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AGRICULTURE HANDBOOK NO. 75

U. S. DEPARTMENT OF AGRICULTURE - Agricultural Marketing Service

Washington, D. C. October 1955

For sale by the Supeiinfendent of Documents, U. S. Government Printing Office, Washington 25, D. C. - Price 35 cents
CONTENTS

Page

Introduction 1

Formation of the egg 1

Formation of the yolk 2

Formation of the white 2

Formation of the shell membranes 4

Formation of the shell 4

Structure and composition of the egg 4

Physical structure 4

Composition of the egg 6

Abnormalities 6

Grading 7

Advantages of grading 7

General application 7

General quality factors g

Exterior quality factors 8

Interior quality factors n

United States Standards, Grades, and Weight Classes for Shell Eggs 17

United States standards for quality of individual shell eggs 17

United States consumer grades and weight classes for shell eggs 17

United States procurement grades and weight classes for shell eggs 18

United States wholesale grades and weight classes for shell eggs 19

Grading eggs 20

Classification of interior quality 20

Classification of exterior quality 22

Weight classification 25

Candling and weighing facilities 25

Candling room 26

Candling bench 27

Candling light 27

Weighing equipment 27

Shell egg grading laboratory 28

Candling technique and grading-room practice 28

Classifying as to weight 28

Classifying by shell factors 29

Classifying by air cell 29

Classifying by white and yolk 30

Classifying by all factors 31

Federal-State grading programs 32

Regulations governing grading of shell eggs 33

Prerequisites to packaging eggs with grade identification labels 35

Costs of service ^~^

The USDA licensed grader ^^

General qualifications ^^

Specific qualifications ^"

Duties and responsibilities •^'

Services to the applicant ^^

Mechanics of grading yz

Legislation affecting grading and marketing of eggs ^^

Federal laws J^

State egg laws

Production and maintenance of egg quality

Breeding- - ^2

Hatching .^

Brooding and raising

Production of high quality eggs
Page

Production and maintenance of egg quality--Continued

Housing 42

Care of eggs on the farm 42

Cleaning eggs on the farm 43

Marketing 43

Station care 43

Distribution 44

Planning grading schools 45

Location and time 45

Equipment and facilities 45

Suggested programs 4^
EGG GRADING MANUAL

Prepared by W. E. Hauver, Jr., and John A. Hamann, marketing specialists

Poultry Division, Agricultural Marketing Service

INTRODUCTION

This manual was prepared as an aid in

teaching beginners as well as experienced

egg graders the correct interpretation and

application of the United States standards,

grades, and weight classes for shell eggs.

It is intended to serve as a guide in short

courses or grading schools and its use

should be supplemented with lectures, group

discussions, and demonstrations as the

needs of any particular group demand.

Although designedprimarily for those entering egg-grading work, this manual should

also prove useful to those teaching the

marketing of eggs in high schools and

colleges.

Descriptions of the various qualities of

individual eggs should assist the student

grader in understanding egg quality. But it

is imperative that the word pictures of the

different qualities be compared with eggs

before the candling light and that the

quality interpretations be checked by

experienced graders. The importance of

practice in candling cannot be stressed too

much. Although it is essential that the

student grader become thoroughly familiar

with the descriptions of the different

qualities, the final measure of a grader's

ability is the accuracy of his interpretation of quality before the candling light.

Occasional comparisons of broken-out appearance with candled appearance are also

very important in developing grading skill.

With continued practice the student grader's

ability to make accurate decisions will increase rapidly. Accurate quality interpretation at normal connmercial candling speed is

what is desired in an egg grader.

This manual not only provides instruction

iï^ ^gg grading, but also gives information

on the formation and structure of the egg,

on production practices that affect quality,

on Federal-State grading programs, and on

the duties and responsibilities of licensed

graders of the United States Department of

Agriculture.

It is essential that the licensed grader

know about eggs, egg quality, and grading

procedures. Such knowledge of the **what*'

and '"how" of the job, coupled with reasonably good judgment, practice, and guidance, should enable one to acquire the necessary skill to determine rapidly the proper

classification of shell eggs according to

official standards of quality.

To be a little better than average, the

grader should have background information

on the reasons why grading of eggs is

necessary. This includes information about

the formation, structure, and composition

of the egg, and the production and conservation of egg quality. Such information

has therefore, been included in this manual. Although some of this material is only

indirectly related to the actual grading

function, a knowledge of egg formation,

composition, and structure will help the

grader do a better job in handling eggs

and in maintaining their quality. Such information will help the grader, particularly

the grader-in-charge of an egg-candling

room, to have a better appreciation and

understanding of his job, and will aid

him in acquiring a reputation for conapetence and in gaining the respect of his

fellow workers.

FORMATION OF THE EGG

The egg, it should be remembered, is a

biological structure intended by Nature for

reproduction of the chicken. It protects and

provides a complete diet for the developing

chick embryo and serves as the principal

source of food for the first few days of the

baby chicken's life. The egg is one of the

most nutritious and versatile of human

foods. As chickens now produce eggs in

abundance, this source of food has become extremely important throughout the

world, nutritionally as well as economically.

The reproductive systena of the hen is

divided into two main parts: Ovary and

oviduct. Most female animals possess both

a right and a left functioning ovary but in

the hen, the right ovary and oviduct normally

remain dormant and the left ovary and

oviduct develop the egg.

The ovary--a cluster of developing yolks,

each separate from the others--is attached

to the middle part of the back about midway

between the neck and the tail (fig. 1). This

organ is fully formed, although very small,

when the chick is hatched. It contains approximately 3,600 to 4,000 minute ova

(future yolks) each within its own sac or

follicle.
FIGURE 1."Position of ovary in hen.

Formation of the Yolk

The three recognized stages of yolk

(ovum) formation (fig. ¿A) are:

First, which is concluded before hatching.

Second, which begins before hatching and

ends 8 to 10 days before sexual nnaturity.

Third, the accelerated stage, which occurs 8 to 10 days before ovulation. This

stage is initiated by the stimulating

hormone of the pituitary gland. The

hormones secreted by the ovary in

turn stimulate the oviduct to activity.

The rate of yolk secretion increases

rapidly from the 9th to 2d day before

ovulation (0.5 to 2.8 grams of yolk

per day) and decreases thereafter.

The yolk grows by the gradual addition

of yolk fluid. Fat soluble dye s--normally

xanthophyll--are transferred rapidly from

the digestive tract to the blood stream and

then to the yolk. Occasionally, what appears

to be concentric layers of alternate darkand light-colored yolk fluid may be observed. However, modern feeding and production practices have reduced the frequency of this occurrence.

The yolk within the ovary develops as

follows:

Starts as a single cell (female reproductive cell or germ) with the vitelline

membrane around it.

Grows slowly at first as food material is added.

Matures as the yolk fluid is added, the

germ stays at the surface of the yolk,

leaving a tubelike structure, the latebra,

extending to the center of the yolk (fig.

3).

Ovulation is the release of a mature

yolk (ovum) from the ovary. Each developing

yolk is enclosed in a yolk sac in which many

blood vessels are profusely distributed.

These blood vessels carry yolk-building

substances to the developing yolk. One

particular area of the yolk sac is free of

blood vessels (stigma or suture line) and

it is normally in this area that ovulation

or release of the mature yolk takes place.

However, the rupture of the yolk sac and

release of the yolk sometimes occur at

other than the stigma, with the result that

one or more blood vessels are ruptured

and blood spots occur on the yolk, or the

white becomes bloody.

Sometimes blood vessels break before

ovulation and blood is released within

the yolk sac. If this occurs several days

before ovulation the blood spot n:iay degenerate and change in color to reddish

brown, brown, tan, or white, and when the

egg is laid, what is commonly called a meat

spot is the result. Microscopic examinations show that meat spots are not sloughedoff pieces of tissue, but generally are

composed only of blood cells.

Ovulation occurs again about 30 minutes

after an egg is laid, during the laying

clutch of a good producing hen.

Formation of the White

The oviduct (fig. 2B) is a long, tubelike

organ lying along the backbone and attached

to it loosely between the ovary and the

tail. This organ, which is approximately

25 to 27 inches long, may be divided into

five areas which perform certain functions

in completing the formation of the egg. It

is in the oviduct that the white, shell

membranes, and shell are secreted.

The first part of the oviduct, usually 3

or 4 inches long, is the infundibulum

commonly called the funnel. It opens into

the body cavity. When ovulation occurs,

the funnel engulfs the yolk and starts it on

its way down the oviduct. Although the main

function of the funnel is to pick up the yolk,

it also serves as a reservoir for male

sperms which, if present, fertilize the germ

and set up embryonic growth. The yolk

moves through the infundibulum or funnel to

the magnum in about 15 minutes. Movement

is brought about by peristaltic action.

The magnum area is about 15 inches long

and the time required for the yolk to travel

through its length is about 3 hours. It is here

that the thick white, which comprises approximately 55 percent of the albumen and

practically all the protein in the albumen,

is secreted. The quality of the white is
A OVARY

^ Mature Yolk within

Yolk Sac or Follicle

^Immature Yolk

0 Empty Follicle

O Stigma or SutureLine

B OVIDUCT

OInfundibulum

O Magnum

O Isthmus

OUterus

^ Vagina

0Cloaca

O Vent

FIGURE 2."Enlarged drawings of A, ovary; B, oviduct.
largely dependent on the amount of ovomucin

secreted by this part of the oviduct.

The isthmus is a constricted area of the

oviduct about 4 inches long, through which

the developing egg passes in about 1-1/4

hours. Here sonne water and mineral salts

are added and the two shell membranes are

deposited.

The uterus, a heavy-walled part of the

oviduct and approximately 4 inche s in length,

supplies the final complement of white and

minerals (which pass through the shell

membranes by osmotic pressure) and then

the shell, shell pigment, and cuticle are

added. The developing egg spends about 21

hours in this area.

Moving finally into the vaginada Z-inch

area, the fully fornned egg enters the

cloaca and the vent, and is laid. The entire

time from ovulation to laying is usually

slightly more than 24 hours. About 1/2 hour

after a hen has laid an egg, she releases

another yolk (ovulation), and it will likewise

travel the length of the oviduct.

The albumen (fig. 3) secreted by the

magnum is a homogenous gel. The mucin

(secreted as fibers) is responsible for the

gel. The portion of the gel immediately

adjacent to the yolk undergoes partial

liquefaction before the egg leaves the

magnum. The spiral movement of the developing egg as it passes through the oviduct

causes the mucin fibers to draw together.

From these strands the chalaziferous layer

and the chalazae are formed. The twisting

and drawing together of these mucin strands

tend to squeeze out thin albumen to form the

inner thin white. Thus three layers of albunnen are formed from the homogenous gel.,

as follows: (1) Chalaziferous layer continuous with the chalazae, (2) the inner thin

white, and (3) the thick white. The outer thin

white (4th layer) is added in the uterus

through the shell membranes. The water and

solids content of the white ultimately become

equally distributed in the various layers of

the white.

Formation of the Shell Membranes

The shell membranes (fig. 3 and 4) are

added as the partly formed egg enters the

isthnniis. The membranes are a closely knit

lacelike nitrogenous compound of a substance similar to that present in chicken's

toe nails.

Formation of the Shell

The shell fig. 3 and 4 is formed in the

uterus and is composed of three layers:

Mannmillary or inner layer consisting of

calcite crystals over the surface of the

outer shell membrane in knoblike formations set perpendicular to the surface

of the shell.

Spongy layer consisting of small calcite

crystals that are not arranged in any order

except in the outer portion of the layer

where crystals are set at right angles to

the shell surface.

Cuticle which is sometimes erroneously

referred to as **bloom" and which is of a

chemical composition similar to the shell

membrane.

Calcium carbonate comprises about 94

percent of the dry shell. A hen may use as

much as 47 percent of her skeletal calcium

for egg shell formation.

Pores are formed through the spongy

layer connecting some of the space between

the knoblike mammilla with the surface.

When the egg is laid, the pores are filled

by the matrix material and covered by the

cuticle.

The egg, as laid, normally has no air

cell. It forms as the egg cools, usually in

the large end of the egg, and develops between the shell membranes. The air cell is

formed as a result of the different rates

of contraction between the shell and its

contents,

STRUCTURE AND COMPOSITION

OF THE EGG

Physical Structure

Yolk

The yolk (fig. 3) consists of the latebra,

germinal disc, concentric rings of yolk

material and the vitelline membrane (a

colorless membrane) which surrounds and

contains the yolk. The yolk constitutes approximately 31 percent of the total weight

of the egg.

White

The white consists of several layers of

albumen which together constitute about 58

percent of the weight of the egg.

The Chalaziferous layer immediately

surrounds the yolk and is continuous with

the chalazae. (Pronounced Kah-lay-za.)

This is a very firm but very thin layer

of albumen. It makes up 3 percent of the

total albunnen.
ALBUMEN

Outer thin

Firm

Inner tiiin

Chalaziteroui

Clialazae

YOLK

Germinal disc (Blosdoderm)

Latebro

Liglit yollt layer

ark yolk layer

Yolk (Vitelline) membrone

SHELL

Cuticle

Spongy (Calcareous)layer

Mammilory layer.

THE PARTS OF AN EGG

FIGURE 3."The parts of an egg.

MEMBRANE

Air cell

Outer shell membrane

Inner shell membrane

PORE CANALS

5. MAMMILLA (MAMMILLARY KNOB)

CUTICLE

2 SPONGY LAYER

3 MAMMILLARY LAYER

j 4 SHELL MEMBRANE

6 PROTEIN MATRIX MATERIAL FORMING

CORE OF THE MAMMILLA

MAGNIFIED RADIAL SECTION THROUGH THE SHELL

FIGURE 4.—Magnified cross section of shell of an egg.
The inner thin layer surrounds the

chalaziferous layer and comprises about

21 percent of the white.

The firm or thick layer of albumen

provides an envelope or jacket which holds

the inner thin white and the yolk. It adheres to the shell membrane at each end

of the egg. Approximately 55 percent of

the white is firm albumen.

The outer thin layer lies just inside the

shell membranes except where the thick

white is attached to shell, and accounts

for about 21 percent of the total albumen.

Shell Membranes

The shell membranes (fig. 3 and 4) are

tough and fibrous and are composed chiefly

of protein, similar in nature to that in hair

and feathers. The inner membrane is thinner

than the outer and together they are only

about twenty-four ten-thousandths of an inch

thick.

Shell

The shell (fig. 4) constitutes approximately 11 percent of the egg and is connposed

of about 94 percent calcium carbonate, 1

percent magnesium carbonate, 1 percent

calcium phosphate, and 4 percent organic

matter, chiefly protein. Pigment, if any, is

laid down in the spongy layer of the shell

and it is derived from the blood.

Composition of the Egg

(including the shell)

An average chicken egg weighs about 57

grams or 2 ounces. It is a very good source

of high-quality protein and of certain minerals and vitamins.

The chemical composition of the egg, in

percentages, is as follows:

Vater Protein Fat Ash

Percent

100

58

31

Percent

65.5

88.0

48.0

Percent

11.8

11.0

17.5

Percent

11.0

0.2

32.5

Percent

11.7

0.8

2 0

Calclvnn

carbonate

Magnesium

oarbonate

Calcium

phosphate

Organic

matter

Percent

11

Percent

94.0

Percent

1.0

Percent

1.0

Percent

4.0

Proteins, Vitamins, and Minerals

(edible portion, not including the shell)

Albumen.--The protein of egg is complete;

it contains ail of the indispensable

amino acids in well-balanced proportions.

The thick white is made up mainly of

the proteins: Ovomucin, ovoalbumen, conalbumen, ovoglobulin, and ovomucoid. Ovomucin gives structure to the thick white.

The albumen contains some water-soluble

B vitamins, especially riboflavin. The latter

gives the greenish tint to the white.

The thin white is composed mostly of

proteins of the sanne kind as contained in

the thick white with the exception of ovomucin.

