PACKAGING

The most familiar egg package is the pulp or foam carton holding 12 eggs. There are sizes other than dozens available in some regions such as 2 1/2 or 3 dozen small eggs per package or packs of 6, 8 or 18. The sponginess of the carton insulates the eggs from jolts. New package designs are constantly being tested to provide the best protection for the eggs.

Whether foam or pulp, the carton prevents loss of moisture and carbon dioxide and also keeps the eggs from picking up undesirable odors and flavors. Even though your refrigerator may have an egg shelf in the door, it is better to store eggs in the carton on an inside shelf for freshness' sake.

Eggs are placed in their cartons large end up to keep the air cell in place and the yolk centered.

The carton shows brand, grade, egg size and nutrient content.

PET FOOD

Eggs are nutritious for many pets as well as humans and are often an important part of prepared pet food formulas.

POACHED EGG

~see Cooking Methods, poached

PRESERVATION

Refrigeration, drying or freezing are the best ways to preserve egg quality. Fresh eggs are so readily available that long storage periods are rarely necessary. However, centuries before modern methods of egg production, transportation and refrigeration became known, man did his ingenious best to preserve the egg intact.

The ancient Chinese stored eggs up to several years by immersion in a variety of such imaginative mixtures as salt and wet clay; cooked rice, salt and lime; or salt and wood ashes mixed with a tea infusion. Although the Chinese ate them with no ill effects of which we are aware, the eggs thus treated bore little similarity to fresh eggs, some exhibiting greenish-gray yolks and albumen resembling brown jelly.

Immersion in different liquids too numerous to mention was explored, lime water being a favorite in the 18th century. During the early 20th century, water glass was used with considerable success. Water glass, a bacteria-resistant solution of sodium silicate, discouraged the entrance of spoilage organisms and evaporation of water from eggs. It did not penetrate the egg shell, imparted no odor or taste to the eggs and was considered to have somewhat antiseptic properties. However, it did a rather poor job at relatively high storage temperatures. Eggs preserved in a water glass solution and stored in a cool place keep 8 to 9 months.

Dry packing in various substances ranging from bran to wood ashes was used occasionally, but costs of transporting the excess weight of the packing material far exceeded the dubious advantages.

In an attempt to seal the shell pores to prevent loss of moisture and carbon dioxide, a great variety of materials including cactus juice, soap and shellac were investigated with varying degrees of success. The only coating considered fairly efficient was oil which is still used today.

Thermostabilization, immersion of the egg for a short time in boiling water to coagulate a thin film of albumen immediately beneath the shell membrane, was rather extensively practice by housewives of the late 19th century. Mild heating destroyed spoilage organisms but did not cook the eggs. If kept in a cool place, thermostabilized eggs coated with oil keep several months although some mold growth may take place.

During the first half of the 20th century, storing eggs in refrigerated warehouses was a common practice. Preservation was later improved with the introduction of carbon dioxide into the  cold storage atmosphere. Today, very few, if any, cold storage eggs find their way to the retail market. ~see Cold Storage, Oiling

PRODUCTION

Prior to World War II, most egg production came from farm flocks of less than 400 hens. By the early 1960's, improved technology and the development of sophisticated mechanical equipment were responsible for a shift from small farm stocks to larger commercial operations. In the major egg producing states, flocks of 100,000 laying hens are not unusual and some flocks number more than 1 million. Each of the 235 million laying birds in the U.S. produces from 250 to 300 eggs a year.

Factors That Influence Egg Production

Genetic pattern of the breed of hen Maximum production of top-quality eggs starts with a closely controlled breeding program emphasizing favorable genetic factors. The Single Comb White Leghorn hen dominates today's egg industry. This breed reaches maturity early, utilizes its feed efficiently, has a relatively small body size, adapts well to different climates and produces a relatively large number of white-shelled eggs, the color preferred by most consumers. Because brown-shelled eggs are favored in the New England region, the Rode Island Red, New Hampshire and Plymouth Rock breeds predominate in that area of the country. ~see Color

Hen's age at egg-laying maturity  Although early starters lay more eggs, maturity too early results in many small eggs.

