned the hatchery, another person owned the farms, still another owned the feed mills, and a fourth owned the processing plant. This caused a lot of inefficiency in the beginning. However, with vertical integration, the process from hatching to processing became controlled by a single owner, making it much more efficient and profitable to raise broilers. Today’s broilers are much meatier than those from 20 years ago, thanks to research done in genetics and nutrition.

Chicken Breeds

There are hundreds of different chicken breeds. Some breeds are good for egg production, some are good for meat production, but most are used for exhibition shows. Below are three breeds that are commonly found in their large scale egg production or meat production farms.

White Leghorn

The white leghorn is the industry standard for egg production. The hens have white feathers, typically weigh less than four pounds, and begin laying eggs around 20 weeks of age. These birds are able to lay between 260-285 eggs, and are the most efficient breed in terms of feed conversion to egg production ratio. They lay a white shell egg. Hens are kept in production anywhere between 1 and 3 years. If the eggs in your fridge are white, more than likely they came from a leghorn!

Rhode Island Red

Rhode Island reds are a popular breed for the egg industry and backyard enthusiasts. Their feathers are red, and also begin laying eggs around 20 weeks of eggs. They are not as efficient in feed conversation as the white leghorn, but they can still lay around 240 eggs per year. Their egg shells are brown in color.


The broiler is the main chicken used for meat production. They are very efficient in feed conversion: it only takes 1.5 pounds of food to gain 1 pound of muscle. It typically takes 6 to 7 weeks to reach a market weight of 6 pounds. These birds have white feathers. They have been bred to have larger breast muscles, which is the most desirable cut of meat for US consumers. In 2015, over 40 billion pounds of chicken was processed.

Chicken Life Cycle

Laying Hens

Laying hens begin as fertilized eggs. Fertilized eggs are sent to a hatching facility, where the eggs are incubated for 21 days until the eggs hatch. Once hatched, the two day old pullets are vaccinated and moved to a grow out facility; they stay there for roughly 19 weeks, where they grow and mature to egg producing age. The pullets are transferred to the laying facility right before they are ready to begin laying eggs. A hen can lay an egg every 24 to 26 hours, and will lay on average 300 eggs in her production life cycle. After a year of laying eggs, the hens are now spent, and are sent to a processing plant.


The broiler life begins the same as a laying hen. Fertilized eggs arrive at the hatching facility, are incubated for 21 days, the day old chicks are given vaccinations, and then are sent to the grow out facility. At the grow out facilities, the chickens have access to fresh water and feed almost 24 hours a day. The lighting in the building is carefully monitored and controlled; the longer the light is on, the more the chickens will eat. This is done so the chickens can reach market weight as soon as possible. Thanks to better breeding stock and work in genetics, a broiler chicken will reach a market weight of 5 pounds in 6 to 7 weeks. Once the birds reach the desired weight, they are taken to the processing plant for harvest.


Chicken and eggs are both great sources of protein and essential nutrients for relatively few calories per serving. Eggs have 13 essential vitamins and minerals, have all nine essential amino acids, and is a great source of protein, vitamin D, vitamin B12, phosphorus and riboflavin. Eggs are very cheap, making them the most affordable source of protein. It is important to know that the color of the egg shell or how the hens are raised does not affect the nutritional content of the eggs. Chicken meat, especially the breast, is another cheap source of protein. Below are the food labels for eggs and chicken breast.   

Egg Nutrition Facts

Boneless, Skinless Chicken Breast Nutrition Facts

Egg Production and Nutrition Video

Check out this cool video produced by Oregon Agriculture in the Classroom. This brief (12 minutes) video explores how eggs get from the hen to the grocery store and all of the nutritional benefits eggs give us.

Oregon AITC also created this worksheet and answer key to accompany the video.
Egg Production and Nutrition Video Questions Worksheet
Egg Production and Nutrition Video Questions Worksheet – KEY

Conventional Cage vs. Cage Free vs. Free Range

There are three different types of ways commercial laying hens are raised. Each has their own advantages and disadvantages, but no one system is superior to the others. Currently, the USDA does not have definitive scientific data stating a nutritional difference in egg nutrition, due to hen housing. Below are the definitions of the different ways laying hens are raised.

Conventional Cage

Hens are kept in cages, normally 6 to 7 hens per cage. They have access to fresh water all day and food. The hens lay their eggs in the cage, and the eggs roll down to a conveyor belt. The hens do not have access to the outside, but the barns are well ventilated, heated in the winter and cooled in the summer.

Cage Free

Hens are kept in a large barn, similar to how broilers are raised. Some systems have nest boxes for the hens to lay their eggs, to make collection easier. There is access to fresh food and water at all times. Like the conventional cage system, the hens do not have access to the outside.

Free Range

Free range is the same as cage free, with one important distinction: free range hens have access to the outside. In addition to the feed available in the barn, the hens may also eat grass and insects, depending on the type of ground outside the barn (grass pasture, gravel, dirt, etc.).


There are millions of great recipes where chicken and eggs are the stars. These versatile foods are great on their own and combined with other yummy flavors to make egg-ceptional dishes.


Spinach and Bacon Quiche, by Paula Dean


  • 6 large eggs, beaten
  • 1 1/2 cups heavy cream
  • salt and pepper
  • 2 cups chopped fresh baby spinach, packaged
  • 1 pound bacon, cooked and crumbled
  • 1 1/2 cups shredded Swiss cheese
  • 1 (9-inch) refrigerated pie crust, fitted to a 9-inch glass pie plate


  1. Preheat over to 375 degrees F
  2. Combine the eggs, cream, salt and pepper in a food processor or blender
  3. Layer the spinach, bacon, and cheese in the bottom of the pie crust
  4. Poor egg mixture on top of spinach, bacon and cheese
  5. Bake for 35 to 45 minutes, until the egg mixture is set
  6. Slice and enjoy!

Find the original recipe here


Chicken Piccata for Two, by Alicia Ross


  • 1/4 cup all-purpose flour
  • 1/2 teaspoon salt
  • 1/4 teaspoon ground black pepper
  • 1/2 teaspoon garlic powder
  • 2 skinless, boneless chicken breast pieces, thinly cut (about 1/4 pound each)
  • 1 tablespoon vegetable oil
  • 1 tablespoon unsalted butter
  • Juice from 1/2 medium lemon
  • 1 teaspoon honey
  • Lemon slices for garnish


In a shallow dish, combine the flour, salt, pepper and garlic powder; dredge the chicken pieces through the mixture, coating each side well. Discard extra flour mixture. Set chicken aside.

Heat oil in a regular skillet over medium-high and swirl to coat bottom well. Place each piece of chicken in the hot oil and cook about 2 minutes on each side, turning as needed. If skillet is not large enough for both pieces to fit without crowding, cook one and then the other. When the chicken is light brown on both sides, remove it to a serving platter.

Remove the skillet from the heat and carefully wipe the remaining oil from the skillet with paper towels. Add the butter to the skillet and swirl to melt. Stir in the lemon juice and honey. Immediately drizzle the lemon mixture over the breasts. Garnish with the reserved lemon slices and serve at once.

Find the original recipe here

Vocabulary Terms

a chicken raised for meat

the process of how eggs are graded using a light

chicken meat that has been cut up and made into a different food product, like nuggest or boneless wings

female chickens that is over one year old

female chickens raised to lay eggs for human consumption

a female chicken that is less than one year old

AITC Resources


Chicken - Life Cycles

Hatching Science

Egg Science: Dissolution and Osmosis