Y oik.--The important yolk proteins are

ovovitellin (about three-fourths of the yolk

protein) and livetin.

The fatty substances of the yolk are

mostly glycerides (true fat), lecithin, and

cholesterol.

Yolk pigments (mostly xanthophyll) come

from green plants and yellow corn that the

birds eat.

The yolk contains practically all of the

known vitamins except vitamin C. The vitelline membrane is mostly protein similar

to that of the shell membranes and is fairly

permeable to water. The higher concentration of the solids of the yolk causes the

yolk to increase in size and grow flabby by

the inflow of water from the white as the

egg ages.

The yolk contains iron, phosphorus,

sulphur, copper, potassium, sodium, magnesium, calcium, chlorine, and manganese,

all of which are essential elements.

Abnormalities

Double-yolked eggs result when two yolks

are shed about the same tinne or w^hen one

day's yolk is lost into the body cavity for

a day and is picked up by the funnel when

the next day's yolk is shed.

Yolkless eggs are usually formed about

a bit of tissue that is sloughed off the ovary

or oviduct. This tissue stimulates the

secreting glands of the oviduct and a

yolkless egg results.

The abnormality of an egg within an egg

is due to reversal of direction of the egg by

the wall of oviduct. One day's egg is added

to the next day's egg and shell is formed

around both.

Bloodspots are caused by a rupture of

one or more small blood vessels in the yolk

follicle at the time of ovulation.

Meat spots are believed tobe degenerated

blood spots which have changed, mostly in

color, as a result of chemical action.
Soft" shelled eggs generally occur when an

egg is prematurely laid, and insufficient

time in the uterus prevents the deposit of

the shell.

Thin-shelled eggs may be caused by

dietary deficiencies, heredity, or disease.

Glassy-and chalky-shelled eggs are

caused by malfunction of the uterus of the

laying bird. Glassy eggs are less porous

and will not hatch but may retain their

quality.

Off-colored yolks are due to substances

in feed that cause off-color.

Off-flavored eggs may be due to disease

or to certain feed flavors.

GRADING

Grading generally involves the sorting

of products according to quality, size,

weight, and other factors that determine

the relative value of the product. The

grading of shell eggs is the classifying of

the individual egg according to established

standards. United States Standards for Quality of Individual Shell Eggs have been

developed on the basis of such interior

quality factors as condition of the white

and yolk, the size and condition of the air

cell, and the exterior quality factors of

cleanliness and soundness of the shell.

These standards cover the entire range

of edible eggs.

Eggs arc also classified according to

weight (or size) expressed in ounces per

dozen. Although eggs are not sold according

to exact weight, they are grouped within

relatively narrow weight ranges or weight

classes, the nninimum weight per unit being

specified.

Egg grading, then, is the grouping of

eggs into lots having sinailar characteristics as to quality and weight.

Although color is not a factor in the

U. S. Standards and Grades, eggs are

sometimes sorted for color and sold as

either ''whites" or *'browns." Usually,

eggs that are sorted as to color and packed

separately, sell better than when sold as

*'mixed colors.'*

Advantages of Grading

Grading aids orderly nnarketing by reducing waste, confusion, and uncertainty

with respect to quality values. Standards

are developed to satisfy the need and desire

of producers, dealers, and consunriers fora

uniform yardstick with which to measure

important differences in quality. The term

** standardization'* implies uniformity.

However, unless the same standard is used

and unless it is applied accurately in all

instances, uniformity in interpretation will

not result. The egg production pattern and

the marketing system in the United States

are such that interstate trading and shipment occur constantly and in large volume.

This situation creates a need for uniform

standards throughout the United States so

that marketing may be facilitated and the

efficiency of distribution increased. To aid

in this situation officials of the U. S.

Department of Agriculture and State and

industry leaders have for a number of

years been encouraging the use of uniform

standards and grades for eggs. That progress has been made is evidenced by the

fact that practically all the eggs traded

on the futures nnarket and nnost of the

eggs sold in other wholesale and jobbing

channels are graded on the basis of United

States standards. Many of the eggs reaching

the consumer are graded and marked according to U. S. standards and grades.

The principal advantage in using official

standards and grades for eggs is that they

furnish an acceptable common language in

trading and marketing the product, thus

making possible:

1. Impartial official grading which elinninates the need for personal inspection

of the eggs by sellers, buyers, and

other interested persons.

Z. Pooling of lots of comparable quality.

3. Development of innproved quality at

producer level through ** buying on

grade" programs.

4. Market price reporting in ternns

understood by all interested parties.

5. Negotiation of loans on generally

accepted quality specifications.

6. A basis for settling disputes involving

quality.

7. A basis for paying damage claims.

8. A standard upon which advertising

may be based.

9. A uniform basis for establishing brand

name s.

10. Establishment of buying guides for

consumers.

General Application

Standards of quality are used as a basis

for establishing grades. Standards of quality

317956 O - 55 - 2
8

apply to the individual eggs; grades apply

to lots of eggs such as dozens, 30-dozen

cases, and carloads. As egg quality is

unstable and grading procedures are largely

subjective, it is necessary to provide tolerances in grades for small percentages of

eggs of a quality lower than that comprising

the major part of the grade. The tolerances

are provided to allow for errors in judgment,

differences in interpretation, and normal

deterioration in quality from the time of

grading during a reasonably short period

until the eggs are sold to the consumer.

The United States Standards for Quality

of Individual Shell Eggs serve not only

as a basis for establishing U, S. grades,

but also for developing State standards

and grades and *'commercial" grades.

The U. S. standards and grades are permissive, that is, they may oir may not be

used by individual producers or handlers.

Many of the State departments of agriculture adopt the United States standards

and grades as a part of their programs for

regulating the marketing of eggs within

their States. Grade specifications in some

States vary somewhat from the U. S.

grades, but the standards of quality are

rather uniformly used throughout the

country. United States standards are often

used by commercial firms as a basis of

buying and selling eggs or in settling controversies that may arise in such transactions. Other firms develop their own

standards and grades, although many of

these are based on the U. S. standards. The

principal change from the U. S. standards

that commercial buyers make in establishing their bases of buying and selling

is the practice of combining several qualities of eggs into one grade in order to

reduce the total number of grades. For

example, several of the lower qualities,

such as C, dirties, and checks, may

be combined into one commercial

grade which may be given a name such as

"number two's," or **under grades."

As previously indicated, there is broad

general use of the U. S. standards and

grades; however, the uniformity of their

application within the States and between

commercial firms may vary considerably.

Official grading programs sponsored by

the U. S. Department of Agriculture in

cooperation with the States are intended to

bring about uniformity in the application of

the standards throughout the country. The

work of graders is continuously supervised

to assure correct interpretation of egg

quality according to the official standards.

GENERAL QUALITY FACTORS

Quality may be defined as the inherent

properties of a product which determine

its degree of excellence. Those conditions

and characteristics which consumers want

and for which they are willing to pay are

in a broad sense factors of quality. Certain

properties, such as size and shell color,

are not considered as factors in most

standards of quality; they, nevertheless,

are important considerations in the minds

of consumers.

Standards of quality have been developed

as a means of classifying individual eggs

according to various groups of conditions

and characteristics that experience and

research have shown to be wanted by consumers and for which they are willing to

pay. Grades are nothing more than specified

combinations of various qualities in dozen

or case lots.

Quality factors may be divided into two

general groups: Sxterior quality factors,

apparent from external observation; and

interior quality factors, which involve the

contents of the shell.

Exterior Quality Factors

Shell Shape and Texture

The normal egg has an oval shape with

one end larger than the other, and it tapers

toward the smaller end. These ends of an

egg are commonly called the large end

(air-cell end) and the small end. Measurements of both strength and appearance of

many eggs by investigators resulted in the

development of the *'ideal" egg shape. This

ideal egg shape is illustrated in figure 5.

The shape of an egg can be considerably

different (fig. 6) from the **ideal" but may

still be considered practically normal. The

grader must keep in mind a mental picture

of the normal or usual shape of an egg

and compare each egg as he grades it with

that picture.

Eggs that are unusual in shape, such as

those having ridges, rough areas, or thin

spots, are placed in the lower grades

(fig. 7 and 8). Shells of such eggs are

usually weaker than normal shells and the

danger of breakage en route to the consunner lowers the utility value of the egg.
FIGURE 5."ldeal egg shape, usually found in AA or A

qua I ity.

FIGURE 6."Practically normal shape which may be found

in AA or A quality.

FIGURE 7.--Slightly abnormal shape, showing definite

ridges and rough shell permitted in B quality.

FIGURE 8."Abnormal shape having pronounced ridges

permitted in C quality.
10

Eggs of abnormal shape also lack consumer

appeal. Therefore, they are excluded from

the better grades.

The specifications of the United States

standards provide three degrees of variation:

Practically normal.--A shell that approximates the usual shape and that is

of good even texture and strength and

free from rough areas or thin spots.

Slight ridges and rough areas that do not

materially affect the shape, texture, and

strength of the shell are permitted. (AA

and A Quality.)

Slightly abnormal.--A shell that may

be somewhat unusual in shape or that may

be slightly faulty in texture or strength.

It may show definite ridges but no pronounced thin spots or rough areas. (B

Quality.)

Abnormal.--A shell that may be decidedly misshapen or faulty in texture or

strength or that may show pronounced

ridges, thin spots, or rough areas. (C

Quality.)

Soundness of Shell

A sound-shelled egg is one whose shell

is unbroken. A checked or cracked shell

is one that is broken but whose shell

membrane is intact. Checks may range from

a very fine, hair-like check (blind check)

that is discernible only before the candling

light or by *'belling,'* to plainly visible

dented checks. *'Blind checks" are the

most common and frequently the most difficult to detect in rapid candling. Such eggs

will not keep well or stand even moderately

rough handling, hence they should be

diverted to immediate use. Body checks are

checks occurring prior to the time the egg

is laid. They are repaired by an additional

deposit of shell over the checked area,

generally resulting in a ridged area noted

in slightly abnormal shells.

*'Belling'* is the practice of tapping two

eggs together gently to assist in the detection of **blind checks** by sound. Candlers

follow this practice in order to verify and

complete the findings arrived at by sound.

A leaker is an egg in which the shell and

the shell membranes are broken and the

contents are free to exude or leak from the

shell.

Cleanliness of Shell

Eggs of AA quality and A quality must have

clean as well as sound shells. However,

small tolerauices to take care of the human

error factor during nornaal candling operations are permitted. Clean eggs are free

from stains, dirt, foreign matter, and discolorations that are readily visible« An egg

may be considered clean if it has only very

small specks or stains, if they are not of

sufficient number or intensity to detract

from the generally clean appearance of the

egg. Eggs that show traces of processing oil

on the shell are considered clean unless

otherwise soiled.

Eggs of B quality and C quality may show

stained shells in the following degrees:

B quality eggs may show slight stains that

do not appreciably detract from the appearance. The stains may cover approximately

1/32 of the shell surface if localizedor 1/16

of the shell surface (fig. 9) if they are

scattered.

C quality eggs may show slight to moderate stains covering not more than 1/4 of

the shell surface (fig. 9) provided they are

not prominent and do not include adhering

dirt.

FIGURE 9.--0ne thirty-second, one-sixteenth, and onefourth of shell surface of an egg—actual size

A dirty egg may have adhering dirt,

prominent stains, or slight to moderate

stains covering more than 1/4 of the shell

surface.

The measurements of 1/32, l/l6,andl/4

are the maximum soiled areas of the shell

surface of an egg permitted in the various

qualities. The illustrations in Figure 9 are

intended as a guide and are not to be

used as an actual measurement in grading.

Graders should learn to determine the

area that constitutes these measurements and then judge eggs having soiled
11

shells against this mental picture. It is difficult to visualize the gathering together of

soiled areas and apply them against a scale.

However, if the grader keeps in naind that

the total area of a normal 2-ounce egg is

about 10-1/2 square inches, 1/32 of the

shell surface of a 2-ounce egg would measure approximately 3/5** x 3/5'*; 1/16would

measure about 4/5" x 4/5"; and 1/4 would

measure a little more than 1-1/2" x 1-1/2".

The terms **slight" and **moderate,* *

describing intensity of stain, may be interpreted as barely detectable for **slight'*

and readily noticeable but not prominent

for "^moderate/'

Color of Shell

Although the U, S. specifications do not

recognize shell color as a quality factor, it

is actually an important factor in marketing.

Certain markets pay higher prices for

white eggs; others prefer brown eggs. If

the market preference is for white eggs,

they should be chalk white--not tinted or

creamy colored. Most markets prefer either

all white eggs or all brown eggs--not mixed

colors packed in the sanne container.

The color of the shell, an inherited characteristic, does not affect the interior quality of the egg.

Interior Quality Factors

Air Cell

As already stated, when the egg is first

laid it has no air cell at all or only a small

one. Its temperature is about 105^ F. and

as the egg cools to room temperature the

liquids contract more than does the shell.

As a result of this contraction, thé inner

shell membrane separates from the outer

to form the air space. Further increase in

the size of the air cell beyond that resulting

from contraction is due to evaporation of

water from the egg. The rapidity with which

this takes place is due to many factors, such

as age, shell texture, temperature, and

humidity. The air cell is nornnally at the

large end of the egg and is one of the first

factors observed in candling.

The air cell is perhaps the one quality

factor that is easiest to evaluate as it can

be judged objectively by a simple measuring

device--the air-cell gauge. In candling, the

air cell is considered by many as a relatively unimportant quality factor for determining the broken-out quality of an egg.

However, the air ceil is one of the factors

of the U. S. standards and, therefore, it

can be the determining factor in classifying

the individual egg as to quality. There are

two measurements of the air cell to be

considered, namely, the depth and the

amount of movement. The practically

regular air cell required in eggs grading

AA and A is one that maintains a practically

fixed position in the egg and shows a fairly

even outline, with not more than two-eighths

inch movement in any direction as the egg

is rotated.

The size and movement of the air cell

which are permitted in the various qualities are as follows:

Quality Depth

1/8 inch

Movement

AA 2/8 inch

A 2/8 inch 2/8 inch

B 3/8 inch May be free

but not bubbly

C No limit No limit

The air-cell gauge may be used by the

beginner until he can learn to judge the

size of the air cell accurately at a quick

glance while candling. More experienced

candlers occasionally use the gauge to

check the accuracy of their determinations.

The depth of the air cell is measured at the

point of greatest distance between the top

of the cell and an imaginary plane passing

through the egg at the lower edge of the

air cell where it touches the shell (fig. 10),

Air-cell movement is the distance the air

cell moves away from its normal position

when the egg, with the air cell uppermost,

is twirled.

Among the air cell defects are:

Tremulous air cells which are in relatively fixed positions but have a slight

movement from side to side as the egg is

moved.

Free air cells in which the shell membranes are intact, but the air cell moves

freely around between them.

Bubbly air cells in which the inner shell

membrane is broken, causing one or more

air bubbles to move about in the white when

the egg is rotated.
12

Point from which

to measure

air cell depth

MeasuringAir cell Depth

Air Cell Gauge

/i tNCM

MCH

% I18CM

FIGURE 10."Gauge for measuring depth of air cell.

Yolk

The appearance of the yolk as the egg is

twirled in candling is one of the best indicators of the interior quality of shell eggs.

The characteristics of the yolk are determined by the shadow that it casts upon the

shell before the candling light. The appearance of the yolk is dependent on the condition of the albumen; however, there are

four factors about the yolk itself that are

considered in judging egg quality by the

yolk. These are:

Position of yolk

Distinctness of yolk shadow outline

Size and shape of yolk

Defects and germ development

Position of the yolk. Normally the yolk

in a new laid egg of high quality occupies

a central position within the egg--vertically as well as horizontally. The distance

the yolk moves away from the center of the

egg as it is properly twirled, indicating

the viscosity of the white, is a measure

of the interior quality. There are three

types of movements that can be detected

(fig. 11). The vertical or up-and-down

movement, the movement or swing of the

yolk to either side around the inside of

the shell, and the spinning motion of the

yolk on the axis formed by the chalazae.

