Egg Industry Terms

Air Cell

The empty space between the white and shell at the large end of the egg. The size of this tiny pocket of air is an indication of freshness. You can see the air cell in the flattened end of a peeled, hard—cooked egg.


Also known as egg white, albumen accounts for most of an egg’s liquid weight, about 67 percent. It contains more than half the total protein and riboflavin. Egg white tends to thin out as an egg ages. That is why fresh eggs sit up tall and firm in the pan while older ones tend to spread out.


Chicken, male or female.


Processors who convert shell eggs into egg products.


Male or female bird used to produce fertile eggs to be hatched for egg production flocks.


The step in grading that lets the egg grader look inside the egg without breaking it to judge its quality. Today most eggs pass on rollers over high-intensity lights which make the interior of the egg visible.


Newly hatched chicken.


Egg shell and yolk color may vary, but color has nothing to do with egg quality, nutritive value, cooking characteristics or shell thickness. The shell color comes from pigments in the outer layer of the shell and may range in various breeds from white to deep brown. The breed of hen determines the color of the shell. The yolk color depends on the diet of the hen.

Contract Production

A production system whereby a farmer (producer) provides the housing, labor and utilities to produce eggs in exchange for a set payment per dozen eggs produced. The company (contractor) provides the chickens, feed, and general flock supervision and assumes all market risk.

Egg Complex

A production system where the laying hens live in multiple houses that are interconnected to the processing facility where the eggs are washed, graded, sized and placed in cartons automatically.

Egg Processing

The washing, candling, grading, sizing and packaging of eggs.

Egg Products

Processed and convenience forms of eggs, which are no longer in their shell (liquid), for commercial, foodservice and home use. These may be whole eggs, or the whites and yolks which have been separated. In this form, they may be sold, further processed, frozen or dried.

Feed Conversion

The number of pounds of feed consumed to produce one dozen eggs.

Fertile Eggs

Eggs which can be incubated and developed into chicks. Fertile eggs are not more nutritious than non fertile eggs and do not keep as well as non fertile eggs.


A house or group of chickens of the same age.


Grades are called AA, A and B. There is no difference in nutritive value between the different grades. There is very little difference in quality between Grades AA and A. Although Grade B eggs are just as wholesome to eat, they rate lower in appearance. Almost no Grade B’s find their way to the retail supermarket.


Classification standard for eggs determined by interior and exterior quality and designated by letters AA, A and B, and set by the United States Department of Agriculture.


A building equipped with machines in which fertile eggs are kept for the 21 days required to hatch chicks.


A mature female chicken.

Lay Cycle

The period of time from the start of egg production in a flock of chickens until the flock is molted or sold. A typical Cal-Maine Foods flock would have a first cycle lasting from 20 weeks of age until 65 weeks, then a six week molt period, and a second cycle lasting from 71 weeks until 105 weeks. Under certain conditions there may be a second molt period and a third lay cycle, but this is not the normal Cal—Maine management practice.


Mature female chicken capable of producing shell eggs.


A natural process occurring when a hen that has been producing eggs rests her body by ceasing egg production for a period of time, after which she will resume egg production.

Molting Program

A six-week period that deliberately causes a flock to begin a molt. This is done by controlling the diet until certain weight goals are reached. This process “recycles” the reproductive system of the hen.


A young female chicken, usually referring to one less than 18 weeks of age.

Rate of Lay

(Also called Hen Day Egg Production)

A percentage which reflects the number of eggs produced by a flock that day (or period of time) divided by the number of birds in the flock.

Salvage Fowl

Hens removed from commercial egg production at the end of their productive laying cycle and sold to fowl processing plants.


The egg’s outer covering, accounting for about 12 percent of its total weight. The shell is largely composed of calcium carbonate (about 94 percent).

Shell Eggs

Chicken eggs produced to be sold to the consumer.


Size is determined by the following USDA minimum egg weights expressed in ounces per dozen eggs:

Size Ounces per Dozen
Jumbo 30
Extra Large 27
Large 24
Medium 21
Small 18
Peewee 15

Several factors influence the size of an egg. The major factor is the age of the hen. As the hen ages, her eggs increase in size. The breed of hen from which the egg comes is a second factor.

UEP Certified

Guidelines developed by the United Egg Producers scientific committee. These guidelines require that laying hens are managed properly, including required space allowances, air quality, feed space, water availability, proper lighting, proper handling, and regular inspection. Documentation and compliance are verified by a USDA (United States Department of Agriculture) audit.
United Egg Producers Certified

Umer-Barry Price Quote

An egg price quotation published each business day by Urner—Barry Publications, Inc. and utilized by egg producers, processors, distributors and purchasers as a basis for negotiating egg prices for sales and purchases at various levels in the chain of egg production, processing and sale.


The yolk or yellow portion makes up about 33 percent of the liquid weight of the egg. It contains all of the fat in the egg and a little less than half of the protein. The yolk of a large egg contains about 59 calories.