Periodic Egg Inspection During Incubation (Candling) - Borotto REAL Series Instruction Manual

8 – Periodic egg inspection during incubation (candling)
Candling is a complicated and delicate operation that may result in errors and eliminating fecundated eggs. Since
it is optional, we advise not to perform it if one has no experience and to proceed with incubation. Otherwise, the
incubated eggs may be periodically inspected by candling. This operation must be performed in a dark room,
using a concentrated beam of light (the egg candler is available on the website www.borotto.com), following the
table below:
Species
Hen
Pheasant
Guinea fowl
Turkey
Grey Partridge / partridge
Peacock
Goose
Mallard and wild duck
Muscovy duck
Extract the eggs from the incubator one by one and check them immediately. The egg may remain outside the
incubator for 2 minutes at most. With a little experience, and using the suitable instrument, the eggs may be
inspected without extracting them from the incubator. In that case, open the incubator and place the candler
onto each egg. The light beam lets you see the embryo. Never turn or shake the eggs with violence as this would
cause the blood vessels to break and result in embryo death.
1st Inspection: start of the incubation
It is usually difficult to see the embryo because it is encased in the yolk: blood vessels are visible near the air cell
and on the tip. If the egg has not been fecundated the inside will be uniform, without any blood vessels and the
yolk will be in the middle. In that case scrap the egg. It is likely that in this stage the inside of eggs with a thick or
brown shell cannot be seen well: these will be checked in the second inspection.
2nd Inspection: development of the embryo
The mesh of blood vessels is normally visible in the tip of the egg and the embryo will appear as a dark spot. If the
blood vessels are not visible this means that the embryo is dead.
3rd Inspection: embryo check
The embryo normally occupies the entire egg, therefore the blood vessels should no longer be visible. The air cell
is large, If the embryo does not occupy the entire space, blood vessels are visible, the air cell is small and the
white has not been used up, this means that the embryo is underdeveloped and the egg must be scrapped.
1st inspection
at 8 days
at 8 days
at 8 days
at 8 days
at 8 days
at 9 days
at 9 days
at 9 days
at 10 days
2nd inspection
at 11 days
at 12 days
at 13 days
at 13 days
at 12 days
at 14 days
at 15 days
at 13 days
at 15 days
Page 13 of 20
3rd inspection
at 18 days
at 20 days
at 23 days
at 25 days
at 20 days
at 25 days
at 27 days
at 24 days
at 30 days
Rev 01