This latter spinning movement allows all

sides of the yolk to be seen and thereby

permits observation of spots, germ development, and blemishes on the yolk.

The horizontal movement or centering is

more difficult to measure than is the

vertical movement. The former is measured

by the distinctness of the yolk outline shadow

and is dependent largely on the viscosity

of the white or albumen.

In order to make observations on a

uniform basis, the amount of twirling given

the egg as it is placed before the candling

light should be standardized.

The terms used to describe yolk centering

are as follows: Well centered--A yolk that

occupies the center of the egg and moves

only slightly from that position as the

egg is twirled (AA Quality). Fairly well

centered--A yolk that is not more than

one-fourth of the distance from its normal

central position toward the ends of the

egg and swings not more than one-half

of the distance from its normal position

toward the sides of the egg as it is twirled

(A Quality). Off center--A yolk that is

distinctly above or below center and swings

jl
close to the sides of the egg as it is twirled

(B and C Quality).

The approximate distances given above--

not more than one-fourth the distance, and

so on--are intended as an aid to candlers.

They are not to be considered as specific

measurements requiring the use of a ruler

or other measuring device, but are designed

to help the candler form his opinion of each

egg--whether the yolk is well centered or

off center (fig. 11).

Distinctness of yolk shadow outline. The

distinctness of the yolk outline or shadow

outline is governed by three factors:

(1) The thickness and consistency of the

albumen. The thicker the albumen the less

distinct the outline appears, because the

yolk is prevented from moving close to the

shell.

(2) Condition of the yolk. This condition

is determined by the presence of blemishes

that show up before the candling light as

dark shadows in the yolk, or the absence of

these blemishes; and the presence or

absence of an off-colored yolk appearance

which shows as a grayish or greenish

shadow.

(3) Color of the yolk. It is difficult to

determine the color of the yolk before the

candling light except off-color. However,

extremes in yolk color may influence the

candieres judgment of egg quality. An ex13

tremely deep-colored yolk, under some

conditions, would cast a darker shadow

before the candling light than would a

lighter yolk. By concentrating on the yolk

outline instead of the depth of the yolk

shadow, therefore, the grader will minimize

the influence of yolk color on his quality

determinations. The color of the yolk and

the firmness of the albumen are two interacting influences that affect the distinctness

of the yolk shadow outline; therefore, a

grader cannot be even reasonably certain

which is the more important factor in any

specific case. The distinctness of the yolk

shadow is the important factor in determining the horizontal centering of the yolk.

The principle of judging distinctness of the

outline rather than the depth or darkness of

the shadow can be illustrated by holding a

ball close to a wall so its shadow falls on

the wall, and then holding it a little farther

away fronri the wall; at the greater distance,

the outline of the shadow is less distinct.

The ternns used to define the four degrees

of distinctness of yolk shadow outline in the

U. S. standards of quality for shell eggs

are: Outline slightly defined--Ayolk outline

that is indistinctly indicated and appears to

blend into the surrounding white as the egg

is twirled (AA Quality). Outline fairly well

defined--A yolk outline that is discernible

but not clearly outlined as the egg is twirled

YOLK CENTERING

VERTICAL HORIZONTAL

,B-C

^—

1 *">N."^'

y^ 1 /^^*\

X \^ '\

/ V

y^

/ } A /

/ -'-ÍSí-^^í.-'\

/ /^>- \

I ,^y^ ^>\ \

' Y \\\ \

Ij ^

^

1 ^\ /

\ \\^ /y i

\ v^^ / V /

^^ y/ /

V^^ ^y

/

/

-A

^AA

^-C

N\A

FIGURE n.--Diagram showing the position of yolk for each quality.
14

(A Quality). Outline well defined--A yolk

outline that is quite definite and distinct

as the egg is twirled (B Quality). Outline

plainly visible--Ayolk outline that is clearly

visible as a dark shadow as the egg is

twirled (C Quality).

Size and shape of yolk--The yolk in a

new-laid egg is round and firm. As the

yolk ages it absorbs water from the albumen

which increases its size and causes it to

stretch and weaken the vitelline membrane

and to assume a somewhat flattened shape

on top and an * *out-of-round'* shape generally, resembling a balloon partially filled

with water. Yolk size and shape are

mentioned only in the lower quality classifications for eggs--B and C--where these

factors become apparent. The terms used

in the U. S. standards of quality for shell

eggs to describe yolk size and shape are:

Slightly enlarged and slightly flattened--A

yolk in which the yolk mennbranes and

tissues have weakened somewhat causing

it to appear slightly enlarged and slightly

flattened (B Quality)- Enlarged and flattened--A yolk in which the yolk membranes

and tissues have weakened and moisture

has been absorbed from the white to such

an extent that it appears definitely enlarged

and flat (C Quality). Occasionally the yolk

will sag and produce two well-defined

shadows, the edges of which overlap.

Defects and germ development. Relatively

little is known about the exact causes of

most yolk defects other than those due to

germ development. Some of the causes

which have been advanced are: Irregular

deposits of light and dark yolk; blemishes

from rubbing; and development of accumulations or clusters of the fat and oil in droplets. The relative viscosity of the albumen

has a direct bearing on the accurate determination of defects on the yolk before the

candling light. Unless yolk defects are very

prominent, detection of thenn is difficult

particularly when the egg has a thick albumen. Germ development is visible before

the candling light and can generally be

detected as a circular dark area near the

center of the yolk shadow. If blood is visible,

the egg must be rejected as inedible.

The terms used to describe yolk defects

are: Free from defects--A yolk that shows

no spots or areas on its surface indicating

the presence of germ development or other

defects (AA Quality). Practically free from

defects--A yolk that shows no germ development but may show other very slight defects

on its surface rA QiiRlitvK Definite but not

serious defects--A yolk that may show

definite spots or areas on its surface but

with only slight indications of germ development or other pronounced or serious defects

( B Quality ). Other serious defects - - A yolk

that shows well-developed spots or areas

and other serious defects, such as an olive

yolk, which do not render the egg inedible

(C Quality). Clearly visible germ development - -Development of the germ spot on the

yolk of a fertile egg that has progressed

to the point where it is plainly visible as a

circular area or spot with no blood in

evidence (C Quality). Blood due to germ

development--Blood caused by development

of the germ in a fertile egg to a point where

it is visible as definite lines or as a blood

ring. Such an egg is classified as inedible.

White

Practically all new-laid eggs containfour

layers of albunnen--inner thin, chalaziferous, thick, and outer thin. The appearance of

the egg before the candling light is governed

largely by the relative proportions of the

thick and outer thin layers of albumen. The

white and yolk are very closely associated

and any discussion of either factor, of necessity, involves the other. However, there

are two important considerations about the

white which are included in standards of

quality: Condition or viscosity, and clarity.

Condition of the white.--The condition of

the white is determined in candling by the

yolk position, the intensity of the yolk

shadow, and the relative freedom of movement of the yolk away from its central

position when the egg is twirled before the

candling light. The grader must judge from

the behavior of the yolk, how the white will

appear when the egg is broken out. The

appearance of the albumen in broken-out

eggs is illustrated in (fig. 14).

In classifying eggs for quality according

to the U. S. Standards of Quality for Individual Shell Eggs, four groupings are made

with respect to the condition of the white.

A firrg white is sufficiently thick or

viscous to permit only limited movement of

the yolk from the center of the egg, thus

preventing the yolk outline frombeing more

than slightly defined or indistinctly indicated

when the egg is twirled.

A reasonably firm white is somewhat less

thick or viscous than a firm white. A

reasonably firm white permits the yolk to
15

move somewhat more freely from its normal position in the center of the egg and

approach the shell more closely. This

would result in a fairly well-defined yolk

outline when the egg is twirled,

A slightly weak white is lacking in thickness or viscosity to an extent that permits

the yolk to move quite freely from its

normal position in the center of the egg. A

slightly weak white will cause the yolk outline to appear well defined when the egg is

twirled.

A weak and watery white is thin and

generally lacking in viscosity. A weak and

watery white permits the yolkto move freely

from the center of the egg and to approach

the shell closely, thus causing the yolk outline to appear plainly visible and dark when

the egg is twirled.

Clarity.--The albumen must be clear if

the egg is to be classified as AA, A, or B.

The viscosity or firmness of the white of

new-laid eggs often influences the correct

appraisal of the clarity factor insofar as

small blood spots are concerned. Small

spots that may be entwined with the chalazae

or that adhere to the well-centered yolk may

often be undetected. Whites that are not

clear because they contain small blood spots

or meat spots (not over 1/8 inch in diameter) are included in C quality. Whites that

are not clear because of other foreign material or because of decomposition are

classed as loss or inedible.

The U. S. Standards of Quality contain

the following descriptive terms relating to

the clarity of the white.

A clear white is free from discoloration

or from foreign bodies floating in it. (Prorninent chalazae should not be confused with

foreign bodies such as spots or blood clots.)

Blood clots or spots(not due to germ development) are sometimes found on the surface of the yolk or floating in the white.

These blood clots may have lost their

characteristic red color and may appear as

small spots or foreign nnaterial commonly

referred to as meat spots. Such blood clots

or spots are incorporated in the egg during

its formation, sometimes even before the

yolk leaves the ovary. If they are small (aggregating not more than 1/8 inch indianneter)

the egg may be classed as **C Quality." If

they are larger or show diffusion of blood

in the white surrounding them, the egg is

classified as loss.

An egg, the white of which has blood diffused through it, is called a bloody white.

Such a condition may be present in newlaid eggs. Eggs with bloody whites are

classed as loss.

Loss and Inedible Eggs

The U. S. Standards of Quality also define

certain eggs as **loss."

**Loss.--An eggthat is inedible, smashed,

or broken so that the contents are leaking,

cooked, frozen, contaminated, or containing

bloody whites, large blood spots, large unsightly meat spots, or other foreign material.'*

Inedible eggs. Inedible eggs are described

in the U. S. standards to include black rots,

white rots, sour eggs, eggs with green

whites, musty eggs, and moldy eggs. These

types of inedible eggs are usually caused

by the growth of bacteria or mold on or in

the egg. Other types of inedible eggs are

those showing blood rings, and those containing embryo chicks (at or beyond the

blood ring stage) which result from germ

development in fertile eggs. Two additional

types of inedible eggs are mixed rots and

eggs with stuck yolks.

The freshly laid egg is usually free of

bacteria on the inside and is well protected

from bacteria by the shell, shell membranes,

and several chemical substances in the egg

white. If subjected to warnn temperatures

or moisture, or both, bacteria are able to

penetrate the egg and overcome the egg*s

defense. When bacteria grow inside the egg

they may form byproducts or cause the contents of the egg to decompose, or both. These

conditions result in the characteristic

colors, appearance or odors from which the

rots take their name.

Stuck yolk occurs when the yolk membrane becomes attached to the shell membrane. It generally occurs in older eggs

that have been left in a fixed position for a

long time. When the thick white becomes

thin, the yolk floats close to the shell and

becomes attached to the shell membrane.

Before the candling light the yolk appears

attached to the shell and snaps back to its

attached position when the twirling motion

of the egg is stopped. If loosened from its

position, the yolk membrane usually breaks,

permitting the yolk content to seep into the

white. The first stage of this condition is

generally referred to as **seeping yolk";

later **mixed rot*' or "addled egg.'*

Mixed rot (addled egg) occurs when the

vitelline membrane of the yolk breaks and

the yolk mixes with the white, resulting ina

317956 O - S5 - 3
16

murkiness throughout the interior of the egg

when viewed before the candling light.

Sour egg is not readily detected by candling because the evidence of the breakdown

of the content is noted only by the sour odor

given off. Generally, eggs in this condition

show a weak white and murky shadow around

an off-center, swollen yolk. Frequently the

content of this type of egg fluoresces under

ultraviolet light.

Eggs with green whites are very difficult

for the inexperienced grader to detect with

the standard candling light. The experienced

grader can detect advanced stages of green

white with a considerable degree of accuracy. The adoption of ultraviolet light in

candling (black light) has made the detection of this type of loss easier. The bacteria

causing green white belong to a group named

Pseudomonas. These organisms produce a

material which fluoresces under ultraviolet

light, giving off a green sheen that makes

possible the detection of this type of loss.

When an egg is broken out under ultraviolet

light, the fluorescence can be noted even

more readily. Frequently the content of this

type of loss egg gives off a sour odor. In

advanced stages of spoilage the white under

ordinary light has a green color, but many

appear perfectly normal in other respects.

In early stages the white rot may be detected by the presence of threadlike shadows

in the thin white. In later stages the yolk

appears severely blemished when viewed

before the candling light, and when broken

shows a crusted appearance. The content

frequently gives off a fruity odor.

Musty eggs frequently appear clear and

free from foreign material when viewed

before the candling light and can generally

be detected only by the characteristic musty

odor emanating from the egg. It might have

been caused by exposure to must odor inthe

case or in nesting material. Another source

of contamination may be the presence of

this odor on the shell itself from previous

contamination. It is said that certain bacteria

that occasionally invade the egg give off this

characteristic odor also. Due to the fact

that this type of loss is impossible to detect

by visual observation, it is of utmost importance that the grader note the odor

emanating from the case and packing material imimediately upon opening the case.

Moldy eggs may be detected by observing

mold spots on the shell or by mold growth

in checked areas of the shell, or by mold

growths (the odor of mold or must may or

may not be present) inside of the egg itself

when viewed before the candling light. The

use of dirty water for washing eggs and

dirty processing oil cooler than the egg,

and the storage of the egg in unusually high

humidity encourage mold growth and mold

penetration through the shell. Advanced

stages of mold growth throughout the entire

egg might have an appearance similar to

that of black rot.

Black rots are generally opaque (with

the exception of the air cell) when viewed

before the candling light. When broken the

content has a muddy brown appearance and

gives off a repulsive, putrid odor. The

bacteria most frequently causing this type

of loss belong to a group named Proteus.

However, when any rot is at an advanced

stage it may appear "black** before the

candling lamp.

Blood rings and embryo chicks are caused

by germ development, occurring in fertile

eggs held at incubation temperatures. At a

rather early stage in incubation (after 24

hours) the embryo develops a circulatory

system. If at this stage the embryo dies the

blood drains to the outer edge of the germ

disc, causing the blood ring. Before the

candling light, it appears as a brilliant

blood-red circle from one-eighth to threeeighths inch in diameter, depending on the

stage of development. If incubation temperatures are maintained for a longer

period, the embryo chick is formed by about

the third day and eventually fills nnostofthe

egg. This can be observed before the candling light as an actual outline of the embryo,

in the early stages.

In addition to the inedible eggs described

above, eggs showing severe shell damage

and the presence of large blood spots or

diffused blood in the white, ar^ classified as

loss.

Smashed or broken eggs are classified as

loss. When damage to the shell and membrane of an egg permit the content to flow

out of the shell, the egg is **loss."

The origin of large blood spots and

bloody whites has already been explained.

They appear as brilliant red in color or as

a dark gray in so-called meat spots, in

contrastto the surrounding lemon-to-orange

colored tinge of the yolk, observed before

the candling light.

Eggs not classified as loss but as **no

grade" include eggs of possible edible

qualities that have been contaminated by

smoke, chemicals, or other foreign ma-
terial which has seriously affected the

character, appearance, or flavor of the eggs.

Earlier in this manual reference was made

to eggs that give off an offensive odor due to

disease or feed flavors. It has been found

that some hens inherit the characteristic of

producing eggs that give off a characteristic

fishy odor. In other instances diseased laying

organs may impart an off odor to the brokenout eggs. High concentrations of fish oil or

garlic fed to hens impart their flavor to the

eggs. Eggs exposed to foreign odors after

they have been laid, may give off these odors.

Eggs stored near kerosene, carbolic acid,

mold, must, fruit, and vegetables, for

example readily absorb odors from these

products.

