Many county fairs have competitive classes for Shell Eggs. Competing in the Egg classes complete a project member’s competition in the poultry project and learning about eggs helps to understand the live bird project. Classes that are offered include: large white, large brown and large colored (blue or green) as well as bantam sized eggs. Some fairs also have classes for duck eggs! There are even classes for egg displays which highlight artistic and creative abilities!

Composition of an Egg

The hen’s egg is a complete unit designed to provide all of the nutrition necessary for the development of an embryo into a chick!

Humans discovered the nutritional value of eggs many thousands of years ago. Archeological records show that nomadic people of Africa searched the dessert for infertile ostrich eggs that had dehydrated in the sun, as a light-weight source of food for their journeys.

Today, eggs are a valuable part of a nutritious diet. Besides carbohydrates, fats, vitamins and minerals, eggs provide the essential amino acids–the building blocks of protein.

Eggs are essential in baking and cooking recipes, providing structural components and flavor.

How an Egg is Formed

The egg is formed in the reproductive tract of the hen. All components necessary for the embryological development of the chick must be included inside the shell. Once the egg is laid, incubation or “pregnancy” takes place entirely outside the female’s body. The proper temperature, humidity, air and occasional rotation of the egg is all that is necessary for the egg to develop!

The female reproductive system has two functions: Reproduction (egg laying) and sex hormone secretion.

The reproductive system is made up of two distinct sections, the ovary and the oviduct. Unlike mammals, birds have one complete reproductive tract (left) and a rudimentary (right) tract.

The ovary, about the size of an almond, produces hormones that cause puberty (sexual maturity) and female characteristics such as plumage colors and feminine body type. Ovarian hormones also control the cyclical production of eggs.

The ovary consists of large mass of tissue that contains immature and yolks in varying stages of development. The number of eggs to be laid is determined by the number of follicles. The follicle contains an ovum (the gamete cell and undeveloped yolk) surrounded by a vascular membrane.

When a pullet has reached maturity, the yolks grow by adding nutrients (dudoplasm). Typically, one yolk reaches its maximum size each day. The follicular membrane thins and ruptures, allowing the yolk and the gamete cell to drop into the oviduct.

The chicken’s oviduct is about 30 inches long. It contains the infundibulum, magnum, isthmus, uterus, and vagina.

The yolk is drawn into the oviduct by the infundibulum (funnel). The yolk begins to spiral in the magnum. The egg white (albumen) is secreted and spun onto the yolk. This spinning action produces the chalazas, tightly wound strands of egg white that assist in holding the yolk in the center of the egg.

If fertilization is to occur, sperm that are stored (up to three weeks after mating) in folds of the magnum (called “sperm nests”) mobilize toward the germ cell on the yolk as it passes by. If the female germ cell and the sperm cell merge, cellular division will occur at a rapid rate over the next 24 hours in the hen. The germinal disc stops developing after the egg is laid (as the temperature drops) until incubation begins again later.

The thin and thick egg white (albumen) will be added in 1-2 hours. The yolk surrounded by egg white enters into the Isthmus where the shell membrane is added over the next 2 hours.

The egg now enters the uterus (shell gland) where the calcium shell is added over the next 20-22 hours. If the egg is brown, the pigment melanin is added about a half hour before the egg is laid.

The egg passes through the vagina and is expelled by the cloaca through the vent to the outside. It is interesting to note that the egg flips in the cloaca, so that the blunt end of the egg is deposited first. As the egg cools down to room temperature, the contents of the egg condense, allowing the shell membrane to pull away from the shell on the blunt end of the egg, creating the air cell.

Abnormalities That May Occur During Egg Production

Sometimes a small blood vessel in the follicular membrane hemorrhages as the yolk is ovulated. This drop of blood will be incorporated into the contents of the egg. This abnormality is called a “blood spot.” If a small piece of membrane breaks free at the time the yolk is ovulated, the egg is formed with a “meat spot” inside. If a piece of membrane drops into the oviduct, separate from the egg, a very tiny egg will be formed.

