To candling call duck eggs mean to check for the development of the embryo inside a call duck egg. To candle the eggs, you will hold each call duck egg against a bright light. Because call duck eggs are more smaller than the eggs of other duck breeds, the internal structure of the egg will be smaller and more dificult to see inside the shell of the egg.
Additionally, call duck eggs take around 26 to 28 days to develop the embryo and hatch the ducklings, so you must monitor the eggs during this time. On day seven of the incubation period, the first candling period occur. Before day seven, the egg may appear to be empty or that there may be only a faint shadow of the yolk inside the egg.
How to Check Call Duck Eggs
On day seven, the embryo’s blood vessels should be visible inside the egg along with the dark center of the egg. The presence of both of these element indicates that the call duck egg is developing normal. If the egg is completely clear, the call duck egg was not fertile.
If there is a thin red ring of blood inside the egg instead of the blood vessels, the embryo has stopped developing inside of the egg. Any call duck eggs with this sign of stop in development should be removed from the incubator, as these eggs can affect the incubating of the other eggs within the incubator. On day fourteen, the second candling period occurs.
At this period, the embryo has developed into a larger dark mass inside of the egg. Additionally, there may be movement of the embryo within the egg. You should also examine the air cell of the egg.
This air cell is located at the blunt end of the egg. The air cell should be larger on day fourteen than it was on day seven. If the air cell is too small, the humidity within the incubator was too high.
If the air cell is too large, the humidity within the incubator was too low. In either of these instance, the humidity within the incubator can be corrected before the lockdown period begins. On day eighteen, the third candling period occurs.
At this point in time, the egg will appear to be mostly opaque to the candlor. The air cell should be approximately one quarter of the total volume of the egg. Additionally, the duckling inside of the egg should be active and moving within the egg.
A lack of movement of the duckling inside of the egg indicates that the embryo is not developing normal. Lockdown of the incubator occurs on day twenty-five. During lockdown, the air cell should be large enough that the beak of the duckling is in contact with the air cell.
During lockdown, the incubator should no longer be turning the eggs. Additionally, the humidity within the incubator should be increased. After lockdown, the incubator should not be opened, as the duckling must complete its hatch process independent of the incubator.
Inside the egg, the duckling will break through the air cell with its beak (internal pip). Outside of the egg, a crack will begin to form in the shell of the call duck egg (external pip). It may take the duckling several hour to “unzip” its shell.
Under no circumstances should you attempt to remove the duckling from the egg shell, as the membrane of the duckling may bleed if the duckling is pulled too early during the incubation period. Overall, candling allows for an understanding of how the incubator is functioning. By canding the eggs, you can determine the efficiency of the humidity within the incubator.
Additionally, you can determine the incubator turning schedule and the stability of the temperature within the incubator through candling. If the temperature within the incubator is too hot or too cold, the development of the embryo within the egg will change. Under normal conditions, call ducklings will hatch between day twenty-six and day twenty-eight.
Thus, preparation for the hatch should of been made even if the 28-day period has not yet passed after the incubation period. Additionally, if the air cell continues to develop and the embryo continues to move normaly during the candling process, there is a greater chance that the duckling will successfully hatch from the egg.