UNITED STATES STANDARDS, GRADES,

AND WEIGHT CLASSES FOR SHELL EGGS

The United States Standards for Quality of

Individual Shell Eggs are applicable only to

eggs of the domesticated chicken that are in

the shell.

United States Standards for Quality of

Individual Shell Eggs

AA Quality.--The shell must be clean,

unbroken, and practically nornnal. The air

cell must not exceed 1/8 inch in depth and

must be practically regular. The white must

be clear and firm so that the yolk will appear

well centered and its outline will be only

slightly defined when the egg is twirled

before the candling light. The yolk must be

free from apparent defects.

A Quality.--The shell must be clean, unbroken, and practically normal. The air cell

must not exceed 1/4 inch in depth and must

be practically regular. The white must be

clear and at least reasonably firm and the

yolk at least fairly well centered and its

outline only fairly well defined when the egg

is twirled before the candling light. The

yolk must be practically free from apparent

defects.

B Quality.--The shell must be unbroken,

may be slightly abnormal, and may show

slight stains but no adhering dirt. Approximately 1/32 of the shell surface may be

slightly stained when the stains are localized

and 1/16 of the shell surface maybe stained

if stains are scattered. The air cell must not

exceed 3/8 inch in depth, may show unlimited

movement, and may be free but not bubbly.

The white must be clear and may be slightly weak so that the yolk may appear offcenter, with its outline well defined when the

17

egg is twirled before the candling light.

The yolk may appear slightly enlarged or

slightly flattened and may show other definite, but not serious defects.

C Quality.--The shell must be unbroken,

may be abnormal and may have slight to

moderate stained areas covering not more

than 1/4 of the shell surface. Prominent

stains and adhering dirt are not permitted.

The air cell may be over 3/8 inch in depth

and be free or bubbly. The white may be

weak or watery so that the yolk may appear

off-center and its outline plainly visible

when the egg is twirled before the candling

light. The yolk may appear dark, enlarged,

and flattened, and may show clearly visible

gernn development but no blood due to such

developnnent. It may show other serious

defects that do not render the egg inedible.

Small blood clots or spots may be present.

Dirty.--The shell must be unbroken but

has adhering dirt or prominent stains, or

slight to moderate stains covering more than

1/4 of the shell surface.

Check. - -Individual egg that has a broken

shell or crack in the shell but with no leakage

of the contents.

Leaker. - - Individual egg that has a break

or crack in the shell and shell membrane,

with contents exuding or free to exude

through the shell or an egg that has 1/4 inch

square of shell missing with the shell membrane intact.

United States Consumer Grades and

Weight Classes for Shell Eggs

These grades are applicable to edible

shell eggs in *'lot" quantities rather than on

an **individuar ' egg basis. A lot may contain any quantity of 2 or more eggs. Reference in these standards to the term **case**

means a case holding 30 dozen eggs as used

in commercial practice in the United States.

Terms that are defined in the United

States Standards for Quality of Individual

Shell Eggs have the same meaning in this

part as in those standards.

An aggregate tolerance of 20 percent is

permitted within each consumer grade. This

tolerance is to take care of differences in

the efficiency of graders, normal changes

in the product under favorable conditions

during reasonable periods between grading

and inspection, and reasonable variations

in interpretations of graders.

Substitution of higher qualities for the

lower qualities specified in a grade is permitted.
18

Svimmary of U. S. Consumer Grades for Shell Eggs

U. S.

consumer

grade

At least ÖO percent

(lot average)^

must be—

AA QualityA Quality or better.

B Qijallty or better.

C Quality or better.

Tolerance permitted^

15 to 20

Not over 5^—

15 to 20

Not over 5-^--

10 to 20

Not over 10^-

Not over 20—

Quality

B, C, or Check.

B.

C or Check.

C.

Dirty or Check.

Dirty or Check.

^In lota or two or more cases, no individual case may fall below 70 percent of the specified quality and no individual case may contain more than

double the tolerance specified foir the respective grade (i. e., in lots of

Grade A, not mare than 10 percent of the qualities in individual cases

within the sample may be C or Check, provided the average is not over 5

percent).

^Within tolerance permitted, an allowance will be made at receiving

points or shipping destination for l/2 percent leakers in Grades AA, A, and

B, and 1 percent in Grade C.

^Substitution of higher qiialities for the lower qualities specified is

permitted.

U. S. Weight Classes for Consumer Grades for Shell Eggs

Size or

weight class

Extra largeLarge———

Medium-——-

Small

PeeweeMinimum

net weight

per dozen

Ounces

30

27

24

21

18

15

Minimum

net weight

per 30 dozen

Pounds

56

50-1/2

A5

39-1/2

34

28

Minimum weight for

individual eggs at

rate per dozen

Ounces

29

26

23

20

17

Minimum weights listed above for individual eggs at the rate per dozen

are permitted in the varioxis size classes only to the extent that they will

not reduce the net weight per dozen below the required miniimim.

designed primarily for Government and

institutional procurement» A lot may contain any quantity of one or more cases.

United States Procurement Grades and

Weight Classes for Shell Eggs

Procurement grades are applicable only

to shell eggs in lot quantities. They are

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For Quality of Individual Shell Eggs.

Substitution of higher qualities for the

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The term "refrigerator eggs'* means

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20

GRADING EGGS

A skilled grader must be able to determine

the interior quality of an egg by candling, to

appraise the condition of the shell, and to

judge the individual egg weight.

The appraisal of interior egg quality by

candling is a skill that requires manual dexterity and the ability to make frequent splitsecond decisions over long periods oftirne.

The experienced egg grader, in the average

grading room, is primarily concerned with

interior egg quality when candling shell eggs,

but he is also concerned with soundness,

cleanliness, and color of the shell, and the

weight or size of the egg. These three primary considerations cannot for all practical

purposes be disassociated; however, in this

section they will be treated separately and in

order of degree of difficulty with which each

is mastered rather than in the order they

are used in the grading operation.

Classification of Interior Quality

In determining interior quality by candling

it is customary to hold two eggs in each hand.

Supporting one egg by the tips of the thumb

and index finger and holding the other against

the palm with the other fingers. The small

ends of the eggs should point toward the palm

of the hand (fig. 12). Aiter one egg in the

hand has been candled, it is shifted back in a

rotating motion to the palm of the hand and

the second egg is brought into candling position. The eggs are viewed alternately before

the light. The uppermost egg in the right hand

is examined first, then the uppermost egg in

the left hand, and this procedure is repeated

after the position of the eggs ineach hand has

been shifted. Aiter the first egg is candled

and the hand is dropped slightly back and

downward, the third and fourth fingers

are relaxed, letting the uncandled egg

roll downward slightly. At the same

time the thumb and index and

FIGURE 12.--The way to hold eggs while candiling.
21

second fingers guide the candled egg into

the palm of the hand. The third and little

finger then roll the uncandled egg into

candling position between the thumb and index finger; meanwhile the little finger

(fourth) and third finger hold the candled

egg in the palm. The position of the eggs is

changed in one hand while one of the eggs

held in the other hand is being candled.

The ability to quickly rotate two eggs in

each hand makes for more rapid work and

should be practiced until reasonable dexterity is acquired. In manipulating eggs

before the candling light, it is important that

the rotation of eggs in each hand, and the

twirling motion before the light become

mechanical. Dexterity in this rotation operation permits the grader to concentrate

entirely on placing the egg before the light

rather than on changing its position or rotating the two eggs and frees him fronn concern over dropping the eggs. It also helps

him to develop a rhythna which improves

uniform timing of judgment, thereby making

possible greater proficiency.

In order to obtain a proper view of the

egg while candling, it is necessary to have

the contents spinning within the shell at the

time of viewing. This can best be achieved

by having the hand that holds the egg to be

viewed arrive at a point near the candling

aperture palnn down. Then by turning the

hand with a snap of the wrist in an arc of

180 the shell and its contents are started

in motion. Stopping the hand motion at the

end of the arc without moving the arm or

body permits the contents to spin within the

shell. The long axis of the egg should be at

about a 45 angle to the candling aperture.

The thumb and index finger should be on

opposite sides of the shell without obstructing the grader's view (fig. 12). After gaining some experience in the candling operation, the grader will learn to have the egg

content spinning at the exact instant the egg

is placed before the candling aperture.

The Factor of Judgment

Even under the most favorable conditions,

egg quality is relatively unstable. The interior quality of the egg deteriorates from

the time it is laid until it is consumed.

Sometimes quality changes render eggs useless for food before they reach consumers.

However, when eggs are properly cared for,

the quality decline can be minimized and the

period of time between original high quality

and uselessness can be lengthened materially. Quality decline is illustrated graphically in figure 13.

In grading eggs, and more specifically in

classifying them according to internal

quality, the grader is merely trying to group

the eggs according to where each is located

on *'quality hill."

Edible eggs are divided into four groups

or qualities as show^n in figure 13, All

clean eggs whose candled characteristics

fall between the top line and point 1 on the

chart are in the best quality class or AA,

those between 1 and Z are in the next quality

or A, between 2 and 3 are inB, and between

3 and 4 are in C, and those at and below

point X are inedible or loss.

It is relatively easy to place eggs properly

if they are midway between the various

points on "quality hill," but judgment and

skill are required to place in the correct

group the eggs that are at or near the

quality division points. It becomes increasingly difficult when brown eggs or mixed

white and browns are being candled. The

real knack in candling is to have a clear

mental picture of the dividing line between

the various quality classes, so that the

eggs may be properly placed in their respective quality groups.

In acquiring skill in judging egg quality

it is helpful to break the classificationdown

into steps, considering separately the various quality factors --shell, air cell, yolk

position and condition, and condition of the

white. The operator can concentrate with

greater ease when each factor is considered

separately. Later, all factors should be considered in combination.

Good judgment in determining albumen

and yolk condition can be developed and

maintained by having the grader break out

^^ ^gg occasionally and check his estimate

of the candled quality with the broken-out

appearance as compared with the chart for

scoring broken-out appearance (fig. 14).

As soon as the grader has acquired a

working knowledge of the standards of quality

and reasonable dexterity in manipulating individual eggs, candling speed will increase.

The accuracy of interpretation of quality

standards depends on the ability to develop

judgment of correct classification. In efficient commercial operations, each grader

must make 7,200 decisions or more a day.

It is, therefore, essential that the grader

develop an ability to make instant decisions.

It has been said that the greatest frequency

of error occurs in instances of repeated
22

EGG QUALITY DECLINE

NORMAL NEW-IAID EGG

QUALITY I

Highest

High

Intermediate

Low

TIME

U. S. DEPARTMENT OF AGRICULTURE NEC. 646-54(4) AGRICULTURAL MARKETING SERVICE

FIGURE 13.—Range of quality in official grades.

indecision as to the placement of individual

eggs. It should be pointed out that mistakes

due to oversight, minor errors in decision,

and differences of opinion between graders

or between graders and supervisors or inspectors are factors that are taken into

consideration in the U. S. grades by providing for tolerances. However, errors beyond

the permitted tolerances result in the incorrect grading of the entire lot of eggs. It is

most important, therefore, that each

grader's decision of egg placement be as

nearly correct as possible.

Speed and accuracy in grading should be

accompanied by constant careful handling of

the product. When eggs are placed into a

carton or filler they should be placed carefully, not dropped. The egg should always

be packed small end down. Cartons of eggs

should be placed on the conveyor belt carefully, not dropped. Eggs should not be placed

into dirty or torn fillers and flats or in

packing materials giving off foreign odors.

Eggs received in cases or packing material

giving off foreign odors should not be graded

unless the egg content is carefully checked

for flavor. It is desirable to grade eggs when

their internal temperature is between 50

and 70 F., but it is imperative to avoid

handling eggs for grading when they are

''sweating*' (when there is condensation of

moisture on the shell) in order to avoid

smearing and staining of the shell. Eggs

from a very cool environment should be

tempered in the candling or other room with

as moderate a temperature as necessary

before candling to avoid **sweating** when

the eggs are candled.

Classification of Exterior Quality

Shell Factors

The external factors of the egg--color,

condition, and cleanliness of the shell--can

be determined without using the candling

light, but soundness of shell shouldbe veri-
23

INTERIOR QUALITY OF EGGS

(Recommended standards fof scoring the qualify of bfol<cn-out csgs)

<

AVERAGE AA

(

c

c

/

\

\

c

')

\

FIGURE 14.--The pictures on this chart show the interior quolity of eggs that meet the specifications of the U.S. Standards

for Quality of Individual Shell Eggs with respect to albumen and yolk quality. Quality factors dealing with the shell, air

cell, and defects are not included. Scores 1, 2, and 3 represent the appearance of broken-out eggs of high, average and

low AA Quality; 4, 5, and 6 represent high, average, and low A Quality; 7, 8, and 9, high, average, and low B Quality,

and 10, 11, and 12, high, average, and low C Quality.

317956 O - 55 - 4
24

fied by candling. All these factors become a

part of the grading and candling operation

under commercial conditions.

Shell Cleanliness

In segregating eggs for shell cleanliness

the grader should make a preliminary examination of the general appearance of the

layer of eggs to be candled at the time the

covering flat and surrounding filler are removed. Eggs with only very small specks

or stains may be considered clean if such

eggs are not present in sufficient number to

detract appreciably fronn the appearance of

the eggs (see U. S. Standards for Quality

of Individual Shell Eggs). While the eggs are

still in standing position (in cup flats) the

eggs with stained or dirty shells should be

removed and candled. The remaining eggs

that appear clean from a top view should be

then gently pushed over on their sides and

again the eggs with stained or dirty shells

should be removed and candled. These two

operations will remove all dirty or stained

eggs that are noticed at first glance.

The remaining eggs in the filler should be

removed, two eggs in each hand, for

candling. On the way to the candling aperture, the eggs in each hand should be rotated under the rays of a light that illuminates the contents of the case, commonly

referred to as a case light. As the eggs are

rotated the shell should be observed for

stains or dirty conditions. This operation

(rotation and observation for dirt) should be

performed rapidly enough so that the motion of the hand from the case light to the

candling aperture is made in one sweeping

motion. Any stained or dirty eggs which are

detected at this point should be candled and

segregated before the candling of clean eggs

is begun. When the eggs are placed before

the candling aperture, previously undetected

dirty or stained shells should be removed.

The grader should always have clean, dry

hands to avoid staining shells. The candling

aperture should be of a nnaterial that will

not mark or stain the shell and will aid in

minimizing breakage.

Shell Soundness

The method of removing leakers and

dented checks need not be emphasized, except to say that it is necessary to remove

such eggs from the lot carefully to avoid

doing further damage to them and dripping

liquid from leakers onto clean eggs.

As the eggs are removed from the case

for candling they should be "belled'* to determine the presence of checked shells.

Belling is accomplished by gently touching

the shells together. This operation can be

made part of the egg rotating motion. Whenever a dull sound is heard instead of a clear

clinking sound, the operator knows that one

of the shells is checked. Both eggs should

then be candled to determine which shell is

broken. In addition, all shells should be

observed before the candling light for possible checks or thin areas that have not been

previously removed. In general, eggs that

have abnormal shells, that are misshapen,

or that have pronounced ridges should be

removed at the same time that dented checks

and leakers are removed.

Shell Color

In giving consideration to shell color, it

should be borne in mind that this factor does

not affect the quality of the egg ahd for this

reason it is not considered in the U. S. standards of quality or grades.

For may years consumers in some areas

of the country have preferred white eggs,

thinking, perhaps, that the quality is better

than that of brown eggs, whereas consumers

in other areas have preferred brown eggs,

thinking they have greater food value. These

opinions do not have any basis in fact, but it

is recognized that brown eggs are more

difficult to classify as to interior quality

than are white eggs. It is also more dificult

to detect small blood spots in brown eggs.

Then, too, consumer preference is an important factor in marketing.