In the event that two or more yolks are ovulated at the same time, a “double yolk” egg will be formed. If these eggs are fertile and are incubated, two chicks will develop but are typically unable to hatch because the chick cannot engineer hatching with “twins” in the shell.

As hens mature, shell deformities such as calcium deposits and thin spots will be produced. If an egg is cracked while in the uterus, the hen will “patch” the egg with additional calcium.

Pure Ameraucana or Auracana chicken eggs are blue through the entire shell, inside and out. Olive green eggs are crossbreds of blue and brown. The pigment is added just to the outside of the shell.

Size of Eggs

The U.S.D.A. has established standard sizes of egg. Baking recipes are precise and require a specific amount of ingredients. Therefore, the standard large egg is 24 ounces per dozen or 2 ounces per egg. Pullets start production by laying Small and Pee Wee eggs, while older hens will lay Extra Large and Jumbos.

Quality Grades of Eggs

Eggs are evaluated for their interior and exterior quality. The U.S.D.A. interior quality grades of eggs are Grade AA, A, B and loss or no grade. The exterior quality grades of eggs are Grade A, B and loss or no grade.

Interior grades of eggs are for the most part an evaluation of the freshness of the egg or factors that would make the egg inedible. An egg is the highest grade when it is first laid. From that point on, it can only go down in quality grade. In other words, the hen produces a quality egg; it is our job to keep it that way!

The interior quality of an egg is determined by candling, the process of shining a light through the egg. The size of the air cell is one of the factors that determine egg quality. As an egg ages, water evaporates through the shell pores. The older an egg is the more time for water to leave the egg and make the air cell larger. The warmer the egg is kept, the faster evaporation occurs and the faster the thick egg white degrades to watery thin egg white. The amount of thin egg white is observed by how pronounced the yolk is seen by candling.

Fresh eggs have strong rounded yolks. But as an egg ages, the vitelline (yolk) membrane breaks down and the yolk becomes flattened and “out of round.” These yolks are elongated and “fill the shell” when candled. These eggs will grade U.S.D.A. B.

Blood spots or meat spots are observed as dark red or brown spots while candling. These eggs are objectionable to consumers and are automatically graded “Loss.”

Poultry producers keep eggs cool and in a humidity controlled environment to prevent loss of quality.

Unless eggs are graded by candling, they should be marketed as “Nest Run” or “Farm Fresh” alerting the consumer of variations in quality.

County fair egg displays

County fair egg displays are evaluated on exterior quality, though some shows will candle them or break out a sample of each dozen. U.S.D.A. exterior quality grades are AA/A, B or NG (Non-Gradable).

Factors that determine exterior quality are: Soundness, Cleanness, Shape, Texture, Thickness and Color Uniformity. Placings are cumulative of the factors, but can never grade higher than the lowest factor.

Soundness A dozen eggs that have no broken eggs will score AA/A Quality. Any broken egg in a dozen will score NG. Broken eggs include checks (hairline crack, membrane intact), Dented Check (cracked and indented, membrane intact), Leaker (cracked, membrane broken, leaking). Consumers check eggs in the store for soundness. If a cracked egg is found they will reject the dozen of eggs.

As important to the consumer as soundness is Cleanness. Not only will a customer refuse to buy a dozen eggs that has a dirty egg in it, but will probably be hesitant to buy eggs ever again! Factors of cleanness include 1) Clean 2) Stained or 3) Adhering Dirt.

A display of eggs that is perfectly clean is AA/A quality. If a carton of eggs has an egg that has a slight stain, amounting to a localized stain of less than 1/32 of the shell or 1/16 of the shell with scattered stain it is a B quality egg. Any carton of eggs that has an egg with more than a slight stain is NG quality. If an egg has Adhering Dirt or Foreign Material it is NG quality. A dirty egg has blood, yolk, albumen, or fecal matter sticking to the surface of the shell.

