7. Aspects of Egg Quality
Egg quality refers to the integrity of the shell, the intensity of the yolk colour,
and the nature of the egg white. For eggs to be stored successfully the shell
needs to be uncracked, clean and dry. The egg shell is porous and hence is
subject to bacterial penetration in wet, soiled conditions.
Egg shells come in a variety of colours from white,
through to speckled, to deep brown. There is no
association between colour and egg quality. Some
eggs may show blood stains or faecal stains when
collected. This is quite normal and these can be
removed by wiping the egg with a clean, damp cloth.
Without access to pigments the yolk colour of the
eggs will become quite pale. While in the presence of
abundant pigments in the feed or via green feed the
yolks can become an intense orange colour. There
is no difference in nutritional value across this range
but there is an aesthetic aspect that most people
prefer a well coloured yolk to a pale yolk. The level of
yolk colour is hence quite manageable.
Whether the eggs are fertile or not makes little
difference to the quality of the eggs. Fertile eggs can
be detected by a slightly enlarged germinal disc on
the yolk to the trained eye – but go largely unnoticed
to most people. A rooster in the flock is necessary
to achieve fertile eggs but makes little difference
to the egg production. So a rooster is an optional
extra – but beware they are noisy and could disturb
the neighbours and at times they can be aggressive
towards people entering the chook house. The hens
will perform quite well without a rooster. Check with
your local council before purchasing a rooster as they
are prohibited in some residential areas.
The white of the egg (the albumen) is sensitive to
storage conditions and time. To preserve the integrity
of the egg white eggs should be collected regularly
and refrigerated. Store eggs in egg cartons with the
rounded (big) end upwards. Write the date eggs were
collected on each egg. Refrigerated eggs will stay
fresh for at least 4 weeks from when they were laid.
If not refrigerated egg whites become quite runny
getting worse over time and accelerated by high
temperatures. The quality of eggs from older hens
tends to be less firm than young birds and can be
exacerbated by low feed intake (hot weather). Some
diseases such as infectious bronchitis can also affect
egg quality.
From time to time meat spots or blood spots may
appear in the albumen. Although these appear
unsightly they are in fact harmless and can be
easily removed.