In recognition of the shell color preference factor, consideration shouldbe givento

separation of eggs according to color in at

least the two top qualities. In general, three

packs are necessary in this procedure:

**Whites,** in which light cream-tinted to

chalk white eggs are packed together;

**Browns,** in which dark cream and dark

brown eggs are packed together; and **Mixed

Colors,*' in which unsegregated whites and

browns are packed together.

Much can be said for the sales value

through added eye appeal of a pack of eggs

carefully grouped as to color. Furthermore,

a carton or case of eggs in which white and

brown eggs (even though of high quality) are

mixed tends to give the impression to the

uninitiated that the lot is heterogeneous in

other respects as well as color.
25

There are a number of ways in which

segregation with respect to shell color can

be handled.

At producer level:

1. Encourage producers to pack brown

eggs separately from white eggs when

both are produced in appreciable quantities.

2. Encourage producers to have flocks

that produce only all white, or flocks

that produce all brown, eggs.

At grading station:

1. Provide bench space in the candling

room for packing two colors of the top

grades and have graders handle segregation at time of examination for cleanliness.

2. Segregate all eggs with respectto shell

color before candling.

3. Segregate top grades with respect to

color after candling. Segregation can

be done manually by a trained operator

in a well-lighted area outside of the

grading room. Recently the Department of Agriculture has designed an

experimental model of a machine that

segregates eggs with respect to shell

color by means of a photoelectric cell,

in which fine gradations of color can

be made at a rapid speed with consistency and accuracy.

When packing brown eggs it is desirable

to confine all of them in one filler or carton to one shade of brown. If occasional

light-brown shells must be included in a

filler containing dark-brown eggs, the light

browns should be placed in the outer edges

of the filler or at either end of the carton.

The same arrangement is suggested when

cream tinted shells are included with chalk

white shells.

Weight Classification

The classification of shell eggs according

to weight (size) is performed simultaneously with the other processes performed in

the candling operation unie s s the weighing is

done separately by automatic weighing devices. The experienced grader dan usually

pick out eggs of different weight classes

from a mixed lot of eggs without more than

an occasional check-weighing of the individual eggs. This skill is acquiredby developing the ability to evaluate size visually and

by a sense of comparative weight and size^ To

assist in acquiring this skill for accurately

classifying eggs with respect to weight, the

following procedure is suggested: The end

of the case to be worked should be placed

directly under the case light, the top flat

being removed. The operator should then

note the degree with which the individual

eggs fill each of the filler cells. An egg

falling into the large weight class will generally touch three or four sides of the cell

and will be standing erect in the cell. An

egg in the medium weight class will have

space between it and the fourth side (filler

cell) and will be leaning slightly away from

the side it is not touching. An egg in the

small weight class will be lying almost on

its side. It should be borne in mind that the

degree to which the cell is filled and the

position of the egg in the cell are only

guideposts to help the grader in acquiring

skill in weight classing. On the basis of the

above raethod, the grader picks out the

medium or small eggs if most of the

eggs in the lot are large; and the large

eggs if the lot is mostly of mediunn-weight

class eggs. The eggs should be checked, as

necessary, on the individual egg scale whenever the grader is in doubt about the weight.

By getting the eggs of obvious different

weight classes sorted first, the grader has

more time to give to determining quality,

thereby increasing the accuracy of his grading.

The grader should not confine the procedure of segregating eggs by weight to the

initial operation but should frequently check

some of the remaining eggs until he acquires

skill. After experience is gained the required frequency of weight checking maybe

reduced.

Skill in grading eggs, and in evaluating

the external and internal quality factors and

properly classifying them in accordance with

the U. S. Standards for Quality of Individual

Shell Eggs, has been considered by some as

relatively simple to acquire. Those who are

informed about egg candling, however, know

that it is rather difficult to become proficient in determining egg quality by candling. It has been said that it takes a year of

training and experience to learn to candle

properly, Z years to become a good candler

and grader, and many years to become an

expert.

CANDLING AND WEIGHING FACILITIES

In order to grade eggs with maximum

,efficiency it is essentialthat adequate facilities be provided.
26

Candling Room

The candling room should be darkened to

the extent necessary to do an adequate and

efficient job. The extent of darkness will

vary depending on the type of candling light

and other equipment used. There should be

no cross beams of light between the grader

and the candling light, except those emanating from his candling light. The candling

light aperture should be so placed that rays

of light coming from it will not shine directly

into the grader's eyes when he is in a position for candling.

it is desirable that the walls and ceiling of

the candling room have smooth, washable

surfaces and be painted with a dark-colored

flat-finish paint to avoid light reflection.

The linear space provided for each grader

depends largely on the number of grades

being packed and the general packing setup

(fig. 15). Sufficient candling bench and shelf

space should be provided for efficient

grading and record control. Consideration

should be given to: Provision for maximunn

concentration by graders (by installing shallow partitions between candling benches) and

'^

ELECTRIC WIRE MOLD

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EGGS

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for minimum movement of graders; ease of

case movement; care and cleanliness of

packing materials; ease of removing empty

cases; convenience to supply of packing materials; and ease of disposing of damaged

packing materials and loss eggs. Sufficient

space should be provided behind the grader

to assure open aisle space atalltimes.lt is

recommended that suitable locker space be

provided for grader's outer garments in an

area or room other than the grading room.

The locker room may serve as a lunchroom.

The floors should be of smooth concrete,

coved into wall intersections and pitched to

trapped floor drains. This construction will

make possible floor wash-down and will

help reduce off odors. If foot mats for

graders are used, they should be of a material that can be washed without moisture

penetration; and consideration maybe given

to artificially heated foot mats.

Sufficient overhead lights should be provided to facilitate cleaning up the room.

It is recommended that the grading room

be equipped with a forced-air ventilator that

provides cool air in warm weather and

heated air in cool weather. Additional facilim.

SECTION A-A

SCALE OF INCHES

0 5 10 20

FIGURE 15.—Diagram of a candling bench.
27

ties might include a humidifier and yearround air conditioner. It is essential that

the forced-air inlet deflect inconning air so

that it will not blow directly on the workers

and that the control switch be located outside

the grading room, accessible only to the

foreman of the candling room.

Candling Bench

The candling bench, or grading bench, may

be one of a number of designs suited to fit

various packing needs. The example shown

in figure 15 illustrates its use for bulkpacking of eggs in 30- or 15-dozen cases. If a

cartoning operation is added, a supply of

one-dozen cartons could be kept on the shelf

above the candling light and an egg case such

as that marked **A** in figure 15 could serve

as a tablefor filling cartons. If a mechanized

cartoning operation is considered for this

type of bench, the part of the partition above

point Y (fig. 15) could be suspended from

the ceiling and serve as a hanger for a conveyor belt carrying inbound empty cartons

to the grader*s bench at **level X*\ The

belt could return along **level Y*' (fig. 15)

and serve as a conveyor for filled cartons.

Basically, the dimensions should remain

as shown in figure 15. An individual egg

scale should be installed over the candling

light. A gravity-roller conveyor for packing

materials may be installed under the candling bench or along the wall in back of the

grader.

In some large operations today, intricate

tabulating systems automatically compute

the weight and quality count for each lot of

eggs graded. This type of operation requires

a type of bench constructed to fit the specialized equipment and room layout.

Candling Light

There are many styles and types of candling lights commercially available in which

the light intensity and the size of the

candling-light opening vary considerably.

Most of these candling lights, however, are

satisfactory, if they are adjusted to provide

comfort and proper illumination for the job.

It is largely a matter of becoming accustomed to the type of light in use. The accuracy of the candling results canbe checked

by breaking out an occasional egg and comparing thebroken-out quality with the quality

determined by candling.

The opening into which the egg is placed

for examination should be no larger than

11/8 inches in diameter.

The opening at the bottom of the light

should be no larger than necessary toprovide

sufficient light to detect dirty eggs and to observe the condition of the packing material.

The light should be adjusted so that the

aperture of the candling light is approximately on the level of the grader*s elbows.

The interior of the candling light should

be kept clean and free from dust to assure

maximum light efficiency.

If a lens and a reflector are used, they

should be freed periodically of the film-like

coating. The reflector should be kept in adjustment and the surface silver should be

intact.

In selecting a candling light, it should be

borne in mind that the grader might adjust

his quality interpretation slightly according

to different types of lights or varied adjustments of the same light. It is best, therefore, to select one type of light and keep it

clean and properly adjusted. Once a grader

has adjusted his candled interpretation to

a reasonably close correlation with the

broken-out appearance of eggs, uniform

grading can be maintained with moderate

supervision.

Weighing Equipment

Individual Egg Scale

Each candling bench should be equipped

with an individual egg scale.

In manual grading in commercial plants,

every egg is not weighed. However, after

check-weighing many individual eggs, the

grader beconnes rather proficient in accurately determining weight of eggs by sight,

and touch. The scale should be handy on each

bench to verify the weight of occasional eggs

about which there is a question. The scale

should have its moving parts enclosed to prevent **fouling'* due to dust. It is recommended that the weight indicator be of a

single-beam type so that **making weight** is

accompanied by a click as the scale beam

comes down. The grader hears this click,

therefore he does not have to wait for his

eyes to become adjusted in the semidarkness

in order to read the scale, nor does he have

to wait for a pendulum counter balance to

come to rest before weight is determined.

Automatic Egg Scale

There are many types of autonriatic and

semi-automatic egg-weighing devices Üiat

can be installed in the egg-grading line. The

weighing operation can precede or follow

the candling operation. If it precedes the
28

candling operation it is important to group

the eggs in each weight class. Weighing

before candling has some distinct advantages: (1) The grader is more inclined

to ignore the weight factor in candling and

thus to devote more attention to the rest of

the grading job; (2) checked eggs thatmight

develop during the weighing operation are

subject to detection; (3) gross errors by mechanical weighing equipment canbe detected.

Weighing after candling has its advantages

too: (1) Loss eggs are not handled twice and

are less likely to be broken; (2) badly dented

checks or leakers are removed and the

danger of fouling the scales with egg liquid

is thereby reduced.

The weighing accuracy of automatic

equipment should be checked at the beginning of each shift and periodically during the

shift. When the weighing is done by electric

contact at the scale balance, care against

fouling of contact points by dust and moisture

is important. When weighing is done by having the egg stop its forward motion just

before the scale beam is automatically released, it is important that the egg come to

rest completely before weighing commences, because the added weight imparted

by the stopping motion of the egg may result in inaccurate segregation as to size.

SHELL EGG GRADING LABORATORY

The laboratory procedure should include

demonstrations of grading-room practice,

correct candling technique, classification

with respect to quality factor s for individual

eggs, and segregation with respect to

weight class. In order to reduce confusion

and fix the standard for each factor in the

beginner's mind, each quality factor should

be considered separately for a number of

lots. Each student should classify various

lots of eggs as the instructor corrects or

adjusts interpretation and technique. After

the student becomes reasonably accurate in

his interpretation of each quality factor considered separately, a trial lot or two should

be considered for all factors simultaneously.

The broken-out egg quality should be compared with the quality interpretation by

candling, and misinterpretations adjusted.

Candling Technique and Grading-Room

Practice

Demonstrate the transfer of 3 dozen eggs

in filler and flat.

Student practice

Describe the candling light.

Adjustment and maintenance.

Demonstrate the use of the individual egg

scale.

Check for accuracy and adjusting.

Demonstrate classification for weight.

Demonstrate classification for stain and

dirt.

Demonstrate '^belling* ' for soundness of

shell.

Demonstrate rotation and candling with

two eggs in each hand.

Student practice--(4), (5), (6), and (7).

1.

2.

4.

5.

7.

Classifying as to Weight

Laboratory Work Sheet No. 1

Lot No. Extra Large Large Medium Small
29

Classifying by Shell Factors

Laboratory Work Sheet No. 2

Shell Factors

Lot No. Clean B (Stain) C (Stain) Dirty

Texture and shape

Checked

Normal Slightly

Abnormal Abnormal

Classifying by Air Cell

Laboratory Work Sheet No. 3

Air Cell

Lot No. AA A B C
30

Classifying by White and Yolk

Laboratory Work Sheet No. 4

White and Yolk

Lot No. AA A B C Loss

Bloody White

White Rot

Mixed Rot

Stuck Yolk

Moldy Eggs

BW Black Rot Black

WR Blood Rings Br

MR Large Meat or Blood Spots B

SY Leakers L

MLDY Smashed S
31

Classifying by All Factors

Laboratory Work Sheet No. 5

All Factors

Lot

No. AA Dirty Checks Leakers Loss Percentage

under oz.

1

Bloody White

White Rot

Mixed Rot

Stuck Yolk

Moldy Eggs

BW Black Rot

WR Blood Rings

MR Large Meat or Blood Spots

SY Leakers

MLDY Smashed

Black

Br

B

L

S
32

FEDERAL-STATE GRADEíG PROGRAMS

For more than 25 years the U.S.Department of Agriculture in cooperation with the

various States has conducted a voluntary

Federal-State egg-grading service. The

legislation authorizing these programs provides that they be conducted on a self-supporting basis financed from fees charged

the applicants for the service.

The grading service is based on the U.

S. Standards for Quality of Individual Shell

Eggs and the U. S. Grades and Weight

Classes for Consumer Grades, for Procurement Grades, and for Wholesale Grades of

Shell Eggs. In addition, contract purchase

specifications serve as another basis for

performing grading or inspection of lots of

eggs tendered for delivery under purchase

agreements. The various purchase specifications are, of course, based on the U. S.

Standards for Quality of Individual Shell

Eggs.

In the early days of the Federal-State

grading service for poultry and eggs, the

work consisted largely of exannining eggs

and poultry purchased by the U. S. Navy,

to determine compliance with procurement

specifications. Grading and inspection service of this type gradually was extended to

other governmental agencies and private

institutions that purchased eggs and poultry

products.

Grading offices were established at the

important terminal markets along the East

and West Coasts as well as in the inland

terminal markets, such as 3t. Louis and

Chicago. These offices, in addition to providing grading service for eggs, poultry,

and poultry products, handled the market

news reporting activities, which began at

about the same time.

The growth of the service was slow at

first, but expansion continued at a steady

pace during the thirties. The most rapid

expansion occurred during World War II in

connection with Government-buying programs for the Armed Forces and lend-lease

activities (fig. 16). The use of the services

and the volume of products inspected and

graded continued to expand after the cessation of hostilities. This expansion was

due in part to the price-support programs

that followed and to the fact that firms had

had experience with Federal-State grading

and inspection programs and were continuing to use thenn in their processing and

marketing programs.

It was during the war period that resident

grading and inspection programs developed

into major importance. Under these programs a qualified USDA licensed grader or

inspector, whose duties included the grading

of shell eggs in accordance with U. S.

standards and grades, and the supervision

of egg-breaking and drying operations, was

placed in the processing plant. With the advent of the **resident grader*' type of

service the volume of products graded and

inspected on a *'fee basis** became (proportionally) less important, considering the

overall volume officially graded and inspected. Resident graders are used in the

producing areas as well as in the distribution centers. The resident type of grading

service offers several advantages over the

terminal market or fee type of grading

service:

(1) Grader is constantly available to grade

and certify the pack, whether in cartons or loose.

(2) Grading is likely to be more uniform

because the grader is continuously

available to check the accuracy of the

various candlers in the egg-grading

room.

(3) Cost of resident grading service is

less per unit than for intermittent fee

grading, when a substantial part of the

eggs handled is graded. In addition,

the resident grader quite often serves

in the capacity of a candling-room

foreman as well as a USDA licensed

grader.

