SHELL SHAPE AND TEXTURE
a. 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.
b. The ideal egg is illustrated in figure 3-1. The shape of an egg can be
considered different 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.
c. Eggs that are unusual in shape, such as those having ridges, rough areas, or
thin spots, are placed in the lower grades (figure 3-1). Shell of such eggs are usually
weaker than normal shells and the danger of breakage en route to the consumer lowers
the utility value of the egg. Eggs of abnormal shape also lack consumer appeal.
Therefore, they are excluded from the better grades.
d. Abnormal shells may result from improper nutrition, disease, or the physical
condition of the hen. Sometimes a shell is cracked while the egg is still in the body of
the hen. These eggs, which are commonly referred to as "body checks," are repaired
by an additional deposit of shell over the cracked area that generally results in a ridged
area. Depending upon the extent and severity of the ridge, these eggs may be classed
as B Quality. When no ridge is in evidence, the egg may be classed as A Quality.
e. Shell eggs are divided into one of two categories of shape:
(1) Practically normal--AA and A Quality. A shell that approximates what is
considered the usual shape. It is of good, even texture and strength, and free from
rough areas or thin spots. Slight ridges and rough areas, such as calcium deposits, are
permitted if they do not materially affect the shape, texture, and strength of the shell.
(2) Abnormal--B Quality. A shell that may be somewhat unusual, or is
decidedly misshapen, or faulty in texture or strength, or that may show pronounced
ridges, thin spots, or rough areas.
SOUNDNESS OF SHELL
a. To be graded AA, A, B, or Dirty, an egg must have a sound (unbroken) shell.
Some shell defects are:
(1) Body checks. These breaks occur before the egg is laid and are healed
within the oviduct. They are not downgraded for soundness, but may be downgraded
for shape since the healing frequently makes the shape of the egg slightly abnormal.