Candling is a process that allow you to look inside of an egg. Candling helps to determine whether an egg is alive or if it is dead. Determining whether an egg is dead is important because dead eggs can release bacteria that can spread to the other eggs within the incubator.
Therefore, you should utilize candling to locate any dead eggs within the incubator so that you can remove those eggs from the incubator. To candle an egg, you utilize both light and darkness. You hold the egg near the light source so that you can look into the egg.
How to Candle Eggs and Find Dead Embryos
If the embryo inside of the egg is alive, you will see red branching lines within the egg, as well as the embryo will create a moving shadow within the egg. If the embryo inside of the egg is dead, you will not see any movement within the egg. If you see red branching lines within the egg, the embryo inside of the egg is likely developing normal.
However, if the interior of the egg is dark and there is no movement within the egg, the embryo within the egg is likely dead. You must practice candling eggs multiple times to learn to recognize these differences. By recognizing the different characteristics of live and dead embryos, you can accurately find any dead egg within the incubator.
The majority of incubation deaths occur between the first and seventh days of incubation. During these early days of incubation, the embryo within the egg is very small. Therefore, even very small changes in temperature or contamination can kill the embryo.
If the embryo dies within the first seven days of incubation, you may notice a blood ring within the egg. The presence of a blood ring within the egg indicates that the embryo has died, and the egg is no longer viable. Therefore, you should remove any egg with a blood ring within it from the incubator to prevent the spread of bacteria to the other eggs within the incubator.
Dead embryos during the mid-incubation period of the incubation process will exhibit different visual characteristics different than those that die during the early incubation period. During the mid-incubation period, the embryo within the egg has time to grow to a larger size. Therefore, you should examine the air cell within the egg for size, as well as the movement within the egg.
Healthy air cells will grow in size during the incubation process. However, the air cell within dead eggs will shrink. Additionally, the contents within dead eggs will turn a uniform dark color, while the contents of live eggs will contain the embryonic structure.
In contrast to dead eggs during the early incubation period, the outside of the egg may still appear clean and normal. However, the embryo within the egg is dead. Therefore, regular candling is required to locate these dead embryos during the mid-incubation period.
During the late stages of incubation, dead eggs that are decomposing may create too much pressure within the eggshell. Too much pressure within the eggshell of a decomposing egg may lead to the eggshell cracking. The contents of the decomposing egg that subsequently leaks from the cracked shell may contaminate the incubator.
Therefore, you must inspect any eggs daily during the lockdown period. Additionally, any egg that exhibits liquid within the incubator or emits a strong smell must be removed from the incubator. If you are not sure as to the state of the eggs, you can perform other tests to determine whether the embryo is alive or dead.
One test is the smell test. Live eggs will almost always have no odor, while dead eggs will have a sulfur smell due to the decomposition of the embryo within the egg. Another test is the float test.
Dead eggs often contain too much gas relative to live eggs, which causes the dead eggs to float higher within a container of water. You can perform these tests in addition to candling the eggs as a backup method. The thickness of the shell of the egg may impact the method by which you candle the eggs.
Chicken eggs have thin shells, so you can use a standard candling light to view the contents of chicken eggs. However, duck and turkey eggs have thicker shells, so you will require a brighter light to effectively candle those types of eggs. Finally, quail eggs are small in size, so you can use a focused beam of light to examine the contents of those eggs.
Each type of egg has a different thickness of shell, so you must use the appropriate light for each type of egg. Candling eggs regularly provides data that can be used to improve the incubation process. Through regular candling, you will begin to recognize the patterns of when the embryos die within the incubation period.
If you find that most embryos die between the fourth and fifth day of incubation, that may indicate that the temperature within the incubator is incorrect. By using the information that you gather from candling the eggs, you can adjust the incubator settings. By adjusting the incubator settings, you can improve the number of eggs that successfully hatch in the future.