Sometimes the term * inspection* ' is used

synonymously with **grading.'* This is perhaps a proper use of the term in referring

to gradings at terminal markets, as inmost

cases that work consists of examining a

representative sample of either graded or

ungraded lots. Thus, it can be said one

**inspects** for grade. This meaning is not

properly associated with the term * *inspection** used for poultry. Inspection of poultry,

of course, pertains to the examination of

poultry and its internal organs during the

evisceration process to deternnine its wholesomeness or fitness for food. And the term

**inspection* * does not apply to programs

in which eggs are graded under the continuous supervision of resident graders and

packed in either 30-dozen cases or in 1-

dozen cartons bearing official grade marks

(fig. 19)- When the resident grader checks

the work of licensees working under his
33

EGGS GRADED UNDER FEDERAL

AND FEDERAL-STATE PROGRAMS

MIL. CASES

1955

NEC. 647-54(4) AGRICULTURAL MARKETING SER.VICE

FIGURE l6."The quantity of shell eggs graded under Federal and Federal-State programs increased from one-half

million cases in 1932 to more than 16 million cases in 1952.

direction, the work is more properly classified as check-grading.

Regulations Governing Grading

of Shell Eggs

Grading services of the U. S. Department

of Agriculture for shell eggs are permissive,

in that individuals, firms, or governmental

agencies that desire these services may

request them on their own volition. Services

are performed on the basis of the *'Regulations Governing the Grading and Inspection of Shell Eggs and United

States Standards, Grades and Weight

Classes for Shell Eggs.'* These regulations, like other regulations governing

marketing service programs, were developed in cooperation with the industry,

including all affected groups, such as marketing and regulatory officials, producers,

handlers, and consumers, as well as on the

advice of inspection and grading officials

throughout the country.

The regulations explain how interested

persons may apply for grading service,

including appeals and regradings. Application for intermittent grading service on a

fee basis is usually made by telephoning

the local USDA grading office, by personally

contacting a grader in the vicinity, or by

contacting the State supervisor's office.

Prospective applicants for egg-grading

service may also contact the Poultry Division, Agricultural Marketing Service, U. S.

Department of Agriculture, Washington 25,

D. C, regarding the availability of grading

service in their areas.

Application for resident grading service

is nnade on special forms which specify the

responsibilities of the applicant and the Department in connection with the performance

of grading service on a continuous basis. The

application form also prescribes the fees
34

and charges that the applicant must pay for

the service.

Federal-State grading service is performed by USDA licensed graders who are

supervised by the State, area, and national

supervisors of the service. Graders maybe

either State or Federal employees or

licensed individuals, trained and qualified to

grade, whose employment status is not spec -

ified. In addition, the regulations provide for

the issuance of limited licenses to persons

qualified to candle and grade eggs under the

U. S. Standards for Quality of Individual

Shell Eggs, applying to eggs purchased from

producers or eggs to be packaged with official grade labels.

Cooperative Agreements

The Federal-State egg grading service is

conducted under cooperative agreements

between the Department and one or more

cooperating parties within each of the States

where service is available. The agreements

are usually nnade with State departments of

agriculture and State extension services, or

State colleges. Occasionally, experiment

stations are cooperators, and in exceptional

cases, trade associations serve as cooperating agencies.

Usually the responsibilities of State

colleges and the extension services apply to

the educational aspects of the grading program, under which they provide training for

prospective graders and explain the

Federal-State program to producers, handlers, and consumers.

State departments of agriculture are

usually responsible for the administrative

phases of the program within their States.

The cooperative agreements vary from

State to State from the standpoint of leadership and other responsibilities.

There are two main types of agreements--State Trust Fund and Federal Trust

Fund agreements. Under the State Trust

Fund agreement, the fees charged are collected by the State and held in trust by the

State. The contracts for service are between the State and the individual firms,

and the resident graders are State employees

or USDA licensees ennployed by the firm.

The Department is reimbursed by the cooperating agency periodically from the trust

fund to cover the cost of the Federal supervision of the program. Under the Federal

Trust Fund agreement, the contracts for

services are between the Departnnent and

the individual firms, and the fees are collected and held in trust by the Department.

The employees doing grading work are

generally Federal employees or licensed

employees of the firms, and the State is

paid periodically out of the trust fund an

amount to cover the costs and expenses incurred by it in performing grading and

supervisory work.

Although two types of cooperative agreements are in effect, nnost of the agreements

are of the Federal Trust Fund type.

Grade Labeling

Under the Federal-State grading program

provision is nnade for the grade identification of the packaged product, whether packed

in a 30-dozen case or a 1-dozen carton.

Usually the grade mark is applied to 30-

dozen cases by means of a rubber stamp

(fig. 17). The stamp also marks the date the

eggs were graded. In many instances when

eggs are packed for delivery on purchase

contracts to institutions, a paper tape must

be placed around each half case and sealed

at the top of the case. In these instances

the grade or acceptance stamp (fig. 18) is

usually applied to the tape at the point of

sealing. Many carload and truck shipments

of officially graded eggs are not stamped

with a grade mark. In these cases, the

buyer and seller rely on the grading certificate to give the grade and percentages

of the various qualities in the lots.

Perhaps one of the greatest values of the

grading program is the grade labeling of

individual cartons of 1-dozen eggs to inform

consunners of the quality. The regulations

U. S. D. A.

OFFICIALLY GRADEO

7-1-54

u. &

GRADE

A6RADEÍ

151

FIGURE 1/•"Official grade stamp for use in terminal

markets.
35

OFFICIALLY GRADEO

7-1-54

FOR N. Y. CITY

220

FIGURE 18.—Official mark to indicate occeptance under

institutional purchase contracts.

provide for the approval of cartons and

grade labels that are used in the labeling program for consumers. The grade

mark used on official grade labels is

contained in a shield design. It contains the following information: (1) The

letters USDA, (2) the U. S. grade and

size, and (3) a phrase such as **Graded

Under Federal-State Supervision'* or

**Graded Under U. S. and (State) Supervision*' (fig. 19). The grade mark nnay be

printed on the carton, or on the sealing

tape. If the egg size appears on the main

panel of the carton, the size designation

need not be shown on the seal (fig. 20).

The date of grading must be placed on the

seal or elsewhere on the carton. It is expressed as the month and day or as the

consecutive day of the year.

FIGURE 20.--Official grade mark for use on carton seals

when size is shown on carton.

cartoned eggs may be grade marked:

1. The eggs nnust be graded by and identified under the supervision of a licensed

grader. The actual grading may be performed by a limited licensed grader. (A

limited licensee is a grader qualified and

licensed to classify eggs according to

United States grades but not authorized

to issue certificates), but must then be

check graded by the supervising grader,

2. If officially identified eggs are held

in excess of four days after official grading, they shall be again check graded in addition to the previous check grading. 3, Eggs

to be packed in consumer packages and grade

marked U. S. AA or U. S, Amust be packed

from eggs of current production. 4. After

January 1, 1956, establishments packing

eggs with official marks in cons\imer packages must meet the facility and operating

requirements set forth in the U, S. D. A.

regulations.

USDA

LARGE

Graded Under

Federal-State Supervision

FIGURE 19.--0fficial grade mark for cartons or seals on

cartons holding l-dozen eggs.

Prerequisites to Packaging Eggs with

Grade Identification Labels

Several requirements must be met before

Costs of Service

As the legislation which authorizes Federal-State egg-grading programs provides that the costs of the service be

covered by fees charged persons who apply for grading and inspection services,

schedules of charges have been established

to cover these costs. Included as cost

items are the salaries of the graders who

perform the service, travel costs incurred

in connection with grading activities,

clerical assistance in typing certificates

and maintaining necessary office records,

supervisory costs at the field level, and

the administrative and overhead costs at

the Washington level. The charges for

grading shell eggs on an intermittent or

**fee basis'* are based on the number

of packages graded. Fees for grading
36

service performed on a resident or continuous grading basis are set forth in the contract fornn and are based on the costs to the

Department in furnishing the grader or

graders to the plant plus an overhead administrative charge, based on the volume

of the product handled in the plant, to cover

supervisory and other costs.

Salaries of resident graders are based

largely on the wages paid for comparable

work in the area where the grader is stationed. The fee schedules applicable to

terminal market or fee grading vary from

time to time as costs change. Whether the

grading is done on a fee basis ora resident

basis, the cost will average only a very

small fraction of a cent per dozen eggs.

THE USDA LICENSED GRADER

In plants using the Federal-State egg

grading service, the representative of the

U, S. Department of Agriculture is the

licensed USDA grader. He is largely responsible for the success of the grading

progranns.

General Qualifications

A licensed resident grader must have a

combination of qualifications. He must have

technical knowledge of and practical experience in the eggbusiness and the stamina

to do a physically tiring day*s work cheerfully and effectively. He should be able to

maintain good relationships between the

industry and the Department.

The technical knowledge and experience

requisite for this job call for familiarity

with the Federal standards of quality for

individual eggs, weight classes, and grades

of eggs, and the ability to apply this knowledge at the grading bench at a rate of

speed that is normal in comnnercial grading.

Additional qualifications that the grader

should have include the ability to instruct

and then correct as necessary, the work of

the egg candlers under his supervision, in

order to insure accurate interpretation of

the standards without upsetting the rate of

production of the grading room. He should

have sufficient background information on

egg formation, structure, production, and

care to be able to explain quality defects

authoritatively in technical or nontechnical

terms to nnanagers, candlers, producers,

or buyers.

The physical work involved in serving as

a USDA resident grader is not arduous by

nature, but standing (generally on a concrete floor) in a comparatively fixed position

for long periods is tiring. Unless the grader

is in average or better than average physical

condition, his judgment and speed will be

impaired before the work day is completed.

Maintenance of good relationships is

necessary because the grader must be an

unbiased observer and reporter of his

findings at all times and should have the

good will of management even when rendering decisions that are adverse to its

interests. Some individuals are not psychologically suited for this type of workbecause

of the strain. Others find it a stimulating

challenge.

Specific Qualifications

To do the best job, a licensed grader must

have certain specific qualifications.

Experience

Experience in candling and grading is

essential. The lack of extensive commercial

grading experience can be overcome, in

part, by intensive training, including much

closely supervised practice. The skill required to candle eggs at normal commercial

operating speed and the ability to grade

accurately for quality can be acquired only

through practice. The amount of experience required will vary with different individuals, depending on their aptitudes for

the work.

Education

Although the amount of formal education

is not too important, the prospective licensee

should have a high school education or the

equivalent. The average grading assignment

requires the preparation of reports and

certificates and the ability to understand

semitechnical detailed instructions.

Age

The age (preferably between 21 and 40)

of the individuali s secondary in determining

the qualifications for egg-grading work.

Maturity is desirable and frequently a

requisite to satisfactory perfornaance as

a licensed grader.

Sound judgment and accuracy of decisions

are usually associated with maturity. Hence,

at times when an adverse decision is re-
37

quired, management is inclined to accept

it more willingly from a mature individual.

If an individual possesses a practical

knowledge of egg-grading operations and

is a skillful egg candler, age is not so

important. On the other hand, if an individual 40 or more years old has never

candled and graded eggs, he may have

difficulty in acquiring the necessary skill.

The rapid coordination between eye and

hand and the dexterity required in manipulating eggs in candling are acquired more

slowly by an older person. It is therefore

desirable to select a younger individual

(under 40) for this type of work. Confidence

is essential in a good grader.

Physical Fitness

Normal good health of the average grader

is sufficient if the tiring effect of standing

in one position for long periods of time

does not detract from the accuracy of good

judgment by the end of a normal work day.

Individuals bothered by ailments such as

varicose veins and flat feet might find the

long hours of standing onhard floors harmful

to their condition. This is equally true if

lifting moderate weights (up to 60 pounds)

and frequent turning of the torso aggravate

other ailments. The individual who is very

much overweight might develop foot and

leg ailments.

Freedom from Red-color Blindness

Although total red blindness is not very

common, an individual so affected should

not endeavor to grade eggs for quality. The

determination of the various qualities in

eggs presupposes the ability on the part of

the grader to classify various shades and

intensities of red into fine gradations. Total

red blindness makes this impossible.

Duties and Responsibilities

An official grader of the U, S. Department

of Agriculture should receive complete

instruction about his duties and responsibilities. Such indoctrination should cover

two fields: The broad general scope of the

overall job, and the specific and detailed

responsibilities as they pertain to any

particular part of the job.

The broad general responsibilities and

duties of the egg grader are to observe and

record accurately the class, quality, and

condition of shell eggs in accordance with

U. S. standards and grades, and to prepare

the necessary memorandums, certificates

and reports in connection therewith, according to the regulations and instructions. The

grader's conduct on and off the job shall

befit the dignity of a representative of the

Department. Official decisions shall be

rendered in a manner that will be a credit

to the Department and will simultaneously

hold and encourage the good will of the user

of the service.

Specific responsibilities include:

Keeping all official supplies, grade

stamps, and equipment under lock and key.

Maintaining a handy reference file of

instructions and regulations.

Correcting egg candlers' misinterpretations of official grades and supervising

the work of candlers as necessary in a

manner that will not disrupt candlingroom production and will obtain the

closest possible relationship between official quality standards and candlers*

versions.

Maintaining permanent records of findings in supervisory check gradings.

Drawing samples personally in a

manner prescribed in the procedure

instructions.

Performing check gradings on cartoned

eggs bearing the official mark.

Examining samples in the sequence

and manner prescribed in the instructions.

Performing an official inspection on

each lot of eggs bearing the official mark.

Personally taking and recording

temperatures of case, storage holding

room, truck, and car.

Personally preparing and signing all

grading memorandums at time of grading.

Carefully checking memorandum totals

and averages when assigning the grade.

Using official terminology when referring to official standards in certificates

or official correspondence.

Issuing on request of applicant an official memorandum and a certificate for

lots of eggs examined.

Including all necessary detail on all

certificates.

Personally handling, or closely supervising, the neat application of the official

grade mark.

Either typing certificates personally or

carefully checking someone else's typing

against memorandums.
38

Signing all original certificates and

initialing all copies.

Arranging for distribution of certificates in accordance with instructions.

Defacing, removing, or causing to be

defaced or removed, any incorrect official identification on any packages containing eggs packaged in the plant.

Preparing all reports on schedule and

in accordance with instructions.

Reporting to the immediate supervisor

any misuse of official identification.

Assisting management whenever possible by calling attention to any factors

that are causing the **down grading*' of a

lot of eggs.

In addition to the responsibilities just

outlined it has frequently proved helpful for

the egg grader to:

Suggest to management methods of

handling, processing, packing, storing,

and shipping of graded eggs in a manner

that will conserve quality.

Contact the supervisor immediately

regarding difficult technical, personnel,

or public relations questions that might

become serious problems.

Services to the Applicant

The official grader furnishes the grading

service stipulated in the terms of the contract between the applicant and the Department. In order to fulfill these requirements

most effectively it is essential that the

grader's activities be confined to the performance of grading service or related

workOne of the most valuable services rendered by the official grader is the issuance of

a grading certificate that is accepted as

prima facie evidence in a court of law. In

addition to this service other important

services are:

Providing an unbiased grading service

for producers of quality eggs.

Providing factual information with respect to quality which will assist producers in improving the quality of eggs

delivered.

Providing an unbiased grade for buyers.

Providing an authentic grading-room

check control on quality.

Providing skilled supervision to the

grading room.

Providing training for new and inexperienced graders.

Providing grading-room supervision

that does not yield qualitywise under sales

pressure.

Providing qualified personnel to pack

products according to official grade requirements.

Placing management in a position to

bid intelligently on deliveries requiring

Federal grading by always drawing adequate samples on lot gradings.

Making it possible for management to

supply grading certificates for such deliveries.

Mechanics of Grading

The procedures to follow whenperforming

official grading are set forth in detail

in the instructions issued to officially

licensed graders.

The actual mechanics of grading of a lot

of shell eggs can best be covered by setting forth the steps to follow for each of

the two types of gradings. (1) Check grade

eggs carrying official grade marks, continuously as they are being packed and also examine a portion of the lot after packing is

completed. (2) Determine the grade of

product on the basis of a representative

sample.