Resistance to disease  Selective breeding is reinforced by good sanitation and vaccination.

Light control  Of primary importance both during the growing and laying periods, controlled, low-intensity light can be used to delay sexual maturity until the bird's body is big enough to produce larger eggs. Today's laying hen doesn't need to depend upon the fickle sun to tell her when laying time has arrived. Intensity and duration of light can be adjusted to regulate production.

Quality of feed   Since more is known about the nutritional requirements of the chicken than of any other domestic animal, it is not surprising that rations are scientifically balance to assure layer health along with optimum quality eggs at least cost.

Temperature  Laying houses maintained between 57 and 79ºF. (14 and 26ºC.) are desirable.

Humidity  A relative humidity between 40 and 60% is best.

Replacing or molting the flock  Molting, or loss of feathers, is a natural occurrence common to all birds regardless of species. As the hen ages, egg quality declines and, at about 18 to 20 months of age, molting occurs and egg production ceases. While some flocks are sold for slaughter at this point, replacement is costly. A fairly common practice is to place the flock into a controlled molt. After a rest period of 4 to 8 weeks, the birds start producing again. Poultrymen have found that with two periods of controlled molting, on at 14 months of age and another at 22 months, egg quality is more consistent than with one molt at 18 or 20 months.

The laying house  In today's egg-laying facilities, temperature, humidity and light are all controlled and the air is kept circulated. The building is well insulated, windowless (to aid light control) and is force-ventilated. Birds are either given the run of the floor area or are housed in cages. Most new construction favors the cage system because of it sanitation and efficiency, but floor operations are also in use.

Feeding  Because care and feeding of hens, maintenance, sanitation and egg gathering all take time and money, there is a strong trend toward automation whenever possible.

Automatic feeders, activated by a time clock, move mash through troughs in the floor or past the cages. Birds at floor level drink from troughs. Those in cages may sip from such sophisticated accessories as self-cleaning drinking cups or nipple valves.

Most poultry rations are of the all-mash type. They are made of sorghum grains, corn, cottonseed meal or soybean oil meal depending upon the part of the country in which the ration is produced and which ingredient is most available. The feed is carefully balanced so that the hen gets just the right amounts of protein, fat, carbohydrates, vitamins and minerals. Today's hen eats a better balanced diet than many people!

The hen's ration may contain the same types of additives approved for human food. Antioxidants or mold inhibitors (also used in mayonnaise and bread) are added to maintain the quality of the feed. And, like people, chickens occasionally require an antibiotic.

An additive is not approved for use in poultry feed unless adequate research has been undertaken to determine its pharmacological properties and possible toxicity and to discover any potentially harmful effects on animals.

Hormones are not fed to poultry in the United States.

How much a hen eats depends upon the hen's size, the rate of egg production, temperature in the laying house and the energy level of the feed. In general, about 4 pounds of feed are required to produce a dozen eggs. A Leghorn chicken eats about 1/4 pound of feed per day. Brown-egg layers are slightly larger and require more food.

Egg quality is affected by the type of feed. Shell strength, for example, is determined by the presence and amounts of vitamin D, calcium and other minerals in the feed. Too little vitamin A can result in blood spots. Yolk color is influenced by pigments in the feed. Maximum egg size requires an adequate amount of protein and essential fatty acids.

Handling  The moment an egg is laid, physical and chemical changes begin to conspire against freshness. Warm temperatures encourage those changes, so newly laid eggs must be gathered frequently and refrigerated quickly.

Some eggs are still gathered by hand, but in most production facilities automated gathering belts do the job. Gathered eggs are moved into refrigerated holding rooms where temperatures are maintained between 40 and 45ºF. (5 and 7ºC.). Humidity is relatively high to minimize moisture loss but should not exceed 80%. Sometimes eggs are oiled as they are gathered. ~see Oiling

Processing and distribution  Some producers sell their eggs nest run (Ungraded) to processing firms which clean, grade, size and carton the eggs and ship them off to retail outlets. Other farms and ranches carry out the entire operation. ~see Egg Products, Egg Products Inspection Act, Grading, Nest Run

PULLET

A young hen, less than 1 year old.