Shape is typically less pronounced that other factors since abnormal shaped eggs are easily discarded. Eggs that have the correct “egg shape” are graded AA/A. If they are decidedly misshapen (irregular or unusual in shape) they will grade B quality. It is important to note that egg shell shape abnormalities associated with ridges, calcium deposits, or rough surfaces and bulges caused by body checks, thin spots, or cracked shells should not be designated as “decidedly misshapen.” These eggs are evaluated in their respective category rather than shape.

The shell of an egg may be 1) sound and strong in Texture or 2) faulty in soundness/strength, possessing rough areas of calcium deposits, body checks, or pronounced ridges. Displays of eggs that contain no defects in texture are AA/A quality. An egg that is weaker in soundness/strength than normal are B quality.

IMPORTANT: an egg designated as decidedly misshapen, calcium deposits, body check, pronounced ridges, pronounced thin spots, check, dented check or leaker IS ALSO to be designated as faulty soundness/strength.

A few scattered calcium deposits decrease the appearance of an egg but are not considered a Texture concern. If the calcium deposits are so large that, when broken off the egg and it effects the soundness of the egg, the egg should be graded B for quality. “Body Checks” occur when the egg is cracked inside the hen but is repaired before being laid. Body checks are graded B quality because it detracts from the overall appearance of the egg. However, it should not be double down-graded for any other factor such as thin spot or misshapen. Pronounced ridges decrease shell soundness/strength and detract from the appearance of the egg. Pronounced ridges are a B quality factor.

Thickness of the shell may be 1) uniform or 2) may contain pronounced thin spots that contribute to the breakage of the egg. If eggs in a display have no defects they will receive an AA/A quality grade. But if an egg has definite thin spots, it will be graded B quality.

The general appearance of a dozen eggs is not a grade factor but Color Uniformity is essential for show winning eggs. Particularly important in brown or colored (blue) eggs, however white eggs may also exhibit variations from cream to bleached white colors. Dark brown Welsummer or Marans eggs are pleasant to the eye, but uniformity over-rides the color variant. Eggs collected from the same hen will typically demonstrate the most color uniformity.

Showing eggs at the county fair is fun and challenging! It takes diligence to select the most uniform and defect- free dozen of eggs for your display. You may sort through all of the fresh eggs that you have available in order to get the best display. Your efforts will be rewarded with the pride that you have in your birds. You may also use your prizes as “bragging rights” when marketing your eggs to others!

Note: Because eggs may contain the Salmonella Pullorum Typhoid bacteria and are a primary means of transferring the disease, your egg display should include NPIP or other Flock Testing certification when entered at the fair.

Creative Egg Displays

For thousands of years, people have been decorating eggs. People are fascinated with the “miracle of life” contained within the egg. The delicate structure of the egg makes it a challenging media to be creative with. Basic colored Easter Eggs or delicately decorated Pysanky Eggs demonstrate creativity and beauty.

Creative egg displays are as unique and creative as the individuals who produce them. Some competitions have very specific requirements for the number of eggs or the theme for the display.

The criterion for judging the eggs will be determined by the show officials. However 1) Creativity 2) Neatness and 3) Development of the theme are major factors in any art display.

Some county fairs admit creative egg projects from non-poultry project members. These exhibitors will learn from the poultry project members and may ultimately become poultry enthusiasts.

Egg displays are sometimes housed in the foods or arts buildings at the fair. It is wonderful to have “cross- campus” mixing of projects. But appropriate displays in the poultry barn will focus on the bird and the achievements of the poultry project member!

The main emphasis on a project like this should be FUN! By completing a creative egg display, you will achieve self-satisfaction and have a rewarding experience that will compliment your poultry project.

Egg Displays – 2015 Wisconsin Junior Poultry Association Show