To candle an duck egg, shine a light source through the shell of the duck egg. Use this process to determine whether there is an embryo inside the duck egg or if the duck egg is no longer viable. Candling allow you to determine which duck eggs contain healthy embryos and which duck eggs contain dead embryos.
By removing the duck eggs that contains dead embryos, you prevent the spread of bacteria from those dead duck eggs to the healthy duck eggs. To candle duck eggs, perform the process around day seven of incubation. Around the first three days of incubation, when candling the duck eggs, the duck eggs will appear clear.
How to Candle Duck Eggs
The duck eggs may display a faint shadow of the yolk, but there will be no veins visible within the duck eggs. Around days four and five, faint red veins may be visible within the duck eggs. However, wait until day seven to candle the duck eggs.
At day seven, healthy duck eggs will display veins distributed across the half of the duck egg shell, a dark dot in the center of the duck egg that represents the embryo, and the air cell at the blunt end of the duck egg. Duck eggs that contains blood rings or that are clear of any contents should be removed from the incubator as they contain dead duck eggs that can spread bacteria to the healthy duck eggs. The air cell within a duck egg contains the air that becomes trapped inside the shell as the duck egg evaporates.
As such, the size of the air cell indicates the level of humidity within the incubator. At the start of incubation, the air cell should be three to five millimeters deep within the duck egg. By day seven, the air cell should be six to eight millimeters deep.
By day fourteen, the air cell should be ten to twelve millimeters deep. By day twenty-one, the air cell should be one-third of the total volume of the duck egg. If the air cell is too small, the humidity within the incubator is too high.
High humidity can lead to the duckling drowning in its egg. Too much humidity within the incubator means you should measure the air cell in five percent increments to find the proper humidity. If the air cell is too large, the humidity within the incubator is too low.
Low humidity can lead to the duckling sticking to the shell. Using a light to observe the duck eggs will reveal different issues with those duck eggs. A blood ring within a duck egg shows that the embryo within the egg has passed on between day three and day nine.
Any duck egg with a blood ring should be removed from the incubator as it may explode and spread bacteria to the healthy duck eggs. A stalled embryo will have faded veins within the egg to a dark mass. However, there will be no movement of the embryo within the egg shell.
A rotten duck egg will appear to be murky green within the egg with an odor of sulfur. These types of duck eggs contain many bacteria. If a duckling has passed on after day twenty-one, it is likely that the duckling experienced low humidity during the lockdown period of the incubation process or the duckling is malpositioned.
In the case where a duckling has passed on, allow the duck egg to be in the incubator for forty-eight hours past the expected hatch date. Duck eggs require different care to chicken eggs due to the different thickness of the shell and the different requirements for incubation. Duck eggs take twenty-eight days to hatch, while chicken eggs take twenty-one days.
Muscovy duck eggs take thirty-five days to hatch. Due to duck eggs having white, green, and black shells that block the light from the candling process, use a thousand-lumen LED candler in the dark to candle the duck eggs. Mist the duck eggs with lukewarm water starting at day seven of incubation.
By misting the duck eggs, you mimic the behavior of a mother duck. This keeps the membrane within the duck egg supple. If you do not mist the duck eggs, the ducklings may struggle to naturaly rotate within their shells while they were still inside of their mother’s eggs.
To ensure the duck eggs hatch successfully, maintain the following settings within the incubator. Maintain a temperature of ninety-nine point five degrees Fahrenheit in a forced-air incubator. Maintain the humidity level between fifty-five and sixty-five percent from day one to day twenty-five of incubation.
Turn the duck eggs three to five times each day. During the lockdown period between day seventeen and twenty-one, stop turning the duck eggs. At this period, increase the humidity within the incubator to seventy-five percent by adding water to the incubator.
Lay the duck eggs on their sides during the lockdown period and do not open the incubator lid during this period as it may allow critical humidity within the duck eggs to escape from the shell of the egg. Common mistakes made during the incubation process include inaccurate records of the duck eggs and candling the eggs before day seven. Use a pencil to mark each duck egg to keep records of how many times you have turned each duck egg.
Keep records of the size of the air cell and the weight of each duck egg each week. After day fourteen of incubation, you can perform a float test by placing the duck eggs into one hundred degree water. However, only perform this test if the duck eggs are past day fourteen of incubation.
Candling sessions should not take longer than thirty minutes to mimic the behavior of a mother duck moving on her nest. If you perform each of these steps correctly, you will increase the number of ducklings that successfully hatch from their eggs.