WilTec 50036 User Manual page 14

the same time. Invasion of bacteria such as Staphylococcus spp., Salmonella spp. and Esche-
richia coli may lead to death of embryos or neonates. Eggs may be cleaner if they are collect-
ed immediately after laying rather than after they have been "set".
Eggs, which are deformed, should not be incubated or placed in incubator.
Eggs which are noted to be cracked at the time of collection are generally discarded, and
grossly contaminated eggs may also be discarded at this time. If such eggs are particularly
valuable, they should be separated from other eggs for incubation, due to the greater risk of
infection.
Eggs which become cracked during incubation may be repaired, if the crack is small, with e.g.
surgical grade cyanoacrylate glue, candle wax dripped onto the crack, nail varnish, correction
fluid or sticky tape (it has been suggested that products containing acetone should be avoided,
due to possible toxicity. Eggs which are cracked should be incubated in an incubator (not un-
der parent or broody), with extra care taken in their handling and monitoring. It is important
to ensure that the material used to cover the crack is applied to the minimum surface of the
shell required to seal the crack. A thin layer of bone cement may be applied over a crushed
area of shell and a hole in the shell may be repaired by gluing an appropriate piece if sterilized
shell, parafilm, tissue or gauze over the defect. Care should be taken to avoid sealing over
larger areas of the shell than absolutely necessary as this prevents necessary gaseous ex-
change.
If the shell membranes have been penetrated the egg is likely to have become contaminated
with pathogens and the yolk, embryo or blood vessels may have been physically damaged.
Hatchability is greatly reduced.
A piped egg which is being parent or broody incubated and becomes damaged should be
moved to a hatching incubator.
Records: Accurate and detailed records are very important in incubation. All eggs should be
individually identified and details recorded including the identity of the parents, and details of
their pedigree, nutrition and breeding and incubation behavior, initial weight, date of setting,
details of incubation such as results of candling, incubator used, weight loss (if this is being
monitored) expected and actual hatching dates, as well as evaluation of the hatched chick or
results of investigation into eggs which fail to hatch.
Parent incubation generally provides the ideal conditions of temperature and humidity for
development and hatching. However, not all species or individuals are equally good sitters,
particularly in captive situations, in which birds may be disturbed and not feel secure. Addi-
tionally, small species in particular are vulnerable to predation while sitting, especially if nest-
ing in an open site. Also, normal incubation behavior may not be suitable for birds being
maintained in an environment very different from their native habitat.
If allowed to sit, hatch and rear their chicks, most birds will produce only one clutch a year,
whereas two, three or even more clutches of eggs may be produced if the eggs are removed.
It may be less easy to monitor parent-sat eggs for fertility and continued development, with an
attendant risk of disturbing the birds.
In captive conditions it may be more likely that nesting materials will not be fresh and clean,
but contaminated with droppings, or include mouldy vegetation.
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Seite 14