In checking the grade of eggs packed by

limited licensed graders a sampling procedure has been developed that includes

drawing and examining samples from each

grader's work during the day. The determination of when and how frequently a

grader*s work is to be sampled is based

on the general quality of the eggs being

graded and the proficiency of the grader. It

should be assumed that important check

periods are: At the beginning of the day;

shortly after the grader returns from a

rest period or lunch; at the beginning of

grading a new lot of eggs; when a lot contains unexpected or variable qualities or

conditions that are not generally prevalent

in incoming eggs or with which the grader

has not had recent experience (such as

stains, small size, blood rings, mixed

colors, or brown shells if white eggs only

have been handled in the past). Obviously

the work of all graders cannot be checked

at all of these stages but keen observation

and regularly prepared graders* performance records maintained by the official

(USDA licensed) grader will be of great

assistance in determining the sequence and
39

timing of the check against each grader's

work. Care should be exercised not to

develop a pattern of inspection that is

familiar to everyone. The checking should

be handled in a manner that will convey a

spirit of helpfulness on the part of the

official grader--not as if he were policing

the work. Constructive results can be

achieved only when the work is checked in

a manner that does not imply the passing

of a test at each check inspection.

In addition to regular check inspection

of the individual grader's work an inspection should be made of a representative

sample of the product drawn from the

pack as it is completed each day. This

inspection should be made to verify findings of periodic checks made during the

day. At the san:ie time a check should be

made on the application of the official n:iark,

the correctness of wording on the package,

condition of the containers, and the product,

packing temperature, and breakage that may

have occurred in packing operations. Records of all check gradings should be made

part of the official grader's permanent

record.

When determining the grade of the product on the basis of percentages of qualities

found in the random sample, it is essential

that an adequate cross-section sample be

drawn. The size of the sample andthe position of the sample in the case, as required by the Federal-State grading service, have proved satisfactory and workable.

It should be pointed out, however, that

these quantities are minimum and the

grader must decide whether or not they

truly represent a cross-section sample. Additional samples must be drawn when any

doubt exists.

Generally, the best procedure to follow

after deciding on the size of sample is to

draw from the truck, railroad car, or

warehouse one case per stack and per layer,

or, if several such lots are involved, a

number of sample cases from each in proportion to the size of the lot. As each sample

case is drawn, it should be numbered and

initialed and one of the adjoining cases in

the stack should be given the same number.

The latter practice enables the grader to

return to the same location in the lot for a

larger Scimple if any one of the samples

drawn is found to be of an unusual character.

While drawing the sample, the grader

should try to detect any odors in the storage

area. The presence of any foreign odor

should be recorded on the grading memorandum. At this time the grader should also

lay his thermometer on the lot of eggs or

hang it nearby to obtain storage temperature.

The general condition of the egg cases in

the lot should be observed and the condition

of the sample cases should be noted on the

memorandum.

After the entire sample has been accumulated and identified by the grader, examination should begin. The half of the caseto be

examined should be placed under the candling

light so that annple case light is provided for

detection of dirty or stained eggs. A thermometer should be placed under the second

filler in the opposite end of the case in order

to obtain case temperature while grading.

Out of each sample case, 100 eggs should

be examined; that is, all but the 8 eggs in

the third layer if the eggs are packed in

fillers, or all but the 20 eggs in the fourth

filler-flat, if that type of package is used.

The eggs should be examined as follows:

In the first case the 3 top fillers; in the

second case, the 2d, 3d, and 4th fillers; in

the third case, the 3d, 4th, and 5th fillers;

in the fourth case, the 1 st, 2d, and 5th fillers;

and in the fifth case, the 1st, 4th, and 5th

fillers. It is felt that 100 eggs is a large

enough number to reflect the quality level

of each sample. Each egg can be considered

as 1 percent of the sample.

In order to improve counting accuracy, 4

empty fillers with flats should be conveniently placed for filling; 3 of them should

be used for eggs of the principal qualities

found and 1 for eggs of qualities occurring

infrequently.

After candling and check-weighing the

^ggs, as described in an earlier section,

the grader should tally up individual egg

qualities and enter the figures on a memorandum. Data on light-weight eggs shouldnot

be recorded in the quality tally. They should

be totaled and listed separately on the memorandum. The eggs examined should be put

into three fillers and theses fillers should

be so placed in the end of the case from

which the eggs were taken that they will always appear as fillers one, two, and three,

regardless of the original position of the

eggs in the case.

At this point the case temperature reading

should be recorded.

The net weight per case should be determined by transferring all eggs, fillers, and

flats from the half of the case examined to a

platform scale. (Scale should be checked

for accuracy before each inspection.) The
40

weight should be multiplied by 2, and 3-1/2

pounds should be deducted as tare, if fillers

and flats are used, or 1-3/4 pounds, if combination filler -flats are used. The difference

is the net weight of the case. The reason for

this rather involved procedure is to eliminate variations in the weight of individual

empty cases. The filler and flat weights at

3-1/2 pounds and filler-flats at 1-3/4 pounds

are seldom in significant variation.

The inexperienced grader may find

"transferring' ' 3 dozen eggs at a time rather

difficult but practice develops proficiency.

Before attempting to pick up a layer of eggs,

the grader should make sure that the filler

and flat are in good condition. He should

grasp the filler and flat in both hands, as

near the ends of Opposite corners as

possible. The first two joints of the fingers

of each hand should hold the corners of the

flat on the under side and the thumbs should

be pressed securely on the top of the filler.

The corners of the filler and flat should then

be lifted and tipped toward each other

slightly, making sure that the filler remains

securely pressed against the flat. Proper

transfer procedure may be checked at this

point: The shape of the filler cells has

changed from square to diamond, the top of

the filler between the hands has become

concave, and the eggs in the center of the

filler have not slipped downward. Now the

filler and flat containing the eggs should be

raised out of the case, the position just described being retained until the flat has

been brought to rest outside the case. To

return the filler and flat to the case, the

grader should insert one of the filler's

corners not being held by him into the

nearest corner of the case, then should settle

into place the diagonally opposite corner of

the filler, after which he should release the

corners being held in his hands. The development of dexterity in this technique is not

absolutely necessary, but most experienced

graders can '*transfer'* proficiently. The

knack, therefore, helps the grader's prestige

and it speeds up his output of work without

egg breakage.

The detailed findings of the grading should

be reviewed for accuracy, the case percentages should be totaled and averaged.

The accuracy of the figures can be checked

by determining whether the totals in the

quality columns (not including figures for

case weight or light-weight eggs) equal

the number of cases multiplied by 100, and

the averages of all quality columns equal

100.

Before affixing his signature to the certificate, the grader should check to make

sure that the data have been accurately

transferred to the certificate from the

memorandum. A covering certificate should

be issued on the day the grading is made, if

at all possible. The certificate and memorandum file should be kept under lock and

key.

Grading certificates are negotiable instruments in trading. It is, therefore, of

utmost importance that the grader realize

that he is accountable for all blank certificates issued to him and that he nnust

keep records to show what was done with

each certificate.

As in any legal document, erasures or

strike-overs should be avoided. Minor corrections that can't always be avoided must

be initialed in ink by the grader. Original

certificates that contain many errors or

that are mutilated must be marked void

and recorded and attached to the list of

certificates that is mailed to the supervisor

each month.

LEGISLATION AFFECTING GRADING

AND MARKETING OF EGGS

Much legislation has been enacted to

regulate the sale of shell eggs. The laws

apply to the edibility of the product and to

its quality and grade. Both Federal and

State laws are applicable to eggs, but practically all of those pertaining to candling

and grading have been enactedby the States.

Federal Laws

The Farm Products Inspection Act of

1917 provided the original authority for

establishing grades and grading service for

voluntary use. Since 1925, the annual Appropriation Act of the Department of Agriculture has continued to provide for the

inspection of agricultural commodities including eggs.

The Federal Food, Drug, and Cosmetic

Act and the regulations for its enforcement

thereunder apply to all food products in

interstate commerce including shell eggs.

This act is designed to prevent the shipment of adulterated and misbranded foods.

In applying this act to shell eggs a small

tolerance for loss eggs is permitted, as it

would be rather difficult, costly, and impractical to eliminate all loss eggs from

wholesale quantities of eggs.

The Packers and Stockyards Act is designed primarily to protect producers and
consumers against unfair, deceptive, and

fraudulent practices and devices in interstate and foreign commerce. The act and

the regulations promulgated thereunder apply to egg handlers only if the handler is

also engaged in the meat packing business,

or operates a stockyard, or is a dealer, or

market agency for livestock products. The

larger meat packers who also handle eggs

are subject to the provisions of the Packers

and Stockyard Act, whereas an operator

engaged exclusively in the egg and poultry

business is not.

STATE EGG LAWS

Egg laws have been enacted in 46 of the

48 States. The laws differ materially as to

their provisions but in recent years, as new

laws have been written and old ones revised,

there has been a tendency toward nnore

uniformity. Some of the earlier egg laws

were probably intended to protect and promote the egg industry of the particular

State and tended to serve as trade barriers.

Most of the recent laws and the revisions

of the older laws, however, are concerned

more with grading, grade labeling, and accurate representation of the product to the

consumer at the retail level. Most of the

enforcement effort is directed toward retail

outlets, although eggs are also inspected at

the wholesale and jobbing levels.

A survey of State egg laws was made

several years ago which indicated that progress was being made in obtaining uniformity

by use of U. S. Standards for quality and

grades for shell eggs. Afew of the facts contained in the report are as follows:

(1) The quality groups specified in egg

standards used by various States

ranged from 1 to 8. However, the most

generally used terms in a majority of

the States are: Grade AA, Grade A,

Grade B, and Grade C. Afew States use

such terms as Fancy, Special, Fresh,

Extras, Standards, and Trades to designate grades.

(2) The survey disclosed that fifteen

States have voluntary grades and 25

States have mandatory grades; 6 other

States have laws regulating the sale

of eggs, but they have not promulgated grades or standards. Only 2

States have no laws, grades, or standards regulating the sale of eggs.

(3) Twenty-four of the State laws include

provisions with regard to fresh eggs.

41

The use of the term 'afresh'* or other

terms that imply freshness in connection with the advertising or selling of

eggs or the labeling of egg containers

is usually prohibited unless the eggs

conform to minimum specifications of

A Quality as provided by law.

(4) Provisions for candling of eggs are

included in the laws of 35 States. In

3 States, egg candling is voluntary;

in 28 States, it is required; 3 States

require candling during specified

times of the year; and 1 State requires candling of all out-of-State

eggs before reselling.

(5) The sale of inedible eggs is prohibited in 34 States.

(6) Six States require out-of-State eggs

to be marked as such. Labeling eggs

which have been shell-treated is required in 12 States and 15 States

require storage eggs to be labeled

as such when offered for sale.

(7) In 37 States, all or part of the size and

weight specifications are the same as

those in the weight classes for consumer grades of eggs issued by the

Department of Agriculture in 1947

(revised in 1948). The terms used to

designate size or weight classes in

the State standards and grades are

much the same as those of the United

States standards and there is some

variation in the weights assigned to

individual size or weight classes.

(8) Twenty-six States now designate

grades by the same terminology (Grade

AA, Grade A, Grade B, and Grade C)

as used in the U. S. grades.

PRODUCTION AND MAINTENANCE

OF EGG QUALITY

The production of eggs has become a

major agricultural industry in this country.

Total production in the United States in

1952 was about 65-1/3 billion eggs. Producing and marketing this large volume of eggs

have been accompanied by an increasing

awareness of the need for quality conservation and in a trend toward specialization.

Breeding, hatching, and raising chickens,

and producing eggs and poultry meat as a

combination commercial operation are seldom practiced today. This fact is evidenced

by the many specialized production and

marketing operations that have come

into being in the poultry industry.
42

Breeding

Shell color and thickness, egg size, quantity of thick white, quantity of eggs produced,

and to some extent blood spots are hereditary factors and can be bred into the egglaying flock. The baby chicks or pullets for

the initial flock or flock replacement should

be procured from a source that can give

reasonable assurance that these factors

have been carefully considered in the breeding program.

Hatching

In order to assure improvedbreeding and

production qualities and to reduce losses

from pullorum disease in poultry, the industry established the National Poultry

Improvement Plan in 1935-

The Plan is adnainistered jointly by the

Agricultural Research Service of the Department and an official State agency in

each of the cooperating States. It operates

according to regulations and standards

under which birds classified with respect

to specific breeding qualities and freedom

from pullorum disease, and hatching eggs,

nnay be produced and marketed by poultrymen. Procurement of baby chicks from

**Plan" hatcheries assists the producer in

the selection of desirable young stock.

Brooding and Raising

The brooding and raising of baby chicks

to laying age may be done by one who

raises poultry for the eggs or by specialists

in the pullet-raising field. Egg producers in

a number of areas today follow the practice

of culling their flocks carefully or entirely

replacing them with laying-age pullets after

their flocks have completed their first year

of production. This practice eliminates for

the specialized egg producer an outlay for

additional space and labor, as well as the

hazards of raising additional birds.

If brooding and raising his own flock replacennents are considered by the egg

producer, it is necessary that thought and

careful planning go into the following:

(1) Selection of the source of baby chicks

(2) Providing separate quarters with sufficient space for raising birds to pullet age

(3) Providing sufficient land to permit rotation of each flock to new soil (not

used for chicks for a year)

(4) Management know-how regarding handling, feeding, watering, vaccination,

and sanitation

Production of High-Quality Eggs

Feeding shares the limelight with breeding in the production of high-quality eggs.

Shell.--The breaking strength of an egg is

affected by the hen*s feed, breeding, age,

and freedona from disease, and by hot

weather. Nowadays the average commercial

feed supplemented with '*grit'* (calcium

carbonate) usually has sufficient calcium,

phosphorus, manganese, and vitamin D to

produce sound shells. Therefore, the source

of shell trouble is more frequently found in

some of the other factors mentioned.

Yolk--Dark pigmentation in the yolk

affects the acceptability of the egg in the

top qualities. Rations high in yellow grains

and green feeds produce dark yellow to

orange-colored yolks. Rations high in green

grasses, silage, and cottonseed meal

(gossypol not removed) will cause the yolks

to acquire a reddish or olive color.

White--To be of fine quality, eggs must

have a high percentage of thick white. A

lack of this factor can be attributed to

breeding and disease of the chickens, and

improper care of the egg after production.

Housing

To produce eggs with fine quality shells,

yolks, and whites adequate housing of the

birds and care of the eggs after they are

produced, is essential. Adequate housing

should include sufficient floor, feeding, and

nest space, and nests having soft clean

nesting material or means for mechanically

removing the egg fronn the nest space.

Clean Eggs--The use of the * ^roll-away""

nest is becoming popular and is effective

in reducing the number of eggs dirtied in

the nest. The yard area surrounding the

laying house should be free from standing

water. Runways to or along the nests for

access to the nests help remove dirt from

hens* feet.

Wire-screened dropping pits reduce the

number of eggs dirtied from soil on the

hens' feet, and tend to reduce loss due to

breakage.

Care of Eggs on the Farm

Immediately after it is laid, an egg begins

to lose quality even if it is removed from
43

the nest, cooled, packed, and marketed

promptly. (See fig. 13.)

Keeping temperature and humidity conditions at an optimum level retards this

loss in quality to a large degree. The

necessary steps are:

1. Gather eggs frequently (at least 3

times a day)

2. Use a clean receptacle with ventilated sides and bottom, preferably

a rubber-coated wire basket

3. Place eggs in basket carefully

4. Never fill basket more than threefourths full

5. Place basket of eggs into cool, hunnid

storage room

6. Do not pack eggs in cases until laying

or nest temperature of eggs is reduced

to storage room temperature, Aclean

basement or an insulated room

equipped with an evaporative cooler

(home-constructed) will serve as a

good storage room

7. Pack eggs in clean, cool packing materials

8. Pack clean eggs separately fromdirty

eggs

9. Dry-clean slightly dirty eggs

Cleaning Eggs on the Farm

Even with good farm-management practices and careful handling a small percentage of dirty eggs will be produced.

