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58 Hand-Rearing Birds

Once the hatchery is operational, routine cleaning of the rooms should be done at least weekly.
This should include wiping down all working surfaces and places where dust might accumulate,
washing the floor, and cleaning water reservoirs in the incubators. Hydrogen peroxide‐based, chlo-
rhexidine and quaternary ammonium disinfectants are good choices for this. Chlorine bleach is
inexpensive but creates noxious fumes and is corrosive to equipment. Water pans and wet bulb
wicks should be replaced with freshly sterilized (autoclaved) or disinfected pans and wicks. Water
reservoirs that cannot be removed for cleaning should be drained and flushed periodically during
the season. A disinfectant footbath placed outside the door reduces contaminants that may be
tracked into the rooms. Trash receptacles may be kept outside to minimize the potential for con-
tamination in the room.
Staff working in the hatchery should organize daily work to minimize the potential for contami-
nants to enter the hatchery. Most of the hatchery work should be done before cleaning messy
enclosures and similar chores. Some facilities choose to use protective clothing, such as lab coats
or coveralls, over work clothes in the hatchery, but this may also serve as a reservoir of contami-
nants in the rooms. Wash hands thoroughly with soap and water (not only hand sanitizer) before
servicing incubators and observe aseptic techniques. When handling eggs, the use of exam gloves
in addition to handwashing may be desirable.

­ Egg­Handling­and Storage

Many factors affect hatchability even before the egg is laid. These include genetics, nutrition, and
exposure to toxins, as well as physiological factors such as age and disease, and behavioral influ-
ences such as stress or physical trauma that can affect egg formation. Much research has been done
on all of these and many other publications are available for reference (Landauer 1967; Romanoff
and Romanoff 1972; Kuehler 1983).
Additional factors influence hatchability once the egg is laid but before incubation starts.
Infection of the incubating egg is one of the main causes of reduced hatchability. Microbial con-
tamination of the shell can come from feces, nest material, or human hands. Physical trauma, such
as cracking or breaking of eggs, is an obvious cause of egg mortality, but any jarring, shaking, or
vibration can disrupt the loosely‐adhered cells of the blastoderm, much like a sand painting, and
cause abnormal twinning, duplications, or complete failure of the embryo. Allowing an egg to roll
or turn over and over in the same direction can cause the chalazae to wind up like rubber bands
and break, causing the embryo to stick to the inner shell membrane.
Environmental conditions prior to incubation affect hatchability. At a temperature of 70 °F
(21 °C) or higher, embryonic development will initiate but different tissues will form at abnormal
rates often resulting in embryonic mortality. Eggs will also lose too much weight through water
evaporation if held at ambient humidity.
Many taxa, such as waterfowl, do not begin incubating until the clutch of eggs is complete. Eggs
of these species tolerate short periods of storage better than those of single‐egg clutches, such as
flamingos, or multiple‐egg clutches of species that begin incubation with the first egg, such as par-
rots. When incubating a lot of eggs of certain precocial species, such as ostrich or pheasant, it is
desirable to synchronize hatching by storing eggs and then setting a group at once. Such eggs may
be stored up to seven days without significant decrease in hatchability. Ideal parameters for egg
storage are 55–60 °F (13–15 °C) and 70–80% relative humidity. Refrigerators designed for wine stor-
age can be set to the appropriate temperature and humidity can be provided the same ways as in
an incubator. Ventilation is not crucial, but it is important to prevent condensation moisture from