Producers must bear in mind that dirty

eggs are covered with bacteria that will

cause spoilage if they enter the egg. Farm

cleaning, therefore, must be performed in

a manner that will minimize the chances

of bacterial penetration of the shell.

However, if these important facts are

forgotten, and accidental or wilful careless

washing is carried on, more damage can

be done than by leaving the dirt on the shell.

Dry Cleaning

Eggs may be satisfactorily and easily

cleaned with a dry abrasive, such as emery

cloth or fine sandpaper mounted on a shoe

buffer. Select only those eggs that are

moderately or slightly dirty or stained

for cleaning and **touch them up'* lightly.

Do not attempt to clean extremely dirty

eggs. They cannot be cleaned well enough

to be classified as clean eggs, and the

chances are they will become brokenduring

the energetic buffing required. Furthermore, the percentage of such eggs should

be very small if dirt sources have been

kept at a minimum.

If a mechanical dry-cleaning unit is used

care should be taken to see that the abrasive

strips are intact and not worn to a

nonabrasive or dirty point. Eggs should

be run through the unit once only. Otherwise they will acquire a shine that is

objectionable in the market place. No

attempt should be made to dry clean

extremely dirty eggs because they will come

out with stained shells.

Wet Cleaning (Washing)

Wetting a dirty shell provides moisture

in which bacteria may breed and assist

their growth and their penetration into the

shell. A washing solution colder than the

egg causes the egg content to contract and

thus allows polluted water to be drawn into

the shell. Therefore, if the washing method

is used to clean dirty eggs the following

precautions should be followed:

1. Wash eggs with water warmer than

the eggs

2. Select a detergent sanitizer that is

compatible with the wash water (varying degrees of hardness of water

causes unfavorable reactions with different quaternary ammonium compounds), and one that will retain its

sanitizing ability longer than its

washing power.

3. The detergent should be one that will

not give off foreign odors that may

be imparted to the egg.

4. Keep wash water as cleanas possible.

5. Rinse by spray or in running warm

water (slightly warmer than the wash

water).

6. Drain dry and case. Do not case wet

eggs.

Marketing

Eggs from farms should be marketed

2 to 3 times a week in clean containers

protected from transportation shock, wind,

and heat or cold. Transportation should be

furnished either by the producer or

receiving station at regular intervals.

Station Care

It is wise to select a marketing firm

that pays the producer on the basis of

quality and not on the basis of one price
44

for all qualities. The latter practice makes

it necessary to lower the price for top

quality to compensate for lots having a

high percentage of low-quality eggs. The

Department has established grades and

provides grading services that are used

effectively by establishments buying on

grade. In addition, the producer should

satisfy himself that the receiving station

is equipped to handle his product efficiently.

The well-equipped receiving station should

have refrigerated truck service for farnn

pickup of quality eggs during the summer

and insulated or possibly heated trucks

for use during severe winter weather.

When received at the plant and before

they are graded, eggs should be put into

a cool (50O to 650F.), humidified room.

Grading

Grading should take place in a cool,

darkened room properly equipped and

operated by trained and carefully supervised graders. In some plants grading

rooms are now air conditioned. The grading

bench and room should be arranged to

enable nninimum lost motion by graders

and grading room helpers. A combination

of roller and belt conveyors to serve the

graders with eggs to be graded and to move

the graded product away fronn their benches

has been worked out satisfactorily. The

use of conveyors and shock-absorbing

hydraulic lifts are helpful in reducing

shocks normally caused by careless or

accidental rough handling.

In order to reduce variations in grade

in cases of eggs as a result of staleness

due to overnight holding in the grading

room, it is advisable to combine part

cases of graded eggs each night. It is

necessary to develop and maintain

a receiving, handling, and shipping supply

control of ungraded and graded eggs.

After eggs are graded and packed in

cases they should immediately be moved

to the shipping room cooler and held there

until ready for distribution. If they are

distributed direct to the retail store, a

refrigerated truck should be used for

summer deliveries and an insulated truck

for winter deliveries. This practice will not

only help to deliver the quality of eggs,

as graded, to the retailer but also will

stress the need of proper care of the

product to the retailer.

Packing

Packing is normally carried on in conjunction with the grading operation. Clean

packaging materials should assure adequate

protection of the product in the handling

required in the receiving station, distribution channels, and in the retail store.

Cases for retail distribution should always

have complete tops.

Distribution

Retail

Fine-quality eggs that have been properly

cared for and packed in attractive cartons

are sometimes handled carelessly by the

retailer.

The wise operator of a receiving station

packing and grading room knows that proper

care of his product in the retail market

will assure repeat sales. He will make

suggestions to the retailer regarding stock

control and care, including volume

delivered, rotation of supply, refrigeration

(50° to 65°F.), and humidity. Bulk stocks

should be stored only under refrigeration

in space that is free from volatile odors

of fruits, vegetables, coal oil, mustiness,

and mold.

Wholesale

Products for wholesale outlets, should

be packaged in good cases having complete

tops and with good packing materials. If

deliveries are by truck the truck should be

refrigerated by a self-contained refrigerator unit and insulated on all surfaces

and doors for warm weather shipments.

For deliveries in extreme winter weather,

the truck should be equipped for heating

with warm air free from foreign odors that

might contaminate the eggs. Truck beds

should be equipped with racks to provide

adequate air movemeni; around the load.

The load should reach to the closed doors,

but if this is not possible, end bracing

should be used to avoid shifting of the load

in transit. The shipping of small lots in

trucks built for carrying heavy loads should

be avoided.

Before shipping by rail the interior of

the refrigerator car (with door closed)

should be examined for any obvious insulation breaks. The floor racks should be in

place and the drain plugs in the ice bunkers

open. It is best to use a car that has just

sufficient space to permit a snug fit for
45

each stack of cases. Loading from either

end provides for working space when

installing bracing between center rows.

Bracing should be sturdy and fit snugly

to avoid load shift in transit. For shipments

requiring 48 or more hours at a time of

year when tennperatures are 70o F. or

higher, the bunkers should be loaded to

capacity with chunk ice and provision

should be made for reicing in transit. For

short hauls or where maximum daytime

temperatures are below 70^ F., smaller

quantities of ice can be used or none at

all.

During extrenciely cold weather refrigerator cars should be lined with building

paper or other insulating material and the

bunker hatches should be closed after

bunker and hatch plugs are in place. The

car should be heated to not nnore than egg

holding-room temperature while loading.

Precautions against exposure, extrenne

heat, cold, and rain should be taken at the

time of loading by using tarpaulin to cover

the loading platfornas.

Before cars or trucks are loaded, they

should be checked for the presence of

foreign odors. Cars or trucks used for

fish, potatoes, citrus fruit, apples, or

cabbage, should be rejected for use in

shipping eggs if the carrier cannot remove

the odor of these products. Cars showing

breaks in the ceiling, walls, or floor surfaces sufficient to admit daylight when

doors are closed, should also iDe rejected.

When both fiber and wood cases make

up the load, the wood cases should always

be on the bottom, and rows of wood cases

should appear on either side of the bracing

point.

PLANNING GRADING SCHOOLS

As is the case in most successful undertakings, good planning is a highly important

phase in conducting an egg-grading school.

The planning should cover ways and means

of financing the school as funds will likely

be needed for supplies of eggs, packing

materials, rentals, manuals, and other

equipment. Consideration might well be

given to charging a laboratory or registration fee to cover the necessary expenses

in conducting the school. An adequate

number of instructors and staff assistants

should be provided to help with the instruction and to assist in setting-up laboratory classes and demonstrations. Carefully

developed plans coupled with energetic

follow-through will usually result in a wellorganized, smooth-running school that

serves as an effective means of teaching

the proper methods and practices of grading

and related subjects. This part of the manual

is intended as a guide to those who wish

to organize and conduct egg grading

schools.

Location and Time

The school should be held as nearly as

possible in the center of the section or

region from which the students are drawn,

it should be held in a place where the

essential equipment and facilities are available and where there is adequate space

for classes and laboratory practice

sessions. Consideration should be given to

locating the school near a place where

board and lodging facilities are available

at reasonable rates.

Egg-grading schools can be held at any

time during the year, but it is desirable

to schedule a time when the regular work

of the prospective students is not too

pressing and when there is a minimum of

conflict with other meetings, expositions,

and special schools. Generally, it is

desirable to hold school in the late winter

or early spring months, although other

times of the year may be equally as desirable. Refresher egg grading schools may

be held just before or during the beginning

stages of the *'spring drop'* in egg quality

or when hot weather eggs or storage eggs

are prevalent. In conducting a series of

schools for an area over a period of several

years it would be desirable to schedule the

schools so that students canbecome familiar

with the general quality of eggs and quality

defects typical of the various seasons.

Equipment ahd Facilities

Facilities and equipment of a size and in

quantities sufficient to accommodate the

number of students and instructors attending

the school, should be provided as follows:

1. A room equipped with tables and

chairs, for lectures and demonstrations.

2. A room for laboratory sessions and

demonstrations. An egg-grading or an

egg-breaking plant that is not in current use would be a desirable place

to hold the school if a room suitable for

the lecture sessions is also available.
46

3. A supply of fillers, flats, filler-flats,

and egg cases.

4. An adequate supply of candling lights

mounted so as to provide ample bench

space, candling light apertures at

correct height, and adequate case

light. These must be located in a

room that can be darkened.

5. An adequate supply of shell eggs. At

least 15 and preferably 30 dozens of

eggs should be available for each

student in attendance. The working

stock of shell eggs must include the

entire range of quality, including

various types of loss and inedible

eggs. It is desirable to have eggs

which cover the complete range of

quality in each of the quality factors.

These are necessary for laboratory

practice sessions as well as for testing and examination purposes.

6. Individual egg scales and scales for

weighing 15 or 30 dozens of eggs.

7. Slide and film strip projectors, motion

picture projector (if tobe used), blackboard, opaque projector, and other

similar facilities.

8. Other materials, such as egg quality

slides, manuals, a supply of specifications of standards and grades, pads,

pencils, and examination papers.

9. Registration blanks, supply of programs, and laboratory forms.

10. Certificates for those who successfully complete the school.

Suggested Programs

Suggestions for 2-, 3-, and 5-day schools

for egg graders are given in the pages that

follow. With variations and rearrangement,

these suggestions could be used for planning

the program to cover a 4-day school or

even a 1-day refresher school for egg

graders.

It may be desirable to supplement the

program with appropriate slides'^, films,

and other visual aids. It may also be helpful

to introduce occasional technical lectures

on one or more of the subjects covered.

It should be remembered that the more

practice sessions in candling that are provided, the better understanding the student

will have of egg grading. The instructors

responsible for setting up the laboratory

classes should include a wide variety of

qualities within the various lots of eggs

used in instruction. The selection and

^ The Department of Agriculture has egg

quality slides available for this purpose.

arrangement of the lots for student practice

and testing is quite important and will

influence considerably the success of the

school.

Suggested 2-day Program for a School for

Egg Grading

First Day of School

Morning Registration

Purpose and plan of the school

Function, advantage, and general application of standards

(Manual)

Fornnation, structure, and

composition of the egg (Manual)

Lunch

Afternoon General quality factors (Manual)

Egg quality slides

Candling room technique and

grading practice (Manual)

Demonstration and student

practice (Laboratory)

1. Transferring eggs out of

and into cases

2. Weight classing

3. Segregation of stains and

dirties

4. Candling and quality

determination

Second Day of School

Morning Review of standards of quality

Laboratory practice--Factor

grading

1. External factors

2. Air cell

3- Yolk

4. White

Comparison of broken-out appearance with candled

appearance

Lunch

Afternoon Laboratory period--Candling

for all factors

Review -- Question-andanswer period

Practical examination

Written examination

Adjournment

Suggested 3-day Program for a School for

Egg Grading

First Day of School

Morning Registration

Purpose and brief outline of

course
Lunch

Afternoon

Morning

Morning

Lunch

Afternoon

Morning

^gg grading, advantages and

general application (Manual)

Formation of the egg (Manual,

supplemented with film, if

possible)

Structure and composition of Lunch

the egg (Manual) Afternoon

The general quality factors

for individual eggs (Manual,

Egg Quality Slides)

Candling room technique and

grading practice (Manual)

Laboratory practice

1. Transferring out of and

into cases

2. Weight classing

3. Segregating of stains and

dirties

4. Candling and quality determination

Second Day of School

The production and maintenance of egg quality (Manual,

supplemented with slides,

film strip, or movies)

Laboratory practice--weight

classes, review of shell fac- Lunch

tors (Manual and Egg Quality Afternoon

Slides)

Reviewing air-cell requirements

Laboratory practice --classifying eggs as to air-cell

factors

Review of quality specifications for yolks and whites

Laboratory practice--classifying eggs on the basis of

the yolk factor and albumen

factor

Laboratory practice, candling

eggs considering all factors

Comparison of broken-out

appearance with candled

appearance

What*s new in egg-quality

research

Third Day of School Morning

Federal-State grading programs for shell eggs

Laboratory period--candling

practice according to all

factors

47

Federal and State Laws applicable to egg grading and

marketing--Relationship to

Federal-State grading programs

Question-and-answer period

General review

Written exanaination

Practical examination

Adjournment

NOTE: The school may be extended into

the fourth day, if desirable and practical,

by devoting more time to laboratory practice in classifying eggs for all factors, and

shifting the examination, general review,

and practical tests to the fourth day.

Suggested 5-day Program for An Egg

Grading and Marketing School

First Day of School

Registration

Purpose and plan of the school

The formation of the egg

(Manual, film)

The structure and composition of the egg (Manual)

New trends in egg marketing

The grading of eggs--Advantage of grading; general application of standards and

grades

What is egg quality--Lecture

and demonstration of

broken-out quality of eggs

General quality factors (Manual)

Laboratory demonstration

and student practice

1. Transferring eggs out of

and into cases

2. Weight classing

3. Segregating of stains and

dirties

4. Candling and quality determination

Second Day of School

U. S. Standards for Quality

of Individual Shell Eggs

Laboratory practice

1. Weight classes and review of shell factors

(Manual, Egg Quality

Slides)
48

Lunch

Afternoon

Morning

Lunch

Afternoon

2. Classifying eggs as to

shell factors

3. Review of air-cell requirements

4. Classifying eggs as to air

cell factors

The production and maintenance of egg quality (Manual, supplemented with

slides, film strip, or

movie)

What* s new in egg-quality and

egg-marketing research

Laboratory practice--Factor

grading

1. External factors

2. Air cell

3. Yolk

4. White

Candling technique and

grading-room practice

(Manual)

Third Day of School

What the consumer wants in

shell eggs (Preference for

weight and quality; package;

label information)

Laboratory practice--

Candling; all factors

Delivering to the consumer

eggs of the quality represented on label

Federal-State grading programs

Proposals for changes in

standards, grades, and regulations

Federal and State Law^s that

relate to egg marketing

Panel discussion--Interrelationship of Federal-State

Morning

Lunch

Afternoon

Morning

Lunch

Afternoon

grading and State law

enforcement programs

Fourth Day of School

Laboratory practice--

Candling; all factors

Demonstration and laboratory

practice--comparison of

broken-out appearance with

candled appearance

U. S. grades of eggs--Consumer, Procurement,

Wholesale

Practice in assigning U. S.

grades to lots of different

quality levels

Review of standards and

grades (Manual and slides)

Grading and inspection procedures (Manual)

Laboratory practice--Establishing the grade on a lot of

eggs (1-, 2-, or 3-case lot)

Cleaning dirty eggs

Fifth Day of School

Shell treatnnent of eggs

Sanitation requirements and

operating procedures applicable to grading and packing

Laboratory period--Review of

standards of quality--

Candling practice; all

factors

Practical exannination--

Candling tests

Review and question-andanswer period

Written examination

Award of certificates of completion

Adjournment

U. S. GOVERNMENT PRINTING OFFICE : 1955 O - 317956